Adds reducers list to InternalAggregation.reduce()

The list of reducers is fed through from the AggregatorFactory

src/main/java/org/elasticsearch/search/aggregations/Aggregator.java

@@ -105,7 +105,7 @@ public abstract class Aggregator extends BucketCollector implements Releasable {
      * Build an empty aggregation.
      */
     public abstract InternalAggregation buildEmptyAggregation();
-
+    
     /** Aggregation mode for sub aggregations. */
     public enum SubAggCollectionMode {
 

src/main/java/org/elasticsearch/search/aggregations/AggregatorFactory.java

@@ -23,10 +23,13 @@ import org.apache.lucene.search.Scorer;
 import org.elasticsearch.common.lease.Releasables;
 import org.elasticsearch.common.util.BigArrays;
 import org.elasticsearch.common.util.ObjectArray;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.internal.SearchContext.Lifetime;
 
 import java.io.IOException;
+import java.util.Collections;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -38,6 +41,7 @@ public abstract class AggregatorFactory {
     protected String type;
     protected AggregatorFactory parent;
     protected AggregatorFactories factories = AggregatorFactories.EMPTY;
+    protected List<Reducer> reducers = Collections.emptyList();
     protected Map<String, Object> metaData;
 
     /**
@@ -79,7 +83,8 @@ public abstract class AggregatorFactory {
         return parent;
     }
 
-    protected abstract Aggregator createInternal(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException;
+    protected abstract Aggregator createInternal(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket,
+            List<Reducer> reducers, Map<String, Object> metaData) throws IOException;
 
     /**
      * Creates the aggregator
@@ -92,7 +97,7 @@ public abstract class AggregatorFactory {
      * @return                      The created aggregator
      */
     public final Aggregator create(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket) throws IOException {
-        return createInternal(context, parent, collectsFromSingleBucket, this.metaData);
+        return createInternal(context, parent, collectsFromSingleBucket, this.reducers, this.metaData);
     }
 
     public void doValidate() {
@@ -102,16 +107,18 @@ public abstract class AggregatorFactory {
         this.metaData = metaData;
     }
 
+
+    public void setReducers(List<Reducer> reducers) {
+        this.reducers = reducers;
+    }
+
+
     /**
      * Utility method. Given an {@link AggregatorFactory} that creates {@link Aggregator}s that only know how
      * to collect bucket <tt>0</tt>, this returns an aggregator that can collect any bucket.
      */
     protected static Aggregator asMultiBucketAggregator(final AggregatorFactory factory, final AggregationContext context, final Aggregator parent) throws IOException {
-        final Aggregator first = factory.create(context, parent, true);
-        final BigArrays bigArrays = context.bigArrays();
-        return new Aggregator() {
-
-            ObjectArray<Aggregator> aggregators;
+        final Aggregator first = factory.create(context, parent, truegator> aggregators;
             ObjectArray<LeafBucketCollector> collectors;
 
             {
@@ -187,9 +194,9 @@ public abstract class AggregatorFactory {
                         LeafBucketCollector collector = collectors.get(bucket);
                         if (collector == null) {
                             Aggregator aggregator = aggregators.get(bucket);
-                            if (aggregator == null) {
-                                aggregator = factory.create(context, parent, true);
-                                aggregator.preCollection();
+                if (aggregator == null) {
+                    aggregator = factory.create(context, parent, true);
+                    aggregator.preCollection();
                                 aggregators.set(bucket, aggregator);
                             }
                             collector = aggregator.getLeafCollector(ctx);
@@ -197,7 +204,7 @@ public abstract class AggregatorFactory {
                             collectors.set(bucket, collector);
                         }
                         collector.collect(doc, 0);
-                    }
+                }
 
                 };
             }

src/main/java/org/elasticsearch/search/aggregations/InternalAggregation.java

@@ -28,6 +28,7 @@ import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentBuilderString;
 import org.elasticsearch.script.ScriptService;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationPath;
 
 import java.io.IOException;
@@ -116,6 +117,8 @@ public abstract class InternalAggregation implements Aggregation, ToXContent, St
 
     protected Map<String, Object> metaData;
 
+    private List<Reducer> reducers;
+
     /** Constructs an un initialized addAggregation (used for serialization) **/
     protected InternalAggregation() {}
 
@@ -124,8 +127,9 @@ public abstract class InternalAggregation implements Aggregation, ToXContent, St
      *
      * @param name The name of the get.
      */
-    protected InternalAggregation(String name, Map<String, Object> metaData) {
+    protected InternalAggregation(String name, List<Reducer> reducers, Map<String, Object> metaData) {
         this.name = name;
+        this.reducers = reducers;
         this.metaData = metaData;
     }
 
@@ -146,7 +150,11 @@ public abstract class InternalAggregation implements Aggregation, ToXContent, St
      * construction.
      */
     public final InternalAggregation reduce(ReduceContext reduceContext) {
-        return doReduce(reduceContext);
+        InternalAggregation aggResult = doReduce(reduceContext);
+        for (Reducer reducer : reducers) {
+            aggResult = reducer.reduce(aggResult, reduceContext);
+        }
+        return aggResult;
     }
 
     public abstract InternalAggregation doReduce(ReduceContext reduceContext);
@@ -180,6 +188,10 @@ public abstract class InternalAggregation implements Aggregation, ToXContent, St
         return metaData;
     }
 
+    public List<Reducer> reducers() {
+        return reducers;
+    }
+
     @Override
     public final XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
         builder.startObject(name);

src/main/java/org/elasticsearch/search/aggregations/InternalMultiBucketAggregation.java

@@ -21,6 +21,7 @@ package org.elasticsearch.search.aggregations;
 
 import org.elasticsearch.ElasticsearchIllegalArgumentException;
 import org.elasticsearch.search.aggregations.bucket.MultiBucketsAggregation;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 
 import java.util.List;
 import java.util.Map;
@@ -30,8 +31,8 @@ public abstract class InternalMultiBucketAggregation extends InternalAggregation
     public InternalMultiBucketAggregation() {
     }
 
-    public InternalMultiBucketAggregation(String name, Map<String, Object> metaData) {
-        super(name, metaData);
+    public InternalMultiBucketAggregation(String name, List<Reducer> reducers, Map<String, Object> metaData) {
+        super(name, reducers, metaData);
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/NonCollectingAggregator.java

@@ -20,9 +20,11 @@
 package org.elasticsearch.search.aggregations;
 
 import org.apache.lucene.index.LeafReaderContext;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -31,12 +33,14 @@ import java.util.Map;
  */
 public abstract class NonCollectingAggregator extends AggregatorBase {
 
-    protected NonCollectingAggregator(String name, AggregationContext context, Aggregator parent, AggregatorFactories subFactories, Map<String, Object> metaData) throws IOException {
-        super(name, subFactories, context, parent, metaData);
+    protected NonCollectingAggregator(String name, AggregationContext context, Aggregator parent, AggregatorFactories subFactories,
+            List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+        super(name, subFactories, context, parent, reducers, metaData);
     }
 
-    protected NonCollectingAggregator(String name, AggregationContext context, Aggregator parent, Map<String, Object> metaData) throws IOException {
-        this(name, context, parent, AggregatorFactories.EMPTY, metaData);
+    protected NonCollectingAggregator(String name, AggregationContext context, Aggregator parent, List<Reducer> reducers,
+            Map<String, Object> metaData) throws IOException {
+        this(name, context, parent, AggregatorFactories.EMPTY, reducers, metaData);
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/bucket/BucketsAggregator.java

@@ -21,6 +21,7 @@ package org.elasticsearch.search.aggregations.bucket;
 import org.elasticsearch.common.lease.Releasable;
 import org.elasticsearch.common.util.BigArrays;
 import org.elasticsearch.common.util.IntArray;
+import org.elasticsearch.search.aggregations.Aggregation;
 import org.elasticsearch.search.aggregations.Aggregator;
 import org.elasticsearch.search.aggregations.AggregatorBase;
 import org.elasticsearch.search.aggregations.AggregatorFactories;
@@ -31,6 +32,7 @@ import org.elasticsearch.search.aggregations.support.AggregationContext;
 
 import java.io.IOException;
 import java.util.Arrays;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -42,9 +44,9 @@ public abstract class BucketsAggregator extends AggregatorBase {
     private IntArray docCounts;
 
     public BucketsAggregator(String name, AggregatorFactories factories,
-                             AggregationContext context, Aggregator parent, Map<String, Object> metaData) throws IOException {
-        super(name, factories, context, parent, metaData);
-        bigArrays = context.bigArrays();
+ AggregationContext context, Aggregator parent,
+            List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+        super(name, factories, context, parent, reducers, metaData);
         docCounts = bigArrays.newIntArray(1, true);
     }
 
@@ -110,11 +112,11 @@ public abstract class BucketsAggregator extends AggregatorBase {
      */
     protected final InternalAggregations bucketAggregations(long bucket) throws IOException {
         final InternalAggregation[] aggregations = new InternalAggregation[subAggregators.length];
-        for (int i = 0; i < subAggregators.length; i++) {
+            for (int i = 0; i < subAggregators.length; i++) {
             aggregations[i] = subAggregators[i].buildAggregation(bucket);
-        }
+            }
         return new InternalAggregations(Arrays.asList(aggregations));
-    }
+                }
 
     /**
      * Utility method to build empty aggregations of the sub aggregators.

src/main/java/org/elasticsearch/search/aggregations/bucket/InternalSingleBucketAggregation.java

@@ -24,6 +24,7 @@ import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.InternalAggregations;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -47,8 +48,8 @@ public abstract class InternalSingleBucketAggregation extends InternalAggregatio
      * @param docCount      The document count in the single bucket.
      * @param aggregations  The already built sub-aggregations that are associated with the bucket.
      */
-    protected InternalSingleBucketAggregation(String name, long docCount, InternalAggregations aggregations, Map<String, Object> metaData) {
-        super(name, metaData);
+    protected InternalSingleBucketAggregation(String name, long docCount, InternalAggregations aggregations, List<Reducer> reducers, Map<String, Object> metaData) {
+        super(name, reducers, metaData);
         this.docCount = docCount;
         this.aggregations = aggregations;
     }

src/main/java/org/elasticsearch/search/aggregations/bucket/SingleBucketAggregator.java

@@ -20,9 +20,11 @@ package org.elasticsearch.search.aggregations.bucket;
 
 import org.elasticsearch.search.aggregations.Aggregator;
 import org.elasticsearch.search.aggregations.AggregatorFactories;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -31,8 +33,9 @@ import java.util.Map;
 public abstract class SingleBucketAggregator extends BucketsAggregator {
 
     protected SingleBucketAggregator(String name, AggregatorFactories factories,
-                                     AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
-        super(name, factories, aggregationContext, parent, metaData);
+ AggregationContext aggregationContext, Aggregator parent,
+            List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+        super(name, factories, aggregationContext, parent, reducers, metaData);
     }
 
 }

src/main/java/org/elasticsearch/search/aggregations/bucket/children/InternalChildren.java

@@ -23,8 +23,10 @@ import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.search.aggregations.AggregationStreams;
 import org.elasticsearch.search.aggregations.InternalAggregations;
 import org.elasticsearch.search.aggregations.bucket.InternalSingleBucketAggregation;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -49,8 +51,9 @@ public class InternalChildren extends InternalSingleBucketAggregation implements
     public InternalChildren() {
     }
 
-    public InternalChildren(String name, long docCount, InternalAggregations aggregations, Map<String, Object> metaData) {
-        super(name, docCount, aggregations, metaData);
+    public InternalChildren(String name, long docCount, InternalAggregations aggregations, List<Reducer> reducers,
+            Map<String, Object> metaData) {
+        super(name, docCount, aggregations, reducers, metaData);
     }
 
     @Override
@@ -60,6 +63,6 @@ public class InternalChildren extends InternalSingleBucketAggregation implements
 
     @Override
     protected InternalSingleBucketAggregation newAggregation(String name, long docCount, InternalAggregations subAggregations) {
-        return new InternalChildren(name, docCount, subAggregations, getMetaData());
+        return new InternalChildren(name, docCount, subAggregations, reducers(), getMetaData());
     }
 }

src/main/java/org/elasticsearch/search/aggregations/bucket/children/ParentToChildrenAggregator.java

@@ -36,6 +36,7 @@ import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.NonCollectingAggregator;
 import org.elasticsearch.search.aggregations.bucket.SingleBucketAggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
@@ -70,8 +71,9 @@ public class ParentToChildrenAggregator extends SingleBucketAggregator {
 
     public ParentToChildrenAggregator(String name, AggregatorFactories factories, AggregationContext aggregationContext,
                                       Aggregator parent, String parentType, Filter childFilter, Filter parentFilter,
-                                      ValuesSource.Bytes.WithOrdinals.ParentChild valuesSource, long maxOrd, Map<String, Object> metaData) throws IOException {
-        super(name, factories, aggregationContext, parent, metaData);
+ ValuesSource.Bytes.WithOrdinals.ParentChild valuesSource,
+            long maxOrd, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+        super(name, factories, aggregationContext, parent, reducers, metaData);
         this.parentType = parentType;
         // these two filters are cached in the parser
         this.childFilter = childFilter;
@@ -84,12 +86,13 @@ public class ParentToChildrenAggregator extends SingleBucketAggregator {
 
     @Override
     public InternalAggregation buildAggregation(long owningBucketOrdinal) throws IOException {
-        return new InternalChildren(name, bucketDocCount(owningBucketOrdinal), bucketAggregations(owningBucketOrdinal), metaData());
+        return new InternalChildren(name, bucketDocCount(owningBucketOrdinal), bucketAggregations(owningBucketOrdinal), reducers(),
+                metaData());
     }
 
     @Override
     public InternalAggregation buildEmptyAggregation() {
-        return new InternalChildren(name, 0, buildEmptySubAggregations(), metaData());
+        return new InternalChildren(name, 0, buildEmptySubAggregations(), reducers(), metaData());
     }
 
     @Override
@@ -199,21 +202,25 @@ public class ParentToChildrenAggregator extends SingleBucketAggregator {
         }
 
         @Override
-        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
-            return new NonCollectingAggregator(name, aggregationContext, parent, metaData) {
+        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, List<Reducer> reducers,
+                Map<String, Object> metaData) throws IOException {
+            return new NonCollectingAggregator(name, aggregationContext, parent, reducers, metaData) {
 
                 @Override
                 public InternalAggregation buildEmptyAggregation() {
-                    return new InternalChildren(name, 0, buildEmptySubAggregations(), metaData());
+                    return new InternalChildren(name, 0, buildEmptySubAggregations(), reducers(), metaData());
                 }
 
             };
         }
 
         @Override
-        protected Aggregator doCreateInternal(ValuesSource.Bytes.WithOrdinals.ParentChild valuesSource, AggregationContext aggregationContext, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
+        protected Aggregator doCreateInternal(ValuesSource.Bytes.WithOrdinals.ParentChild valuesSource,
+                AggregationContext aggregationContext, Aggregator parent, boolean collectsFromSingleBucket, List<Reducer> reducers,
+                Map<String, Object> metaData) throws IOException {
             long maxOrd = valuesSource.globalMaxOrd(aggregationContext.searchContext().searcher(), parentType);
-            return new ParentToChildrenAggregator(name, factories, aggregationContext, parent, parentType, childFilter, parentFilter, valuesSource, maxOrd, metaData);
+            return new ParentToChildrenAggregator(name, factories, aggregationContext, parent, parentType, childFilter, parentFilter,
+                    valuesSource, maxOrd, reducers, metaData);
         }
 
     }

src/main/java/org/elasticsearch/search/aggregations/bucket/filter/FilterAggregator.java

@@ -22,6 +22,7 @@ import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.search.Filter;
 import org.apache.lucene.util.Bits;
 import org.elasticsearch.common.lucene.docset.DocIdSets;
+import org.elasticsearch.search.aggregations.AggregationExecutionException;
 import org.elasticsearch.search.aggregations.Aggregator;
 import org.elasticsearch.search.aggregations.AggregatorFactories;
 import org.elasticsearch.search.aggregations.AggregatorFactory;
@@ -29,9 +30,11 @@ import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
 import org.elasticsearch.search.aggregations.bucket.SingleBucketAggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -45,9 +48,9 @@ public class FilterAggregator extends SingleBucketAggregator {
                             org.apache.lucene.search.Filter filter,
                             AggregatorFactories factories,
                             AggregationContext aggregationContext,
-                            Aggregator parent,
+ Aggregator parent, List<Reducer> reducers,
                             Map<String, Object> metaData) throws IOException {
-        super(name, factories, aggregationContext, parent, metaData);
+        super(name, factories, aggregationContext, parent, reducers, metaData);
         this.filter = filter;
     }
 
@@ -58,23 +61,24 @@ public class FilterAggregator extends SingleBucketAggregator {
         // no need to provide deleted docs to the filter
         final Bits bits = DocIdSets.asSequentialAccessBits(ctx.reader().maxDoc(), filter.getDocIdSet(ctx, null));
         return new LeafBucketCollectorBase(sub, null) {
-            @Override
+    @Override
             public void collect(int doc, long bucket) throws IOException {
-                if (bits.get(doc)) {
+        if (bits.get(doc)) {
                     collectBucket(sub, doc, bucket);
                 }
-            }
+        }
         };
     }
 
     @Override
     public InternalAggregation buildAggregation(long owningBucketOrdinal) throws IOException {
-        return new InternalFilter(name, bucketDocCount(owningBucketOrdinal), bucketAggregations(owningBucketOrdinal), metaData());
+        return new InternalFilter(name, bucketDocCount(owningBucketOrdinal), bucketAggregations(owningBucketOrdinal), reducers(),
+                metaData());
     }
 
     @Override
     public InternalAggregation buildEmptyAggregation() {
-        return new InternalFilter(name, 0, buildEmptySubAggregations(), metaData());
+        return new InternalFilter(name, 0, buildEmptySubAggregations(), reducers(), metaData());
     }
 
     public static class Factory extends AggregatorFactory {
@@ -87,8 +91,9 @@ public class FilterAggregator extends SingleBucketAggregator {
         }
 
         @Override
-        public Aggregator createInternal(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
-            return new FilterAggregator(name, filter, factories, context, parent, metaData);
+        public Aggregator createInternal(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket,
+                List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+            return new FilterAggregator(name, filter, factories, context, parent, reducers, metaData);
         }
 
     }

src/main/java/org/elasticsearch/search/aggregations/bucket/filter/InternalFilter.java

@@ -22,8 +22,10 @@ import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.search.aggregations.AggregationStreams;
 import org.elasticsearch.search.aggregations.InternalAggregations;
 import org.elasticsearch.search.aggregations.bucket.InternalSingleBucketAggregation;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -48,8 +50,8 @@ public class InternalFilter extends InternalSingleBucketAggregation implements F
 
     InternalFilter() {} // for serialization
 
-    InternalFilter(String name, long docCount, InternalAggregations subAggregations, Map<String, Object> metaData) {
-        super(name, docCount, subAggregations, metaData);
+    InternalFilter(String name, long docCount, InternalAggregations subAggregations, List<Reducer> reducers, Map<String, Object> metaData) {
+        super(name, docCount, subAggregations, reducers, metaData);
     }
 
     @Override
@@ -59,6 +61,6 @@ public class InternalFilter extends InternalSingleBucketAggregation implements F
 
     @Override
     protected InternalSingleBucketAggregation newAggregation(String name, long docCount, InternalAggregations subAggregations) {
-        return new InternalFilter(name, docCount, subAggregations, getMetaData());
+        return new InternalFilter(name, docCount, subAggregations, reducers(), getMetaData());
     }
 }

src/main/java/org/elasticsearch/search/aggregations/bucket/filters/FiltersAggregator.java

@@ -25,6 +25,7 @@ import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.search.Filter;
 import org.apache.lucene.util.Bits;
 import org.elasticsearch.common.lucene.docset.DocIdSets;
+import org.elasticsearch.search.aggregations.AggregationExecutionException;
 import org.elasticsearch.search.aggregations.Aggregator;
 import org.elasticsearch.search.aggregations.AggregatorFactories;
 import org.elasticsearch.search.aggregations.AggregatorFactory;
@@ -33,6 +34,7 @@ import org.elasticsearch.search.aggregations.InternalAggregations;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
 import org.elasticsearch.search.aggregations.bucket.BucketsAggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 
 import java.io.IOException;
@@ -59,8 +61,9 @@ public class FiltersAggregator extends BucketsAggregator {
     private final boolean keyed;
 
     public FiltersAggregator(String name, AggregatorFactories factories, List<KeyedFilter> filters, boolean keyed, AggregationContext aggregationContext,
-            Aggregator parent, Map<String, Object> metaData) throws IOException {
-        super(name, factories, aggregationContext, parent, metaData);
+ Aggregator parent, List<Reducer> reducers, Map<String, Object> metaData)
+            throws IOException {
+        super(name, factories, aggregationContext, parent, reducers, metaData);
         this.keyed = keyed;
         this.filters = filters.toArray(new KeyedFilter[filters.size()]);
     }
@@ -73,16 +76,16 @@ public class FiltersAggregator extends BucketsAggregator {
         final Bits[] bits = new Bits[filters.length];
         for (int i = 0; i < filters.length; ++i) {
             bits[i] = DocIdSets.asSequentialAccessBits(ctx.reader().maxDoc(), filters[i].filter.getDocIdSet(ctx, null));
-        }
+    }
         return new LeafBucketCollectorBase(sub, null) {
-            @Override
+    @Override
             public void collect(int doc, long bucket) throws IOException {
-                for (int i = 0; i < bits.length; i++) {
-                    if (bits[i].get(doc)) {
+        for (int i = 0; i < bits.length; i++) {
+            if (bits[i].get(doc)) {
                         collectBucket(sub, doc, bucketOrd(bucket, i));
                     }
-                }
             }
+        }
         };
     }
 
@@ -95,7 +98,7 @@ public class FiltersAggregator extends BucketsAggregator {
             InternalFilters.Bucket bucket = new InternalFilters.Bucket(filter.key, bucketDocCount(bucketOrd), bucketAggregations(bucketOrd), keyed);
             buckets.add(bucket);
         }
-        return new InternalFilters(name, buckets, keyed, metaData());
+        return new InternalFilters(name, buckets, keyed, reducers(), metaData());
     }
 
     @Override
@@ -106,7 +109,7 @@ public class FiltersAggregator extends BucketsAggregator {
             InternalFilters.Bucket bucket = new InternalFilters.Bucket(filters[i].key, 0, subAggs, keyed);
             buckets.add(bucket);
         }
-        return new InternalFilters(name, buckets, keyed, metaData());
+        return new InternalFilters(name, buckets, keyed, reducers(), metaData());
     }
 
     final long bucketOrd(long owningBucketOrdinal, int filterOrd) {
@@ -125,8 +128,9 @@ public class FiltersAggregator extends BucketsAggregator {
         }
 
         @Override
-        public Aggregator createInternal(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
-            return new FiltersAggregator(name, factories, filters, keyed, context, parent, metaData);
+        public Aggregator createInternal(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket,
+                List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+            return new FiltersAggregator(name, factories, filters, keyed, context, parent, reducers, metaData);
         }
     }
 

src/main/java/org/elasticsearch/search/aggregations/bucket/filters/InternalFilters.java

@@ -31,6 +31,7 @@ import org.elasticsearch.search.aggregations.InternalAggregations;
 import org.elasticsearch.search.aggregations.InternalMultiBucketAggregation;
 import org.elasticsearch.search.aggregations.bucket.BucketStreamContext;
 import org.elasticsearch.search.aggregations.bucket.BucketStreams;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -163,8 +164,8 @@ public class InternalFilters extends InternalMultiBucketAggregation implements F
 
     public InternalFilters() {} // for serialization
 
-    public InternalFilters(String name, List<Bucket> buckets, boolean keyed, Map<String, Object> metaData) {
-        super(name, metaData);
+    public InternalFilters(String name, List<Bucket> buckets, boolean keyed, List<Reducer> reducers, Map<String, Object> metaData) {
+        super(name, reducers, metaData);
         this.buckets = buckets;
         this.keyed = keyed;
     }
@@ -211,7 +212,7 @@ public class InternalFilters extends InternalMultiBucketAggregation implements F
             }
         }
 
-        InternalFilters reduced = new InternalFilters(name, new ArrayList<Bucket>(bucketsList.size()), keyed, getMetaData());
+        InternalFilters reduced = new InternalFilters(name, new ArrayList<Bucket>(bucketsList.size()), keyed, reducers(), getMetaData());
         for (List<Bucket> sameRangeList : bucketsList) {
             reduced.buckets.add((sameRangeList.get(0)).reduce(sameRangeList, reduceContext));
         }

src/main/java/org/elasticsearch/search/aggregations/bucket/geogrid/GeoHashGridAggregator.java

@@ -28,12 +28,14 @@ import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
 import org.elasticsearch.search.aggregations.InternalAggregations;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.bucket.BucketsAggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -49,8 +51,10 @@ public class GeoHashGridAggregator extends BucketsAggregator {
     private final LongHash bucketOrds;
 
     public GeoHashGridAggregator(String name, AggregatorFactories factories, ValuesSource.Numeric valuesSource,
-                              int requiredSize, int shardSize, AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
-        super(name, factories, aggregationContext, parent, metaData);
+ int requiredSize,
+            int shardSize, AggregationContext aggregationContext, Aggregator parent, List<Reducer> reducers, Map<String, Object> metaData)
+            throws IOException {
+        super(name, factories, aggregationContext, parent, reducers, metaData);
         this.valuesSource = valuesSource;
         this.requiredSize = requiredSize;
         this.shardSize = shardSize;
@@ -126,12 +130,12 @@ public class GeoHashGridAggregator extends BucketsAggregator {
             bucket.aggregations = bucketAggregations(bucket.bucketOrd);
             list[i] = bucket;
         }
-        return new InternalGeoHashGrid(name, requiredSize, Arrays.asList(list), metaData());
+        return new InternalGeoHashGrid(name, requiredSize, Arrays.asList(list), reducers(), metaData());
     }
 
     @Override
     public InternalGeoHashGrid buildEmptyAggregation() {
-        return new InternalGeoHashGrid(name, requiredSize, Collections.<InternalGeoHashGrid.Bucket>emptyList(), metaData());
+        return new InternalGeoHashGrid(name, requiredSize, Collections.<InternalGeoHashGrid.Bucket> emptyList(), reducers(), metaData());
     }
 
 

src/main/java/org/elasticsearch/search/aggregations/bucket/geogrid/GeoHashGridParser.java

@@ -34,6 +34,7 @@ import org.elasticsearch.search.aggregations.AggregatorFactory;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.NonCollectingAggregator;
 import org.elasticsearch.search.aggregations.bucket.BucketUtils;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
@@ -43,6 +44,7 @@ import org.elasticsearch.search.internal.SearchContext;
 
 import java.io.IOException;
 import java.util.Collections;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -123,9 +125,11 @@ public class GeoHashGridParser implements Aggregator.Parser {
         }
 
         @Override
-        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
-            final InternalAggregation aggregation = new InternalGeoHashGrid(name, requiredSize, Collections.<InternalGeoHashGrid.Bucket>emptyList(), metaData);
-            return new NonCollectingAggregator(name, aggregationContext, parent, metaData) {
+        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, List<Reducer> reducers,
+                Map<String, Object> metaData) throws IOException {
+            final InternalAggregation aggregation = new InternalGeoHashGrid(name, requiredSize,
+                    Collections.<InternalGeoHashGrid.Bucket> emptyList(), reducers, metaData);
+            return new NonCollectingAggregator(name, aggregationContext, parent, reducers, metaData) {
                 public InternalAggregation buildEmptyAggregation() {
                     return aggregation;
                 }
@@ -133,12 +137,15 @@ public class GeoHashGridParser implements Aggregator.Parser {
         }
 
         @Override
-        protected Aggregator doCreateInternal(final ValuesSource.GeoPoint valuesSource, AggregationContext aggregationContext, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
+        protected Aggregator doCreateInternal(final ValuesSource.GeoPoint valuesSource, AggregationContext aggregationContext,
+                Aggregator parent, boolean collectsFromSingleBucket, List<Reducer> reducers, Map<String, Object> metaData)
+                throws IOException {
             if (collectsFromSingleBucket == false) {
                 return asMultiBucketAggregator(this, aggregationContext, parent);
             }
             ValuesSource.Numeric cellIdSource = new CellIdSource(valuesSource, precision);
-            return new GeoHashGridAggregator(name, factories, cellIdSource, requiredSize, shardSize, aggregationContext, parent, metaData);
+            return new GeoHashGridAggregator(name, factories, cellIdSource, requiredSize, shardSize, aggregationContext, parent, reducers,
+                    metaData);
 
         }
 

src/main/java/org/elasticsearch/search/aggregations/bucket/geogrid/InternalGeoHashGrid.java

@@ -32,6 +32,7 @@ import org.elasticsearch.search.aggregations.InternalAggregations;
 import org.elasticsearch.search.aggregations.InternalMultiBucketAggregation;
 import org.elasticsearch.search.aggregations.bucket.BucketStreamContext;
 import org.elasticsearch.search.aggregations.bucket.BucketStreams;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -170,8 +171,9 @@ public class InternalGeoHashGrid extends InternalMultiBucketAggregation implemen
     InternalGeoHashGrid() {
     } // for serialization
 
-    public InternalGeoHashGrid(String name, int requiredSize, Collection<Bucket> buckets, Map<String, Object> metaData) {
-        super(name, metaData);
+    public InternalGeoHashGrid(String name, int requiredSize, Collection<Bucket> buckets, List<Reducer> reducers,
+            Map<String, Object> metaData) {
+        super(name, reducers, metaData);
         this.requiredSize = requiredSize;
         this.buckets = buckets;
     }
@@ -218,7 +220,7 @@ public class InternalGeoHashGrid extends InternalMultiBucketAggregation implemen
         for (int i = ordered.size() - 1; i >= 0; i--) {
             list[i] = ordered.pop();
         }
-        return new InternalGeoHashGrid(getName(), requiredSize, Arrays.asList(list), getMetaData());
+        return new InternalGeoHashGrid(getName(), requiredSize, Arrays.asList(list), reducers(), getMetaData());
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/bucket/global/GlobalAggregator.java

@@ -28,9 +28,11 @@ import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
 import org.elasticsearch.search.aggregations.bucket.SingleBucketAggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -38,8 +40,9 @@ import java.util.Map;
  */
 public class GlobalAggregator extends SingleBucketAggregator {
 
-    public GlobalAggregator(String name, AggregatorFactories subFactories, AggregationContext aggregationContext, Map<String, Object> metaData) throws IOException {
-        super(name, subFactories, aggregationContext, null, metaData);
+    public GlobalAggregator(String name, AggregatorFactories subFactories, AggregationContext aggregationContext, List<Reducer> reducers,
+            Map<String, Object> metaData) throws IOException {
+        super(name, subFactories, aggregationContext, null, reducers, metaData);
     }
 
     @Override
@@ -50,14 +53,15 @@ public class GlobalAggregator extends SingleBucketAggregator {
             public void collect(int doc, long bucket) throws IOException {
                 assert bucket == 0 : "global aggregator can only be a top level aggregator";
                 collectBucket(sub, doc, bucket);
-            }
+    }
         };
     }
 
     @Override
     public InternalAggregation buildAggregation(long owningBucketOrdinal) throws IOException {
         assert owningBucketOrdinal == 0 : "global aggregator can only be a top level aggregator";
-        return new InternalGlobal(name, bucketDocCount(owningBucketOrdinal), bucketAggregations(owningBucketOrdinal), metaData());
+        return new InternalGlobal(name, bucketDocCount(owningBucketOrdinal), bucketAggregations(owningBucketOrdinal), reducers(),
+                metaData());
     }
 
     @Override
@@ -72,7 +76,8 @@ public class GlobalAggregator extends SingleBucketAggregator {
         }
 
         @Override
-        public Aggregator createInternal(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
+        public Aggregator createInternal(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket,
+                List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
             if (parent != null) {
                 throw new AggregationExecutionException("Aggregation [" + parent.name() + "] cannot have a global " +
                         "sub-aggregation [" + name + "]. Global aggregations can only be defined as top level aggregations");
@@ -80,7 +85,7 @@ public class GlobalAggregator extends SingleBucketAggregator {
             if (collectsFromSingleBucket == false) {
                 throw new ElasticsearchIllegalStateException();
             }
-            return new GlobalAggregator(name, factories, context, metaData);
+            return new GlobalAggregator(name, factories, context, reducers, metaData);
         }
 
     }

src/main/java/org/elasticsearch/search/aggregations/bucket/global/InternalGlobal.java

@@ -22,8 +22,10 @@ import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.search.aggregations.AggregationStreams;
 import org.elasticsearch.search.aggregations.InternalAggregations;
 import org.elasticsearch.search.aggregations.bucket.InternalSingleBucketAggregation;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -49,8 +51,8 @@ public class InternalGlobal extends InternalSingleBucketAggregation implements G
 
     InternalGlobal() {} // for serialization
 
-    InternalGlobal(String name, long docCount, InternalAggregations aggregations, Map<String, Object> metaData) {
-        super(name, docCount, aggregations, metaData);
+    InternalGlobal(String name, long docCount, InternalAggregations aggregations, List<Reducer> reducers, Map<String, Object> metaData) {
+        super(name, docCount, aggregations, reducers, metaData);
     }
 
     @Override
@@ -60,6 +62,6 @@ public class InternalGlobal extends InternalSingleBucketAggregation implements G
 
     @Override
     protected InternalSingleBucketAggregation newAggregation(String name, long docCount, InternalAggregations subAggregations) {
-        return new InternalGlobal(name, docCount, subAggregations, getMetaData());
+        return new InternalGlobal(name, docCount, subAggregations, reducers(), getMetaData());
     }
 }

src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/HistogramAggregator.java

@@ -31,6 +31,7 @@ import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
 import org.elasticsearch.search.aggregations.bucket.BucketsAggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
@@ -62,9 +63,10 @@ public class HistogramAggregator extends BucketsAggregator {
                                boolean keyed, long minDocCount, @Nullable ExtendedBounds extendedBounds,
                                @Nullable ValuesSource.Numeric valuesSource, @Nullable ValueFormatter formatter,
                                InternalHistogram.Factory<?> histogramFactory,
-                               AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
+ AggregationContext aggregationContext,
+            Aggregator parent, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
 
-        super(name, factories, aggregationContext, parent, metaData);
+        super(name, factories, aggregationContext, parent, reducers, metaData);
         this.rounding = rounding;
         this.order = order;
         this.keyed = keyed;
@@ -130,13 +132,14 @@ public class HistogramAggregator extends BucketsAggregator {
 
         // value source will be null for unmapped fields
         InternalHistogram.EmptyBucketInfo emptyBucketInfo = minDocCount == 0 ? new InternalHistogram.EmptyBucketInfo(rounding, buildEmptySubAggregations(), extendedBounds) : null;
-        return histogramFactory.create(name, buckets, order, minDocCount, emptyBucketInfo, formatter, keyed, metaData());
+        return histogramFactory.create(name, buckets, order, minDocCount, emptyBucketInfo, formatter, keyed, reducers(), metaData());
     }
 
     @Override
     public InternalAggregation buildEmptyAggregation() {
         InternalHistogram.EmptyBucketInfo emptyBucketInfo = minDocCount == 0 ? new InternalHistogram.EmptyBucketInfo(rounding, buildEmptySubAggregations(), extendedBounds) : null;
-        return histogramFactory.create(name, Collections.emptyList(), order, minDocCount, emptyBucketInfo, formatter, keyed, metaData());
+        return histogramFactory.create(name, Collections.emptyList(), order, minDocCount, emptyBucketInfo, formatter, keyed, reducers(),
+                metaData());
     }
 
     @Override
@@ -167,12 +170,15 @@ public class HistogramAggregator extends BucketsAggregator {
         }
 
         @Override
-        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
-            return new HistogramAggregator(name, factories, rounding, order, keyed, minDocCount, null, null, config.formatter(), histogramFactory, aggregationContext, parent, metaData);
+        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, List<Reducer> reducers,
+                Map<String, Object> metaData) throws IOException {
+            return new HistogramAggregator(name, factories, rounding, order, keyed, minDocCount, null, null, config.formatter(),
+                    histogramFactory, aggregationContext, parent, reducers, metaData);
         }
 
         @Override
-        protected Aggregator doCreateInternal(ValuesSource.Numeric valuesSource, AggregationContext aggregationContext, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
+        protected Aggregator doCreateInternal(ValuesSource.Numeric valuesSource, AggregationContext aggregationContext, Aggregator parent,
+                boolean collectsFromSingleBucket, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
             if (collectsFromSingleBucket == false) {
                 return asMultiBucketAggregator(this, aggregationContext, parent);
             }
@@ -185,7 +191,8 @@ public class HistogramAggregator extends BucketsAggregator {
                 extendedBounds.processAndValidate(name, aggregationContext.searchContext(), config.parser());
                 roundedBounds = extendedBounds.round(rounding);
             }
-            return new HistogramAggregator(name, factories, rounding, order, keyed, minDocCount, roundedBounds, valuesSource, config.formatter(), histogramFactory, aggregationContext, parent, metaData);
+            return new HistogramAggregator(name, factories, rounding, order, keyed, minDocCount, roundedBounds, valuesSource,
+                    config.formatter(), histogramFactory, aggregationContext, parent, reducers, metaData);
         }
 
     }

src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/InternalDateHistogram.java

@@ -22,6 +22,7 @@ import org.elasticsearch.common.Nullable;
 import org.elasticsearch.search.aggregations.InternalAggregation.Type;
 import org.elasticsearch.search.aggregations.InternalAggregations;
 import org.elasticsearch.search.aggregations.bucket.histogram.InternalHistogram.EmptyBucketInfo;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 import org.joda.time.DateTime;
 import org.joda.time.DateTimeZone;
@@ -75,8 +76,10 @@ public class InternalDateHistogram {
 
         @Override
         public InternalHistogram create(String name, List<InternalDateHistogram.Bucket> buckets, InternalOrder order,
-                                            long minDocCount, EmptyBucketInfo emptyBucketInfo, @Nullable ValueFormatter formatter, boolean keyed, Map<String, Object> metaData) {
-            return new InternalHistogram(name, buckets, order, minDocCount, emptyBucketInfo, formatter, keyed, this, metaData);
+ long minDocCount,
+                EmptyBucketInfo emptyBucketInfo, @Nullable ValueFormatter formatter, boolean keyed, List<Reducer> reducers,
+                Map<String, Object> metaData) {
+            return new InternalHistogram(name, buckets, order, minDocCount, emptyBucketInfo, formatter, keyed, this, reducers, metaData);
         }
 
         @Override

src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/InternalHistogram.java

@@ -37,6 +37,7 @@ import org.elasticsearch.search.aggregations.InternalAggregations;
 import org.elasticsearch.search.aggregations.InternalMultiBucketAggregation;
 import org.elasticsearch.search.aggregations.bucket.BucketStreamContext;
 import org.elasticsearch.search.aggregations.bucket.BucketStreams;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatterStreams;
 
@@ -233,8 +234,9 @@ public class InternalHistogram<B extends InternalHistogram.Bucket> extends Inter
         }
 
         public InternalHistogram<B> create(String name, List<B> buckets, InternalOrder order, long minDocCount,
-                                           EmptyBucketInfo emptyBucketInfo, @Nullable ValueFormatter formatter, boolean keyed, Map<String, Object> metaData) {
-            return new InternalHistogram<>(name, buckets, order, minDocCount, emptyBucketInfo, formatter, keyed, this, metaData);
+                EmptyBucketInfo emptyBucketInfo, @Nullable ValueFormatter formatter, boolean keyed, List<Reducer> reducers,
+                Map<String, Object> metaData) {
+            return new InternalHistogram<>(name, buckets, order, minDocCount, emptyBucketInfo, formatter, keyed, this, reducers, metaData);
         }
 
         public B createBucket(long key, long docCount, InternalAggregations aggregations, boolean keyed, @Nullable ValueFormatter formatter) {
@@ -259,8 +261,8 @@ public class InternalHistogram<B extends InternalHistogram.Bucket> extends Inter
 
     InternalHistogram(String name, List<B> buckets, InternalOrder order, long minDocCount,
  EmptyBucketInfo emptyBucketInfo,
-            @Nullable ValueFormatter formatter, boolean keyed, Factory<B> factory, Map<String, Object> metaData) {
-        super(name, metaData);
+            @Nullable ValueFormatter formatter, boolean keyed, Factory<B> factory, List<Reducer> reducers, Map<String, Object> metaData) {
+        super(name, reducers, metaData);
         this.buckets = buckets;
         this.order = order;
         assert (minDocCount == 0) == (emptyBucketInfo != null);
@@ -432,7 +434,8 @@ public class InternalHistogram<B extends InternalHistogram.Bucket> extends Inter
             CollectionUtil.introSort(reducedBuckets, order.comparator());
         }
 
-        return getFactory().create(getName(), reducedBuckets, order, minDocCount, emptyBucketInfo, formatter, keyed, getMetaData());
+        return getFactory().create(getName(), reducedBuckets, order, minDocCount, emptyBucketInfo, formatter, keyed, reducers(),
+                getMetaData());
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/bucket/missing/InternalMissing.java

@@ -22,8 +22,10 @@ import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.search.aggregations.AggregationStreams;
 import org.elasticsearch.search.aggregations.InternalAggregations;
 import org.elasticsearch.search.aggregations.bucket.InternalSingleBucketAggregation;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -50,8 +52,8 @@ public class InternalMissing extends InternalSingleBucketAggregation implements
     InternalMissing() {
     }
 
-    InternalMissing(String name, long docCount, InternalAggregations aggregations, Map<String, Object> metaData) {
-        super(name, docCount, aggregations, metaData);
+    InternalMissing(String name, long docCount, InternalAggregations aggregations, List<Reducer> reducers, Map<String, Object> metaData) {
+        super(name, docCount, aggregations, reducers, metaData);
     }
 
     @Override
@@ -61,6 +63,6 @@ public class InternalMissing extends InternalSingleBucketAggregation implements
 
     @Override
     protected InternalSingleBucketAggregation newAggregation(String name, long docCount, InternalAggregations subAggregations) {
-        return new InternalMissing(name, docCount, subAggregations, getMetaData());
+        return new InternalMissing(name, docCount, subAggregations, reducers(), getMetaData());
     }
 }

src/main/java/org/elasticsearch/search/aggregations/bucket/missing/MissingAggregator.java

@@ -26,12 +26,14 @@ import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
 import org.elasticsearch.search.aggregations.bucket.SingleBucketAggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
 import org.elasticsearch.search.aggregations.support.ValuesSourceConfig;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -42,8 +44,9 @@ public class MissingAggregator extends SingleBucketAggregator {
     private final ValuesSource valuesSource;
 
     public MissingAggregator(String name, AggregatorFactories factories, ValuesSource valuesSource,
-                             AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
-        super(name, factories, aggregationContext, parent, metaData);
+ AggregationContext aggregationContext,
+            Aggregator parent, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+        super(name, factories, aggregationContext, parent, reducers, metaData);
         this.valuesSource = valuesSource;
     }
 
@@ -69,12 +72,13 @@ public class MissingAggregator extends SingleBucketAggregator {
 
     @Override
     public InternalAggregation buildAggregation(long owningBucketOrdinal) throws IOException {
-        return new InternalMissing(name, bucketDocCount(owningBucketOrdinal), bucketAggregations(owningBucketOrdinal), metaData());
+        return new InternalMissing(name, bucketDocCount(owningBucketOrdinal), bucketAggregations(owningBucketOrdinal), reducers(),
+                metaData());
     }
 
     @Override
     public InternalAggregation buildEmptyAggregation() {
-        return new InternalMissing(name, 0, buildEmptySubAggregations(), metaData());
+        return new InternalMissing(name, 0, buildEmptySubAggregations(), reducers(), metaData());
     }
 
     public static class Factory extends ValuesSourceAggregatorFactory<ValuesSource>  {
@@ -84,13 +88,15 @@ public class MissingAggregator extends SingleBucketAggregator {
         }
 
         @Override
-        protected MissingAggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
-            return new MissingAggregator(name, factories, null, aggregationContext, parent, metaData);
+        protected MissingAggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, List<Reducer> reducers,
+                Map<String, Object> metaData) throws IOException {
+            return new MissingAggregator(name, factories, null, aggregationContext, parent, reducers, metaData);
         }
 
         @Override
-        protected MissingAggregator doCreateInternal(ValuesSource valuesSource, AggregationContext aggregationContext, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
-            return new MissingAggregator(name, factories, valuesSource, aggregationContext, parent, metaData);
+        protected MissingAggregator doCreateInternal(ValuesSource valuesSource, AggregationContext aggregationContext, Aggregator parent,
+                boolean collectsFromSingleBucket, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+            return new MissingAggregator(name, factories, valuesSource, aggregationContext, parent, reducers, metaData);
         }
     }
 

src/main/java/org/elasticsearch/search/aggregations/bucket/nested/InternalNested.java

@@ -22,8 +22,10 @@ import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.search.aggregations.AggregationStreams;
 import org.elasticsearch.search.aggregations.InternalAggregations;
 import org.elasticsearch.search.aggregations.bucket.InternalSingleBucketAggregation;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -49,8 +51,9 @@ public class InternalNested extends InternalSingleBucketAggregation implements N
     public InternalNested() {
     }
 
-    public InternalNested(String name, long docCount, InternalAggregations aggregations, Map<String, Object> metaData) {
-        super(name, docCount, aggregations, metaData);
+    public InternalNested(String name, long docCount, InternalAggregations aggregations, List<Reducer> reducers,
+            Map<String, Object> metaData) {
+        super(name, docCount, aggregations, reducers, metaData);
     }
 
     @Override
@@ -60,6 +63,6 @@ public class InternalNested extends InternalSingleBucketAggregation implements N
 
     @Override
     protected InternalSingleBucketAggregation newAggregation(String name, long docCount, InternalAggregations subAggregations) {
-        return new InternalNested(name, docCount, subAggregations, getMetaData());
+        return new InternalNested(name, docCount, subAggregations, reducers(), getMetaData());
     }
 }

src/main/java/org/elasticsearch/search/aggregations/bucket/nested/InternalReverseNested.java

@@ -22,8 +22,10 @@ import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.search.aggregations.AggregationStreams;
 import org.elasticsearch.search.aggregations.InternalAggregations;
 import org.elasticsearch.search.aggregations.bucket.InternalSingleBucketAggregation;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -49,8 +51,9 @@ public class InternalReverseNested extends InternalSingleBucketAggregation imple
     public InternalReverseNested() {
     }
 
-    public InternalReverseNested(String name, long docCount, InternalAggregations aggregations, Map<String, Object> metaData) {
-        super(name, docCount, aggregations, metaData);
+    public InternalReverseNested(String name, long docCount, InternalAggregations aggregations, List<Reducer> reducers,
+            Map<String, Object> metaData) {
+        super(name, docCount, aggregations, reducers, metaData);
     }
 
     @Override
@@ -60,6 +63,6 @@ public class InternalReverseNested extends InternalSingleBucketAggregation imple
 
     @Override
     protected InternalSingleBucketAggregation newAggregation(String name, long docCount, InternalAggregations subAggregations) {
-        return new InternalReverseNested(name, docCount, subAggregations, getMetaData());
+        return new InternalReverseNested(name, docCount, subAggregations, reducers(), getMetaData());
     }
 }

src/main/java/org/elasticsearch/search/aggregations/bucket/nested/NestedAggregator.java

@@ -39,9 +39,11 @@ import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
 import org.elasticsearch.search.aggregations.NonCollectingAggregator;
 import org.elasticsearch.search.aggregations.bucket.SingleBucketAggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -55,8 +57,8 @@ public class NestedAggregator extends SingleBucketAggregator {
     private DocIdSetIterator childDocs;
     private BitSet parentDocs;
 
-    public NestedAggregator(String name, AggregatorFactories factories, ObjectMapper objectMapper, AggregationContext aggregationContext, Aggregator parentAggregator, Map<String, Object> metaData, FilterCachingPolicy filterCachingPolicy) throws IOException {
-        super(name, factories, aggregationContext, parentAggregator, metaData);
+    public NestedAggregator(String name, AggregatorFactories factories, ObjectMapper objectMapper, AggregationContext aggregationContext, Aggregator parentAggregator, List<Reducer> reducers, Map<String, Object> metaData, FilterCachingPolicy filterCachingPolicy) throws IOException {
+        super(name, factories, aggregationContext, parentAggregator, reducers, metaData);
         childFilter = aggregationContext.searchContext().filterCache().cache(objectMapper.nestedTypeFilter(), null, filterCachingPolicy);
     }
 
@@ -64,68 +66,69 @@ public class NestedAggregator extends SingleBucketAggregator {
     public LeafBucketCollector getLeafCollector(final LeafReaderContext ctx, final LeafBucketCollector sub) throws IOException {
         // Reset parentFilter, so we resolve the parentDocs for each new segment being searched
         this.parentFilter = null;
-        // In ES if parent is deleted, then also the children are deleted. Therefore acceptedDocs can also null here.
+            // In ES if parent is deleted, then also the children are deleted. Therefore acceptedDocs can also null here.
         DocIdSet childDocIdSet = childFilter.getDocIdSet(ctx, null);
-        if (DocIdSets.isEmpty(childDocIdSet)) {
-            childDocs = null;
-        } else {
-            childDocs = childDocIdSet.iterator();
-        }
+            if (DocIdSets.isEmpty(childDocIdSet)) {
+                childDocs = null;
+            } else {
+                childDocs = childDocIdSet.iterator();
+            }
 
         return new LeafBucketCollectorBase(sub, null) {
-            @Override
+    @Override
             public void collect(int parentDoc, long bucket) throws IOException {
-                // here we translate the parent doc to a list of its nested docs, and then call super.collect for evey one of them so they'll be collected
+        // here we translate the parent doc to a list of its nested docs, and then call super.collect for evey one of them so they'll be collected
 
-                // if parentDoc is 0 then this means that this parent doesn't have child docs (b/c these appear always before the parent doc), so we can skip:
-                if (parentDoc == 0 || childDocs == null) {
-                    return;
-                }
-                if (parentFilter == null) {
-                    // The aggs are instantiated in reverse, first the most inner nested aggs and lastly the top level aggs
-                    // So at the time a nested 'nested' aggs is parsed its closest parent nested aggs hasn't been constructed.
-                    // So the trick is to set at the last moment just before needed and we can use its child filter as the
-                    // parent filter.
+        // if parentDoc is 0 then this means that this parent doesn't have child docs (b/c these appear always before the parent doc), so we can skip:
+        if (parentDoc == 0 || childDocs == null) {
+            return;
+        }
+        if (parentFilter == null) {
+            // The aggs are instantiated in reverse, first the most inner nested aggs and lastly the top level aggs
+            // So at the time a nested 'nested' aggs is parsed its closest parent nested aggs hasn't been constructed.
+            // So the trick is to set at the last moment just before needed and we can use its child filter as the
+            // parent filter.
 
-                    // Additional NOTE: Before this logic was performed in the setNextReader(...) method, but the the assumption
-                    // that aggs instances are constructed in reverse doesn't hold when buckets are constructed lazily during
-                    // aggs execution
+            // Additional NOTE: Before this logic was performed in the setNextReader(...) method, but the the assumption
+            // that aggs instances are constructed in reverse doesn't hold when buckets are constructed lazily during
+            // aggs execution
                     Filter parentFilterNotCached = findClosestNestedPath(parent());
-                    if (parentFilterNotCached == null) {
-                        parentFilterNotCached = NonNestedDocsFilter.INSTANCE;
-                    }
-                    parentFilter = context.searchContext().bitsetFilterCache().getBitDocIdSetFilter(parentFilterNotCached);
+            if (parentFilterNotCached == null) {
+                parentFilterNotCached = NonNestedDocsFilter.INSTANCE;
+            }
+            parentFilter = context.searchContext().bitsetFilterCache().getBitDocIdSetFilter(parentFilterNotCached);
                     BitDocIdSet parentSet = parentFilter.getDocIdSet(ctx);
-                    if (DocIdSets.isEmpty(parentSet)) {
-                        // There are no parentDocs in the segment, so return and set childDocs to null, so we exit early for future invocations.
-                        childDocs = null;
-                        return;
-                    } else {
-                        parentDocs = parentSet.bits();
-                    }
-                }
+            if (DocIdSets.isEmpty(parentSet)) {
+                // There are no parentDocs in the segment, so return and set childDocs to null, so we exit early for future invocations.
+                childDocs = null;
+                return;
+            } else {
+                parentDocs = parentSet.bits();
+            }
+        }
 
-                final int prevParentDoc = parentDocs.prevSetBit(parentDoc - 1);
-                int childDocId = childDocs.docID();
-                if (childDocId <= prevParentDoc) {
-                    childDocId = childDocs.advance(prevParentDoc + 1);
-                }
+        final int prevParentDoc = parentDocs.prevSetBit(parentDoc - 1);
+        int childDocId = childDocs.docID();
+        if (childDocId <= prevParentDoc) {
+            childDocId = childDocs.advance(prevParentDoc + 1);
+        }
 
-                for (; childDocId < parentDoc; childDocId = childDocs.nextDoc()) {
+        for (; childDocId < parentDoc; childDocId = childDocs.nextDoc()) {
                     collectBucket(sub, childDocId, bucket);
                 }
-            }
+        }
         };
     }
         
     @Override
     public InternalAggregation buildAggregation(long owningBucketOrdinal) throws IOException {
-        return new InternalNested(name, bucketDocCount(owningBucketOrdinal), bucketAggregations(owningBucketOrdinal), metaData());
+        return new InternalNested(name, bucketDocCount(owningBucketOrdinal), bucketAggregations(owningBucketOrdinal), reducers(),
+                metaData());
     }
 
         @Override
     public InternalAggregation buildEmptyAggregation() {
-        return new InternalNested(name, 0, buildEmptySubAggregations(), metaData());
+        return new InternalNested(name, 0, buildEmptySubAggregations(), reducers(), metaData());
     }
 
     private static Filter findClosestNestedPath(Aggregator parent) {
@@ -151,33 +154,35 @@ public class NestedAggregator extends SingleBucketAggregator {
         }
 
         @Override
-        public Aggregator createInternal(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
+        public Aggregator createInternal(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket,
+                List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
             if (collectsFromSingleBucket == false) {
                 return asMultiBucketAggregator(this, context, parent);
             }
             MapperService.SmartNameObjectMapper mapper = context.searchContext().smartNameObjectMapper(path);
             if (mapper == null) {
-                return new Unmapped(name, context, parent, metaData);
+                return new Unmapped(name, context, parent, reducers, metaData);
             }
             ObjectMapper objectMapper = mapper.mapper();
             if (objectMapper == null) {
-                return new Unmapped(name, context, parent, metaData);
+                return new Unmapped(name, context, parent, reducers, metaData);
             }
             if (!objectMapper.nested().isNested()) {
                 throw new AggregationExecutionException("[nested] nested path [" + path + "] is not nested");
             }
-            return new NestedAggregator(name, factories, objectMapper, context, parent, metaData, filterCachingPolicy);
+            return new NestedAggregator(name, factories, objectMapper, context, parent, reducers, metaData, filterCachingPolicy);
         }
 
         private final static class Unmapped extends NonCollectingAggregator {
 
-            public Unmapped(String name, AggregationContext context, Aggregator parent, Map<String, Object> metaData) throws IOException {
-                super(name, context, parent, metaData);
+            public Unmapped(String name, AggregationContext context, Aggregator parent, List<Reducer> reducers, Map<String, Object> metaData)
+                    throws IOException {
+                super(name, context, parent, reducers, metaData);
             }
 
             @Override
             public InternalAggregation buildEmptyAggregation() {
-                return new InternalNested(name, 0, buildEmptySubAggregations(), metaData());
+                return new InternalNested(name, 0, buildEmptySubAggregations(), reducers(), metaData());
             }
         }
     }

src/main/java/org/elasticsearch/search/aggregations/bucket/nested/ReverseNestedAggregator.java

@@ -40,9 +40,11 @@ import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
 import org.elasticsearch.search.aggregations.NonCollectingAggregator;
 import org.elasticsearch.search.aggregations.bucket.SingleBucketAggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -52,8 +54,10 @@ public class ReverseNestedAggregator extends SingleBucketAggregator {
 
     private final BitDocIdSetFilter parentFilter;
 
-    public ReverseNestedAggregator(String name, AggregatorFactories factories, ObjectMapper objectMapper, AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
-        super(name, factories, aggregationContext, parent, metaData);
+    public ReverseNestedAggregator(String name, AggregatorFactories factories, ObjectMapper objectMapper,
+            AggregationContext aggregationContext, Aggregator parent, List<Reducer> reducers, Map<String, Object> metaData)
+            throws IOException {
+        super(name, factories, aggregationContext, parent, reducers, metaData);
         if (objectMapper == null) {
             parentFilter = context.searchContext().bitsetFilterCache().getBitDocIdSetFilter(NonNestedDocsFilter.INSTANCE);
         } else {
@@ -64,33 +68,33 @@ public class ReverseNestedAggregator extends SingleBucketAggregator {
 
     @Override
     protected LeafBucketCollector getLeafCollector(LeafReaderContext ctx, final LeafBucketCollector sub) throws IOException {
-        // In ES if parent is deleted, then also the children are deleted, so the child docs this agg receives
-        // must belong to parent docs that is alive. For this reason acceptedDocs can be null here.
+            // In ES if parent is deleted, then also the children are deleted, so the child docs this agg receives
+            // must belong to parent docs that is alive. For this reason acceptedDocs can be null here.
         BitDocIdSet docIdSet = parentFilter.getDocIdSet(ctx);
         final BitSet parentDocs;
-        if (DocIdSets.isEmpty(docIdSet)) {
+            if (DocIdSets.isEmpty(docIdSet)) {
             return LeafBucketCollector.NO_OP_COLLECTOR;
-        } else {
-            parentDocs = docIdSet.bits();
-        }
+            } else {
+                parentDocs = docIdSet.bits();
+            }
         final LongIntOpenHashMap bucketOrdToLastCollectedParentDoc = new LongIntOpenHashMap(32);
         return new LeafBucketCollectorBase(sub, null) {
-            @Override
+    @Override
             public void collect(int childDoc, long bucket) throws IOException {
-                // fast forward to retrieve the parentDoc this childDoc belongs to
-                final int parentDoc = parentDocs.nextSetBit(childDoc);
-                assert childDoc <= parentDoc && parentDoc != DocIdSetIterator.NO_MORE_DOCS;
+        // fast forward to retrieve the parentDoc this childDoc belongs to
+        final int parentDoc = parentDocs.nextSetBit(childDoc);
+        assert childDoc <= parentDoc && parentDoc != DocIdSetIterator.NO_MORE_DOCS;
                 if (bucketOrdToLastCollectedParentDoc.containsKey(bucket)) {
-                    int lastCollectedParentDoc = bucketOrdToLastCollectedParentDoc.lget();
-                    if (parentDoc > lastCollectedParentDoc) {
+            int lastCollectedParentDoc = bucketOrdToLastCollectedParentDoc.lget();
+            if (parentDoc > lastCollectedParentDoc) {
                         collectBucket(sub, parentDoc, bucket);
-                        bucketOrdToLastCollectedParentDoc.lset(parentDoc);
-                    }
-                } else {
+                bucketOrdToLastCollectedParentDoc.lset(parentDoc);
+            }
+        } else {
                     collectBucket(sub, parentDoc, bucket);
                     bucketOrdToLastCollectedParentDoc.put(bucket, parentDoc);
-                }
-            }
+        }
+    }
         };
     }
 
@@ -105,12 +109,13 @@ public class ReverseNestedAggregator extends SingleBucketAggregator {
 
     @Override
     public InternalAggregation buildAggregation(long owningBucketOrdinal) throws IOException {
-        return new InternalReverseNested(name, bucketDocCount(owningBucketOrdinal), bucketAggregations(owningBucketOrdinal), metaData());
+        return new InternalReverseNested(name, bucketDocCount(owningBucketOrdinal), bucketAggregations(owningBucketOrdinal), reducers(),
+                metaData());
     }
 
     @Override
     public InternalAggregation buildEmptyAggregation() {
-        return new InternalReverseNested(name, 0, buildEmptySubAggregations(), metaData());
+        return new InternalReverseNested(name, 0, buildEmptySubAggregations(), reducers(), metaData());
     }
 
     Filter getParentFilter() {
@@ -127,7 +132,8 @@ public class ReverseNestedAggregator extends SingleBucketAggregator {
         }
 
         @Override
-        public Aggregator createInternal(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
+        public Aggregator createInternal(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket,
+                List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
             // Early validation
             NestedAggregator closestNestedAggregator = findClosestNestedAggregator(parent);
             if (closestNestedAggregator == null) {
@@ -138,11 +144,11 @@ public class ReverseNestedAggregator extends SingleBucketAggregator {
             if (path != null) {
                 MapperService.SmartNameObjectMapper mapper = context.searchContext().smartNameObjectMapper(path);
                 if (mapper == null) {
-                    return new Unmapped(name, context, parent, metaData);
+                    return new Unmapped(name, context, parent, reducers, metaData);
                 }
                 objectMapper = mapper.mapper();
                 if (objectMapper == null) {
-                    return new Unmapped(name, context, parent, metaData);
+                    return new Unmapped(name, context, parent, reducers, metaData);
                 }
                 if (!objectMapper.nested().isNested()) {
                     throw new AggregationExecutionException("[reverse_nested] nested path [" + path + "] is not nested");
@@ -150,18 +156,19 @@ public class ReverseNestedAggregator extends SingleBucketAggregator {
             } else {
                 objectMapper = null;
             }
-            return new ReverseNestedAggregator(name, factories, objectMapper, context, parent, metaData);
+            return new ReverseNestedAggregator(name, factories, objectMapper, context, parent, reducers, metaData);
         }
 
         private final static class Unmapped extends NonCollectingAggregator {
 
-            public Unmapped(String name, AggregationContext context, Aggregator parent, Map<String, Object> metaData) throws IOException {
-                super(name, context, parent, metaData);
+            public Unmapped(String name, AggregationContext context, Aggregator parent, List<Reducer> reducers, Map<String, Object> metaData)
+                    throws IOException {
+                super(name, context, parent, reducers, metaData);
             }
 
             @Override
             public InternalAggregation buildEmptyAggregation() {
-                return new InternalReverseNested(name, 0, buildEmptySubAggregations(), metaData());
+                return new InternalReverseNested(name, 0, buildEmptySubAggregations(), reducers(), metaData());
             }
         }
     }

src/main/java/org/elasticsearch/search/aggregations/bucket/range/InternalRange.java

@@ -31,6 +31,7 @@ import org.elasticsearch.search.aggregations.InternalAggregations;
 import org.elasticsearch.search.aggregations.InternalMultiBucketAggregation;
 import org.elasticsearch.search.aggregations.bucket.BucketStreamContext;
 import org.elasticsearch.search.aggregations.bucket.BucketStreams;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatterStreams;
 
@@ -219,8 +220,9 @@ public class InternalRange<B extends InternalRange.Bucket> extends InternalMulti
             return TYPE.name();
         }
 
-        public R create(String name, List<B> ranges, @Nullable ValueFormatter formatter, boolean keyed, Map<String, Object> metaData) {
-            return (R) new InternalRange<>(name, ranges, formatter, keyed, metaData);
+        public R create(String name, List<B> ranges, @Nullable ValueFormatter formatter, boolean keyed, List<Reducer> reducers,
+                Map<String, Object> metaData) {
+            return (R) new InternalRange<>(name, ranges, formatter, keyed, reducers, metaData);
         }
 
 
@@ -236,8 +238,9 @@ public class InternalRange<B extends InternalRange.Bucket> extends InternalMulti
 
     public InternalRange() {} // for serialization
 
-    public InternalRange(String name, List<B> ranges, @Nullable ValueFormatter formatter, boolean keyed, Map<String, Object> metaData) {
-        super(name, metaData);
+    public InternalRange(String name, List<B> ranges, @Nullable ValueFormatter formatter, boolean keyed, List<Reducer> reducers,
+            Map<String, Object> metaData) {
+        super(name, reducers, metaData);
         this.ranges = ranges;
         this.formatter = formatter;
         this.keyed = keyed;
@@ -277,7 +280,7 @@ public class InternalRange<B extends InternalRange.Bucket> extends InternalMulti
         for (int i = 0; i < this.ranges.size(); ++i) {
             ranges.add((B) rangeList[i].get(0).reduce(rangeList[i], reduceContext));
         }
-        return getFactory().create(name, ranges, formatter, keyed, getMetaData());
+        return getFactory().create(name, ranges, formatter, keyed, reducers(), getMetaData());
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/bucket/range/RangeAggregator.java

@@ -33,6 +33,7 @@ import org.elasticsearch.search.aggregations.InternalAggregations;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.NonCollectingAggregator;
 import org.elasticsearch.search.aggregations.bucket.BucketsAggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
@@ -104,10 +105,10 @@ public class RangeAggregator extends BucketsAggregator {
                            List<Range> ranges,
                            boolean keyed,
                            AggregationContext aggregationContext,
-                           Aggregator parent,
+            Aggregator parent, List<Reducer> reducers,
                            Map<String, Object> metaData) throws IOException {
 
-        super(name, factories, aggregationContext, parent, metaData);
+        super(name, factories, aggregationContext, parent, reducers, metaData);
         assert valuesSource != null;
         this.valuesSource = valuesSource;
         this.formatter = format != null ? format.formatter() : null;
@@ -139,64 +140,64 @@ public class RangeAggregator extends BucketsAggregator {
             final LeafBucketCollector sub) throws IOException {
         final SortedNumericDoubleValues values = valuesSource.doubleValues(ctx);
         return new LeafBucketCollectorBase(sub, values) {
-            @Override
+    @Override
             public void collect(int doc, long bucket) throws IOException {
-                values.setDocument(doc);
-                final int valuesCount = values.count();
-                for (int i = 0, lo = 0; i < valuesCount; ++i) {
-                    final double value = values.valueAt(i);
+        values.setDocument(doc);
+        final int valuesCount = values.count();
+        for (int i = 0, lo = 0; i < valuesCount; ++i) {
+            final double value = values.valueAt(i);
                     lo = collect(doc, value, bucket, lo);
-                }
+        }
+    }
+
+    private int collect(int doc, double value, long owningBucketOrdinal, int lowBound) throws IOException {
+        int lo = lowBound, hi = ranges.length - 1; // all candidates are between these indexes
+        int mid = (lo + hi) >>> 1;
+        while (lo <= hi) {
+            if (value < ranges[mid].from) {
+                hi = mid - 1;
+            } else if (value >= maxTo[mid]) {
+                lo = mid + 1;
+            } else {
+                break;
             }
+            mid = (lo + hi) >>> 1;
+        }
+        if (lo > hi) return lo; // no potential candidate
 
-            private int collect(int doc, double value, long owningBucketOrdinal, int lowBound) throws IOException {
-                int lo = lowBound, hi = ranges.length - 1; // all candidates are between these indexes
-                int mid = (lo + hi) >>> 1;
-                while (lo <= hi) {
-                    if (value < ranges[mid].from) {
-                        hi = mid - 1;
-                    } else if (value >= maxTo[mid]) {
-                        lo = mid + 1;
-                    } else {
-                        break;
-                    }
-                    mid = (lo + hi) >>> 1;
-                }
-                if (lo > hi) return lo; // no potential candidate
+        // binary search the lower bound
+        int startLo = lo, startHi = mid;
+        while (startLo <= startHi) {
+            final int startMid = (startLo + startHi) >>> 1;
+            if (value >= maxTo[startMid]) {
+                startLo = startMid + 1;
+            } else {
+                startHi = startMid - 1;
+            }
+        }
 
-                // binary search the lower bound
-                int startLo = lo, startHi = mid;
-                while (startLo <= startHi) {
-                    final int startMid = (startLo + startHi) >>> 1;
-                    if (value >= maxTo[startMid]) {
-                        startLo = startMid + 1;
-                    } else {
-                        startHi = startMid - 1;
-                    }
-                }
+        // binary search the upper bound
+        int endLo = mid, endHi = hi;
+        while (endLo <= endHi) {
+            final int endMid = (endLo + endHi) >>> 1;
+            if (value < ranges[endMid].from) {
+                endHi = endMid - 1;
+            } else {
+                endLo = endMid + 1;
+            }
+        }
 
-                // binary search the upper bound
-                int endLo = mid, endHi = hi;
-                while (endLo <= endHi) {
-                    final int endMid = (endLo + endHi) >>> 1;
-                    if (value < ranges[endMid].from) {
-                        endHi = endMid - 1;
-                    } else {
-                        endLo = endMid + 1;
-                    }
-                }
+        assert startLo == lowBound || value >= maxTo[startLo - 1];
+        assert endHi == ranges.length - 1 || value < ranges[endHi + 1].from;
 
-                assert startLo == lowBound || value >= maxTo[startLo - 1];
-                assert endHi == ranges.length - 1 || value < ranges[endHi + 1].from;
-
-                for (int i = startLo; i <= endHi; ++i) {
-                    if (ranges[i].matches(value)) {
+        for (int i = startLo; i <= endHi; ++i) {
+            if (ranges[i].matches(value)) {
                         collectBucket(sub, doc, subBucketOrdinal(owningBucketOrdinal, i));
-                    }
-                }
-
-                return endHi + 1;
             }
+        }
+
+        return endHi + 1;
+    }
         };
     }
 
@@ -215,7 +216,7 @@ public class RangeAggregator extends BucketsAggregator {
             buckets.add(bucket);
         }
         // value source can be null in the case of unmapped fields
-        return rangeFactory.create(name, buckets, formatter, keyed, metaData());
+        return rangeFactory.create(name, buckets, formatter, keyed, reducers(), metaData());
     }
 
     @Override
@@ -229,7 +230,7 @@ public class RangeAggregator extends BucketsAggregator {
             buckets.add(bucket);
         }
         // value source can be null in the case of unmapped fields
-        return rangeFactory.create(name, buckets, formatter, keyed, metaData());
+        return rangeFactory.create(name, buckets, formatter, keyed, reducers(), metaData());
     }
 
     private static final void sortRanges(final Range[] ranges) {
@@ -266,10 +267,10 @@ public class RangeAggregator extends BucketsAggregator {
                         ValueFormat format,
                         AggregationContext context,
                         Aggregator parent,
-                        InternalRange.Factory factory,
+ InternalRange.Factory factory, List<Reducer> reducers,
                         Map<String, Object> metaData) throws IOException {
 
-            super(name, context, parent, metaData);
+            super(name, context, parent, reducers, metaData);
             this.ranges = ranges;
             ValueParser parser = format != null ? format.parser() : ValueParser.RAW;
             for (Range range : this.ranges) {
@@ -287,7 +288,7 @@ public class RangeAggregator extends BucketsAggregator {
             for (RangeAggregator.Range range : ranges) {
                 buckets.add(factory.createBucket(range.key, range.from, range.to, 0, subAggs, keyed, formatter));
             }
-            return factory.create(name, buckets, formatter, keyed, metaData());
+            return factory.create(name, buckets, formatter, keyed, reducers(), metaData());
         }
     }
 
@@ -305,13 +306,15 @@ public class RangeAggregator extends BucketsAggregator {
         }
 
         @Override
-        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
-            return new Unmapped(name, ranges, keyed, config.format(), aggregationContext, parent, rangeFactory, metaData);
+        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, List<Reducer> reducers,
+                Map<String, Object> metaData) throws IOException {
+            return new Unmapped(name, ranges, keyed, config.format(), aggregationContext, parent, rangeFactory, reducers, metaData);
         }
 
         @Override
-        protected Aggregator doCreateInternal(ValuesSource.Numeric valuesSource, AggregationContext aggregationContext, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
-            return new RangeAggregator(name, factories, valuesSource, config.format(), rangeFactory, ranges, keyed, aggregationContext, parent, metaData);
+        protected Aggregator doCreateInternal(ValuesSource.Numeric valuesSource, AggregationContext aggregationContext, Aggregator parent,
+                boolean collectsFromSingleBucket, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+            return new RangeAggregator(name, factories, valuesSource, config.format(), rangeFactory, ranges, keyed, aggregationContext, parent, reducers, metaData);
         }
     }
 

src/main/java/org/elasticsearch/search/aggregations/bucket/range/date/InternalDateRange.java

@@ -26,6 +26,7 @@ import org.elasticsearch.search.aggregations.InternalAggregations;
 import org.elasticsearch.search.aggregations.bucket.BucketStreamContext;
 import org.elasticsearch.search.aggregations.bucket.BucketStreams;
 import org.elasticsearch.search.aggregations.bucket.range.InternalRange;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 import org.joda.time.DateTime;
 import org.joda.time.DateTimeZone;
@@ -120,8 +121,9 @@ public class InternalDateRange extends InternalRange<InternalDateRange.Bucket> {
         }
 
         @Override
-        public InternalDateRange create(String name, List<InternalDateRange.Bucket> ranges, ValueFormatter formatter, boolean keyed, Map<String, Object> metaData) {
-            return new InternalDateRange(name, ranges, formatter, keyed, metaData);
+        public InternalDateRange create(String name, List<InternalDateRange.Bucket> ranges, ValueFormatter formatter, boolean keyed,
+                List<Reducer> reducers, Map<String, Object> metaData) {
+            return new InternalDateRange(name, ranges, formatter, keyed, reducers, metaData);
         }
 
         @Override
@@ -132,8 +134,9 @@ public class InternalDateRange extends InternalRange<InternalDateRange.Bucket> {
 
     InternalDateRange() {} // for serialization
 
-    InternalDateRange(String name, List<InternalDateRange.Bucket> ranges, @Nullable ValueFormatter formatter, boolean keyed, Map<String, Object> metaData) {
-        super(name, ranges, formatter, keyed, metaData);
+    InternalDateRange(String name, List<InternalDateRange.Bucket> ranges, @Nullable ValueFormatter formatter, boolean keyed,
+            List<Reducer> reducers, Map<String, Object> metaData) {
+        super(name, ranges, formatter, keyed, reducers, metaData);
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/bucket/range/geodistance/GeoDistanceParser.java

@@ -35,6 +35,7 @@ import org.elasticsearch.search.aggregations.AggregatorFactory;
 import org.elasticsearch.search.aggregations.bucket.range.InternalRange;
 import org.elasticsearch.search.aggregations.bucket.range.RangeAggregator;
 import org.elasticsearch.search.aggregations.bucket.range.RangeAggregator.Unmapped;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.GeoPointParser;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
@@ -179,14 +180,18 @@ public class GeoDistanceParser implements Aggregator.Parser {
         }
 
         @Override
-        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
-            return new Unmapped(name, ranges, keyed, null, aggregationContext, parent, rangeFactory, metaData);
+        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, List<Reducer> reducers,
+                Map<String, Object> metaData) throws IOException {
+            return new Unmapped(name, ranges, keyed, null, aggregationContext, parent, rangeFactory, reducers, metaData);
         }
 
         @Override
-        protected Aggregator doCreateInternal(final ValuesSource.GeoPoint valuesSource, AggregationContext aggregationContext, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
+        protected Aggregator doCreateInternal(final ValuesSource.GeoPoint valuesSource, AggregationContext aggregationContext,
+                Aggregator parent, boolean collectsFromSingleBucket, List<Reducer> reducers, Map<String, Object> metaData)
+                throws IOException {
             DistanceSource distanceSource = new DistanceSource(valuesSource, distanceType, origin, unit);
-            return new RangeAggregator(name, factories, distanceSource, null, rangeFactory, ranges, keyed, aggregationContext, parent, metaData);
+            return new RangeAggregator(name, factories, distanceSource, null, rangeFactory, ranges, keyed, aggregationContext, parent,
+                    reducers, metaData);
         }
 
         private static class DistanceSource extends ValuesSource.Numeric {

src/main/java/org/elasticsearch/search/aggregations/bucket/range/geodistance/InternalGeoDistance.java

@@ -26,6 +26,7 @@ import org.elasticsearch.search.aggregations.InternalAggregations;
 import org.elasticsearch.search.aggregations.bucket.BucketStreamContext;
 import org.elasticsearch.search.aggregations.bucket.BucketStreams;
 import org.elasticsearch.search.aggregations.bucket.range.InternalRange;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 
 import java.io.IOException;
@@ -108,8 +109,9 @@ public class InternalGeoDistance extends InternalRange<InternalGeoDistance.Bucke
         }
 
         @Override
-        public InternalGeoDistance create(String name, List<Bucket> ranges, @Nullable ValueFormatter formatter, boolean keyed, Map<String, Object> metaData) {
-            return new InternalGeoDistance(name, ranges, formatter, keyed, metaData);
+        public InternalGeoDistance create(String name, List<Bucket> ranges, @Nullable ValueFormatter formatter, boolean keyed,
+                List<Reducer> reducers, Map<String, Object> metaData) {
+            return new InternalGeoDistance(name, ranges, formatter, keyed, reducers, metaData);
         }
 
         @Override
@@ -120,8 +122,9 @@ public class InternalGeoDistance extends InternalRange<InternalGeoDistance.Bucke
 
     InternalGeoDistance() {} // for serialization
 
-    public InternalGeoDistance(String name, List<Bucket> ranges, @Nullable ValueFormatter formatter, boolean keyed, Map<String, Object> metaData) {
-        super(name, ranges, formatter, keyed, metaData);
+    public InternalGeoDistance(String name, List<Bucket> ranges, @Nullable ValueFormatter formatter, boolean keyed, List<Reducer> reducers,
+            Map<String, Object> metaData) {
+        super(name, ranges, formatter, keyed, reducers, metaData);
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/bucket/range/ipv4/InternalIPv4Range.java

@@ -26,6 +26,7 @@ import org.elasticsearch.search.aggregations.InternalAggregations;
 import org.elasticsearch.search.aggregations.bucket.BucketStreamContext;
 import org.elasticsearch.search.aggregations.bucket.BucketStreams;
 import org.elasticsearch.search.aggregations.bucket.range.InternalRange;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 
 import java.io.IOException;
@@ -117,8 +118,9 @@ public class InternalIPv4Range extends InternalRange<InternalIPv4Range.Bucket> {
         }
 
         @Override
-        public InternalIPv4Range create(String name, List<Bucket> ranges, @Nullable ValueFormatter formatter, boolean keyed, Map<String, Object> metaData) {
-            return new InternalIPv4Range(name, ranges, keyed, metaData);
+        public InternalIPv4Range create(String name, List<Bucket> ranges, @Nullable ValueFormatter formatter, boolean keyed,
+                List<Reducer> reducers, Map<String, Object> metaData) {
+            return new InternalIPv4Range(name, ranges, keyed, reducers, metaData);
         }
 
         @Override
@@ -129,8 +131,9 @@ public class InternalIPv4Range extends InternalRange<InternalIPv4Range.Bucket> {
 
     public InternalIPv4Range() {} // for serialization
 
-    public InternalIPv4Range(String name, List<InternalIPv4Range.Bucket> ranges, boolean keyed, Map<String, Object> metaData) {
-        super(name, ranges, ValueFormatter.IPv4, keyed, metaData);
+    public InternalIPv4Range(String name, List<InternalIPv4Range.Bucket> ranges, boolean keyed, List<Reducer> reducers,
+            Map<String, Object> metaData) {
+        super(name, ranges, ValueFormatter.IPv4, keyed, reducers, metaData);
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/bucket/significant/GlobalOrdinalsSignificantTermsAggregator.java

@@ -29,6 +29,7 @@ import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.bucket.terms.GlobalOrdinalsStringTermsAggregator;
 import org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.internal.ContextIndexSearcher;
@@ -36,6 +37,7 @@ import org.elasticsearch.search.internal.ContextIndexSearcher;
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -49,9 +51,10 @@ public class GlobalOrdinalsSignificantTermsAggregator extends GlobalOrdinalsStri
     public GlobalOrdinalsSignificantTermsAggregator(String name, AggregatorFactories factories, ValuesSource.Bytes.WithOrdinals.FieldData valuesSource,
                                                     BucketCountThresholds bucketCountThresholds,
                                                     IncludeExclude includeExclude, AggregationContext aggregationContext, Aggregator parent,
-                                                    SignificantTermsAggregatorFactory termsAggFactory, Map<String, Object> metaData) throws IOException {
+            SignificantTermsAggregatorFactory termsAggFactory, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
 
-        super(name, factories, valuesSource, null, bucketCountThresholds, includeExclude, aggregationContext, parent, SubAggCollectionMode.DEPTH_FIRST, false, metaData);
+        super(name, factories, valuesSource, maxOrd, null, bucketCountThresholds, includeExclude, aggregationContext, parent,
+                SubAggCollectionMode.DEPTH_FIRST, false, reducers, metaData);
         this.termsAggFactory = termsAggFactory;
     }
 
@@ -62,8 +65,8 @@ public class GlobalOrdinalsSignificantTermsAggregator extends GlobalOrdinalsStri
             @Override
             public void collect(int doc, long bucket) throws IOException {
                 super.collect(doc, bucket);
-                numCollectedDocs++;
-            }
+        numCollectedDocs++;
+    }
         };
     }
 
@@ -124,7 +127,9 @@ public class GlobalOrdinalsSignificantTermsAggregator extends GlobalOrdinalsStri
             list[i] = bucket;
         }
 
-        return new SignificantStringTerms(subsetSize, supersetSize, name, bucketCountThresholds.getRequiredSize(), bucketCountThresholds.getMinDocCount(), termsAggFactory.getSignificanceHeuristic(), Arrays.asList(list), metaData());
+        return new SignificantStringTerms(subsetSize, supersetSize, name, bucketCountThresholds.getRequiredSize(),
+                bucketCountThresholds.getMinDocCount(), termsAggFactory.getSignificanceHeuristic(), Arrays.asList(list), reducers(),
+                metaData());
     }
 
     @Override
@@ -133,7 +138,9 @@ public class GlobalOrdinalsSignificantTermsAggregator extends GlobalOrdinalsStri
         ContextIndexSearcher searcher = context.searchContext().searcher();
         IndexReader topReader = searcher.getIndexReader();
         int supersetSize = topReader.numDocs();
-        return new SignificantStringTerms(0, supersetSize, name, bucketCountThresholds.getRequiredSize(), bucketCountThresholds.getMinDocCount(), termsAggFactory.getSignificanceHeuristic(), Collections.<InternalSignificantTerms.Bucket>emptyList(), metaData());
+        return new SignificantStringTerms(0, supersetSize, name, bucketCountThresholds.getRequiredSize(),
+                bucketCountThresholds.getMinDocCount(), termsAggFactory.getSignificanceHeuristic(),
+                Collections.<InternalSignificantTerms.Bucket> emptyList(), reducers(), metaData());
     }
 
     @Override
@@ -145,8 +152,8 @@ public class GlobalOrdinalsSignificantTermsAggregator extends GlobalOrdinalsStri
 
         private final LongHash bucketOrds;
 
-        public WithHash(String name, AggregatorFactories factories, ValuesSource.Bytes.WithOrdinals.FieldData valuesSource, BucketCountThresholds bucketCountThresholds, IncludeExclude includeExclude, AggregationContext aggregationContext, Aggregator parent, SignificantTermsAggregatorFactory termsAggFactory, Map<String, Object> metaData) throws IOException {
-            super(name, factories, valuesSource, bucketCountThresholds, includeExclude, aggregationContext, parent, termsAggFactory, metaData);
+        public WithHash(String name, AggregatorFactories factories, ValuesSource.Bytes.WithOrdinals.FieldData valuesSource, BucketCountThresholds bucketCountThresholds, IncludeExclude includeExclude, AggregationContext aggregationContext, Aggregator parent, SignificantTermsAggregatorFactory termsAggFactory, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+            super(name, factories, valuesSource, bucketCountThresholds, includeExclude, aggregationContext, parent, termsAggFactory, reducers, metaData);
             bucketOrds = new LongHash(1, aggregationContext.bigArrays());
         }
 
@@ -157,20 +164,20 @@ public class GlobalOrdinalsSignificantTermsAggregator extends GlobalOrdinalsStri
                 @Override
                 public void collect(int doc, long bucket) throws IOException {
                     assert bucket == 0;
-                    numCollectedDocs++;
-                    globalOrds.setDocument(doc);
-                    final int numOrds = globalOrds.cardinality();
-                    for (int i = 0; i < numOrds; i++) {
-                        final long globalOrd = globalOrds.ordAt(i);
-                        long bucketOrd = bucketOrds.add(globalOrd);
-                        if (bucketOrd < 0) {
-                            bucketOrd = -1 - bucketOrd;
+            numCollectedDocs++;
+            globalOrds.setDocument(doc);
+            final int numOrds = globalOrds.cardinality();
+            for (int i = 0; i < numOrds; i++) {
+                final long globalOrd = globalOrds.ordAt(i);
+                long bucketOrd = bucketOrds.add(globalOrd);
+                if (bucketOrd < 0) {
+                    bucketOrd = -1 - bucketOrd;
                             collectExistingBucket(sub, doc, bucketOrd);
-                        } else {
+                } else {
                             collectBucket(sub, doc, bucketOrd);
                         }
-                    }
                 }
+            }
             };
         }
 

src/main/java/org/elasticsearch/search/aggregations/bucket/significant/InternalSignificantTerms.java

@@ -27,6 +27,7 @@ import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.InternalAggregations;
 import org.elasticsearch.search.aggregations.InternalMultiBucketAggregation;
 import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristic;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -122,8 +123,9 @@ public abstract class InternalSignificantTerms extends InternalMultiBucketAggreg
         }
     }
 
-    protected InternalSignificantTerms(long subsetSize, long supersetSize, String name, int requiredSize, long minDocCount, SignificanceHeuristic significanceHeuristic, List<Bucket> buckets, Map<String, Object> metaData) {
-        super(name, metaData);
+    protected InternalSignificantTerms(long subsetSize, long supersetSize, String name, int requiredSize, long minDocCount,
+            SignificanceHeuristic significanceHeuristic, List<Bucket> buckets, List<Reducer> reducers, Map<String, Object> metaData) {
+        super(name, reducers, metaData);
         this.requiredSize = requiredSize;
         this.minDocCount = minDocCount;
         this.buckets = buckets;

src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantLongTerms.java

@@ -28,6 +28,7 @@ import org.elasticsearch.search.aggregations.bucket.BucketStreamContext;
 import org.elasticsearch.search.aggregations.bucket.BucketStreams;
 import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristic;
 import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristicStreams;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatterStreams;
 
@@ -159,9 +160,11 @@ public class SignificantLongTerms extends InternalSignificantTerms {
     } // for serialization
 
     public SignificantLongTerms(long subsetSize, long supersetSize, String name, @Nullable ValueFormatter formatter,
-                                int requiredSize, long minDocCount, SignificanceHeuristic significanceHeuristic, List<InternalSignificantTerms.Bucket> buckets, Map<String, Object> metaData) {
+ int requiredSize,
+            long minDocCount, SignificanceHeuristic significanceHeuristic, List<InternalSignificantTerms.Bucket> buckets,
+            List<Reducer> reducers, Map<String, Object> metaData) {
 
-        super(subsetSize, supersetSize, name, requiredSize, minDocCount, significanceHeuristic, buckets, metaData);
+        super(subsetSize, supersetSize, name, requiredSize, minDocCount, significanceHeuristic, buckets, reducers, metaData);
         this.formatter = formatter;
     }
 
@@ -173,7 +176,8 @@ public class SignificantLongTerms extends InternalSignificantTerms {
     @Override
     InternalSignificantTerms newAggregation(long subsetSize, long supersetSize,
             List<InternalSignificantTerms.Bucket> buckets) {
-        return new SignificantLongTerms(subsetSize, supersetSize, getName(), formatter, requiredSize, minDocCount, significanceHeuristic, buckets, getMetaData());
+        return new SignificantLongTerms(subsetSize, supersetSize, getName(), formatter, requiredSize, minDocCount, significanceHeuristic,
+                buckets, reducers(), getMetaData());
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantLongTermsAggregator.java

@@ -28,6 +28,7 @@ import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.bucket.terms.LongTermsAggregator;
 import org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.format.ValueFormat;
@@ -36,6 +37,7 @@ import org.elasticsearch.search.internal.ContextIndexSearcher;
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -45,9 +47,12 @@ public class SignificantLongTermsAggregator extends LongTermsAggregator {
 
     public SignificantLongTermsAggregator(String name, AggregatorFactories factories, ValuesSource.Numeric valuesSource, @Nullable ValueFormat format,
               BucketCountThresholds bucketCountThresholds,
-              AggregationContext aggregationContext, Aggregator parent, SignificantTermsAggregatorFactory termsAggFactory, IncludeExclude.LongFilter includeExclude, Map<String, Object> metaData) throws IOException {
+ AggregationContext aggregationContext,
+            Aggregator parent, SignificantTermsAggregatorFactory termsAggFactory, IncludeExclude.LongFilter includeExclude,
+            List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
 
-        super(name, factories, valuesSource, format, null, bucketCountThresholds, aggregationContext, parent, SubAggCollectionMode.DEPTH_FIRST, false, includeExclude, metaData);
+        super(name, factories, valuesSource, format, null, bucketCountThresholds, aggregationContext, parent,
+                SubAggCollectionMode.DEPTH_FIRST, false, includeExclude, reducers, metaData);
         this.termsAggFactory = termsAggFactory;
     }
 
@@ -102,7 +107,9 @@ public class SignificantLongTermsAggregator extends LongTermsAggregator {
             bucket.aggregations = bucketAggregations(bucket.bucketOrd);
             list[i] = bucket;
         }
-        return new SignificantLongTerms(subsetSize, supersetSize, name, formatter, bucketCountThresholds.getRequiredSize(), bucketCountThresholds.getMinDocCount(), termsAggFactory.getSignificanceHeuristic(), Arrays.asList(list), metaData());
+        return new SignificantLongTerms(subsetSize, supersetSize, name, formatter, bucketCountThresholds.getRequiredSize(),
+                bucketCountThresholds.getMinDocCount(), termsAggFactory.getSignificanceHeuristic(), Arrays.asList(list), reducers(),
+                metaData());
     }
 
     @Override
@@ -111,7 +118,9 @@ public class SignificantLongTermsAggregator extends LongTermsAggregator {
         ContextIndexSearcher searcher = context.searchContext().searcher();
         IndexReader topReader = searcher.getIndexReader();
         int supersetSize = topReader.numDocs();
-        return new SignificantLongTerms(0, supersetSize, name, formatter, bucketCountThresholds.getRequiredSize(), bucketCountThresholds.getMinDocCount(), termsAggFactory.getSignificanceHeuristic(), Collections.<InternalSignificantTerms.Bucket>emptyList(), metaData());
+        return new SignificantLongTerms(0, supersetSize, name, formatter, bucketCountThresholds.getRequiredSize(),
+                bucketCountThresholds.getMinDocCount(), termsAggFactory.getSignificanceHeuristic(),
+                Collections.<InternalSignificantTerms.Bucket> emptyList(), reducers(), metaData());
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantStringTerms.java

@@ -29,6 +29,7 @@ import org.elasticsearch.search.aggregations.bucket.BucketStreamContext;
 import org.elasticsearch.search.aggregations.bucket.BucketStreams;
 import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristic;
 import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristicStreams;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -152,8 +153,10 @@ public class SignificantStringTerms extends InternalSignificantTerms {
     SignificantStringTerms() {} // for serialization
 
     public SignificantStringTerms(long subsetSize, long supersetSize, String name, int requiredSize,
-            long minDocCount, SignificanceHeuristic significanceHeuristic, List<InternalSignificantTerms.Bucket> buckets, Map<String, Object> metaData) {
-        super(subsetSize, supersetSize, name, requiredSize, minDocCount, significanceHeuristic, buckets, metaData);
+ long minDocCount,
+            SignificanceHeuristic significanceHeuristic, List<InternalSignificantTerms.Bucket> buckets, List<Reducer> reducers,
+            Map<String, Object> metaData) {
+        super(subsetSize, supersetSize, name, requiredSize, minDocCount, significanceHeuristic, buckets, reducers, metaData);
     }
 
     @Override
@@ -164,7 +167,8 @@ public class SignificantStringTerms extends InternalSignificantTerms {
     @Override
     InternalSignificantTerms newAggregation(long subsetSize, long supersetSize,
             List<InternalSignificantTerms.Bucket> buckets) {
-        return new SignificantStringTerms(subsetSize, supersetSize, getName(), requiredSize, minDocCount, significanceHeuristic, buckets, getMetaData());
+        return new SignificantStringTerms(subsetSize, supersetSize, getName(), requiredSize, minDocCount, significanceHeuristic, buckets,
+                reducers(), getMetaData());
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantStringTermsAggregator.java

@@ -28,6 +28,7 @@ import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.bucket.terms.StringTermsAggregator;
 import org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.internal.ContextIndexSearcher;
@@ -35,6 +36,7 @@ import org.elasticsearch.search.internal.ContextIndexSearcher;
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -48,9 +50,11 @@ public class SignificantStringTermsAggregator extends StringTermsAggregator {
     public SignificantStringTermsAggregator(String name, AggregatorFactories factories, ValuesSource valuesSource,
             BucketCountThresholds bucketCountThresholds,
             IncludeExclude includeExclude, AggregationContext aggregationContext, Aggregator parent,
-            SignificantTermsAggregatorFactory termsAggFactory, Map<String, Object> metaData) throws IOException {
+ SignificantTermsAggregatorFactory termsAggFactory, List<Reducer> reducers, Map<String, Object> metaData)
+            throws IOException {
 
-        super(name, factories, valuesSource, null, bucketCountThresholds, includeExclude, aggregationContext, parent, SubAggCollectionMode.DEPTH_FIRST, false, metaData);
+        super(name, factories, valuesSource, null, bucketCountThresholds, includeExclude, aggregationContext, parent,
+                SubAggCollectionMode.DEPTH_FIRST, false, reducers, metaData);
         this.termsAggFactory = termsAggFactory;
     }
 
@@ -107,7 +111,9 @@ public class SignificantStringTermsAggregator extends StringTermsAggregator {
             list[i] = bucket;
         }
 
-        return new SignificantStringTerms(subsetSize, supersetSize, name, bucketCountThresholds.getRequiredSize(), bucketCountThresholds.getMinDocCount(), termsAggFactory.getSignificanceHeuristic(), Arrays.asList(list), metaData());
+        return new SignificantStringTerms(subsetSize, supersetSize, name, bucketCountThresholds.getRequiredSize(),
+                bucketCountThresholds.getMinDocCount(), termsAggFactory.getSignificanceHeuristic(), Arrays.asList(list), reducers(),
+                metaData());
     }
 
     @Override
@@ -116,7 +122,9 @@ public class SignificantStringTermsAggregator extends StringTermsAggregator {
         ContextIndexSearcher searcher = context.searchContext().searcher();
         IndexReader topReader = searcher.getIndexReader();
         int supersetSize = topReader.numDocs();
-        return new SignificantStringTerms(0, supersetSize, name, bucketCountThresholds.getRequiredSize(), bucketCountThresholds.getMinDocCount(), termsAggFactory.getSignificanceHeuristic(), Collections.<InternalSignificantTerms.Bucket>emptyList(), metaData());
+        return new SignificantStringTerms(0, supersetSize, name, bucketCountThresholds.getRequiredSize(),
+                bucketCountThresholds.getMinDocCount(), termsAggFactory.getSignificanceHeuristic(),
+                Collections.<InternalSignificantTerms.Bucket> emptyList(), reducers(), metaData());
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantTermsAggregatorFactory.java

@@ -39,6 +39,7 @@ import org.elasticsearch.search.aggregations.NonCollectingAggregator;
 import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristic;
 import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregator;
 import org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
@@ -46,6 +47,7 @@ import org.elasticsearch.search.aggregations.support.ValuesSourceConfig;
 import org.elasticsearch.search.internal.SearchContext;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -64,8 +66,10 @@ public class SignificantTermsAggregatorFactory extends ValuesSourceAggregatorFac
             @Override
             Aggregator create(String name, AggregatorFactories factories, ValuesSource valuesSource,
                               TermsAggregator.BucketCountThresholds bucketCountThresholds, IncludeExclude includeExclude,
-                              AggregationContext aggregationContext, Aggregator parent, SignificantTermsAggregatorFactory termsAggregatorFactory, Map<String, Object> metaData) throws IOException {
-                return new SignificantStringTermsAggregator(name, factories, valuesSource, bucketCountThresholds, includeExclude, aggregationContext, parent, termsAggregatorFactory, metaData);
+                    AggregationContext aggregationContext, Aggregator parent, SignificantTermsAggregatorFactory termsAggregatorFactory,
+                    List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+                return new SignificantStringTermsAggregator(name, factories, valuesSource, bucketCountThresholds, includeExclude,
+                        aggregationContext, parent, termsAggregatorFactory, reducers, metaData);
             }
 
         },
@@ -74,10 +78,11 @@ public class SignificantTermsAggregatorFactory extends ValuesSourceAggregatorFac
             @Override
             Aggregator create(String name, AggregatorFactories factories, ValuesSource valuesSource,
                               TermsAggregator.BucketCountThresholds bucketCountThresholds, IncludeExclude includeExclude,
-                              AggregationContext aggregationContext, Aggregator parent, SignificantTermsAggregatorFactory termsAggregatorFactory, Map<String, Object> metaData) throws IOException {
+                    AggregationContext aggregationContext, Aggregator parent, SignificantTermsAggregatorFactory termsAggregatorFactory,
+                    List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
                 ValuesSource.Bytes.WithOrdinals valueSourceWithOrdinals = (ValuesSource.Bytes.WithOrdinals) valuesSource;
                 IndexSearcher indexSearcher = aggregationContext.searchContext().searcher();
-                return new GlobalOrdinalsSignificantTermsAggregator(name, factories, (ValuesSource.Bytes.WithOrdinals.FieldData) valuesSource, bucketCountThresholds, includeExclude, aggregationContext, parent, termsAggregatorFactory, metaData);
+                return new GlobalOrdinalsSignificantTermsAggregator(name, factories, (ValuesSource.Bytes.WithOrdinals.FieldData) valuesSource, bucketCountThresholds, includeExclude, aggregationContext, parent, termsAggregatorFactory, reducers, metaData);
             }
 
         },
@@ -86,8 +91,11 @@ public class SignificantTermsAggregatorFactory extends ValuesSourceAggregatorFac
             @Override
             Aggregator create(String name, AggregatorFactories factories, ValuesSource valuesSource,
                               TermsAggregator.BucketCountThresholds bucketCountThresholds, IncludeExclude includeExclude,
-                              AggregationContext aggregationContext, Aggregator parent, SignificantTermsAggregatorFactory termsAggregatorFactory, Map<String, Object> metaData) throws IOException {
-                return new GlobalOrdinalsSignificantTermsAggregator.WithHash(name, factories, (ValuesSource.Bytes.WithOrdinals.FieldData) valuesSource, bucketCountThresholds, includeExclude, aggregationContext, parent, termsAggregatorFactory, metaData);
+                    AggregationContext aggregationContext, Aggregator parent, SignificantTermsAggregatorFactory termsAggregatorFactory,
+                    List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+                return new GlobalOrdinalsSignificantTermsAggregator.WithHash(name, factories,
+                        (ValuesSource.Bytes.WithOrdinals.FieldData) valuesSource, bucketCountThresholds, includeExclude,
+                        aggregationContext, parent, termsAggregatorFactory, reducers, metaData);
             }
         };
 
@@ -108,7 +116,8 @@ public class SignificantTermsAggregatorFactory extends ValuesSourceAggregatorFac
 
         abstract Aggregator create(String name, AggregatorFactories factories, ValuesSource valuesSource,
                                    TermsAggregator.BucketCountThresholds bucketCountThresholds, IncludeExclude includeExclude,
-                                   AggregationContext aggregationContext, Aggregator parent, SignificantTermsAggregatorFactory termsAggregatorFactory, Map<String, Object> metaData) throws IOException;
+                AggregationContext aggregationContext, Aggregator parent, SignificantTermsAggregatorFactory termsAggregatorFactory,
+                List<Reducer> reducers, Map<String, Object> metaData) throws IOException;
 
         @Override
         public String toString() {
@@ -145,9 +154,11 @@ public class SignificantTermsAggregatorFactory extends ValuesSourceAggregatorFac
     }
 
     @Override
-    protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
-        final InternalAggregation aggregation = new UnmappedSignificantTerms(name, bucketCountThresholds.getRequiredSize(), bucketCountThresholds.getMinDocCount(), metaData);
-        return new NonCollectingAggregator(name, aggregationContext, parent, metaData) {
+    protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, List<Reducer> reducers,
+            Map<String, Object> metaData) throws IOException {
+        final InternalAggregation aggregation = new UnmappedSignificantTerms(name, bucketCountThresholds.getRequiredSize(),
+                bucketCountThresholds.getMinDocCount(), reducers, metaData);
+        return new NonCollectingAggregator(name, aggregationContext, parent, reducers, metaData) {
             @Override
             public InternalAggregation buildEmptyAggregation() {
                 return aggregation;
@@ -156,7 +167,8 @@ public class SignificantTermsAggregatorFactory extends ValuesSourceAggregatorFac
     }
 
     @Override
-    protected Aggregator doCreateInternal(ValuesSource valuesSource, AggregationContext aggregationContext, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
+    protected Aggregator doCreateInternal(ValuesSource valuesSource, AggregationContext aggregationContext, Aggregator parent,
+            boolean collectsFromSingleBucket, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
         if (collectsFromSingleBucket == false) {
             return asMultiBucketAggregator(this, aggregationContext, parent);
         }
@@ -179,7 +191,8 @@ public class SignificantTermsAggregatorFactory extends ValuesSourceAggregatorFac
                 }
             }
             assert execution != null;
-            return execution.create(name, factories, valuesSource, bucketCountThresholds, includeExclude, aggregationContext, parent, this, metaData);
+            return execution.create(name, factories, valuesSource, bucketCountThresholds, includeExclude, aggregationContext, parent, this,
+                    reducers, metaData);
         }
 
         
@@ -197,7 +210,8 @@ public class SignificantTermsAggregatorFactory extends ValuesSourceAggregatorFac
             if (includeExclude != null) {
                 longFilter = includeExclude.convertToLongFilter();
             }
-            return new SignificantLongTermsAggregator(name, factories, (ValuesSource.Numeric) valuesSource, config.format(), bucketCountThresholds, aggregationContext, parent, this, longFilter, metaData);
+            return new SignificantLongTermsAggregator(name, factories, (ValuesSource.Numeric) valuesSource, config.format(),
+                    bucketCountThresholds, aggregationContext, parent, this, longFilter, reducers, metaData);
         }
 
         throw new AggregationExecutionException("sigfnificant_terms aggregation cannot be applied to field [" + config.fieldContext().field() +

src/main/java/org/elasticsearch/search/aggregations/bucket/significant/UnmappedSignificantTerms.java

@@ -24,9 +24,9 @@ import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.search.aggregations.AggregationStreams;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.bucket.significant.heuristics.JLHScore;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 
 import java.io.IOException;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
@@ -56,10 +56,10 @@ public class UnmappedSignificantTerms extends InternalSignificantTerms {
 
     UnmappedSignificantTerms() {} // for serialization
 
-    public UnmappedSignificantTerms(String name, int requiredSize, long minDocCount, Map<String, Object> metaData) {
+    public UnmappedSignificantTerms(String name, int requiredSize, long minDocCount, List<Reducer> reducers, Map<String, Object> metaData) {
         //We pass zero for index/subset sizes because for the purpose of significant term analysis 
         // we assume an unmapped index's size is irrelevant to the proceedings. 
-        super(0, 0, name, requiredSize, minDocCount, JLHScore.INSTANCE, BUCKETS, metaData);
+        super(0, 0, name, requiredSize, minDocCount, JLHScore.INSTANCE, BUCKETS, reducers, metaData);
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/bucket/terms/AbstractStringTermsAggregator.java

@@ -22,27 +22,30 @@ package org.elasticsearch.search.aggregations.bucket.terms;
 import org.elasticsearch.search.aggregations.Aggregator;
 import org.elasticsearch.search.aggregations.AggregatorFactories;
 import org.elasticsearch.search.aggregations.InternalAggregation;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 
 import java.io.IOException;
 import java.util.Collections;
+import java.util.List;
 import java.util.Map;
 
 abstract class AbstractStringTermsAggregator extends TermsAggregator {
 
     protected final boolean showTermDocCountError;
 
-    public AbstractStringTermsAggregator(String name, AggregatorFactories factories,
-            AggregationContext context, Aggregator parent,
-            Terms.Order order, BucketCountThresholds bucketCountThresholds,
-            SubAggCollectionMode subAggCollectMode, boolean showTermDocCountError, Map<String, Object> metaData) throws IOException {
-        super(name, factories, context, parent, bucketCountThresholds, order, subAggCollectMode, metaData);
+    public AbstractStringTermsAggregator(String name, AggregatorFactories factories, AggregationContext context, Aggregator parent,
+            Terms.Order order, BucketCountThresholds bucketCountThresholds, SubAggCollectionMode subAggCollectMode,
+            boolean showTermDocCountError, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+        super(name, factories, context, parent, bucketCountThresholds, order, subAggCollectMode, reducers, metaData);
         this.showTermDocCountError = showTermDocCountError;
     }
 
     @Override
     public InternalAggregation buildEmptyAggregation() {
-        return new StringTerms(name, order, bucketCountThresholds.getRequiredSize(), bucketCountThresholds.getShardSize(), bucketCountThresholds.getMinDocCount(), Collections.<InternalTerms.Bucket>emptyList(), showTermDocCountError, 0, 0, metaData());
+        return new StringTerms(name, order, bucketCountThresholds.getRequiredSize(), bucketCountThresholds.getShardSize(),
+                bucketCountThresholds.getMinDocCount(), Collections.<InternalTerms.Bucket> emptyList(), showTermDocCountError, 0, 0,
+                reducers(), metaData());
     }
 
 }

src/main/java/org/elasticsearch/search/aggregations/bucket/terms/DoubleTerms.java

@@ -27,6 +27,7 @@ import org.elasticsearch.search.aggregations.AggregationStreams;
 import org.elasticsearch.search.aggregations.InternalAggregations;
 import org.elasticsearch.search.aggregations.bucket.BucketStreamContext;
 import org.elasticsearch.search.aggregations.bucket.BucketStreams;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatterStreams;
 
@@ -156,8 +157,11 @@ public class DoubleTerms extends InternalTerms {
 
     DoubleTerms() {} // for serialization
 
-    public DoubleTerms(String name, Terms.Order order, @Nullable ValueFormatter formatter, int requiredSize, int shardSize, long minDocCount, List<InternalTerms.Bucket> buckets, boolean showTermDocCountError, long docCountError, long otherDocCount, Map<String, Object> metaData) {
-        super(name, order, requiredSize, shardSize, minDocCount, buckets, showTermDocCountError, docCountError, otherDocCount, metaData);
+    public DoubleTerms(String name, Terms.Order order, @Nullable ValueFormatter formatter, int requiredSize, int shardSize,
+            long minDocCount, List<InternalTerms.Bucket> buckets, boolean showTermDocCountError, long docCountError, long otherDocCount,
+            List<Reducer> reducers, Map<String, Object> metaData) {
+        super(name, order, requiredSize, shardSize, minDocCount, buckets, showTermDocCountError, docCountError, otherDocCount, reducers,
+                metaData);
         this.formatter = formatter;
     }
 
@@ -167,8 +171,10 @@ public class DoubleTerms extends InternalTerms {
     }
 
     @Override
-    protected InternalTerms newAggregation(String name, List<InternalTerms.Bucket> buckets, boolean showTermDocCountError, long docCountError, long otherDocCount, Map<String, Object> metaData) {
-        return new DoubleTerms(name, order, formatter, requiredSize, shardSize, minDocCount, buckets, showTermDocCountError, docCountError, otherDocCount, metaData);
+    protected InternalTerms newAggregation(String name, List<InternalTerms.Bucket> buckets, boolean showTermDocCountError,
+            long docCountError, long otherDocCount, List<Reducer> reducers, Map<String, Object> metaData) {
+        return new DoubleTerms(name, order, formatter, requiredSize, shardSize, minDocCount, buckets, showTermDocCountError, docCountError,
+                otherDocCount, reducers, metaData);
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/bucket/terms/DoubleTermsAggregator.java

@@ -26,6 +26,7 @@ import org.elasticsearch.index.fielddata.FieldData;
 import org.elasticsearch.search.aggregations.Aggregator;
 import org.elasticsearch.search.aggregations.AggregatorFactories;
 import org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSource.Numeric;
@@ -33,6 +34,7 @@ import org.elasticsearch.search.aggregations.support.format.ValueFormat;
 
 import java.io.IOException;
 import java.util.Arrays;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -41,8 +43,11 @@ import java.util.Map;
 public class DoubleTermsAggregator extends LongTermsAggregator {
 
     public DoubleTermsAggregator(String name, AggregatorFactories factories, ValuesSource.Numeric valuesSource, @Nullable ValueFormat format,
-            Terms.Order order, BucketCountThresholds bucketCountThresholds, AggregationContext aggregationContext, Aggregator parent, SubAggCollectionMode collectionMode, boolean showTermDocCountError, IncludeExclude.LongFilter longFilter, Map<String, Object> metaData) throws IOException {
-        super(name, factories, valuesSource, format, order, bucketCountThresholds, aggregationContext, parent, collectionMode, showTermDocCountError, longFilter, metaData);
+ Terms.Order order, BucketCountThresholds bucketCountThresholds,
+            AggregationContext aggregationContext, Aggregator parent, SubAggCollectionMode collectionMode, boolean showTermDocCountError,
+            IncludeExclude.LongFilter longFilter, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+        super(name, factories, valuesSource, format, order, bucketCountThresholds, aggregationContext, parent, collectionMode,
+                showTermDocCountError, longFilter, reducers, metaData);
     }
 
     @Override
@@ -73,7 +78,9 @@ public class DoubleTermsAggregator extends LongTermsAggregator {
         for (int i = 0; i < buckets.length; ++i) {
             buckets[i] = convertToDouble(buckets[i]);
         }
-        return new DoubleTerms(terms.getName(), terms.order, terms.formatter, terms.requiredSize, terms.shardSize, terms.minDocCount, Arrays.asList(buckets), terms.showTermDocCountError, terms.docCountError, terms.otherDocCount, terms.getMetaData());
+        return new DoubleTerms(terms.getName(), terms.order, terms.formatter, terms.requiredSize, terms.shardSize, terms.minDocCount,
+                Arrays.asList(buckets), terms.showTermDocCountError, terms.docCountError, terms.otherDocCount, terms.reducers(),
+                terms.getMetaData());
     }
 
 }

src/main/java/org/elasticsearch/search/aggregations/bucket/terms/GlobalOrdinalsStringTermsAggregator.java

@@ -44,11 +44,13 @@ import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.bucket.terms.InternalTerms.Bucket;
 import org.elasticsearch.search.aggregations.bucket.terms.support.BucketPriorityQueue;
 import org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 
 import java.io.IOException;
 import java.util.Arrays;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -71,8 +73,8 @@ public class GlobalOrdinalsStringTermsAggregator extends AbstractStringTermsAggr
 
     public GlobalOrdinalsStringTermsAggregator(String name, AggregatorFactories factories, ValuesSource.Bytes.WithOrdinals.FieldData valuesSource,
                                                Terms.Order order, BucketCountThresholds bucketCountThresholds,
-                                               IncludeExclude includeExclude, AggregationContext aggregationContext, Aggregator parent, SubAggCollectionMode collectionMode, boolean showTermDocCountError, Map<String, Object> metaData) throws IOException {
-        super(name, factories, aggregationContext, parent, order, bucketCountThresholds, collectionMode, showTermDocCountError, metaData);
+                                               IncludeExclude includeExclude, AggregationContext aggregationContext, Aggregator parent, SubAggCollectionMode collectionMode, boolean showTermDocCountError, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+        super(name, factories, aggregationContext, parent, order, bucketCountThresholds, collectionMode, showTermDocCountError, reducers, reducers, metaData);
         this.valuesSource = valuesSource;
         this.includeExclude = includeExclude;
     }
@@ -196,7 +198,9 @@ public class GlobalOrdinalsStringTermsAggregator extends AbstractStringTermsAggr
             bucket.docCountError = 0;
         }
 
-        return new StringTerms(name, order, bucketCountThresholds.getRequiredSize(), bucketCountThresholds.getShardSize(), bucketCountThresholds.getMinDocCount(), Arrays.asList(list), showTermDocCountError, 0, otherDocCount, metaData());
+        return new StringTerms(name, order, bucketCountThresholds.getRequiredSize(), bucketCountThresholds.getShardSize(),
+                bucketCountThresholds.getMinDocCount(), Arrays.asList(list), showTermDocCountError, 0, otherDocCount, reducers(),
+                metaData());
     }
 
     /**
@@ -261,8 +265,8 @@ public class GlobalOrdinalsStringTermsAggregator extends AbstractStringTermsAggr
 
         public WithHash(String name, AggregatorFactories factories, ValuesSource.Bytes.WithOrdinals.FieldData valuesSource,
                         Terms.Order order, BucketCountThresholds bucketCountThresholds, IncludeExclude includeExclude, AggregationContext aggregationContext,
-                        Aggregator parent, SubAggCollectionMode collectionMode, boolean showTermDocCountError, Map<String, Object> metaData) throws IOException {
-            super(name, factories, valuesSource, order, bucketCountThresholds, includeExclude, aggregationContext, parent, collectionMode, showTermDocCountError, metaData);
+                        Aggregator parent, SubAggCollectionMode collectionMode, boolean showTermDocCountError, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+            super(name, factories, valuesSource, order, bucketCountThresholds, includeExclude, aggregationContext, parent, collectionMode, showTermDocCountError, reducers, metaData);
             bucketOrds = new LongHash(1, aggregationContext.bigArrays());
         }
 
@@ -329,8 +333,8 @@ public class GlobalOrdinalsStringTermsAggregator extends AbstractStringTermsAggr
         private RandomAccessOrds segmentOrds;
 
         public LowCardinality(String name, AggregatorFactories factories, ValuesSource.Bytes.WithOrdinals.FieldData valuesSource,
-                              Terms.Order order, BucketCountThresholds bucketCountThresholds, AggregationContext aggregationContext, Aggregator parent, SubAggCollectionMode collectionMode, boolean showTermDocCountError, Map<String, Object> metaData) throws IOException {
-            super(name, factories, valuesSource, order, bucketCountThresholds, null, aggregationContext, parent, collectionMode, showTermDocCountError, metaData);
+                              Terms.Order order, BucketCountThresholds bucketCountThresholds, AggregationContext aggregationContext, Aggregator parent, SubAggCollectionMode collectionMode, boolean showTermDocCountError, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+            super(name, factories, valuesSource, order, bucketCountThresholds, null, aggregationContext, parent, collectionMode, showTermDocCountError, reducers, metaData);
             assert factories == null || factories.count() == 0;
             this.segmentDocCounts = context.bigArrays().newIntArray(1, true);
         }
@@ -409,7 +413,7 @@ public class GlobalOrdinalsStringTermsAggregator extends AbstractStringTermsAggr
                 }
                 final long ord = i - 1; // remember we do +1 when counting
                 final long globalOrd = mapping == null ? ord : mapping.getGlobalOrd(ord);
-                incrementBucketDocCount(globalOrd, inc);
+                    incrementBucketDocCount(globalOrd, inc);
             }
         }
     }

src/main/java/org/elasticsearch/search/aggregations/bucket/terms/InternalTerms.java

@@ -31,6 +31,7 @@ import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.InternalAggregations;
 import org.elasticsearch.search.aggregations.InternalMultiBucketAggregation;
 import org.elasticsearch.search.aggregations.bucket.terms.support.BucketPriorityQueue;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 
 import java.util.ArrayList;
@@ -121,8 +122,9 @@ public abstract class InternalTerms extends InternalMultiBucketAggregation imple
 
     protected InternalTerms() {} // for serialization
 
-    protected InternalTerms(String name, Terms.Order order, int requiredSize, int shardSize, long minDocCount, List<Bucket> buckets, boolean showTermDocCountError, long docCountError, long otherDocCount, Map<String, Object> metaData) {
-        super(name, metaData);
+    protected InternalTerms(String name, Terms.Order order, int requiredSize, int shardSize, long minDocCount, List<Bucket> buckets,
+            boolean showTermDocCountError, long docCountError, long otherDocCount, List<Reducer> reducers, Map<String, Object> metaData) {
+        super(name, reducers, metaData);
         this.order = order;
         this.requiredSize = requiredSize;
         this.shardSize = shardSize;
@@ -220,9 +222,10 @@ public abstract class InternalTerms extends InternalMultiBucketAggregation imple
         } else {
             docCountError = aggregations.size() == 1 ? 0 : sumDocCountError;
         }
-        return newAggregation(name, Arrays.asList(list), showTermDocCountError, docCountError, otherDocCount, getMetaData());
+        return newAggregation(name, Arrays.asList(list), showTermDocCountError, docCountError, otherDocCount, reducers(), getMetaData());
     }
 
-    protected abstract InternalTerms newAggregation(String name, List<Bucket> buckets, boolean showTermDocCountError, long docCountError, long otherDocCount, Map<String, Object> metaData);
+    protected abstract InternalTerms newAggregation(String name, List<Bucket> buckets, boolean showTermDocCountError, long docCountError,
+            long otherDocCount, List<Reducer> reducers, Map<String, Object> metaData);
 
 }

src/main/java/org/elasticsearch/search/aggregations/bucket/terms/LongTerms.java

@@ -26,6 +26,7 @@ import org.elasticsearch.search.aggregations.AggregationStreams;
 import org.elasticsearch.search.aggregations.InternalAggregations;
 import org.elasticsearch.search.aggregations.bucket.BucketStreamContext;
 import org.elasticsearch.search.aggregations.bucket.BucketStreams;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatterStreams;
 
@@ -155,8 +156,11 @@ public class LongTerms extends InternalTerms {
 
     LongTerms() {} // for serialization
 
-    public LongTerms(String name, Terms.Order order, @Nullable ValueFormatter formatter, int requiredSize, int shardSize, long minDocCount, List<InternalTerms.Bucket> buckets, boolean showTermDocCountError, long docCountError, long otherDocCount, Map<String, Object> metaData) {
-        super(name, order, requiredSize, shardSize, minDocCount, buckets, showTermDocCountError, docCountError, otherDocCount, metaData);
+    public LongTerms(String name, Terms.Order order, @Nullable ValueFormatter formatter, int requiredSize, int shardSize, long minDocCount,
+            List<InternalTerms.Bucket> buckets, boolean showTermDocCountError, long docCountError, long otherDocCount,
+            List<Reducer> reducers, Map<String, Object> metaData) {
+        super(name, order, requiredSize, shardSize, minDocCount, buckets, showTermDocCountError, docCountError, otherDocCount, reducers,
+                metaData);
         this.formatter = formatter;
     }
 
@@ -166,8 +170,10 @@ public class LongTerms extends InternalTerms {
     }
 
     @Override
-    protected InternalTerms newAggregation(String name, List<InternalTerms.Bucket> buckets, boolean showTermDocCountError, long docCountError, long otherDocCount, Map<String, Object> metaData) {
-        return new LongTerms(name, order, formatter, requiredSize, shardSize, minDocCount, buckets, showTermDocCountError, docCountError, otherDocCount, metaData);
+    protected InternalTerms newAggregation(String name, List<InternalTerms.Bucket> buckets, boolean showTermDocCountError,
+            long docCountError, long otherDocCount, List<Reducer> reducers, Map<String, Object> metaData) {
+        return new LongTerms(name, order, formatter, requiredSize, shardSize, minDocCount, buckets, showTermDocCountError, docCountError,
+                otherDocCount, reducers, metaData);
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/bucket/terms/LongTermsAggregator.java

@@ -31,6 +31,7 @@ import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.bucket.terms.support.BucketPriorityQueue;
 import org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude;
 import org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude.LongFilter;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.format.ValueFormat;
@@ -39,6 +40,7 @@ import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -53,15 +55,17 @@ public class LongTermsAggregator extends TermsAggregator {
     private LongFilter longFilter;
 
     public LongTermsAggregator(String name, AggregatorFactories factories, ValuesSource.Numeric valuesSource, @Nullable ValueFormat format,
-            Terms.Order order, BucketCountThresholds bucketCountThresholds, AggregationContext aggregationContext, Aggregator parent, SubAggCollectionMode subAggCollectMode, boolean showTermDocCountError, IncludeExclude.LongFilter longFilter, Map<String, Object> metaData) throws IOException {
-        super(name, factories, aggregationContext, parent, bucketCountThresholds, order, subAggCollectMode, metaData);
+            Terms.Order order, BucketCountThresholds bucketCountThresholds, AggregationContext aggregationContext, Aggregator parent,
+            SubAggCollectionMode subAggCollectMode, boolean showTermDocCountError, IncludeExclude.LongFilter longFilter,
+            List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+        super(name, factories, aggregationContext, parent, bucketCountThresholds, order, subAggCollectMode, reducers, metaData);
         this.valuesSource = valuesSource;
         this.showTermDocCountError = showTermDocCountError;
         this.formatter = format != null ? format.formatter() : null;
         this.longFilter = longFilter;
         bucketOrds = new LongHash(1, aggregationContext.bigArrays());
     }
-
+    
     @Override
     public boolean needsScores() {
         return (valuesSource != null && valuesSource.needsScores()) || super.needsScores();
@@ -76,30 +80,30 @@ public class LongTermsAggregator extends TermsAggregator {
             final LeafBucketCollector sub) throws IOException {
         final SortedNumericDocValues values = getValues(valuesSource, ctx);
         return new LeafBucketCollectorBase(sub, values) {
-            @Override
-            public void collect(int doc, long owningBucketOrdinal) throws IOException {
-                assert owningBucketOrdinal == 0;
-                values.setDocument(doc);
-                final int valuesCount = values.count();
+    @Override
+    public void collect(int doc, long owningBucketOrdinal) throws IOException {
+        assert owningBucketOrdinal == 0;
+        values.setDocument(doc);
+        final int valuesCount = values.count();
 
-                long previous = Long.MAX_VALUE;
-                for (int i = 0; i < valuesCount; ++i) {
-                    final long val = values.valueAt(i);
-                    if (previous != val || i == 0) {
-                        if ((longFilter == null) || (longFilter.accept(val))) {
-                            long bucketOrdinal = bucketOrds.add(val);
-                            if (bucketOrdinal < 0) { // already seen
-                                bucketOrdinal = - 1 - bucketOrdinal;
+        long previous = Long.MAX_VALUE;
+        for (int i = 0; i < valuesCount; ++i) {
+            final long val = values.valueAt(i);
+            if (previous != val || i == 0) {
+                if ((longFilter == null) || (longFilter.accept(val))) {
+                    long bucketOrdinal = bucketOrds.add(val);
+                    if (bucketOrdinal < 0) { // already seen
+                        bucketOrdinal = - 1 - bucketOrdinal;
                                 collectExistingBucket(sub, doc, bucketOrdinal);
-                            } else {
+                    } else {
                                 collectBucket(sub, doc, bucketOrdinal);
-                            }
-                        }
-
-                        previous = val;
-                    }
+                    }                       
                 }
+                
+                previous = val;
             }
+        }
+    }
         };
     }
 
@@ -148,7 +152,7 @@ public class LongTermsAggregator extends TermsAggregator {
             list[i] = bucket;
             otherDocCount -= bucket.docCount;
         }
-
+      
         runDeferredCollections(survivingBucketOrds);
 
         //Now build the aggs
@@ -156,14 +160,18 @@ public class LongTermsAggregator extends TermsAggregator {
           list[i].aggregations = bucketAggregations(list[i].bucketOrd);
           list[i].docCountError = 0;
         }
-
-        return new LongTerms(name, order, formatter, bucketCountThresholds.getRequiredSize(), bucketCountThresholds.getShardSize(), bucketCountThresholds.getMinDocCount(), Arrays.asList(list), showTermDocCountError, 0, otherDocCount, metaData());
+        
+        return new LongTerms(name, order, formatter, bucketCountThresholds.getRequiredSize(), bucketCountThresholds.getShardSize(),
+                bucketCountThresholds.getMinDocCount(), Arrays.asList(list), showTermDocCountError, 0, otherDocCount, reducers(),
+                metaData());
     }
-
-
+    
+    
     @Override
     public InternalAggregation buildEmptyAggregation() {
-        return new LongTerms(name, order, formatter, bucketCountThresholds.getRequiredSize(), bucketCountThresholds.getShardSize(), bucketCountThresholds.getMinDocCount(), Collections.<InternalTerms.Bucket>emptyList(), showTermDocCountError, 0, 0, metaData());
+        return new LongTerms(name, order, formatter, bucketCountThresholds.getRequiredSize(), bucketCountThresholds.getShardSize(),
+                bucketCountThresholds.getMinDocCount(), Collections.<InternalTerms.Bucket> emptyList(), showTermDocCountError, 0, 0,
+                reducers(), metaData());
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/bucket/terms/StringTerms.java

@@ -27,6 +27,7 @@ import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.InternalAggregations;
 import org.elasticsearch.search.aggregations.bucket.BucketStreamContext;
 import org.elasticsearch.search.aggregations.bucket.BucketStreams;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -150,8 +151,11 @@ public class StringTerms extends InternalTerms {
 
     StringTerms() {} // for serialization
 
-    public StringTerms(String name, Terms.Order order, int requiredSize, int shardSize, long minDocCount, List<InternalTerms.Bucket> buckets, boolean showTermDocCountError, long docCountError, long otherDocCount, Map<String, Object> metaData) {
-        super(name, order, requiredSize, shardSize, minDocCount, buckets, showTermDocCountError, docCountError, otherDocCount, metaData);
+    public StringTerms(String name, Terms.Order order, int requiredSize, int shardSize, long minDocCount,
+            List<InternalTerms.Bucket> buckets, boolean showTermDocCountError, long docCountError, long otherDocCount,
+            List<Reducer> reducers, Map<String, Object> metaData) {
+        super(name, order, requiredSize, shardSize, minDocCount, buckets, showTermDocCountError, docCountError, otherDocCount, reducers,
+                metaData);
     }
 
     @Override
@@ -160,8 +164,10 @@ public class StringTerms extends InternalTerms {
     }
 
     @Override
-    protected InternalTerms newAggregation(String name, List<InternalTerms.Bucket> buckets, boolean showTermDocCountError, long docCountError, long otherDocCount, Map<String, Object> metaData) {
-        return new StringTerms(name, order, requiredSize, shardSize, minDocCount, buckets, showTermDocCountError, docCountError, otherDocCount, metaData);
+    protected InternalTerms newAggregation(String name, List<InternalTerms.Bucket> buckets, boolean showTermDocCountError,
+            long docCountError, long otherDocCount, List<Reducer> reducers, Map<String, Object> metaData) {
+        return new StringTerms(name, order, requiredSize, shardSize, minDocCount, buckets, showTermDocCountError, docCountError,
+                otherDocCount, reducers, metaData);
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/bucket/terms/StringTermsAggregator.java

@@ -31,11 +31,13 @@ import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.bucket.terms.support.BucketPriorityQueue;
 import org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 
 import java.io.IOException;
 import java.util.Arrays;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -49,9 +51,12 @@ public class StringTermsAggregator extends AbstractStringTermsAggregator {
 
     public StringTermsAggregator(String name, AggregatorFactories factories, ValuesSource valuesSource,
             Terms.Order order, BucketCountThresholds bucketCountThresholds,
-            IncludeExclude includeExclude, AggregationContext aggregationContext, Aggregator parent, SubAggCollectionMode collectionMode, boolean showTermDocCountError, Map<String, Object> metaData) throws IOException {
+ IncludeExclude includeExclude, AggregationContext aggregationContext,
+            Aggregator parent, SubAggCollectionMode collectionMode, boolean showTermDocCountError, List<Reducer> reducers,
+            Map<String, Object> metaData) throws IOException {
 
-        super(name, factories, aggregationContext, parent, order, bucketCountThresholds, collectionMode, showTermDocCountError, metaData);
+        super(name, factories, aggregationContext, parent, order, bucketCountThresholds, collectionMode, showTermDocCountError, reducers,
+                metaData);
         this.valuesSource = valuesSource;
         this.includeExclude = includeExclude;
         bucketOrds = new BytesRefHash(1, aggregationContext.bigArrays());
@@ -158,7 +163,9 @@ public class StringTermsAggregator extends AbstractStringTermsAggregator {
           bucket.docCountError = 0;
         }
         
-        return new StringTerms(name, order, bucketCountThresholds.getRequiredSize(), bucketCountThresholds.getShardSize(), bucketCountThresholds.getMinDocCount(), Arrays.asList(list), showTermDocCountError, 0, otherDocCount, metaData());
+        return new StringTerms(name, order, bucketCountThresholds.getRequiredSize(), bucketCountThresholds.getShardSize(),
+                bucketCountThresholds.getMinDocCount(), Arrays.asList(list), showTermDocCountError, 0, otherDocCount, reducers(),
+                metaData());
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsAggregator.java

@@ -28,11 +28,13 @@ import org.elasticsearch.search.aggregations.AggregatorFactories;
 import org.elasticsearch.search.aggregations.bucket.BucketsAggregator;
 import org.elasticsearch.search.aggregations.bucket.terms.InternalOrder.Aggregation;
 import org.elasticsearch.search.aggregations.bucket.terms.InternalOrder.CompoundOrder;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.AggregationPath;
 
 import java.io.IOException;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
@@ -135,8 +137,8 @@ public abstract class TermsAggregator extends BucketsAggregator {
     protected final Set<Aggregator> aggsUsedForSorting = new HashSet<>();
     protected final SubAggCollectionMode collectMode;
 
-    public TermsAggregator(String name, AggregatorFactories factories, AggregationContext context, Aggregator parent, BucketCountThresholds bucketCountThresholds, Terms.Order order, SubAggCollectionMode collectMode, Map<String, Object> metaData) throws IOException {
-        super(name, factories, context, parent, metaData);
+    public TermsAggregator(String name, AggregatorFactories factories, AggregationContext context, Aggregator parent, BucketCountThresholds bucketCountThresholds, Terms.Order order, SubAggCollectionMode collectMode, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+        super(name, factories, context, parent, reducers, metaData);
         this.bucketCountThresholds = bucketCountThresholds;
         this.order = InternalOrder.validate(order, this);
         this.collectMode = collectMode;

src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsAggregatorFactory.java

@@ -1,4 +1,4 @@
-/*
+List</*
  * Licensed to Elasticsearch under one or more contributor
  * license agreements. See the NOTICE file distributed with
  * this work for additional information regarding copyright
@@ -29,12 +29,14 @@ import org.elasticsearch.search.aggregations.AggregatorFactories;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.NonCollectingAggregator;
 import org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
 import org.elasticsearch.search.aggregations.support.ValuesSourceConfig;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -49,8 +51,10 @@ public class TermsAggregatorFactory extends ValuesSourceAggregatorFactory<Values
             @Override
             Aggregator create(String name, AggregatorFactories factories, ValuesSource valuesSource,
                               Terms.Order order, TermsAggregator.BucketCountThresholds bucketCountThresholds, IncludeExclude includeExclude,
-                              AggregationContext aggregationContext, Aggregator parent, SubAggCollectionMode subAggCollectMode, boolean showTermDocCountError, Map<String, Object> metaData) throws IOException {
-                return new StringTermsAggregator(name, factories, valuesSource, order, bucketCountThresholds, includeExclude, aggregationContext, parent, subAggCollectMode, showTermDocCountError, metaData);
+                    AggregationContext aggregationContext, Aggregator parent, SubAggCollectionMode subAggCollectMode,
+                    boolean showTermDocCountError, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+                return new StringTermsAggregator(name, factories, valuesSource, order, bucketCountThresholds, includeExclude,
+                        aggregationContext, parent, subAggCollectMode, showTermDocCountError, reducers, metaData);
             }
 
             @Override
@@ -64,8 +68,8 @@ public class TermsAggregatorFactory extends ValuesSourceAggregatorFactory<Values
             @Override
             Aggregator create(String name, AggregatorFactories factories, ValuesSource valuesSource,
                               Terms.Order order, TermsAggregator.BucketCountThresholds bucketCountThresholds, IncludeExclude includeExclude,
-                              AggregationContext aggregationContext, Aggregator parent, SubAggCollectionMode subAggCollectMode, boolean showTermDocCountError, Map<String, Object> metaData) throws IOException {
-                return new GlobalOrdinalsStringTermsAggregator(name, factories, (ValuesSource.Bytes.WithOrdinals.FieldData) valuesSource, order, bucketCountThresholds, includeExclude, aggregationContext, parent, subAggCollectMode, showTermDocCountError, metaData);
+                              AggregationContext aggregationContext, Aggregator parent, SubAggCollectionMode subAggCollectMode, boolean showTermDocCountError, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+                return new GlobalOrdinalsStringTermsAggregator(name, factories, (ValuesSource.Bytes.WithOrdinals.FieldData) valuesSource, order, bucketCountThresholds, includeExclude, aggregationContext, parent, subAggCollectMode, showTermDocCountError, reducers, metaData);
             }
 
             @Override
@@ -79,8 +83,8 @@ public class TermsAggregatorFactory extends ValuesSourceAggregatorFactory<Values
             @Override
             Aggregator create(String name, AggregatorFactories factories, ValuesSource valuesSource,
                               Terms.Order order, TermsAggregator.BucketCountThresholds bucketCountThresholds, IncludeExclude includeExclude,
-                              AggregationContext aggregationContext, Aggregator parent, SubAggCollectionMode subAggCollectMode, boolean showTermDocCountError, Map<String, Object> metaData) throws IOException {
-                return new GlobalOrdinalsStringTermsAggregator.WithHash(name, factories, (ValuesSource.Bytes.WithOrdinals.FieldData) valuesSource, order, bucketCountThresholds, includeExclude, aggregationContext, parent, subAggCollectMode, showTermDocCountError, metaData);
+                              AggregationContext aggregationContext, Aggregator parent, SubAggCollectionMode subAggCollectMode, boolean showTermDocCountError, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+                return new GlobalOrdinalsStringTermsAggregator.WithHash(name, factories, (ValuesSource.Bytes.WithOrdinals.FieldData) valuesSource, order, bucketCountThresholds, includeExclude, aggregationContext, parent, subAggCollectMode, showTermDocCountError, reducers, metaData);
             }
 
             @Override
@@ -93,11 +97,12 @@ public class TermsAggregatorFactory extends ValuesSourceAggregatorFactory<Values
             @Override
             Aggregator create(String name, AggregatorFactories factories, ValuesSource valuesSource,
                               Terms.Order order, TermsAggregator.BucketCountThresholds bucketCountThresholds, IncludeExclude includeExclude,
-                              AggregationContext aggregationContext, Aggregator parent, SubAggCollectionMode subAggCollectMode, boolean showTermDocCountError, Map<String, Object> metaData) throws IOException {
+                    AggregationContext aggregationContext, Aggregator parent, SubAggCollectionMode subAggCollectMode,
+                    boolean showTermDocCountError, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
                 if (includeExclude != null || factories.count() > 0) {
-                    return GLOBAL_ORDINALS.create(name, factories, valuesSource, order, bucketCountThresholds, includeExclude, aggregationContext, parent, subAggCollectMode, showTermDocCountError, metaData);
+                    return GLOBAL_ORDINALS.create(name, factories, valuesSource, order, bucketCountThresholds, includeExclude, aggregationContext, parent, subAggCollectMode, showTermDocCountError, reducers, metaData);
                 }
-                return new GlobalOrdinalsStringTermsAggregator.LowCardinality(name, factories, (ValuesSource.Bytes.WithOrdinals.FieldData) valuesSource, order, bucketCountThresholds, aggregationContext, parent, subAggCollectMode, showTermDocCountError, metaData);
+                return new GlobalOrdinalsStringTermsAggregator.LowCardinality(name, factories, (ValuesSource.Bytes.WithOrdinals.FieldData) valuesSource, order, bucketCountThresholds, aggregationContext, parent, subAggCollectMode, showTermDocCountError, reducers, metaData);
             }
 
             @Override
@@ -124,7 +129,7 @@ public class TermsAggregatorFactory extends ValuesSourceAggregatorFactory<Values
         abstract Aggregator create(String name, AggregatorFactories factories, ValuesSource valuesSource,
                                    Terms.Order order, TermsAggregator.BucketCountThresholds bucketCountThresholds,
                                    IncludeExclude includeExclude, AggregationContext aggregationContext, Aggregator parent,
-                                   SubAggCollectionMode subAggCollectMode, boolean showTermDocCountError, Map<String, Object> metaData) throws IOException;
+                                   SubAggCollectionMode subAggCollectMode, boolean showTermDocCountError, List<Reducer> reducers, Map<String, Object> metaData) throws IOException;
 
         abstract boolean needsGlobalOrdinals();
 
@@ -152,9 +157,11 @@ public class TermsAggregatorFactory extends ValuesSourceAggregatorFactory<Values
     }
 
     @Override
-    protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
-        final InternalAggregation aggregation = new UnmappedTerms(name, order, bucketCountThresholds.getRequiredSize(), bucketCountThresholds.getShardSize(), bucketCountThresholds.getMinDocCount(), metaData);
-        return new NonCollectingAggregator(name, aggregationContext, parent, factories, metaData) {
+    protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, List<Reducer> reducers,
+            Map<String, Object> metaData) throws IOException {
+        final InternalAggregation aggregation = new UnmappedTerms(name, order, bucketCountThresholds.getRequiredSize(),
+                bucketCountThresholds.getShardSize(), bucketCountThresholds.getMinDocCount(), reducers, metaData);
+        return new NonCollectingAggregator(name, aggregationContext, parent, factories, reducers, metaData) {
             {
                 // even in the case of an unmapped aggregator, validate the order
                 InternalOrder.validate(order, this);
@@ -167,7 +174,8 @@ public class TermsAggregatorFactory extends ValuesSourceAggregatorFactory<Values
     }
 
     @Override
-    protected Aggregator doCreateInternal(ValuesSource valuesSource, AggregationContext aggregationContext, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
+    protected Aggregator doCreateInternal(ValuesSource valuesSource, AggregationContext aggregationContext, Aggregator parent,
+            boolean collectsFromSingleBucket, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
         if (collectsFromSingleBucket == false) {
             return asMultiBucketAggregator(this, aggregationContext, parent);
         }
@@ -217,7 +225,7 @@ public class TermsAggregatorFactory extends ValuesSourceAggregatorFactory<Values
             }
 
             assert execution != null;
-            return execution.create(name, factories, valuesSource, order, bucketCountThresholds, includeExclude, aggregationContext, parent, collectMode, showTermDocCountError, metaData);
+            return execution.create(name, factories, valuesSource, order, bucketCountThresholds, includeExclude, aggregationContext, parent, collectMode, showTermDocCountError, reducers, metaData);
         }
 
         if ((includeExclude != null) && (includeExclude.isRegexBased())) {
@@ -233,13 +241,14 @@ public class TermsAggregatorFactory extends ValuesSourceAggregatorFactory<Values
                 }
                 return new DoubleTermsAggregator(name, factories, (ValuesSource.Numeric) valuesSource, config.format(),
                         order, bucketCountThresholds, aggregationContext, parent, collectMode,
-                        showTermDocCountError, longFilter, metaData);
+ showTermDocCountError, longFilter, reducers,
+                        metaData);
             }
             if (includeExclude != null) {
                 longFilter = includeExclude.convertToLongFilter();
             }
             return new LongTermsAggregator(name, factories, (ValuesSource.Numeric) valuesSource, config.format(),
-                    order, bucketCountThresholds, aggregationContext, parent, collectMode, showTermDocCountError, longFilter, metaData);
+                    order, bucketCountThresholds, aggregationContext, parent, collectMode, showTermDocCountError, longFilter, reducers, metaData);
         }
 
         throw new AggregationExecutionException("terms aggregation cannot be applied to field [" + config.fieldContext().field() +

src/main/java/org/elasticsearch/search/aggregations/bucket/terms/UnmappedTerms.java

@@ -23,6 +23,7 @@ import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.search.aggregations.AggregationStreams;
 import org.elasticsearch.search.aggregations.InternalAggregation;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 
 import java.io.IOException;
 import java.util.Collections;
@@ -54,8 +55,9 @@ public class UnmappedTerms extends InternalTerms {
 
     UnmappedTerms() {} // for serialization
 
-    public UnmappedTerms(String name, Terms.Order order, int requiredSize, int shardSize, long minDocCount, Map<String, Object> metaData) {
-        super(name, order, requiredSize, shardSize, minDocCount, BUCKETS, false, 0, 0, metaData);
+    public UnmappedTerms(String name, Terms.Order order, int requiredSize, int shardSize, long minDocCount, List<Reducer> reducers,
+            Map<String, Object> metaData) {
+        super(name, order, requiredSize, shardSize, minDocCount, BUCKETS, false, 0, 0, reducers, metaData);
     }
 
     @Override
@@ -91,7 +93,8 @@ public class UnmappedTerms extends InternalTerms {
     }
 
     @Override
-    protected InternalTerms newAggregation(String name, List<Bucket> buckets, boolean showTermDocCountError, long docCountError, long otherDocCount, Map<String, Object> metaData) {
+    protected InternalTerms newAggregation(String name, List<Bucket> buckets, boolean showTermDocCountError, long docCountError,
+            long otherDocCount, List<Reducer> reducers, Map<String, Object> metaData) {
         throw new UnsupportedOperationException("How did you get there?");
     }
 

src/main/java/org/elasticsearch/search/aggregations/metrics/InternalMetricsAggregation.java

@@ -20,14 +20,16 @@
 package org.elasticsearch.search.aggregations.metrics;
 
 import org.elasticsearch.search.aggregations.InternalAggregation;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 
+import java.util.List;
 import java.util.Map;
 
 public abstract class InternalMetricsAggregation extends InternalAggregation {
 
     protected InternalMetricsAggregation() {} // for serialization
 
-    protected InternalMetricsAggregation(String name, Map<String, Object> metaData) {
-        super(name, metaData);
+    protected InternalMetricsAggregation(String name, List<Reducer> reducers, Map<String, Object> metaData) {
+        super(name, reducers, metaData);
     }
 }

src/main/java/org/elasticsearch/search/aggregations/metrics/InternalNumericMetricsAggregation.java

@@ -19,6 +19,7 @@
 package org.elasticsearch.search.aggregations.metrics;
 
 import org.elasticsearch.ElasticsearchIllegalArgumentException;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 
 import java.util.List;
@@ -35,8 +36,8 @@ public abstract class InternalNumericMetricsAggregation extends InternalMetricsA
 
         protected SingleValue() {}
 
-        protected SingleValue(String name, Map<String, Object> metaData) {
-            super(name, metaData);
+        protected SingleValue(String name, List<Reducer> reducers, Map<String, Object> metaData) {
+            super(name, reducers, metaData);
         }
 
         public String getValueAsString() {
@@ -64,8 +65,8 @@ public abstract class InternalNumericMetricsAggregation extends InternalMetricsA
 
         protected MultiValue() {}
 
-        protected MultiValue(String name, Map<String, Object> metaData) {
-            super(name, metaData);
+        protected MultiValue(String name, List<Reducer> reducers, Map<String, Object> metaData) {
+            super(name, reducers, metaData);
         }
 
         public abstract double value(String name);
@@ -92,8 +93,8 @@ public abstract class InternalNumericMetricsAggregation extends InternalMetricsA
 
     private InternalNumericMetricsAggregation() {} // for serialization
 
-    private InternalNumericMetricsAggregation(String name, Map<String, Object> metaData) {
-        super(name, metaData);
+    private InternalNumericMetricsAggregation(String name, List<Reducer> reducers, Map<String, Object> metaData) {
+        super(name, reducers, metaData);
     }
 
 }

src/main/java/org/elasticsearch/search/aggregations/metrics/MetricsAggregator.java

@@ -22,14 +22,17 @@ package org.elasticsearch.search.aggregations.metrics;
 import org.elasticsearch.search.aggregations.Aggregator;
 import org.elasticsearch.search.aggregations.AggregatorBase;
 import org.elasticsearch.search.aggregations.AggregatorFactories;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 public abstract class MetricsAggregator extends AggregatorBase {
     
-    protected MetricsAggregator(String name, AggregationContext context, Aggregator parent, Map<String, Object> metaData) throws IOException {
-        super(name, AggregatorFactories.EMPTY, context, parent, metaData);
+    protected MetricsAggregator(String name, AggregationContext context, Aggregator parent, List<Reducer> reducers,
+            Map<String, Object> metaData) throws IOException {
+        super(name, AggregatorFactories.EMPTY, context, parent, reducers, metaData);
     }
 }

src/main/java/org/elasticsearch/search/aggregations/metrics/NumericMetricsAggregator.java

@@ -19,9 +19,11 @@
 package org.elasticsearch.search.aggregations.metrics;
 
 import org.elasticsearch.search.aggregations.Aggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -29,14 +31,16 @@ import java.util.Map;
  */
 public abstract class NumericMetricsAggregator extends MetricsAggregator {
 
-    private NumericMetricsAggregator(String name, AggregationContext context, Aggregator parent, Map<String, Object> metaData) throws IOException {
-        super(name, context, parent, metaData);
+    private NumericMetricsAggregator(String name, AggregationContext context, Aggregator parent, List<Reducer> reducers,
+            Map<String, Object> metaData) throws IOException {
+        super(name, context, parent, reducers, metaData);
     }
 
     public static abstract class SingleValue extends NumericMetricsAggregator {
 
-        protected SingleValue(String name, AggregationContext context, Aggregator parent, Map<String, Object> metaData) throws IOException {
-            super(name, context, parent, metaData);
+        protected SingleValue(String name, AggregationContext context, Aggregator parent, List<Reducer> reducers,
+                Map<String, Object> metaData) throws IOException {
+            super(name, context, parent, reducers, metaData);
         }
 
         public abstract double metric(long owningBucketOrd);
@@ -44,8 +48,9 @@ public abstract class NumericMetricsAggregator extends MetricsAggregator {
 
     public static abstract class MultiValue extends NumericMetricsAggregator {
 
-        protected MultiValue(String name, AggregationContext context, Aggregator parent, Map<String, Object> metaData) throws IOException {
-            super(name, context, parent, metaData);
+        protected MultiValue(String name, AggregationContext context, Aggregator parent, List<Reducer> reducers,
+                Map<String, Object> metaData) throws IOException {
+            super(name, context, parent, reducers, metaData);
         }
 
         public abstract boolean hasMetric(String name);

src/main/java/org/elasticsearch/search/aggregations/metrics/avg/AvgAggregator.java

@@ -30,6 +30,7 @@ import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
 import org.elasticsearch.search.aggregations.metrics.NumericMetricsAggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
@@ -37,6 +38,7 @@ import org.elasticsearch.search.aggregations.support.ValuesSourceConfig;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -51,8 +53,9 @@ public class AvgAggregator extends NumericMetricsAggregator.SingleValue {
     ValueFormatter formatter;
 
     public AvgAggregator(String name, ValuesSource.Numeric valuesSource, @Nullable ValueFormatter formatter,
-            AggregationContext context, Aggregator parent, Map<String, Object> metaData) throws IOException {
-        super(name,context, parent, metaData);
+ AggregationContext context,
+            Aggregator parent, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+        super(name, context, parent, reducers, metaData);
         this.valuesSource = valuesSource;
         this.formatter = formatter;
         if (valuesSource != null) {
@@ -72,22 +75,22 @@ public class AvgAggregator extends NumericMetricsAggregator.SingleValue {
             final LeafBucketCollector sub) throws IOException {
         if (valuesSource == null) {
             return LeafBucketCollector.NO_OP_COLLECTOR;
-        }
+    }
         final BigArrays bigArrays = context.bigArrays();
         final SortedNumericDoubleValues values = valuesSource.doubleValues(ctx);
         return new LeafBucketCollectorBase(sub, values) {
-            @Override
+    @Override
             public void collect(int doc, long bucket) throws IOException {
                 counts = bigArrays.grow(counts, bucket + 1);
                 sums = bigArrays.grow(sums, bucket + 1);
 
-                values.setDocument(doc);
-                final int valueCount = values.count();
+        values.setDocument(doc);
+        final int valueCount = values.count();
                 counts.increment(bucket, valueCount);
-                double sum = 0;
-                for (int i = 0; i < valueCount; i++) {
-                    sum += values.valueAt(i);
-                }
+        double sum = 0;
+        for (int i = 0; i < valueCount; i++) {
+            sum += values.valueAt(i);
+        }
                 sums.increment(bucket, sum);
             }
         };
@@ -103,12 +106,12 @@ public class AvgAggregator extends NumericMetricsAggregator.SingleValue {
         if (valuesSource == null || bucket >= sums.size()) {
             return buildEmptyAggregation();
         }
-        return new InternalAvg(name, sums.get(bucket), counts.get(bucket), formatter, metaData());
+        return new InternalAvg(name, sums.get(bucket), counts.get(bucket), formatter, reducers(), metaData());
     }
 
     @Override
     public InternalAggregation buildEmptyAggregation() {
-        return new InternalAvg(name, 0.0, 0l, formatter, metaData());
+        return new InternalAvg(name, 0.0, 0l, formatter, reducers(), metaData());
     }
 
     public static class Factory extends ValuesSourceAggregatorFactory.LeafOnly<ValuesSource.Numeric> {
@@ -118,13 +121,15 @@ public class AvgAggregator extends NumericMetricsAggregator.SingleValue {
         }
 
         @Override
-        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
-            return new AvgAggregator(name, null, config.formatter(), aggregationContext, parent, metaData);
+        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, List<Reducer> reducers,
+                Map<String, Object> metaData) throws IOException {
+            return new AvgAggregator(name, null, config.formatter(), aggregationContext, parent, reducers, metaData);
         }
 
         @Override
-        protected Aggregator doCreateInternal(ValuesSource.Numeric valuesSource, AggregationContext aggregationContext, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
-            return new AvgAggregator(name, valuesSource, config.formatter(), aggregationContext, parent, metaData);
+        protected Aggregator doCreateInternal(ValuesSource.Numeric valuesSource, AggregationContext aggregationContext, Aggregator parent,
+                boolean collectsFromSingleBucket, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+            return new AvgAggregator(name, valuesSource, config.formatter(), aggregationContext, parent, reducers, metaData);
         }
     }
 

src/main/java/org/elasticsearch/search/aggregations/metrics/avg/InternalAvg.java

@@ -25,10 +25,12 @@ import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.search.aggregations.AggregationStreams;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.metrics.InternalNumericMetricsAggregation;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatterStreams;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -56,8 +58,9 @@ public class InternalAvg extends InternalNumericMetricsAggregation.SingleValue i
 
     InternalAvg() {} // for serialization
 
-    public InternalAvg(String name, double sum, long count, @Nullable ValueFormatter formatter, Map<String, Object> metaData) {
-        super(name, metaData);
+    public InternalAvg(String name, double sum, long count, @Nullable ValueFormatter formatter, List<Reducer> reducers,
+            Map<String, Object> metaData) {
+        super(name, reducers, metaData);
         this.sum = sum;
         this.count = count;
         this.valueFormatter = formatter;
@@ -85,7 +88,7 @@ public class InternalAvg extends InternalNumericMetricsAggregation.SingleValue i
             count += ((InternalAvg) aggregation).count;
             sum += ((InternalAvg) aggregation).sum;
         }
-        return new InternalAvg(getName(), sum, count, valueFormatter, getMetaData());
+        return new InternalAvg(getName(), sum, count, valueFormatter, reducers(), getMetaData());
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/metrics/cardinality/CardinalityAggregator.java

@@ -42,11 +42,13 @@ import org.elasticsearch.search.aggregations.Aggregator;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.metrics.NumericMetricsAggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -66,8 +68,8 @@ public class CardinalityAggregator extends NumericMetricsAggregator.SingleValue
     private ValueFormatter formatter;
 
     public CardinalityAggregator(String name, ValuesSource valuesSource, boolean rehash, int precision, @Nullable ValueFormatter formatter,
-                                 AggregationContext context, Aggregator parent, Map<String, Object> metaData) throws IOException {
-        super(name, context, parent, metaData);
+            AggregationContext context, Aggregator parent, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+        super(name, context, parent, reducers, metaData);
         this.valuesSource = valuesSource;
         this.rehash = rehash;
         this.precision = precision;
@@ -156,12 +158,12 @@ public class CardinalityAggregator extends NumericMetricsAggregator.SingleValue
         // this Aggregator (and its HLL++ counters) is released.
         HyperLogLogPlusPlus copy = new HyperLogLogPlusPlus(precision, BigArrays.NON_RECYCLING_INSTANCE, 1);
         copy.merge(0, counts, owningBucketOrdinal);
-        return new InternalCardinality(name, copy, formatter, metaData());
+        return new InternalCardinality(name, copy, formatter, reducers(), metaData());
     }
 
     @Override
     public InternalAggregation buildEmptyAggregation() {
-        return new InternalCardinality(name, null, formatter, metaData());
+        return new InternalCardinality(name, null, formatter, reducers(), metaData());
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/metrics/cardinality/CardinalityAggregatorFactory.java

@@ -22,12 +22,14 @@ package org.elasticsearch.search.aggregations.metrics.cardinality;
 import org.elasticsearch.search.aggregations.AggregationExecutionException;
 import org.elasticsearch.search.aggregations.Aggregator;
 import org.elasticsearch.search.aggregations.bucket.SingleBucketAggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
 import org.elasticsearch.search.aggregations.support.ValuesSourceConfig;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 final class CardinalityAggregatorFactory extends ValuesSourceAggregatorFactory<ValuesSource> {
@@ -46,16 +48,19 @@ final class CardinalityAggregatorFactory extends ValuesSourceAggregatorFactory<V
     }
 
     @Override
-    protected Aggregator createUnmapped(AggregationContext context, Aggregator parent, Map<String, Object> metaData) throws IOException {
-        return new CardinalityAggregator(name, null, true, precision(parent), config.formatter(), context, parent, metaData);
+    protected Aggregator createUnmapped(AggregationContext context, Aggregator parent, List<Reducer> reducers, Map<String, Object> metaData)
+            throws IOException {
+        return new CardinalityAggregator(name, null, true, precision(parent), config.formatter(), context, parent, reducers, metaData);
     }
 
     @Override
-    protected Aggregator doCreateInternal(ValuesSource valuesSource, AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
+    protected Aggregator doCreateInternal(ValuesSource valuesSource, AggregationContext context, Aggregator parent,
+            boolean collectsFromSingleBucket, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
         if (!(valuesSource instanceof ValuesSource.Numeric) && !rehash) {
             throw new AggregationExecutionException("Turning off rehashing for cardinality aggregation [" + name + "] on non-numeric values in not allowed");
         }
-        return new CardinalityAggregator(name, valuesSource, rehash, precision(parent), config.formatter(), context, parent, metaData);
+        return new CardinalityAggregator(name, valuesSource, rehash, precision(parent), config.formatter(), context, parent, reducers,
+                metaData);
     }
 
     /*

src/main/java/org/elasticsearch/search/aggregations/metrics/cardinality/InternalCardinality.java

@@ -27,6 +27,7 @@ import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.search.aggregations.AggregationStreams;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.metrics.InternalNumericMetricsAggregation;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatterStreams;
 
@@ -53,8 +54,9 @@ public final class InternalCardinality extends InternalNumericMetricsAggregation
 
     private HyperLogLogPlusPlus counts;
 
-    InternalCardinality(String name, HyperLogLogPlusPlus counts, @Nullable ValueFormatter formatter, Map<String, Object> metaData) {
-        super(name, metaData);
+    InternalCardinality(String name, HyperLogLogPlusPlus counts, @Nullable ValueFormatter formatter, List<Reducer> reducers,
+            Map<String, Object> metaData) {
+        super(name, reducers, metaData);
         this.counts = counts;
         this.valueFormatter = formatter;
     }
@@ -107,7 +109,7 @@ public final class InternalCardinality extends InternalNumericMetricsAggregation
             if (cardinality.counts != null) {
                 if (reduced == null) {
                     reduced = new InternalCardinality(name, new HyperLogLogPlusPlus(cardinality.counts.precision(),
-                            BigArrays.NON_RECYCLING_INSTANCE, 1), this.valueFormatter, getMetaData());
+                            BigArrays.NON_RECYCLING_INSTANCE, 1), this.valueFormatter, reducers(), getMetaData());
                 }
                 reduced.merge(cardinality);
             }

src/main/java/org/elasticsearch/search/aggregations/metrics/geobounds/GeoBoundsAggregator.java

@@ -30,12 +30,14 @@ import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
 import org.elasticsearch.search.aggregations.metrics.MetricsAggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
 import org.elasticsearch.search.aggregations.support.ValuesSourceConfig;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 public final class GeoBoundsAggregator extends MetricsAggregator {
@@ -50,8 +52,10 @@ public final class GeoBoundsAggregator extends MetricsAggregator {
     DoubleArray negRights;
 
     protected GeoBoundsAggregator(String name, AggregationContext aggregationContext,
-            Aggregator parent, ValuesSource.GeoPoint valuesSource, boolean wrapLongitude, Map<String, Object> metaData) throws IOException {
-        super(name, aggregationContext, parent, metaData);
+ Aggregator parent,
+            ValuesSource.GeoPoint valuesSource, boolean wrapLongitude, List<Reducer> reducers, Map<String, Object> metaData)
+            throws IOException {
+        super(name, aggregationContext, parent, reducers, metaData);
         this.valuesSource = valuesSource;
         this.wrapLongitude = wrapLongitude;
         if (valuesSource != null) {
@@ -149,13 +153,13 @@ public final class GeoBoundsAggregator extends MetricsAggregator {
         double posRight = posRights.get(owningBucketOrdinal);
         double negLeft = negLefts.get(owningBucketOrdinal);
         double negRight = negRights.get(owningBucketOrdinal);
-        return new InternalGeoBounds(name, top, bottom, posLeft, posRight, negLeft, negRight, wrapLongitude, metaData());
+        return new InternalGeoBounds(name, top, bottom, posLeft, posRight, negLeft, negRight, wrapLongitude, reducers(), metaData());
     }
 
     @Override
     public InternalAggregation buildEmptyAggregation() {
         return new InternalGeoBounds(name, Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY, Double.POSITIVE_INFINITY,
-                Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY, Double.NEGATIVE_INFINITY, wrapLongitude, metaData());
+                Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY, Double.NEGATIVE_INFINITY, wrapLongitude, reducers(), metaData());
     }
     
     @Override
@@ -173,14 +177,16 @@ public final class GeoBoundsAggregator extends MetricsAggregator {
         }
 
         @Override
-        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
-            return new GeoBoundsAggregator(name, aggregationContext, parent, null, wrapLongitude, metaData);
+        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, List<Reducer> reducers,
+                Map<String, Object> metaData) throws IOException {
+            return new GeoBoundsAggregator(name, aggregationContext, parent, null, wrapLongitude, reducers, metaData);
         }
 
         @Override
         protected Aggregator doCreateInternal(ValuesSource.GeoPoint valuesSource, AggregationContext aggregationContext,
-                Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
-            return new GeoBoundsAggregator(name, aggregationContext, parent, valuesSource, wrapLongitude, metaData);
+ Aggregator parent,
+                boolean collectsFromSingleBucket, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+            return new GeoBoundsAggregator(name, aggregationContext, parent, valuesSource, wrapLongitude, reducers, metaData);
         }
 
     }

src/main/java/org/elasticsearch/search/aggregations/metrics/geobounds/InternalGeoBounds.java

@@ -27,6 +27,7 @@ import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.search.aggregations.AggregationStreams;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.metrics.InternalMetricsAggregation;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 
 import java.io.IOException;
 import java.util.List;
@@ -56,8 +57,9 @@ public class InternalGeoBounds extends InternalMetricsAggregation implements Geo
     }
     
     InternalGeoBounds(String name, double top, double bottom, double posLeft, double posRight,
-            double negLeft, double negRight, boolean wrapLongitude, Map<String, Object> metaData) {
-        super(name, metaData);
+ double negLeft, double negRight,
+            boolean wrapLongitude, List<Reducer> reducers, Map<String, Object> metaData) {
+        super(name, reducers, metaData);
         this.top = top;
         this.bottom = bottom;
         this.posLeft = posLeft;
@@ -103,7 +105,7 @@ public class InternalGeoBounds extends InternalMetricsAggregation implements Geo
                 negRight = bounds.negRight;
             }
         }
-        return new InternalGeoBounds(name, top, bottom, posLeft, posRight, negLeft, negRight, wrapLongitude, getMetaData());
+        return new InternalGeoBounds(name, top, bottom, posLeft, posRight, negLeft, negRight, wrapLongitude, reducers(), getMetaData());
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/metrics/max/InternalMax.java

@@ -25,10 +25,12 @@ import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.search.aggregations.AggregationStreams;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.metrics.InternalNumericMetricsAggregation;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatterStreams;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -55,8 +57,8 @@ public class InternalMax extends InternalNumericMetricsAggregation.SingleValue i
 
     InternalMax() {} // for serialization
 
-    public InternalMax(String name, double max, @Nullable ValueFormatter formatter, Map<String, Object> metaData) {
-        super(name, metaData);
+    public InternalMax(String name, double max, @Nullable ValueFormatter formatter, List<Reducer> reducers, Map<String, Object> metaData) {
+        super(name, reducers, metaData);
         this.valueFormatter = formatter;
         this.max = max;
     }
@@ -81,7 +83,7 @@ public class InternalMax extends InternalNumericMetricsAggregation.SingleValue i
         for (InternalAggregation aggregation : reduceContext.aggregations()) {
             max = Math.max(max, ((InternalMax) aggregation).max);
         }
-        return new InternalMax(name, max, valueFormatter, getMetaData());
+        return new InternalMax(name, max, valueFormatter, reducers(), getMetaData());
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/metrics/max/MaxAggregator.java

@@ -31,6 +31,7 @@ import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
 import org.elasticsearch.search.aggregations.metrics.NumericMetricsAggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
@@ -38,6 +39,7 @@ import org.elasticsearch.search.aggregations.support.ValuesSourceConfig;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -51,8 +53,9 @@ public class MaxAggregator extends NumericMetricsAggregator.SingleValue {
     DoubleArray maxes;
 
     public MaxAggregator(String name, ValuesSource.Numeric valuesSource, @Nullable ValueFormatter formatter,
-            AggregationContext context, Aggregator parent, Map<String, Object> metaData) throws IOException {
-        super(name, context, parent, metaData);
+ AggregationContext context,
+            Aggregator parent, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+        super(name, context, parent, reducers, metaData);
         this.valuesSource = valuesSource;
         this.formatter = formatter;
         if (valuesSource != null) {
@@ -71,22 +74,22 @@ public class MaxAggregator extends NumericMetricsAggregator.SingleValue {
             final LeafBucketCollector sub) throws IOException {
         if (valuesSource == null) {
             return LeafBucketCollector.NO_OP_COLLECTOR;
-        }
+    }
         final BigArrays bigArrays = context.bigArrays();
         final SortedNumericDoubleValues allValues = valuesSource.doubleValues(ctx);
         final NumericDoubleValues values = MultiValueMode.MAX.select(allValues, Double.NEGATIVE_INFINITY);
         return new LeafBucketCollectorBase(sub, allValues) {
 
-            @Override
+    @Override
             public void collect(int doc, long bucket) throws IOException {
                 if (bucket >= maxes.size()) {
-                    long from = maxes.size();
+            long from = maxes.size();
                     maxes = bigArrays.grow(maxes, bucket + 1);
-                    maxes.fill(from, maxes.size(), Double.NEGATIVE_INFINITY);
-                }
-                final double value = values.get(doc);
+            maxes.fill(from, maxes.size(), Double.NEGATIVE_INFINITY);
+        }
+        final double value = values.get(doc);
                 double max = maxes.get(bucket);
-                max = Math.max(max, value);
+        max = Math.max(max, value);
                 maxes.set(bucket, max);
             }
 
@@ -103,12 +106,12 @@ public class MaxAggregator extends NumericMetricsAggregator.SingleValue {
         if (valuesSource == null || bucket >= maxes.size()) {
             return buildEmptyAggregation();
         }
-        return new InternalMax(name, maxes.get(bucket), formatter, metaData());
+        return new InternalMax(name, maxes.get(bucket), formatter, reducers(),  metaData());
     }
 
     @Override
     public InternalAggregation buildEmptyAggregation() {
-        return new InternalMax(name, Double.NEGATIVE_INFINITY, formatter, metaData());
+        return new InternalMax(name, Double.NEGATIVE_INFINITY, formatter, reducers(), metaData());
     }
 
     public static class Factory extends ValuesSourceAggregatorFactory.LeafOnly<ValuesSource.Numeric> {
@@ -118,13 +121,15 @@ public class MaxAggregator extends NumericMetricsAggregator.SingleValue {
         }
 
         @Override
-        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
-            return new MaxAggregator(name, null, config.formatter(), aggregationContext, parent, metaData);
+        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, List<Reducer> reducers,
+                Map<String, Object> metaData) throws IOException {
+            return new MaxAggregator(name, null, config.formatter(), aggregationContext, parent, reducers, metaData);
         }
 
         @Override
-        protected Aggregator doCreateInternal(ValuesSource.Numeric valuesSource, AggregationContext aggregationContext, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
-            return new MaxAggregator(name, valuesSource, config.formatter(), aggregationContext, parent, metaData);
+        protected Aggregator doCreateInternal(ValuesSource.Numeric valuesSource, AggregationContext aggregationContext, Aggregator parent,
+                boolean collectsFromSingleBucket, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+            return new MaxAggregator(name, valuesSource, config.formatter(), aggregationContext, parent, reducers, metaData);
         }
     }
 

src/main/java/org/elasticsearch/search/aggregations/metrics/min/InternalMin.java

@@ -25,10 +25,12 @@ import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.search.aggregations.AggregationStreams;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.metrics.InternalNumericMetricsAggregation;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatterStreams;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -56,8 +58,8 @@ public class InternalMin extends InternalNumericMetricsAggregation.SingleValue i
 
     InternalMin() {} // for serialization
 
-    public InternalMin(String name, double min, @Nullable ValueFormatter formatter, Map<String, Object> metaData) {
-        super(name, metaData);
+    public InternalMin(String name, double min, @Nullable ValueFormatter formatter, List<Reducer> reducers, Map<String, Object> metaData) {
+        super(name, reducers, metaData);
         this.min = min;
         this.valueFormatter = formatter;
     }
@@ -82,7 +84,7 @@ public class InternalMin extends InternalNumericMetricsAggregation.SingleValue i
         for (InternalAggregation aggregation : reduceContext.aggregations()) {
             min = Math.min(min, ((InternalMin) aggregation).min);
         }
-        return new InternalMin(getName(), min, this.valueFormatter, getMetaData());
+        return new InternalMin(getName(), min, this.valueFormatter, reducers(), getMetaData());
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/metrics/min/MinAggregator.java

@@ -31,6 +31,7 @@ import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
 import org.elasticsearch.search.aggregations.metrics.NumericMetricsAggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
@@ -38,6 +39,7 @@ import org.elasticsearch.search.aggregations.support.ValuesSourceConfig;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -51,8 +53,9 @@ public class MinAggregator extends NumericMetricsAggregator.SingleValue {
     DoubleArray mins;
 
     public MinAggregator(String name, ValuesSource.Numeric valuesSource, @Nullable ValueFormatter formatter,
-            AggregationContext context, Aggregator parent, Map<String, Object> metaData) throws IOException {
-        super(name, context, parent, metaData);
+ AggregationContext context,
+            Aggregator parent, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+        super(name, context, parent, reducers, metaData);
         this.valuesSource = valuesSource;
         if (valuesSource != null) {
             mins = context.bigArrays().newDoubleArray(1, false);
@@ -71,22 +74,22 @@ public class MinAggregator extends NumericMetricsAggregator.SingleValue {
             final LeafBucketCollector sub) throws IOException {
         if (valuesSource == null) {
             return LeafBucketCollector.NO_OP_COLLECTOR;
-        }
+    }
         final BigArrays bigArrays = context.bigArrays();
         final SortedNumericDoubleValues allValues = valuesSource.doubleValues(ctx);
         final NumericDoubleValues values = MultiValueMode.MIN.select(allValues, Double.POSITIVE_INFINITY);
         return new LeafBucketCollectorBase(sub, allValues) {
 
-            @Override
+    @Override
             public void collect(int doc, long bucket) throws IOException {
                 if (bucket >= mins.size()) {
-                    long from = mins.size();
+            long from = mins.size();
                     mins = bigArrays.grow(mins, bucket + 1);
-                    mins.fill(from, mins.size(), Double.POSITIVE_INFINITY);
-                }
-                final double value = values.get(doc);
+            mins.fill(from, mins.size(), Double.POSITIVE_INFINITY);
+        }
+        final double value = values.get(doc);
                 double min = mins.get(bucket);
-                min = Math.min(min, value);
+        min = Math.min(min, value);
                 mins.set(bucket, min);
             }
 
@@ -103,12 +106,12 @@ public class MinAggregator extends NumericMetricsAggregator.SingleValue {
         if (valuesSource == null || bucket >= mins.size()) {
             return buildEmptyAggregation();
         }
-        return new InternalMin(name, mins.get(bucket), formatter, metaData());
+        return new InternalMin(name, mins.get(bucket), formatter, reducers(), metaData());
     }
 
     @Override
     public InternalAggregation buildEmptyAggregation() {
-        return new InternalMin(name, Double.POSITIVE_INFINITY, formatter, metaData());
+        return new InternalMin(name, Double.POSITIVE_INFINITY, formatter, reducers(), metaData());
     }
 
     public static class Factory extends ValuesSourceAggregatorFactory.LeafOnly<ValuesSource.Numeric> {
@@ -118,13 +121,15 @@ public class MinAggregator extends NumericMetricsAggregator.SingleValue {
         }
 
         @Override
-        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
-            return new MinAggregator(name, null, config.formatter(), aggregationContext, parent, metaData);
+        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, List<Reducer> reducers,
+                Map<String, Object> metaData) throws IOException {
+            return new MinAggregator(name, null, config.formatter(), aggregationContext, parent, reducers, metaData);
         }
 
         @Override
-        protected Aggregator doCreateInternal(ValuesSource.Numeric valuesSource, AggregationContext aggregationContext, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
-            return new MinAggregator(name, valuesSource, config.formatter(), aggregationContext, parent, metaData);
+        protected Aggregator doCreateInternal(ValuesSource.Numeric valuesSource, AggregationContext aggregationContext, Aggregator parent,
+                boolean collectsFromSingleBucket, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+            return new MinAggregator(name, valuesSource, config.formatter(), aggregationContext, parent, reducers, metaData);
         }
     }
 

src/main/java/org/elasticsearch/search/aggregations/metrics/percentiles/AbstractInternalPercentiles.java

@@ -28,6 +28,7 @@ import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.metrics.InternalNumericMetricsAggregation;
 import org.elasticsearch.search.aggregations.metrics.percentiles.tdigest.TDigestState;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatterStreams;
 
@@ -44,8 +45,9 @@ abstract class AbstractInternalPercentiles extends InternalNumericMetricsAggrega
     AbstractInternalPercentiles() {} // for serialization
 
     public AbstractInternalPercentiles(String name, double[] keys, TDigestState state, boolean keyed, @Nullable ValueFormatter formatter,
+            List<Reducer> reducers,
             Map<String, Object> metaData) {
-        super(name, metaData);
+        super(name, reducers, metaData);
         this.keys = keys;
         this.state = state;
         this.keyed = keyed;
@@ -70,10 +72,11 @@ abstract class AbstractInternalPercentiles extends InternalNumericMetricsAggrega
             }
             merged.add(percentiles.state);
         }
-        return createReduced(getName(), keys, merged, keyed, getMetaData());
+        return createReduced(getName(), keys, merged, keyed, reducers(), getMetaData());
     }
 
-    protected abstract AbstractInternalPercentiles createReduced(String name, double[] keys, TDigestState merged, boolean keyed, Map<String, Object> metaData);
+    protected abstract AbstractInternalPercentiles createReduced(String name, double[] keys, TDigestState merged, boolean keyed,
+            List<Reducer> reducers, Map<String, Object> metaData);
 
     @Override
     protected void doReadFrom(StreamInput in) throws IOException {

src/main/java/org/elasticsearch/search/aggregations/metrics/percentiles/AbstractPercentilesAggregator.java

@@ -31,11 +31,13 @@ import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.metrics.NumericMetricsAggregator;
 import org.elasticsearch.search.aggregations.metrics.percentiles.tdigest.TDigestState;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 public abstract class AbstractPercentilesAggregator extends NumericMetricsAggregator.MultiValue {
@@ -53,8 +55,9 @@ public abstract class AbstractPercentilesAggregator extends NumericMetricsAggreg
 
     public AbstractPercentilesAggregator(String name, ValuesSource.Numeric valuesSource, AggregationContext context,
                                  Aggregator parent, double[] keys, double compression, boolean keyed,
-                                 @Nullable ValueFormatter formatter, Map<String, Object> metaData) throws IOException {
-        super(name, context, parent, metaData);
+ @Nullable ValueFormatter formatter, List<Reducer> reducers,
+            Map<String, Object> metaData) throws IOException {
+        super(name, context, parent, reducers, metaData);
         this.valuesSource = valuesSource;
         this.keyed = keyed;
         this.formatter = formatter;

src/main/java/org/elasticsearch/search/aggregations/metrics/percentiles/InternalPercentileRanks.java

@@ -24,10 +24,12 @@ import org.elasticsearch.common.inject.internal.Nullable;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.search.aggregations.AggregationStreams;
 import org.elasticsearch.search.aggregations.metrics.percentiles.tdigest.TDigestState;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 
 import java.io.IOException;
 import java.util.Iterator;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -53,8 +55,9 @@ public class InternalPercentileRanks extends AbstractInternalPercentiles impleme
     InternalPercentileRanks() {} // for serialization
 
     public InternalPercentileRanks(String name, double[] cdfValues, TDigestState state, boolean keyed, @Nullable ValueFormatter formatter,
+            List<Reducer> reducers,
             Map<String, Object> metaData) {
-        super(name, cdfValues, state, keyed, formatter, metaData);
+        super(name, cdfValues, state, keyed, formatter, reducers, metaData);
     }
 
     @Override
@@ -77,8 +80,9 @@ public class InternalPercentileRanks extends AbstractInternalPercentiles impleme
         return percent(key);
     }
 
-    protected AbstractInternalPercentiles createReduced(String name, double[] keys, TDigestState merged, boolean keyed, Map<String, Object> metaData) {
-        return new InternalPercentileRanks(name, keys, merged, keyed, valueFormatter, metaData);
+    protected AbstractInternalPercentiles createReduced(String name, double[] keys, TDigestState merged, boolean keyed,
+            List<Reducer> reducers, Map<String, Object> metaData) {
+        return new InternalPercentileRanks(name, keys, merged, keyed, valueFormatter, reducers, metaData);
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/metrics/percentiles/InternalPercentiles.java

@@ -24,10 +24,12 @@ import org.elasticsearch.common.inject.internal.Nullable;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.search.aggregations.AggregationStreams;
 import org.elasticsearch.search.aggregations.metrics.percentiles.tdigest.TDigestState;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 
 import java.io.IOException;
 import java.util.Iterator;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -53,8 +55,9 @@ public class InternalPercentiles extends AbstractInternalPercentiles implements
     InternalPercentiles() {} // for serialization
 
     public InternalPercentiles(String name, double[] percents, TDigestState state, boolean keyed, @Nullable ValueFormatter formatter,
+            List<Reducer> reducers,
             Map<String, Object> metaData) {
-        super(name, percents, state, keyed, formatter, metaData);
+        super(name, percents, state, keyed, formatter, reducers, metaData);
     }
 
     @Override
@@ -77,8 +80,9 @@ public class InternalPercentiles extends AbstractInternalPercentiles implements
         return percentile(key);
     }
 
-    protected AbstractInternalPercentiles createReduced(String name, double[] keys, TDigestState merged, boolean keyed, Map<String, Object> metaData) {
-        return new InternalPercentiles(name, keys, merged, keyed, valueFormatter, metaData);
+    protected AbstractInternalPercentiles createReduced(String name, double[] keys, TDigestState merged, boolean keyed,
+            List<Reducer> reducers, Map<String, Object> metaData) {
+        return new InternalPercentiles(name, keys, merged, keyed, valueFormatter, reducers, metaData);
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/metrics/percentiles/PercentileRanksAggregator.java

@@ -22,6 +22,7 @@ import org.elasticsearch.common.inject.internal.Nullable;
 import org.elasticsearch.search.aggregations.Aggregator;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.metrics.percentiles.tdigest.TDigestState;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSource.Numeric;
@@ -30,6 +31,7 @@ import org.elasticsearch.search.aggregations.support.ValuesSourceConfig;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -37,10 +39,10 @@ import java.util.Map;
  */
 public class PercentileRanksAggregator extends AbstractPercentilesAggregator {
 
-    public PercentileRanksAggregator(String name, Numeric valuesSource, AggregationContext context,
-            Aggregator parent, double[] percents, double compression, boolean keyed, @Nullable ValueFormatter formatter,
-            Map<String, Object> metaData) throws IOException {
-        super(name, valuesSource, context, parent, percents, compression, keyed, formatter, metaData);
+    public PercentileRanksAggregator(String name, Numeric valuesSource, AggregationContext context, Aggregator parent, double[] percents,
+            double compression, boolean keyed, @Nullable ValueFormatter formatter, List<Reducer> reducers, Map<String, Object> metaData)
+            throws IOException {
+        super(name, valuesSource, context, parent, percents, compression, keyed, formatter, reducers, metaData);
     }
 
     @Override
@@ -49,13 +51,13 @@ public class PercentileRanksAggregator extends AbstractPercentilesAggregator {
         if (state == null) {
             return buildEmptyAggregation();
         } else {
-            return new InternalPercentileRanks(name, keys, state, keyed, formatter, metaData());
+            return new InternalPercentileRanks(name, keys, state, keyed, formatter, reducers(), metaData());
         }
     }
 
     @Override
     public InternalAggregation buildEmptyAggregation() {
-        return new InternalPercentileRanks(name, keys, new TDigestState(compression), keyed, formatter, metaData());
+        return new InternalPercentileRanks(name, keys, new TDigestState(compression), keyed, formatter, reducers(), metaData());
     }
 
     @Override
@@ -83,15 +85,19 @@ public class PercentileRanksAggregator extends AbstractPercentilesAggregator {
         }
 
         @Override
-        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
+        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, List<Reducer> reducers,
+                Map<String, Object> metaData) throws IOException {
             return new PercentileRanksAggregator(name, null, aggregationContext, parent, values, compression, keyed, config.formatter(),
+                    reducers,
                     metaData);
         }
 
         @Override
-        protected Aggregator doCreateInternal(ValuesSource.Numeric valuesSource, AggregationContext aggregationContext, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
+        protected Aggregator doCreateInternal(ValuesSource.Numeric valuesSource, AggregationContext aggregationContext, Aggregator parent,
+                boolean collectsFromSingleBucket, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
             return new PercentileRanksAggregator(name, valuesSource, aggregationContext, parent, values, compression,
-                    keyed, config.formatter(), metaData);
+ keyed,
+                    config.formatter(), reducers, metaData);
         }
     }
 }

src/main/java/org/elasticsearch/search/aggregations/metrics/percentiles/PercentilesAggregator.java

@@ -22,6 +22,7 @@ import org.elasticsearch.common.inject.internal.Nullable;
 import org.elasticsearch.search.aggregations.Aggregator;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.metrics.percentiles.tdigest.TDigestState;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSource.Numeric;
@@ -30,6 +31,7 @@ import org.elasticsearch.search.aggregations.support.ValuesSourceConfig;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -38,9 +40,10 @@ import java.util.Map;
 public class PercentilesAggregator extends AbstractPercentilesAggregator {
 
     public PercentilesAggregator(String name, Numeric valuesSource, AggregationContext context,
-            Aggregator parent, double[] percents, double compression, boolean keyed, @Nullable ValueFormatter formatter,
+ Aggregator parent, double[] percents,
+            double compression, boolean keyed, @Nullable ValueFormatter formatter, List<Reducer> reducers,
             Map<String, Object> metaData) throws IOException {
-        super(name, valuesSource, context, parent, percents, compression, keyed, formatter, metaData);
+        super(name, valuesSource, context, parent, percents, compression, keyed, formatter, reducers, metaData);
     }
 
     @Override
@@ -49,7 +52,7 @@ public class PercentilesAggregator extends AbstractPercentilesAggregator {
         if (state == null) {
             return buildEmptyAggregation();
         } else {
-            return new InternalPercentiles(name, keys, state, keyed, formatter, metaData());
+            return new InternalPercentiles(name, keys, state, keyed, formatter, reducers(), metaData());
         }
     }
     
@@ -65,7 +68,7 @@ public class PercentilesAggregator extends AbstractPercentilesAggregator {
 
     @Override
     public InternalAggregation buildEmptyAggregation() {
-        return new InternalPercentiles(name, keys, new TDigestState(compression), keyed, formatter, metaData());
+        return new InternalPercentiles(name, keys, new TDigestState(compression), keyed, formatter, reducers(), metaData());
     }
 
     public static class Factory extends ValuesSourceAggregatorFactory.LeafOnly<ValuesSource.Numeric> {
@@ -83,15 +86,19 @@ public class PercentilesAggregator extends AbstractPercentilesAggregator {
         }
 
         @Override
-        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
+        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, List<Reducer> reducers,
+                Map<String, Object> metaData) throws IOException {
             return new PercentilesAggregator(name, null, aggregationContext, parent, percents, compression, keyed, config.formatter(),
+                    reducers,
                     metaData);
         }
 
         @Override
-        protected Aggregator doCreateInternal(ValuesSource.Numeric valuesSource, AggregationContext aggregationContext, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
+        protected Aggregator doCreateInternal(ValuesSource.Numeric valuesSource, AggregationContext aggregationContext, Aggregator parent,
+                boolean collectsFromSingleBucket, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
             return new PercentilesAggregator(name, valuesSource, aggregationContext, parent, percents, compression,
-                    keyed, config.formatter(), metaData);
+ keyed,
+                    config.formatter(), reducers, metaData);
         }
     }
 }

src/main/java/org/elasticsearch/search/aggregations/metrics/scripted/InternalScriptedMetric.java

@@ -28,6 +28,7 @@ import org.elasticsearch.script.ScriptService.ScriptType;
 import org.elasticsearch.search.aggregations.AggregationStreams;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.metrics.InternalMetricsAggregation;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -61,13 +62,13 @@ public class InternalScriptedMetric extends InternalMetricsAggregation implement
     private InternalScriptedMetric() {
     }
 
-    private InternalScriptedMetric(String name, Map<String, Object> metaData) {
-        super(name, metaData);
+    private InternalScriptedMetric(String name, List<Reducer> reducers, Map<String, Object> metaData) {
+        super(name, reducers, metaData);
     }
 
     public InternalScriptedMetric(String name, Object aggregation, String scriptLang, ScriptType scriptType, String reduceScript,
-            Map<String, Object> reduceParams, Map<String, Object> metaData) {
-        this(name, metaData);
+            Map<String, Object> reduceParams, List<Reducer> reducers, Map<String, Object> metaData) {
+        this(name, reducers, metaData);
         this.aggregation = aggregation;
         this.scriptType = scriptType;
         this.reduceScript = reduceScript;
@@ -104,7 +105,7 @@ public class InternalScriptedMetric extends InternalMetricsAggregation implement
             aggregation = aggregationObjects;
         }
         return new InternalScriptedMetric(firstAggregation.getName(), aggregation, firstAggregation.scriptLang, firstAggregation.scriptType,
-                firstAggregation.reduceScript, firstAggregation.reduceParams, getMetaData());
+ firstAggregation.reduceScript, firstAggregation.reduceParams, reducers(), getMetaData());
 
     }
 

src/main/java/org/elasticsearch/search/aggregations/metrics/scripted/ScriptedMetricAggregator.java

@@ -31,6 +31,7 @@ import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.metrics.MetricsAggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.internal.SearchContext;
 
@@ -57,8 +58,9 @@ public class ScriptedMetricAggregator extends MetricsAggregator {
 
     protected ScriptedMetricAggregator(String name, String scriptLang, ScriptType initScriptType, String initScript,
             ScriptType mapScriptType, String mapScript, ScriptType combineScriptType, String combineScript, ScriptType reduceScriptType,
-            String reduceScript, Map<String, Object> params, Map<String, Object> reduceParams, AggregationContext context, Aggregator parent, Map<String, Object> metaData) throws IOException {
-        super(name, context, parent, metaData);
+            String reduceScript, Map<String, Object> params, Map<String, Object> reduceParams, AggregationContext context,
+            Aggregator parent, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+        super(name, context, parent, reducers, metaData);
         this.scriptService = context.searchContext().scriptService();
         this.scriptLang = scriptLang;
         this.reduceScriptType = reduceScriptType;
@@ -112,12 +114,13 @@ public class ScriptedMetricAggregator extends MetricsAggregator {
         } else {
             aggregation = params.get("_agg");
         }
-        return new InternalScriptedMetric(name, aggregation, scriptLang, reduceScriptType, reduceScript, reduceParams, metaData());
+        return new InternalScriptedMetric(name, aggregation, scriptLang, reduceScriptType, reduceScript, reduceParams, reducers(),
+                metaData());
     }
 
     @Override
     public InternalAggregation buildEmptyAggregation() {
-        return new InternalScriptedMetric(name, null, scriptLang, reduceScriptType, reduceScript, reduceParams, metaData());
+        return new InternalScriptedMetric(name, null, scriptLang, reduceScriptType, reduceScript, reduceParams, reducers(), metaData());
     }
 
     public static class Factory extends AggregatorFactory {
@@ -151,7 +154,8 @@ public class ScriptedMetricAggregator extends MetricsAggregator {
         }
 
         @Override
-        public Aggregator createInternal(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
+        public Aggregator createInternal(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket,
+                List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
             if (collectsFromSingleBucket == false) {
                 return asMultiBucketAggregator(this, context, parent);
             }
@@ -164,7 +168,7 @@ public class ScriptedMetricAggregator extends MetricsAggregator {
                 reduceParams = deepCopyParams(this.reduceParams, context.searchContext());
             }
             return new ScriptedMetricAggregator(name, scriptLang, initScriptType, initScript, mapScriptType, mapScript, combineScriptType,
-                    combineScript, reduceScriptType, reduceScript, params, reduceParams, context, parent, metaData);
+                    combineScript, reduceScriptType, reduceScript, params, reduceParams, context, parent, reducers, metaData);
         }
         
         @SuppressWarnings({ "unchecked" })

src/main/java/org/elasticsearch/search/aggregations/metrics/stats/InternalStats.java

@@ -26,10 +26,12 @@ import org.elasticsearch.common.xcontent.XContentBuilderString;
 import org.elasticsearch.search.aggregations.AggregationStreams;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.metrics.InternalNumericMetricsAggregation;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatterStreams;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -69,8 +71,9 @@ public class InternalStats extends InternalNumericMetricsAggregation.MultiValue
     protected InternalStats() {} // for serialization
 
     public InternalStats(String name, long count, double sum, double min, double max, @Nullable ValueFormatter formatter,
+            List<Reducer> reducers,
             Map<String, Object> metaData) {
-        super(name, metaData);
+        super(name, reducers, metaData);
         this.count = count;
         this.sum = sum;
         this.min = min;
@@ -160,7 +163,7 @@ public class InternalStats extends InternalNumericMetricsAggregation.MultiValue
             max = Math.max(max, stats.getMax());
             sum += stats.getSum();
         }
-        return new InternalStats(name, count, sum, min, max, valueFormatter, getMetaData());
+        return new InternalStats(name, count, sum, min, max, valueFormatter, reducers(), getMetaData());
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/metrics/stats/StatsAggegator.java

@@ -31,6 +31,7 @@ import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
 import org.elasticsearch.search.aggregations.metrics.NumericMetricsAggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
@@ -38,6 +39,7 @@ import org.elasticsearch.search.aggregations.support.ValuesSourceConfig;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -55,8 +57,9 @@ public class StatsAggegator extends NumericMetricsAggregator.MultiValue {
 
 
     public StatsAggegator(String name, ValuesSource.Numeric valuesSource, @Nullable ValueFormatter formatter,
-            AggregationContext context, Aggregator parent, Map<String, Object> metaData) throws IOException {
-        super(name, context, parent, metaData);
+ AggregationContext context,
+            Aggregator parent, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+        super(name, context, parent, reducers, metaData);
         this.valuesSource = valuesSource;
         if (valuesSource != null) {
             final BigArrays bigArrays = context.bigArrays();
@@ -80,35 +83,35 @@ public class StatsAggegator extends NumericMetricsAggregator.MultiValue {
             final LeafBucketCollector sub) throws IOException {
         if (valuesSource == null) {
             return LeafBucketCollector.NO_OP_COLLECTOR;
-        }
+    }
         final BigArrays bigArrays = context.bigArrays();
         final SortedNumericDoubleValues values = valuesSource.doubleValues(ctx);
         return new LeafBucketCollectorBase(sub, values) {
-            @Override
+    @Override
             public void collect(int doc, long bucket) throws IOException {
                 if (bucket >= counts.size()) {
-                    final long from = counts.size();
+            final long from = counts.size();
                     final long overSize = BigArrays.overSize(bucket + 1);
-                    counts = bigArrays.resize(counts, overSize);
-                    sums = bigArrays.resize(sums, overSize);
-                    mins = bigArrays.resize(mins, overSize);
-                    maxes = bigArrays.resize(maxes, overSize);
-                    mins.fill(from, overSize, Double.POSITIVE_INFINITY);
-                    maxes.fill(from, overSize, Double.NEGATIVE_INFINITY);
-                }
+            counts = bigArrays.resize(counts, overSize);
+            sums = bigArrays.resize(sums, overSize);
+            mins = bigArrays.resize(mins, overSize);
+            maxes = bigArrays.resize(maxes, overSize);
+            mins.fill(from, overSize, Double.POSITIVE_INFINITY);
+            maxes.fill(from, overSize, Double.NEGATIVE_INFINITY);
+        }
 
-                values.setDocument(doc);
-                final int valuesCount = values.count();
+        values.setDocument(doc);
+        final int valuesCount = values.count();
                 counts.increment(bucket, valuesCount);
-                double sum = 0;
+        double sum = 0;
                 double min = mins.get(bucket);
                 double max = maxes.get(bucket);
-                for (int i = 0; i < valuesCount; i++) {
-                    double value = values.valueAt(i);
-                    sum += value;
-                    min = Math.min(min, value);
-                    max = Math.max(max, value);
-                }
+        for (int i = 0; i < valuesCount; i++) {
+            double value = values.valueAt(i);
+            sum += value;
+            min = Math.min(min, value);
+            max = Math.max(max, value);
+        }
                 sums.increment(bucket, sum);
                 mins.set(bucket, min);
                 maxes.set(bucket, max);
@@ -145,12 +148,12 @@ public class StatsAggegator extends NumericMetricsAggregator.MultiValue {
             return buildEmptyAggregation();
         }
         return new InternalStats(name, counts.get(bucket), sums.get(bucket), mins.get(bucket),
-                maxes.get(bucket), formatter, metaData());
+                maxes.get(bucket), formatter, reducers(), metaData());
     }
 
     @Override
     public InternalAggregation buildEmptyAggregation() {
-        return new InternalStats(name, 0, 0, Double.POSITIVE_INFINITY, Double.NEGATIVE_INFINITY, formatter, metaData());
+        return new InternalStats(name, 0, 0, Double.POSITIVE_INFINITY, Double.NEGATIVE_INFINITY, formatter, reducers(), metaData());
     }
 
     public static class Factory extends ValuesSourceAggregatorFactory.LeafOnly<ValuesSource.Numeric> {
@@ -160,13 +163,15 @@ public class StatsAggegator extends NumericMetricsAggregator.MultiValue {
         }
 
         @Override
-        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
-            return new StatsAggegator(name, null, config.formatter(), aggregationContext, parent, metaData);
+        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, List<Reducer> reducers,
+                Map<String, Object> metaData) throws IOException {
+            return new StatsAggegator(name, null, config.formatter(), aggregationContext, parent, reducers, metaData);
         }
 
         @Override
-        protected Aggregator doCreateInternal(ValuesSource.Numeric valuesSource, AggregationContext aggregationContext, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
-            return new StatsAggegator(name, valuesSource, config.formatter(), aggregationContext, parent, metaData);
+        protected Aggregator doCreateInternal(ValuesSource.Numeric valuesSource, AggregationContext aggregationContext, Aggregator parent,
+                boolean collectsFromSingleBucket, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+            return new StatsAggegator(name, valuesSource, config.formatter(), aggregationContext, parent, reducers, metaData);
         }
     }
 

src/main/java/org/elasticsearch/search/aggregations/metrics/stats/extended/ExtendedStatsAggregator.java

@@ -31,6 +31,7 @@ import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
 import org.elasticsearch.search.aggregations.metrics.NumericMetricsAggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
@@ -38,6 +39,7 @@ import org.elasticsearch.search.aggregations.support.ValuesSourceConfig;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -55,10 +57,10 @@ public class ExtendedStatsAggregator extends NumericMetricsAggregator.MultiValue
     DoubleArray maxes;
     DoubleArray sumOfSqrs;
 
-    public ExtendedStatsAggregator(String name, ValuesSource.Numeric valuesSource,
-                                   @Nullable ValueFormatter formatter, AggregationContext context,
-                                   Aggregator parent, double sigma, Map<String, Object> metaData) throws IOException {
-        super(name, context, parent, metaData);
+    public ExtendedStatsAggregator(String name, ValuesSource.Numeric valuesSource, @Nullable ValueFormatter formatter,
+            AggregationContext context, Aggregator parent, double sigma, List<Reducer> reducers, Map<String, Object> metaData)
+            throws IOException {
+        super(name, context, parent, reducers, metaData);
         this.valuesSource = valuesSource;
         this.formatter = formatter;
         this.sigma = sigma;
@@ -167,16 +169,19 @@ public class ExtendedStatsAggregator extends NumericMetricsAggregator.MultiValue
     @Override
     public InternalAggregation buildAggregation(long owningBucketOrdinal) {
         if (valuesSource == null) {
-            return new InternalExtendedStats(name, 0, 0d, Double.POSITIVE_INFINITY, Double.NEGATIVE_INFINITY, 0d, 0d, formatter, metaData());
+            return new InternalExtendedStats(name, 0, 0d, Double.POSITIVE_INFINITY, Double.NEGATIVE_INFINITY, 0d, 0d, formatter,
+                    reducers(), metaData());
         }
         assert owningBucketOrdinal < counts.size();
         return new InternalExtendedStats(name, counts.get(owningBucketOrdinal), sums.get(owningBucketOrdinal),
-                mins.get(owningBucketOrdinal), maxes.get(owningBucketOrdinal), sumOfSqrs.get(owningBucketOrdinal), sigma, formatter, metaData());
+                mins.get(owningBucketOrdinal), maxes.get(owningBucketOrdinal), sumOfSqrs.get(owningBucketOrdinal), sigma, formatter,
+                reducers(), metaData());
     }
 
     @Override
     public InternalAggregation buildEmptyAggregation() {
-        return new InternalExtendedStats(name, 0, 0d, Double.POSITIVE_INFINITY, Double.NEGATIVE_INFINITY, 0d, 0d, formatter, metaData());
+        return new InternalExtendedStats(name, 0, 0d, Double.POSITIVE_INFINITY, Double.NEGATIVE_INFINITY, 0d, 0d, formatter, reducers(),
+                metaData());
     }
 
     @Override
@@ -195,13 +200,16 @@ public class ExtendedStatsAggregator extends NumericMetricsAggregator.MultiValue
         }
 
         @Override
-        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
-            return new ExtendedStatsAggregator(name, null, config.formatter(), aggregationContext, parent, sigma, metaData);
+        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, List<Reducer> reducers,
+                Map<String, Object> metaData) throws IOException {
+            return new ExtendedStatsAggregator(name, null, config.formatter(), aggregationContext, parent, sigma, reducers, metaData);
         }
 
         @Override
-        protected Aggregator doCreateInternal(ValuesSource.Numeric valuesSource, AggregationContext aggregationContext, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
-            return new ExtendedStatsAggregator(name, valuesSource, config.formatter(), aggregationContext, parent, sigma, metaData);
+        protected Aggregator doCreateInternal(ValuesSource.Numeric valuesSource, AggregationContext aggregationContext, Aggregator parent,
+                boolean collectsFromSingleBucket, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+            return new ExtendedStatsAggregator(name, valuesSource, config.formatter(), aggregationContext, parent, sigma, reducers,
+                    metaData);
         }
     }
 }

src/main/java/org/elasticsearch/search/aggregations/metrics/stats/extended/InternalExtendedStats.java

@@ -27,9 +27,11 @@ import org.elasticsearch.common.xcontent.XContentBuilderString;
 import org.elasticsearch.search.aggregations.AggregationStreams;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.metrics.stats.InternalStats;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -67,8 +69,9 @@ public class InternalExtendedStats extends InternalStats implements ExtendedStat
     InternalExtendedStats() {} // for serialization
 
     public InternalExtendedStats(String name, long count, double sum, double min, double max, double sumOfSqrs,
-            double sigma, @Nullable ValueFormatter formatter, Map<String, Object> metaData) {
-        super(name, count, sum, min, max, formatter, metaData);
+ double sigma,
+            @Nullable ValueFormatter formatter, List<Reducer> reducers, Map<String, Object> metaData) {
+        super(name, count, sum, min, max, formatter, reducers, metaData);
         this.sumOfSqrs = sumOfSqrs;
         this.sigma = sigma;
     }
@@ -150,7 +153,8 @@ public class InternalExtendedStats extends InternalStats implements ExtendedStat
             sumOfSqrs += stats.getSumOfSquares();
         }
         final InternalStats stats = super.doReduce(reduceContext);
-        return new InternalExtendedStats(name, stats.getCount(), stats.getSum(), stats.getMin(), stats.getMax(), sumOfSqrs, sigma, valueFormatter, getMetaData());
+        return new InternalExtendedStats(name, stats.getCount(), stats.getSum(), stats.getMin(), stats.getMax(), sumOfSqrs, sigma,
+                valueFormatter, reducers(), getMetaData());
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/metrics/sum/InternalSum.java

@@ -25,10 +25,12 @@ import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.search.aggregations.AggregationStreams;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.metrics.InternalNumericMetricsAggregation;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatterStreams;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -55,8 +57,8 @@ public class InternalSum extends InternalNumericMetricsAggregation.SingleValue i
 
     InternalSum() {} // for serialization
 
-    InternalSum(String name, double sum, @Nullable ValueFormatter formatter, Map<String, Object> metaData) {
-        super(name, metaData);
+    InternalSum(String name, double sum, @Nullable ValueFormatter formatter, List<Reducer> reducers, Map<String, Object> metaData) {
+        super(name, reducers, metaData);
         this.sum = sum;
         this.valueFormatter = formatter;
     }
@@ -81,7 +83,7 @@ public class InternalSum extends InternalNumericMetricsAggregation.SingleValue i
         for (InternalAggregation aggregation : reduceContext.aggregations()) {
             sum += ((InternalSum) aggregation).sum;
         }
-        return new InternalSum(name, sum, valueFormatter, getMetaData());
+        return new InternalSum(name, sum, valueFormatter, reducers(), getMetaData());
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/metrics/sum/SumAggregator.java

@@ -29,6 +29,7 @@ import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
 import org.elasticsearch.search.aggregations.metrics.NumericMetricsAggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
@@ -36,6 +37,7 @@ import org.elasticsearch.search.aggregations.support.ValuesSourceConfig;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -49,8 +51,9 @@ public class SumAggregator extends NumericMetricsAggregator.SingleValue {
     DoubleArray sums;
 
     public SumAggregator(String name, ValuesSource.Numeric valuesSource, @Nullable ValueFormatter formatter,
-            AggregationContext context, Aggregator parent, Map<String, Object> metaData) throws IOException {
-        super(name, context, parent, metaData);
+ AggregationContext context,
+            Aggregator parent, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+        super(name, context, parent, reducers, metaData);
         this.valuesSource = valuesSource;
         this.formatter = formatter;
         if (valuesSource != null) {
@@ -68,19 +71,19 @@ public class SumAggregator extends NumericMetricsAggregator.SingleValue {
             final LeafBucketCollector sub) throws IOException {
         if (valuesSource == null) {
             return LeafBucketCollector.NO_OP_COLLECTOR;
-        }
+    }
         final BigArrays bigArrays = context.bigArrays();
         final SortedNumericDoubleValues values = valuesSource.doubleValues(ctx);
         return new LeafBucketCollectorBase(sub, values) {
-            @Override
+    @Override
             public void collect(int doc, long bucket) throws IOException {
                 sums = bigArrays.grow(sums, bucket + 1);
-                values.setDocument(doc);
-                final int valuesCount = values.count();
-                double sum = 0;
-                for (int i = 0; i < valuesCount; i++) {
-                    sum += values.valueAt(i);
-                }
+        values.setDocument(doc);
+        final int valuesCount = values.count();
+        double sum = 0;
+        for (int i = 0; i < valuesCount; i++) {
+            sum += values.valueAt(i);
+        }
                 sums.increment(bucket, sum);
             }
         };
@@ -96,12 +99,12 @@ public class SumAggregator extends NumericMetricsAggregator.SingleValue {
         if (valuesSource == null || bucket >= sums.size()) {
             return buildEmptyAggregation();
         }
-        return new InternalSum(name, sums.get(bucket), formatter, metaData());
+        return new InternalSum(name, sums.get(bucket), formatter, reducers(), metaData());
     }
 
     @Override
     public InternalAggregation buildEmptyAggregation() {
-        return new InternalSum(name, 0.0, formatter, metaData());
+        return new InternalSum(name, 0.0, formatter, reducers(), metaData());
     }
 
     public static class Factory extends ValuesSourceAggregatorFactory.LeafOnly<ValuesSource.Numeric> {
@@ -111,13 +114,15 @@ public class SumAggregator extends NumericMetricsAggregator.SingleValue {
         }
 
         @Override
-        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
-            return new SumAggregator(name, null, config.formatter(), aggregationContext, parent, metaData);
+        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, List<Reducer> reducers,
+                Map<String, Object> metaData) throws IOException {
+            return new SumAggregator(name, null, config.formatter(), aggregationContext, parent, reducers, metaData);
         }
 
         @Override
-        protected Aggregator doCreateInternal(ValuesSource.Numeric valuesSource, AggregationContext aggregationContext, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
-            return new SumAggregator(name, valuesSource, config.formatter(), aggregationContext, parent, metaData);
+        protected Aggregator doCreateInternal(ValuesSource.Numeric valuesSource, AggregationContext aggregationContext, Aggregator parent,
+                boolean collectsFromSingleBucket, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+            return new SumAggregator(name, valuesSource, config.formatter(), aggregationContext, parent, reducers, metaData);
         }
     }
 

src/main/java/org/elasticsearch/search/aggregations/metrics/tophits/TopHitsAggregator.java

@@ -36,10 +36,12 @@ import org.elasticsearch.search.aggregations.AggregationInitializationException;
 import org.elasticsearch.search.aggregations.Aggregator;
 import org.elasticsearch.search.aggregations.AggregatorFactories;
 import org.elasticsearch.search.aggregations.AggregatorFactory;
+import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.metrics.MetricsAggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.fetch.FetchPhase;
 import org.elasticsearch.search.fetch.FetchSearchResult;
@@ -48,6 +50,7 @@ import org.elasticsearch.search.internal.InternalSearchHits;
 import org.elasticsearch.search.internal.SubSearchContext;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -68,8 +71,9 @@ public class TopHitsAggregator extends MetricsAggregator {
     final SubSearchContext subSearchContext;
     final LongObjectPagedHashMap<TopDocsAndLeafCollector> topDocsCollectors;
 
-    public TopHitsAggregator(FetchPhase fetchPhase, SubSearchContext subSearchContext, String name, AggregationContext context, Aggregator parent, Map<String, Object> metaData) throws IOException {
-        super(name, context, parent, metaData);
+    public TopHitsAggregator(FetchPhase fetchPhase, SubSearchContext subSearchContext, String name, AggregationContext context,
+            Aggregator parent, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+        super(name, context, parent, reducers, metaData);
         this.fetchPhase = fetchPhase;
         topDocsCollectors = new LongObjectPagedHashMap<>(1, context.bigArrays());
         this.subSearchContext = subSearchContext;
@@ -82,8 +86,8 @@ public class TopHitsAggregator extends MetricsAggregator {
             return sort.needsScores() || subSearchContext.trackScores();
         } else {
             // sort by score
-            return true;
-        }
+        return true;
+    }
     }
 
     @Override
@@ -180,8 +184,9 @@ public class TopHitsAggregator extends MetricsAggregator {
         }
 
         @Override
-        public Aggregator createInternal(AggregationContext aggregationContext, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
-            return new TopHitsAggregator(fetchPhase, subSearchContext, name, aggregationContext, parent, metaData);
+        public Aggregator createInternal(AggregationContext aggregationContext, Aggregator parent, boolean collectsFromSingleBucket,
+                List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+            return new TopHitsAggregator(fetchPhase, subSearchContext, name, aggregationContext, parent, reducers, metaData);
         }
 
         @Override

src/main/java/org/elasticsearch/search/aggregations/metrics/valuecount/InternalValueCount.java

@@ -25,9 +25,11 @@ import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.search.aggregations.AggregationStreams;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.metrics.InternalNumericMetricsAggregation;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -54,8 +56,9 @@ public class InternalValueCount extends InternalNumericMetricsAggregation.Single
 
     InternalValueCount() {} // for serialization
 
-    public InternalValueCount(String name, long value, @Nullable ValueFormatter formatter, Map<String, Object> metaData) {
-        super(name, metaData);
+    public InternalValueCount(String name, long value, @Nullable ValueFormatter formatter, List<Reducer> reducers,
+            Map<String, Object> metaData) {
+        super(name, reducers, metaData);
         this.value = value;
         this.valueFormatter = formatter;
     }
@@ -81,7 +84,7 @@ public class InternalValueCount extends InternalNumericMetricsAggregation.Single
         for (InternalAggregation aggregation : reduceContext.aggregations()) {
             valueCount += ((InternalValueCount) aggregation).value;
         }
-        return new InternalValueCount(name, valueCount, valueFormatter, getMetaData());
+        return new InternalValueCount(name, valueCount, valueFormatter, reducers(), getMetaData());
     }
 
     @Override

src/main/java/org/elasticsearch/search/aggregations/metrics/valuecount/ValueCountAggregator.java

@@ -29,6 +29,7 @@ import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.LeafBucketCollector;
 import org.elasticsearch.search.aggregations.LeafBucketCollectorBase;
 import org.elasticsearch.search.aggregations.metrics.NumericMetricsAggregator;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
@@ -36,6 +37,7 @@ import org.elasticsearch.search.aggregations.support.ValuesSourceConfig;
 import org.elasticsearch.search.aggregations.support.format.ValueFormatter;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -53,8 +55,9 @@ public class ValueCountAggregator extends NumericMetricsAggregator.SingleValue {
     LongArray counts;
 
     public ValueCountAggregator(String name, ValuesSource valuesSource, @Nullable ValueFormatter formatter,
-            AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
-        super(name, aggregationContext, parent, metaData);
+            AggregationContext aggregationContext, Aggregator parent, List<Reducer> reducers, Map<String, Object> metaData)
+            throws IOException {
+        super(name, aggregationContext, parent, reducers, metaData);
         this.valuesSource = valuesSource;
         this.formatter = formatter;
         if (valuesSource != null) {
@@ -67,17 +70,17 @@ public class ValueCountAggregator extends NumericMetricsAggregator.SingleValue {
             final LeafBucketCollector sub) throws IOException {
         if (valuesSource == null) {
             return LeafBucketCollector.NO_OP_COLLECTOR;
-        }
+    }
         final BigArrays bigArrays = context.bigArrays();
         final SortedBinaryDocValues values = valuesSource.bytesValues(ctx);
         return new LeafBucketCollectorBase(sub, values) {
 
-            @Override
+    @Override
             public void collect(int doc, long bucket) throws IOException {
                 counts = bigArrays.grow(counts, bucket + 1);
                 values.setDocument(doc);
                 counts.increment(bucket, values.count());
-            }
+    }
 
         };
     }
@@ -92,12 +95,12 @@ public class ValueCountAggregator extends NumericMetricsAggregator.SingleValue {
         if (valuesSource == null || bucket >= counts.size()) {
             return buildEmptyAggregation();
         }
-        return new InternalValueCount(name, counts.get(bucket), formatter, metaData());
+        return new InternalValueCount(name, counts.get(bucket), formatter, reducers(), metaData());
     }
 
     @Override
     public InternalAggregation buildEmptyAggregation() {
-        return new InternalValueCount(name, 0l, formatter, metaData());
+        return new InternalValueCount(name, 0l, formatter, reducers(), metaData());
     }
 
     @Override
@@ -112,13 +115,15 @@ public class ValueCountAggregator extends NumericMetricsAggregator.SingleValue {
         }
 
         @Override
-        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException {
-            return new ValueCountAggregator(name, null, config.formatter(), aggregationContext, parent, metaData);
+        protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, List<Reducer> reducers,
+                Map<String, Object> metaData) throws IOException {
+            return new ValueCountAggregator(name, null, config.formatter(), aggregationContext, parent, reducers, metaData);
         }
 
         @Override
-        protected Aggregator doCreateInternal(VS valuesSource, AggregationContext aggregationContext, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
-            return new ValueCountAggregator(name, valuesSource, config.formatter(), aggregationContext, parent,
+        protected Aggregator doCreateInternal(VS valuesSource, AggregationContext aggregationContext, Aggregator parent,
+                boolean collectsFromSingleBucket, List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
+            return new ValueCountAggregator(name, valuesSource, config.formatter(), aggregationContext, parent, reducers,
                     metaData);
         }
 

src/main/java/org/elasticsearch/search/aggregations/reducers/Reducer.java

@@ -0,0 +1,63 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.search.aggregations.reducers;
+
+import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.search.aggregations.InternalAggregation;
+import org.elasticsearch.search.aggregations.InternalAggregation.ReduceContext;
+import org.elasticsearch.search.internal.SearchContext;
+
+import java.io.IOException;
+
+public abstract class Reducer {
+
+    /**
+     * Parses the reducer request and creates the appropriate reducer factory
+     * for it.
+     * 
+     * @see {@link ReducerFactory}
+     */
+    public static interface Parser {
+
+        /**
+         * @return The reducer type this parser is associated with.
+         */
+        String type();
+
+        /**
+         * Returns the reducer factory with which this parser is associated.
+         * 
+         * @param reducerName
+         *            The name of the reducer
+         * @param parser
+         *            The xcontent parser
+         * @param context
+         *            The search context
+         * @return The resolved reducer factory
+         * @throws java.io.IOException
+         *             When parsing fails
+         */
+        ReducerFactory parse(String reducerName, XContentParser parser, SearchContext context) throws IOException;
+
+    }
+
+    public abstract InternalAggregation reduce(InternalAggregation aggregation, ReduceContext reduceContext);
+
+}

src/main/java/org/elasticsearch/search/aggregations/reducers/ReducerFactory.java

@@ -0,0 +1,88 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.elasticsearch.search.aggregations.reducers;
+
+import org.elasticsearch.common.io.stream.Streamable;
+import org.elasticsearch.search.aggregations.Aggregator;
+import org.elasticsearch.search.aggregations.support.AggregationContext;
+
+import java.io.IOException;
+import java.util.Map;
+
+/**
+ * A factory that knows how to create an {@link Aggregator} of a specific type.
+ */
+public abstract class ReducerFactory implements Streamable {
+
+    protected String name;
+    protected String type;
+    protected Map<String, Object> metaData;
+
+    /**
+     * Constructs a new reducer factory.
+     * 
+     * @param name
+     *            The aggregation name
+     * @param type
+     *            The aggregation type
+     */
+    public ReducerFactory(String name, String type) {
+        this.name = name;
+        this.type = type;
+    }
+
+    /**
+     * Validates the state of this factory (makes sure the factory is properly configured)
+     */
+    public final void validate() {
+        doValidate();
+    }
+
+    protected abstract Reducer createInternal(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket,
+            Map<String, Object> metaData) throws IOException;
+
+    /**
+     * Creates the reducer
+     * 
+     * @param context
+     *            The aggregation context
+     * @param parent
+     *            The parent aggregator (if this is a top level factory, the
+     *            parent will be {@code null})
+     * @param collectsFromSingleBucket
+     *            If true then the created aggregator will only be collected
+     *            with <tt>0</tt> as a bucket ordinal. Some factories can take
+     *            advantage of this in order to return more optimized
+     *            implementations.
+     * 
+     * @return The created aggregator
+     */
+    public final Reducer create(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket) throws IOException {
+        Reducer aggregator = createInternal(context, parent, collectsFromSingleBucket, this.metaData);
+        return aggregator;
+    }
+
+    public void doValidate() {
+    }
+
+    public void setMetaData(Map<String, Object> metaData) {
+        this.metaData = metaData;
+    }
+
+}

src/main/java/org/elasticsearch/search/aggregations/support/ValuesSourceAggregatorFactory.java

@@ -18,10 +18,16 @@
  */
 package org.elasticsearch.search.aggregations.support;
 
-import org.elasticsearch.search.aggregations.*;
+import org.elasticsearch.search.aggregations.AggregationExecutionException;
+import org.elasticsearch.search.aggregations.AggregationInitializationException;
+import org.elasticsearch.search.aggregations.Aggregator;
+import org.elasticsearch.search.aggregations.AggregatorFactories;
+import org.elasticsearch.search.aggregations.AggregatorFactory;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.aggregations.support.format.ValueFormat;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -49,12 +55,13 @@ public abstract class ValuesSourceAggregatorFactory<VS extends ValuesSource> ext
     }
 
     @Override
-    public Aggregator createInternal(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException {
+    public Aggregator createInternal(AggregationContext context, Aggregator parent, boolean collectsFromSingleBucket,
+            List<Reducer> reducers, Map<String, Object> metaData) throws IOException {
         if (config.unmapped()) {
-            return createUnmapped(context, parent, metaData);
+            return createUnmapped(context, parent, reducers, metaData);
         }
         VS vs = context.valuesSource(config);
-        return doCreateInternal(vs, context, parent, collectsFromSingleBucket, metaData);
+        return doCreateInternal(vs, context, parent, collectsFromSingleBucket, reducers, metaData);
     }
 
     @Override
@@ -64,9 +71,11 @@ public abstract class ValuesSourceAggregatorFactory<VS extends ValuesSource> ext
         }
     }
 
-    protected abstract Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, Map<String, Object> metaData) throws IOException;
+    protected abstract Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent, List<Reducer> reducers,
+            Map<String, Object> metaData) throws IOException;
 
-    protected abstract Aggregator doCreateInternal(VS valuesSource, AggregationContext aggregationContext, Aggregator parent, boolean collectsFromSingleBucket, Map<String, Object> metaData) throws IOException;
+    protected abstract Aggregator doCreateInternal(VS valuesSource, AggregationContext aggregationContext, Aggregator parent,
+            boolean collectsFromSingleBucket, List<Reducer> reducers, Map<String, Object> metaData) throws IOException;
 
     private void resolveValuesSourceConfigFromAncestors(String aggName, AggregatorFactory parent, Class<VS> requiredValuesSourceType) {
         ValuesSourceConfig config;

src/test/java/org/elasticsearch/search/aggregations/bucket/significant/SignificanceHeuristicTests.java

@@ -30,7 +30,16 @@ import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.json.JsonXContent;
 import org.elasticsearch.search.SearchShardTarget;
 import org.elasticsearch.search.aggregations.InternalAggregations;
-import org.elasticsearch.search.aggregations.bucket.significant.heuristics.*;
+import org.elasticsearch.search.aggregations.bucket.significant.heuristics.ChiSquare;
+import org.elasticsearch.search.aggregations.bucket.significant.heuristics.GND;
+import org.elasticsearch.search.aggregations.bucket.significant.heuristics.JLHScore;
+import org.elasticsearch.search.aggregations.bucket.significant.heuristics.MutualInformation;
+import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristic;
+import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristicBuilder;
+import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristicParser;
+import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristicParserMapper;
+import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristicStreams;
+import org.elasticsearch.search.aggregations.reducers.Reducer;
 import org.elasticsearch.search.internal.SearchContext;
 import org.elasticsearch.test.ElasticsearchIntegrationTest;
 import org.elasticsearch.test.ElasticsearchTestCase;
@@ -41,11 +50,16 @@ import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 
-import static org.hamcrest.Matchers.*;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.greaterThan;
+import static org.hamcrest.Matchers.greaterThanOrEqualTo;
+import static org.hamcrest.Matchers.lessThan;
+import static org.hamcrest.Matchers.lessThanOrEqualTo;
 
 /**
  *
@@ -96,13 +110,15 @@ public class SignificanceHeuristicTests extends ElasticsearchTestCase {
         if (randomBoolean()) {
             BytesRef term = new BytesRef("123.0");
             buckets.add(new SignificantLongTerms.Bucket(1, 2, 3, 4, 123, InternalAggregations.EMPTY, null));
-            sTerms[0] = new SignificantLongTerms(10, 20, "some_name", null, 1, 1, heuristic, buckets, null);
+            sTerms[0] = new SignificantLongTerms(10, 20, "some_name", null, 1, 1, heuristic, buckets,
+                    (List<Reducer>) Collections.EMPTY_LIST, null);
             sTerms[1] = new SignificantLongTerms();
         } else {
 
             BytesRef term = new BytesRef("someterm");
             buckets.add(new SignificantStringTerms.Bucket(term, 1, 2, 3, 4, InternalAggregations.EMPTY));
-            sTerms[0] = new SignificantStringTerms(10, 20, "some_name", 1, 1, heuristic, buckets, null);
+            sTerms[0] = new SignificantStringTerms(10, 20, "some_name", 1, 1, heuristic, buckets, (List<Reducer>) Collections.EMPTY_LIST,
+                    null);
             sTerms[1] = new SignificantStringTerms();
         }
         return sTerms;