Merge branch 'master' into enhancement/use_shard_bulk_for_single_ops

core/src/main/java/org/elasticsearch/Version.java

@@ -102,6 +102,8 @@ public class Version {
     // no version constant for 5.1.0 due to inadvertent release
     public static final int V_5_1_1_ID_UNRELEASED = 5010199;
     public static final Version V_5_1_1_UNRELEASED = new Version(V_5_1_1_ID_UNRELEASED, org.apache.lucene.util.Version.LUCENE_6_3_0);
+    public static final int V_5_1_2_ID_UNRELEASED = 5010299;
+    public static final Version V_5_1_2_UNRELEASED = new Version(V_5_1_2_ID_UNRELEASED, org.apache.lucene.util.Version.LUCENE_6_3_0);
     public static final int V_5_2_0_ID_UNRELEASED = 5020099;
     public static final Version V_5_2_0_UNRELEASED = new Version(V_5_2_0_ID_UNRELEASED, org.apache.lucene.util.Version.LUCENE_6_3_0);
     public static final int V_6_0_0_alpha1_ID_UNRELEASED = 6000001;
@@ -126,6 +128,8 @@ public class Version {
                 return V_6_0_0_alpha1_UNRELEASED;
             case V_5_2_0_ID_UNRELEASED:
                 return V_5_2_0_UNRELEASED;
+            case V_5_1_2_ID_UNRELEASED:
+                return V_5_1_2_UNRELEASED;
             case V_5_1_1_ID_UNRELEASED:
                 return V_5_1_1_UNRELEASED;
             case V_5_0_3_ID_UNRELEASED:

core/src/main/java/org/elasticsearch/action/bulk/BulkRequest.java

@@ -48,9 +48,10 @@ import org.elasticsearch.search.fetch.subphase.FetchSourceContext;
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Objects;
-import java.util.stream.Collectors;
+import java.util.Set;
 
 import static org.elasticsearch.action.ValidateActions.addValidationError;
 
@@ -73,6 +74,7 @@ public class BulkRequest extends ActionRequest implements CompositeIndicesReques
      * the one with the least casts.
      */
     final List<DocWriteRequest> requests = new ArrayList<>();
+    private final Set<String> indices = new HashSet<>();
     List<Object> payloads = null;
 
     protected TimeValue timeout = BulkShardRequest.DEFAULT_TIMEOUT;
@@ -114,6 +116,7 @@ public class BulkRequest extends ActionRequest implements CompositeIndicesReques
         } else {
             throw new IllegalArgumentException("No support for request [" + request + "]");
         }
+        indices.add(request.index());
         return this;
     }
 
@@ -145,6 +148,7 @@ public class BulkRequest extends ActionRequest implements CompositeIndicesReques
         addPayload(payload);
         // lack of source is validated in validate() method
         sizeInBytes += (request.source() != null ? request.source().length() : 0) + REQUEST_OVERHEAD;
+        indices.add(request.index());
         return this;
     }
 
@@ -172,6 +176,7 @@ public class BulkRequest extends ActionRequest implements CompositeIndicesReques
         if (request.script() != null) {
             sizeInBytes += request.script().getIdOrCode().length() * 2;
         }
+        indices.add(request.index());
         return this;
     }
 
@@ -187,6 +192,7 @@ public class BulkRequest extends ActionRequest implements CompositeIndicesReques
         requests.add(request);
         addPayload(payload);
         sizeInBytes += REQUEST_OVERHEAD;
+        indices.add(request.index());
         return this;
     }
 
@@ -548,4 +554,10 @@ public class BulkRequest extends ActionRequest implements CompositeIndicesReques
         refreshPolicy.writeTo(out);
         timeout.writeTo(out);
     }
+
+    @Override
+    public String getDescription() {
+        return "requests[" + requests.size() + "], indices[" + Strings.collectionToDelimitedString(indices, ", ") + "]";
+    }
+
 }

core/src/main/java/org/elasticsearch/action/bulk/BulkShardRequest.java

@@ -100,6 +100,11 @@ public class BulkShardRequest extends ReplicatedWriteRequest<BulkShardRequest> {
         return b.toString();
     }
 
+    @Override
+    public String getDescription() {
+        return "requests[" + items.length + "], index[" + index + "]";
+    }
+
     @Override
     public void onRetry() {
         for (BulkItemRequest item : items) {

core/src/main/java/org/elasticsearch/action/bulk/TransportShardBulkAction.java

@@ -523,8 +523,8 @@ public class TransportShardBulkAction extends TransportWriteAction<BulkShardRequ
     }
 
     public static Engine.DeleteResult executeDeleteRequestOnReplica(DeleteRequest request, IndexShard replica) {
-        final Engine.Delete delete =
-                replica.prepareDeleteOnReplica(request.type(), request.id(), request.seqNo(), request.version(), request.versionType());
+        final Engine.Delete delete = replica.prepareDeleteOnReplica(request.type(), request.id(),
+                request.seqNo(), request.primaryTerm(), request.version(), request.versionType());
         return replica.delete(delete);
     }
 }

core/src/main/java/org/elasticsearch/action/index/TransportIndexAction.java

@@ -111,4 +111,3 @@ public class TransportIndexAction extends TransportWriteAction<IndexRequest, Ind
         return shardBulkAction.executeSingleItemBulkRequestOnReplica(request, replica);
     }
 }
-

core/src/main/java/org/elasticsearch/common/lucene/uid/Versions.java

@@ -19,14 +19,25 @@
 
 package org.elasticsearch.common.lucene.uid;
 
+import org.apache.lucene.index.Fields;
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.LeafReader;
 import org.apache.lucene.index.LeafReader.CoreClosedListener;
 import org.apache.lucene.index.LeafReaderContext;
+import org.apache.lucene.index.NumericDocValues;
+import org.apache.lucene.index.PostingsEnum;
+import org.apache.lucene.index.SortedNumericDocValues;
 import org.apache.lucene.index.Term;
+import org.apache.lucene.index.Terms;
+import org.apache.lucene.index.TermsEnum;
+import org.apache.lucene.search.DocIdSetIterator;
+import org.apache.lucene.util.Bits;
+import org.apache.lucene.util.BytesRef;
 import org.apache.lucene.util.CloseableThreadLocal;
 import org.elasticsearch.common.util.concurrent.ConcurrentCollections;
+import org.elasticsearch.index.mapper.SeqNoFieldMapper;
 import org.elasticsearch.index.mapper.UidFieldMapper;
+import org.elasticsearch.index.seqno.SequenceNumbersService;
 
 import java.io.IOException;
 import java.util.List;
@@ -143,4 +154,115 @@ public class Versions {
         final DocIdAndVersion docIdAndVersion = loadDocIdAndVersion(reader, term);
         return docIdAndVersion == null ? NOT_FOUND : docIdAndVersion.version;
     }
+
+
+    /**
+     * Returns the sequence number for the given uid term, returning
+     * {@code SequenceNumbersService.UNASSIGNED_SEQ_NO} if none is found.
+     */
+    public static long loadSeqNo(IndexReader reader, Term term) throws IOException {
+        assert term.field().equals(UidFieldMapper.NAME) : "can only load _seq_no by uid";
+        List<LeafReaderContext> leaves = reader.leaves();
+        if (leaves.isEmpty()) {
+            return SequenceNumbersService.UNASSIGNED_SEQ_NO;
+        }
+
+        // iterate backwards to optimize for the frequently updated documents
+        // which are likely to be in the last segments
+        for (int i = leaves.size() - 1; i >= 0; i--) {
+            LeafReader leaf = leaves.get(i).reader();
+            Bits liveDocs = leaf.getLiveDocs();
+
+            TermsEnum termsEnum = null;
+            SortedNumericDocValues dvField = null;
+            PostingsEnum docsEnum = null;
+
+            final Fields fields = leaf.fields();
+            if (fields != null) {
+                Terms terms = fields.terms(UidFieldMapper.NAME);
+                if (terms != null) {
+                    termsEnum = terms.iterator();
+                    assert termsEnum != null;
+                    dvField = leaf.getSortedNumericDocValues(SeqNoFieldMapper.NAME);
+                    assert dvField != null;
+
+                    final BytesRef id = term.bytes();
+                    if (termsEnum.seekExact(id)) {
+                        // there may be more than one matching docID, in the
+                        // case of nested docs, so we want the last one:
+                        docsEnum = termsEnum.postings(docsEnum, 0);
+                        int docID = DocIdSetIterator.NO_MORE_DOCS;
+                        for (int d = docsEnum.nextDoc(); d != DocIdSetIterator.NO_MORE_DOCS; d = docsEnum.nextDoc()) {
+                            if (liveDocs != null && liveDocs.get(d) == false) {
+                                continue;
+                            }
+                            docID = d;
+                        }
+
+                        if (docID != DocIdSetIterator.NO_MORE_DOCS) {
+                            dvField.setDocument(docID);
+                            assert dvField.count() == 1 : "expected only a single value for _seq_no but got " +
+                                    dvField.count();
+                            return dvField.valueAt(0);
+                        }
+                    }
+                }
+            }
+
+        }
+        return SequenceNumbersService.UNASSIGNED_SEQ_NO;
+    }
+
+    /**
+     * Returns the primary term for the given uid term, returning {@code 0} if none is found.
+     */
+    public static long loadPrimaryTerm(IndexReader reader, Term term) throws IOException {
+        assert term.field().equals(UidFieldMapper.NAME) : "can only load _primary_term by uid";
+        List<LeafReaderContext> leaves = reader.leaves();
+        if (leaves.isEmpty()) {
+            return 0;
+        }
+
+        // iterate backwards to optimize for the frequently updated documents
+        // which are likely to be in the last segments
+        for (int i = leaves.size() - 1; i >= 0; i--) {
+            LeafReader leaf = leaves.get(i).reader();
+            Bits liveDocs = leaf.getLiveDocs();
+
+            TermsEnum termsEnum = null;
+            NumericDocValues dvField = null;
+            PostingsEnum docsEnum = null;
+
+            final Fields fields = leaf.fields();
+            if (fields != null) {
+                Terms terms = fields.terms(UidFieldMapper.NAME);
+                if (terms != null) {
+                    termsEnum = terms.iterator();
+                    assert termsEnum != null;
+                    dvField = leaf.getNumericDocValues(SeqNoFieldMapper.PRIMARY_TERM_NAME);
+                    assert dvField != null;
+
+                    final BytesRef id = term.bytes();
+                    if (termsEnum.seekExact(id)) {
+                        // there may be more than one matching docID, in the
+                        // case of nested docs, so we want the last one:
+                        docsEnum = termsEnum.postings(docsEnum, 0);
+                        int docID = DocIdSetIterator.NO_MORE_DOCS;
+                        for (int d = docsEnum.nextDoc(); d != DocIdSetIterator.NO_MORE_DOCS; d = docsEnum.nextDoc()) {
+                            if (liveDocs != null && liveDocs.get(d) == false) {
+                                continue;
+                            }
+                            docID = d;
+                        }
+
+                        if (docID != DocIdSetIterator.NO_MORE_DOCS) {
+                            return dvField.get(docID);
+                        }
+                    }
+                }
+            }
+
+        }
+        return 0;
+    }
 }

core/src/main/java/org/elasticsearch/index/engine/Engine.java

@@ -47,6 +47,7 @@ import org.elasticsearch.ExceptionsHelper;
 import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.collect.ImmutableOpenMap;
+import org.elasticsearch.common.collect.Tuple;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.io.stream.Writeable;
@@ -925,13 +926,15 @@ public abstract class Engine implements Closeable {
         private final Term uid;
         private final long version;
         private final long seqNo;
+        private final long primaryTerm;
         private final VersionType versionType;
         private final Origin origin;
         private final long startTime;
 
-        public Operation(Term uid, long seqNo, long version, VersionType versionType, Origin origin, long startTime) {
+        public Operation(Term uid, long seqNo, long primaryTerm, long version, VersionType versionType, Origin origin, long startTime) {
             this.uid = uid;
             this.seqNo = seqNo;
+            this.primaryTerm = primaryTerm;
             this.version = version;
             this.versionType = versionType;
             this.origin = origin;
@@ -965,6 +968,10 @@ public abstract class Engine implements Closeable {
             return seqNo;
         }
 
+        public long primaryTerm() {
+            return primaryTerm;
+        }
+
         public abstract int estimatedSizeInBytes();
 
         public VersionType versionType() {
@@ -991,9 +998,9 @@ public abstract class Engine implements Closeable {
         private final long autoGeneratedIdTimestamp;
         private final boolean isRetry;
 
-        public Index(Term uid, ParsedDocument doc, long seqNo, long version, VersionType versionType, Origin origin, long startTime,
-                     long autoGeneratedIdTimestamp, boolean isRetry) {
-            super(uid, seqNo, version, versionType, origin, startTime);
+        public Index(Term uid, ParsedDocument doc, long seqNo, long primaryTerm, long version, VersionType versionType, Origin origin,
+                     long startTime, long autoGeneratedIdTimestamp, boolean isRetry) {
+            super(uid, seqNo, primaryTerm, version, versionType, origin, startTime);
             this.doc = doc;
             this.isRetry = isRetry;
             this.autoGeneratedIdTimestamp = autoGeneratedIdTimestamp;
@@ -1004,7 +1011,8 @@ public abstract class Engine implements Closeable {
         } // TEST ONLY
 
         Index(Term uid, ParsedDocument doc, long version) {
-            this(uid, doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, version, VersionType.INTERNAL, Origin.PRIMARY, System.nanoTime(), -1, false);
+            this(uid, doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, version, VersionType.INTERNAL,
+                    Origin.PRIMARY, System.nanoTime(), -1, false);
         }
 
         public ParsedDocument parsedDoc() {
@@ -1071,18 +1079,20 @@ public abstract class Engine implements Closeable {
         private final String type;
         private final String id;
 
-        public Delete(String type, String id, Term uid, long seqNo, long version, VersionType versionType, Origin origin, long startTime) {
-            super(uid, seqNo, version, versionType, origin, startTime);
+        public Delete(String type, String id, Term uid, long seqNo, long primaryTerm, long version, VersionType versionType,
+                      Origin origin, long startTime) {
+            super(uid, seqNo, primaryTerm, version, versionType, origin, startTime);
             this.type = type;
             this.id = id;
         }
 
         public Delete(String type, String id, Term uid) {
-            this(type, id, uid, SequenceNumbersService.UNASSIGNED_SEQ_NO, Versions.MATCH_ANY, VersionType.INTERNAL, Origin.PRIMARY, System.nanoTime());
+            this(type, id, uid, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, Versions.MATCH_ANY, VersionType.INTERNAL, Origin.PRIMARY, System.nanoTime());
         }
 
         public Delete(Delete template, VersionType versionType) {
-            this(template.type(), template.id(), template.uid(), template.seqNo(), template.version(), versionType, template.origin(), template.startTime());
+            this(template.type(), template.id(), template.uid(), template.seqNo(), template.primaryTerm(), template.version(),
+                    versionType, template.origin(), template.startTime());
         }
 
         @Override

core/src/main/java/org/elasticsearch/index/engine/InternalEngine.java

@@ -650,6 +650,16 @@ public class InternalEngine extends Engine {
                 }
                 updatedVersion = index.versionType().updateVersion(currentVersion, expectedVersion);
                 index.parsedDoc().version().setLongValue(updatedVersion);
+
+                // Update the document's sequence number and primary term, the
+                // sequence number here is derived here from either the sequence
+                // number service if this is on the primary, or the existing
+                // document's sequence number if this is on the replica. The
+                // primary term here has already been set, see
+                // IndexShard.prepareIndex where the Engine.Index operation is
+                // created
+                index.parsedDoc().updateSeqID(seqNo, index.primaryTerm());
+
                 if (currentVersion == Versions.NOT_FOUND && forceUpdateDocument == false) {
                     // document does not exists, we can optimize for create, but double check if assertions are running
                     assert assertDocDoesNotExist(index, canOptimizeAddDocument == false);

core/src/main/java/org/elasticsearch/index/mapper/DocumentParser.java

@@ -148,7 +148,7 @@ final class DocumentParser {
     private static ParsedDocument parsedDocument(SourceToParse source, ParseContext.InternalParseContext context, Mapping update) {
         return new ParsedDocument(
             context.version(),
-            context.seqNo(),
+            context.seqID(),
             context.sourceToParse().id(),
             context.sourceToParse().type(),
             source.routing(),

core/src/main/java/org/elasticsearch/index/mapper/ParseContext.java

@@ -29,6 +29,7 @@ import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.lucene.all.AllEntries;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.index.mapper.SeqNoFieldMapper;
 
 import java.util.ArrayList;
 import java.util.Iterator;
@@ -254,13 +255,13 @@ public abstract class ParseContext {
         }
 
         @Override
-        public Field seqNo() {
-            return in.seqNo();
+        public SeqNoFieldMapper.SequenceID seqID() {
+            return in.seqID();
         }
 
         @Override
-        public void seqNo(Field seqNo) {
-            in.seqNo(seqNo);
+        public void seqID(SeqNoFieldMapper.SequenceID seqID) {
+            in.seqID(seqID);
         }
 
         @Override
@@ -310,7 +311,7 @@ public abstract class ParseContext {
 
         private Field version;
 
-        private Field seqNo;
+        private SeqNoFieldMapper.SequenceID seqID;
 
         private final AllEntries allEntries;
 
@@ -404,16 +405,15 @@ public abstract class ParseContext {
         }
 
         @Override
-        public Field seqNo() {
-            return this.seqNo;
+        public SeqNoFieldMapper.SequenceID seqID() {
+            return this.seqID;
         }
 
         @Override
-        public void seqNo(Field seqNo) {
-            this.seqNo = seqNo;
+        public void seqID(SeqNoFieldMapper.SequenceID seqID) {
+            this.seqID = seqID;
         }
 
-
         @Override
         public AllEntries allEntries() {
             return this.allEntries;
@@ -540,9 +540,9 @@ public abstract class ParseContext {
 
     public abstract void version(Field version);
 
-    public abstract Field seqNo();
+    public abstract SeqNoFieldMapper.SequenceID seqID();
 
-    public abstract void seqNo(Field seqNo);
+    public abstract void seqID(SeqNoFieldMapper.SequenceID seqID);
 
     public final boolean includeInAll(Boolean includeInAll, FieldMapper mapper) {
         return includeInAll(includeInAll, mapper.fieldType().indexOptions() != IndexOptions.NONE);

core/src/main/java/org/elasticsearch/index/mapper/ParsedDocument.java

@@ -23,6 +23,7 @@ import org.apache.lucene.document.Field;
 import org.apache.lucene.util.BytesRef;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.index.mapper.ParseContext.Document;
+import org.elasticsearch.index.mapper.SeqNoFieldMapper;
 
 import java.util.List;
 
@@ -35,7 +36,7 @@ public class ParsedDocument {
 
     private final String id, type;
     private final BytesRef uid;
-    private final Field seqNo;
+    private final SeqNoFieldMapper.SequenceID seqID;
 
     private final String routing;
 
@@ -47,9 +48,8 @@ public class ParsedDocument {
 
     private String parent;
 
-    public ParsedDocument(
-        Field version,
-        Field seqNo,
+    public ParsedDocument(Field version,
+                          SeqNoFieldMapper.SequenceID seqID,
                           String id,
                           String type,
                           String routing,
@@ -57,7 +57,7 @@ public class ParsedDocument {
                           BytesReference source,
                           Mapping dynamicMappingsUpdate) {
         this.version = version;
-        this.seqNo = seqNo;
+        this.seqID = seqID;
         this.id = id;
         this.type = type;
         this.uid = Uid.createUidAsBytes(type, id);
@@ -83,8 +83,10 @@ public class ParsedDocument {
         return version;
     }
 
-    public Field seqNo() {
-        return seqNo;
+    public void updateSeqID(long sequenceNumber, long primaryTerm) {
+        this.seqID.seqNo.setLongValue(sequenceNumber);
+        this.seqID.seqNoDocValue.setLongValue(sequenceNumber);
+        this.seqID.primaryTerm.setLongValue(primaryTerm);
     }
 
     public String routing() {

core/src/main/java/org/elasticsearch/index/mapper/SeqNoFieldMapper.java

@@ -0,0 +1,298 @@
+/*
+ * 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.index.mapper;
+
+import org.apache.lucene.document.Field;
+import org.apache.lucene.document.LongPoint;
+import org.apache.lucene.document.NumericDocValuesField;
+import org.apache.lucene.document.SortedNumericDocValuesField;
+import org.apache.lucene.index.DocValuesType;
+import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.index.IndexableField;
+import org.apache.lucene.index.LeafReader;
+import org.apache.lucene.index.LeafReaderContext;
+import org.apache.lucene.index.NumericDocValues;
+import org.apache.lucene.index.PointValues;
+import org.apache.lucene.search.BoostQuery;
+import org.apache.lucene.search.MatchNoDocsQuery;
+import org.apache.lucene.search.Query;
+import org.apache.lucene.util.Bits;
+import org.apache.lucene.util.BytesRef;
+import org.elasticsearch.action.fieldstats.FieldStats;
+import org.elasticsearch.common.Nullable;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.index.fielddata.IndexFieldData;
+import org.elasticsearch.index.fielddata.IndexNumericFieldData.NumericType;
+import org.elasticsearch.index.fielddata.plain.DocValuesIndexFieldData;
+import org.elasticsearch.index.mapper.MappedFieldType;
+import org.elasticsearch.index.mapper.Mapper;
+import org.elasticsearch.index.mapper.MapperParsingException;
+import org.elasticsearch.index.mapper.MetadataFieldMapper;
+import org.elasticsearch.index.mapper.ParseContext;
+import org.elasticsearch.index.mapper.ParseContext.Document;
+import org.elasticsearch.index.query.QueryShardContext;
+import org.elasticsearch.index.query.QueryShardException;
+import org.elasticsearch.index.seqno.SequenceNumbersService;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+
+/**
+ * Mapper for the {@code _seq_no} field.
+ *
+ * We expect to use the seq# for sorting, during collision checking and for
+ * doing range searches. Therefore the {@code _seq_no} field is stored both
+ * as a numeric doc value and as numeric indexed field.
+ *
+ * This mapper also manages the primary term field, which has no ES named
+ * equivalent. The primary term is only used during collision after receiving
+ * identical seq# values for two document copies. The primary term is stored as
+ * a doc value field without being indexed, since it is only intended for use
+ * as a key-value lookup.
+
+ */
+public class SeqNoFieldMapper extends MetadataFieldMapper {
+
+    /**
+     * A sequence ID, which is made up of a sequence number (both the searchable
+     * and doc_value version of the field) and the primary term.
+     */
+    public static class SequenceID {
+
+        public final Field seqNo;
+        public final Field seqNoDocValue;
+        public final Field primaryTerm;
+
+        public SequenceID(Field seqNo, Field seqNoDocValue, Field primaryTerm) {
+            Objects.requireNonNull(seqNo, "sequence number field cannot be null");
+            Objects.requireNonNull(seqNoDocValue, "sequence number dv field cannot be null");
+            Objects.requireNonNull(primaryTerm, "primary term field cannot be null");
+            this.seqNo = seqNo;
+            this.seqNoDocValue = seqNoDocValue;
+            this.primaryTerm = primaryTerm;
+        }
+
+        public static SequenceID emptySeqID() {
+            return new SequenceID(new LongPoint(NAME, SequenceNumbersService.UNASSIGNED_SEQ_NO),
+                    new SortedNumericDocValuesField(NAME, SequenceNumbersService.UNASSIGNED_SEQ_NO),
+                    new NumericDocValuesField(PRIMARY_TERM_NAME, 0));
+        }
+    }
+
+    public static final String NAME = "_seq_no";
+    public static final String CONTENT_TYPE = "_seq_no";
+    public static final String PRIMARY_TERM_NAME = "_primary_term";
+
+    public static class SeqNoDefaults {
+        public static final String NAME = SeqNoFieldMapper.NAME;
+        public static final MappedFieldType FIELD_TYPE = new SeqNoFieldType();
+
+        static {
+            FIELD_TYPE.setName(NAME);
+            FIELD_TYPE.setDocValuesType(DocValuesType.SORTED);
+            FIELD_TYPE.setHasDocValues(true);
+            FIELD_TYPE.freeze();
+        }
+    }
+
+    public static class Builder extends MetadataFieldMapper.Builder<Builder, SeqNoFieldMapper> {
+
+        public Builder() {
+            super(SeqNoDefaults.NAME, SeqNoDefaults.FIELD_TYPE, SeqNoDefaults.FIELD_TYPE);
+        }
+
+        @Override
+        public SeqNoFieldMapper build(BuilderContext context) {
+            return new SeqNoFieldMapper(context.indexSettings());
+        }
+    }
+
+    public static class TypeParser implements MetadataFieldMapper.TypeParser {
+        @Override
+        public MetadataFieldMapper.Builder<?, ?> parse(String name, Map<String, Object> node, ParserContext parserContext)
+                throws MapperParsingException {
+            throw new MapperParsingException(NAME + " is not configurable");
+        }
+
+        @Override
+        public MetadataFieldMapper getDefault(Settings indexSettings, MappedFieldType fieldType, String typeName) {
+            return new SeqNoFieldMapper(indexSettings);
+        }
+    }
+
+    static final class SeqNoFieldType extends MappedFieldType {
+
+        public SeqNoFieldType() {
+        }
+
+        protected SeqNoFieldType(SeqNoFieldType ref) {
+            super(ref);
+        }
+
+        @Override
+        public MappedFieldType clone() {
+            return new SeqNoFieldType(this);
+        }
+
+        @Override
+        public String typeName() {
+            return CONTENT_TYPE;
+        }
+
+        private long parse(Object value) {
+            if (value instanceof Number) {
+                double doubleValue = ((Number) value).doubleValue();
+                if (doubleValue < Long.MIN_VALUE || doubleValue > Long.MAX_VALUE) {
+                    throw new IllegalArgumentException("Value [" + value + "] is out of range for a long");
+                }
+                if (doubleValue % 1 != 0) {
+                    throw new IllegalArgumentException("Value [" + value + "] has a decimal part");
+                }
+                return ((Number) value).longValue();
+            }
+            if (value instanceof BytesRef) {
+                value = ((BytesRef) value).utf8ToString();
+            }
+            return Long.parseLong(value.toString());
+        }
+
+        @Override
+        public Query termQuery(Object value, @Nullable QueryShardContext context) {
+            long v = parse(value);
+            return LongPoint.newExactQuery(name(), v);
+        }
+
+        @Override
+        public Query termsQuery(List<?> values, @Nullable QueryShardContext context) {
+            long[] v = new long[values.size()];
+            for (int i = 0; i < values.size(); ++i) {
+                v[i] = parse(values.get(i));
+            }
+            return LongPoint.newSetQuery(name(), v);
+        }
+
+        @Override
+        public Query rangeQuery(Object lowerTerm, Object upperTerm, boolean includeLower,
+                                boolean includeUpper, QueryShardContext context) {
+            long l = Long.MIN_VALUE;
+            long u = Long.MAX_VALUE;
+            if (lowerTerm != null) {
+                l = parse(lowerTerm);
+                if (includeLower == false) {
+                    if (l == Long.MAX_VALUE) {
+                        return new MatchNoDocsQuery();
+                    }
+                    ++l;
+                }
+            }
+            if (upperTerm != null) {
+                u = parse(upperTerm);
+                if (includeUpper == false) {
+                    if (u == Long.MIN_VALUE) {
+                        return new MatchNoDocsQuery();
+                    }
+                    --u;
+                }
+            }
+            return LongPoint.newRangeQuery(name(), l, u);
+        }
+
+        @Override
+        public IndexFieldData.Builder fielddataBuilder() {
+            failIfNoDocValues();
+            return new DocValuesIndexFieldData.Builder().numericType(NumericType.LONG);
+        }
+
+        @Override
+        public FieldStats stats(IndexReader reader) throws IOException {
+            String fieldName = name();
+            long size = PointValues.size(reader, fieldName);
+            if (size == 0) {
+                return null;
+            }
+            int docCount = PointValues.getDocCount(reader, fieldName);
+            byte[] min = PointValues.getMinPackedValue(reader, fieldName);
+            byte[] max = PointValues.getMaxPackedValue(reader, fieldName);
+            return new FieldStats.Long(reader.maxDoc(),docCount, -1L, size, true, false,
+                    LongPoint.decodeDimension(min, 0), LongPoint.decodeDimension(max, 0));
+        }
+
+    }
+
+    public SeqNoFieldMapper(Settings indexSettings) {
+        super(NAME, SeqNoDefaults.FIELD_TYPE, SeqNoDefaults.FIELD_TYPE, indexSettings);
+    }
+
+    @Override
+    public void preParse(ParseContext context) throws IOException {
+        super.parse(context);
+    }
+
+    @Override
+    protected void parseCreateField(ParseContext context, List<IndexableField> fields) throws IOException {
+        // see InternalEngine.innerIndex to see where the real version value is set
+        // also see ParsedDocument.updateSeqID (called by innerIndex)
+        SequenceID seqID = SequenceID.emptySeqID();
+        context.seqID(seqID);
+        fields.add(seqID.seqNo);
+        fields.add(seqID.seqNoDocValue);
+        fields.add(seqID.primaryTerm);
+    }
+
+    @Override
+    public Mapper parse(ParseContext context) throws IOException {
+        // fields are added in parseCreateField
+        return null;
+    }
+
+    @Override
+    public void postParse(ParseContext context) throws IOException {
+        // In the case of nested docs, let's fill nested docs with seqNo=1 and
+        // primaryTerm=0 so that Lucene doesn't write a Bitset for documents
+        // that don't have the field. This is consistent with the default value
+        // for efficiency.
+        for (int i = 1; i < context.docs().size(); i++) {
+            final Document doc = context.docs().get(i);
+            doc.add(new LongPoint(NAME, 1));
+            doc.add(new SortedNumericDocValuesField(NAME, 1L));
+            doc.add(new NumericDocValuesField(PRIMARY_TERM_NAME, 0L));
+        }
+    }
+
+    @Override
+    protected String contentType() {
+        return CONTENT_TYPE;
+    }
+
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        return builder;
+    }
+
+    @Override
+    protected void doMerge(Mapper mergeWith, boolean updateAllTypes) {
+        // nothing to do
+    }
+
+}

core/src/main/java/org/elasticsearch/index/mapper/internal/SeqNoFieldMapper.java

@@ -1,197 +0,0 @@
-/*
- * 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.index.mapper.internal;
-
-import org.apache.lucene.document.Field;
-import org.apache.lucene.document.NumericDocValuesField;
-import org.apache.lucene.index.DocValuesType;
-import org.apache.lucene.index.IndexReader;
-import org.apache.lucene.index.IndexableField;
-import org.apache.lucene.index.LeafReader;
-import org.apache.lucene.index.LeafReaderContext;
-import org.apache.lucene.index.NumericDocValues;
-import org.apache.lucene.search.Query;
-import org.apache.lucene.util.Bits;
-import org.elasticsearch.action.fieldstats.FieldStats;
-import org.elasticsearch.common.Nullable;
-import org.elasticsearch.common.settings.Settings;
-import org.elasticsearch.common.xcontent.XContentBuilder;
-import org.elasticsearch.index.mapper.MappedFieldType;
-import org.elasticsearch.index.mapper.Mapper;
-import org.elasticsearch.index.mapper.MapperParsingException;
-import org.elasticsearch.index.mapper.MetadataFieldMapper;
-import org.elasticsearch.index.mapper.ParseContext;
-import org.elasticsearch.index.mapper.ParseContext.Document;
-import org.elasticsearch.index.query.QueryShardContext;
-import org.elasticsearch.index.query.QueryShardException;
-import org.elasticsearch.index.seqno.SequenceNumbersService;
-
-import java.io.IOException;
-import java.util.List;
-import java.util.Map;
-
-/** Mapper for the _seq_no field. */
-public class SeqNoFieldMapper extends MetadataFieldMapper {
-
-    public static final String NAME = "_seq_no";
-    public static final String CONTENT_TYPE = "_seq_no";
-
-    public static class Defaults {
-
-        public static final String NAME = SeqNoFieldMapper.NAME;
-        public static final MappedFieldType FIELD_TYPE = new SeqNoFieldType();
-
-        static {
-            FIELD_TYPE.setName(NAME);
-            FIELD_TYPE.setDocValuesType(DocValuesType.NUMERIC);
-            FIELD_TYPE.setHasDocValues(true);
-            FIELD_TYPE.freeze();
-        }
-    }
-
-    public static class Builder extends MetadataFieldMapper.Builder<Builder, SeqNoFieldMapper> {
-
-        public Builder() {
-            super(Defaults.NAME, Defaults.FIELD_TYPE, Defaults.FIELD_TYPE);
-        }
-
-        @Override
-        public SeqNoFieldMapper build(BuilderContext context) {
-            return new SeqNoFieldMapper(context.indexSettings());
-        }
-    }
-
-    public static class TypeParser implements MetadataFieldMapper.TypeParser {
-        @Override
-        public MetadataFieldMapper.Builder<?, ?> parse(String name, Map<String, Object> node, ParserContext parserContext)
-                throws MapperParsingException {
-            throw new MapperParsingException(NAME + " is not configurable");
-        }
-
-        @Override
-        public MetadataFieldMapper getDefault(Settings indexSettings, MappedFieldType fieldType, String typeName) {
-            return new SeqNoFieldMapper(indexSettings);
-        }
-    }
-
-    static final class SeqNoFieldType extends MappedFieldType {
-
-        public SeqNoFieldType() {
-        }
-
-        protected SeqNoFieldType(SeqNoFieldType ref) {
-            super(ref);
-        }
-
-        @Override
-        public MappedFieldType clone() {
-            return new SeqNoFieldType(this);
-        }
-
-        @Override
-        public String typeName() {
-            return CONTENT_TYPE;
-        }
-
-        @Override
-        public Query termQuery(Object value, @Nullable QueryShardContext context) {
-            throw new QueryShardException(context, "SeqNoField field [" + name() + "] is not searchable");
-        }
-
-        @Override
-        public FieldStats stats(IndexReader reader) throws IOException {
-            // TODO: remove implementation when late-binding commits are possible
-            final List<LeafReaderContext> leaves = reader.leaves();
-            if (leaves.isEmpty()) {
-                return null;
-            }
-
-            long currentMin = Long.MAX_VALUE;
-            long currentMax = Long.MIN_VALUE;
-            boolean found = false;
-            for (int i = 0; i < leaves.size(); i++) {
-                final LeafReader leaf = leaves.get(i).reader();
-                final NumericDocValues values = leaf.getNumericDocValues(name());
-                if (values == null) continue;
-                final Bits bits = leaf.getLiveDocs();
-                for (int docID = 0; docID < leaf.maxDoc(); docID++) {
-                    if (bits == null || bits.get(docID)) {
-                        found = true;
-                        final long value = values.get(docID);
-                        currentMin = Math.min(currentMin, value);
-                        currentMax = Math.max(currentMax, value);
-                    }
-                }
-            }
-
-            return found ? new FieldStats.Long(reader.maxDoc(), 0, -1, -1, false, true, currentMin, currentMax) : null;
-        }
-
-    }
-
-    public SeqNoFieldMapper(Settings indexSettings) {
-        super(NAME, Defaults.FIELD_TYPE, Defaults.FIELD_TYPE, indexSettings);
-    }
-
-    @Override
-    public void preParse(ParseContext context) throws IOException {
-        super.parse(context);
-    }
-
-    @Override
-    protected void parseCreateField(ParseContext context, List<IndexableField> fields) throws IOException {
-        // see InternalEngine.updateVersion to see where the real version value is set
-        final Field seqNo = new NumericDocValuesField(NAME, SequenceNumbersService.UNASSIGNED_SEQ_NO);
-        context.seqNo(seqNo);
-        fields.add(seqNo);
-    }
-
-    @Override
-    public Mapper parse(ParseContext context) throws IOException {
-        // _seq_no added in pre-parse
-        return null;
-    }
-
-    @Override
-    public void postParse(ParseContext context) throws IOException {
-        // In the case of nested docs, let's fill nested docs with seqNo=1 so that Lucene doesn't write a Bitset for documents
-        // that don't have the field. This is consistent with the default value for efficiency.
-        for (int i = 1; i < context.docs().size(); i++) {
-            final Document doc = context.docs().get(i);
-            doc.add(new NumericDocValuesField(NAME, 1L));
-        }
-    }
-
-    @Override
-    protected String contentType() {
-        return CONTENT_TYPE;
-    }
-
-    @Override
-    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
-        return builder;
-    }
-
-    @Override
-    protected void doMerge(Mapper mergeWith, boolean updateAllTypes) {
-        // nothing to do
-    }
-
-}

core/src/main/java/org/elasticsearch/index/shard/IndexShard.java

@@ -510,7 +510,7 @@ public class IndexShard extends AbstractIndexShardComponent implements IndicesCl
                                               boolean isRetry) {
         try {
             verifyPrimary();
-            return prepareIndex(docMapper(source.type()), source, SequenceNumbersService.UNASSIGNED_SEQ_NO, version, versionType,
+            return prepareIndex(docMapper(source.type()), source, SequenceNumbersService.UNASSIGNED_SEQ_NO, primaryTerm, version, versionType,
                 Engine.Operation.Origin.PRIMARY, autoGeneratedIdTimestamp, isRetry);
         } catch (Exception e) {
             verifyNotClosed(e);
@@ -522,16 +522,17 @@ public class IndexShard extends AbstractIndexShardComponent implements IndicesCl
                                               boolean isRetry) {
         try {
             verifyReplicationTarget();
-            return prepareIndex(docMapper(source.type()), source, seqNo, version, versionType, Engine.Operation.Origin.REPLICA, autoGeneratedIdTimestamp,
-                isRetry);
+            return prepareIndex(docMapper(source.type()), source, seqNo, primaryTerm, version, versionType,
+                    Engine.Operation.Origin.REPLICA, autoGeneratedIdTimestamp, isRetry);
         } catch (Exception e) {
             verifyNotClosed(e);
             throw e;
         }
     }
 
-    static Engine.Index prepareIndex(DocumentMapperForType docMapper, SourceToParse source, long seqNo, long version, VersionType versionType,
-                                     Engine.Operation.Origin origin, long autoGeneratedIdTimestamp, boolean isRetry) {
+    static Engine.Index prepareIndex(DocumentMapperForType docMapper, SourceToParse source, long seqNo, long primaryTerm, long version,
+                                     VersionType versionType, Engine.Operation.Origin origin, long autoGeneratedIdTimestamp,
+                                     boolean isRetry) {
         long startTime = System.nanoTime();
         ParsedDocument doc = docMapper.getDocumentMapper().parse(source);
         if (docMapper.getMapping() != null) {
@@ -540,8 +541,7 @@ public class IndexShard extends AbstractIndexShardComponent implements IndicesCl
         MappedFieldType uidFieldType = docMapper.getDocumentMapper().uidMapper().fieldType();
         Query uidQuery = uidFieldType.termQuery(doc.uid(), null);
         Term uid = MappedFieldType.extractTerm(uidQuery);
-        doc.seqNo().setLongValue(seqNo);
-        return new Engine.Index(uid, doc, seqNo, version, versionType, origin, startTime, autoGeneratedIdTimestamp, isRetry);
+        return new Engine.Index(uid, doc, seqNo, primaryTerm, version, versionType, origin, startTime, autoGeneratedIdTimestamp, isRetry);
     }
 
     public Engine.IndexResult index(Engine.Index index) {
@@ -573,21 +573,24 @@ public class IndexShard extends AbstractIndexShardComponent implements IndicesCl
         final MappedFieldType uidFieldType = documentMapper.uidMapper().fieldType();
         final Query uidQuery = uidFieldType.termQuery(Uid.createUid(type, id), null);
         final Term uid = MappedFieldType.extractTerm(uidQuery);
-        return prepareDelete(type, id, uid, SequenceNumbersService.UNASSIGNED_SEQ_NO, version, versionType, Engine.Operation.Origin.PRIMARY);
+        return prepareDelete(type, id, uid, SequenceNumbersService.UNASSIGNED_SEQ_NO, primaryTerm, version,
+                versionType, Engine.Operation.Origin.PRIMARY);
     }
 
-    public Engine.Delete prepareDeleteOnReplica(String type, String id, long seqNo, long version, VersionType versionType) {
+    public Engine.Delete prepareDeleteOnReplica(String type, String id, long seqNo, long primaryTerm,
+                                                long version, VersionType versionType) {
         verifyReplicationTarget();
         final DocumentMapper documentMapper = docMapper(type).getDocumentMapper();
         final MappedFieldType uidFieldType = documentMapper.uidMapper().fieldType();
         final Query uidQuery = uidFieldType.termQuery(Uid.createUid(type, id), null);
         final Term uid = MappedFieldType.extractTerm(uidQuery);
-        return prepareDelete(type, id, uid, seqNo, version, versionType, Engine.Operation.Origin.REPLICA);
+        return prepareDelete(type, id, uid, seqNo, primaryTerm, version, versionType, Engine.Operation.Origin.REPLICA);
     }
 
-    static Engine.Delete prepareDelete(String type, String id, Term uid, long seqNo, long version, VersionType versionType, Engine.Operation.Origin origin) {
+    static Engine.Delete prepareDelete(String type, String id, Term uid, long seqNo, long primaryTerm, long version,
+                                       VersionType versionType, Engine.Operation.Origin origin) {
         long startTime = System.nanoTime();
-        return new Engine.Delete(type, id, uid, seqNo, version, versionType, origin, startTime);
+        return new Engine.Delete(type, id, uid, seqNo, primaryTerm, version, versionType, origin, startTime);
     }
 
     public Engine.DeleteResult delete(Engine.Delete delete) {

core/src/main/java/org/elasticsearch/index/shard/TranslogRecoveryPerformer.java

@@ -155,7 +155,7 @@ public class TranslogRecoveryPerformer {
                     // we set canHaveDuplicates to true all the time such that we de-optimze the translog case and ensure that all
                     // autoGeneratedID docs that are coming from the primary are updated correctly.
                     Engine.Index engineIndex = IndexShard.prepareIndex(docMapper(index.type()), source(shardId.getIndexName(), index.type(), index.id(), index.source())
-                            .routing(index.routing()).parent(index.parent()), index.seqNo(),
+                            .routing(index.routing()).parent(index.parent()), index.seqNo(), index.primaryTerm(),
                             index.version(), index.versionType().versionTypeForReplicationAndRecovery(), origin, index.getAutoGeneratedIdTimestamp(), true);
                     maybeAddMappingUpdate(engineIndex.type(), engineIndex.parsedDoc().dynamicMappingsUpdate(), engineIndex.id(), allowMappingUpdates);
                     if (logger.isTraceEnabled()) {
@@ -170,7 +170,8 @@ public class TranslogRecoveryPerformer {
                         logger.trace("[translog] recover [delete] op of [{}][{}]", uid.type(), uid.id());
                     }
                     final Engine.Delete engineDelete = new Engine.Delete(uid.type(), uid.id(), delete.uid(), delete.seqNo(),
-                        delete.version(), delete.versionType().versionTypeForReplicationAndRecovery(), origin, System.nanoTime());
+                            delete.primaryTerm(), delete.version(), delete.versionType().versionTypeForReplicationAndRecovery(),
+                            origin, System.nanoTime());
                     delete(engine, engineDelete);
                     break;
                 default:

core/src/main/java/org/elasticsearch/index/translog/Translog.java

@@ -825,6 +825,7 @@ public class Translog extends AbstractIndexShardComponent implements IndexShardC
         private final long autoGeneratedIdTimestamp;
         private final String type;
         private long seqNo = SequenceNumbersService.UNASSIGNED_SEQ_NO;
+        private long primaryTerm = 0;
         private final long version;
         private final VersionType versionType;
         private final BytesReference source;
@@ -853,6 +854,7 @@ public class Translog extends AbstractIndexShardComponent implements IndexShardC
             }
             if (format >= FORMAT_SEQ_NO) {
                 seqNo = in.readVLong();
+                primaryTerm = in.readVLong();
             }
         }
 
@@ -863,6 +865,7 @@ public class Translog extends AbstractIndexShardComponent implements IndexShardC
             this.routing = index.routing();
             this.parent = index.parent();
             this.seqNo = indexResult.getSeqNo();
+            this.primaryTerm = index.primaryTerm();
             this.version = indexResult.getVersion();
             this.versionType = index.versionType();
             this.autoGeneratedIdTimestamp = index.getAutoGeneratedIdTimestamp();
@@ -914,6 +917,10 @@ public class Translog extends AbstractIndexShardComponent implements IndexShardC
             return seqNo;
         }
 
+        public long primaryTerm() {
+            return primaryTerm;
+        }
+
         public long version() {
             return this.version;
         }
@@ -940,6 +947,7 @@ public class Translog extends AbstractIndexShardComponent implements IndexShardC
             out.writeByte(versionType.getValue());
             out.writeLong(autoGeneratedIdTimestamp);
             out.writeVLong(seqNo);
+            out.writeVLong(primaryTerm);
         }
 
         @Override
@@ -955,6 +963,7 @@ public class Translog extends AbstractIndexShardComponent implements IndexShardC
 
             if (version != index.version ||
                     seqNo != index.seqNo ||
+                    primaryTerm != index.primaryTerm ||
                     id.equals(index.id) == false ||
                     type.equals(index.type) == false ||
                     versionType != index.versionType ||
@@ -974,6 +983,7 @@ public class Translog extends AbstractIndexShardComponent implements IndexShardC
             int result = id.hashCode();
             result = 31 * result + type.hashCode();
             result = 31 * result + Long.hashCode(seqNo);
+            result = 31 * result + Long.hashCode(primaryTerm);
             result = 31 * result + Long.hashCode(version);
             result = 31 * result + versionType.hashCode();
             result = 31 * result + source.hashCode();
@@ -1003,6 +1013,7 @@ public class Translog extends AbstractIndexShardComponent implements IndexShardC
 
         private Term uid;
         private long seqNo = SequenceNumbersService.UNASSIGNED_SEQ_NO;
+        private long primaryTerm = 0;
         private long version = Versions.MATCH_ANY;
         private VersionType versionType = VersionType.INTERNAL;
 
@@ -1015,21 +1026,23 @@ public class Translog extends AbstractIndexShardComponent implements IndexShardC
             assert versionType.validateVersionForWrites(this.version);
             if (format >= FORMAT_SEQ_NO) {
                 seqNo = in.readVLong();
+                primaryTerm = in.readVLong();
             }
         }
 
         public Delete(Engine.Delete delete, Engine.DeleteResult deleteResult) {
-            this(delete.uid(), deleteResult.getSeqNo(), deleteResult.getVersion(), delete.versionType());
+            this(delete.uid(), deleteResult.getSeqNo(), delete.primaryTerm(), deleteResult.getVersion(), delete.versionType());
         }
 
         /** utility for testing */
         public Delete(Term uid) {
-            this(uid, 0, Versions.MATCH_ANY, VersionType.INTERNAL);
+            this(uid, 0, 0, Versions.MATCH_ANY, VersionType.INTERNAL);
         }
 
-        public Delete(Term uid, long seqNo, long version, VersionType versionType) {
+        public Delete(Term uid, long seqNo, long primaryTerm, long version, VersionType versionType) {
             this.uid = uid;
             this.seqNo = seqNo;
+            this.primaryTerm = primaryTerm;
             this.version = version;
             this.versionType = versionType;
         }
@@ -1052,6 +1065,10 @@ public class Translog extends AbstractIndexShardComponent implements IndexShardC
             return seqNo;
         }
 
+        public long primaryTerm() {
+            return primaryTerm;
+        }
+
         public long version() {
             return this.version;
         }
@@ -1073,6 +1090,7 @@ public class Translog extends AbstractIndexShardComponent implements IndexShardC
             out.writeLong(version);
             out.writeByte(versionType.getValue());
             out.writeVLong(seqNo);
+            out.writeVLong(primaryTerm);
         }
 
         @Override
@@ -1086,7 +1104,9 @@ public class Translog extends AbstractIndexShardComponent implements IndexShardC
 
             Delete delete = (Delete) o;
 
-            return version == delete.version && seqNo == delete.seqNo &&
+            return version == delete.version &&
+                    seqNo == delete.seqNo &&
+                    primaryTerm == delete.primaryTerm &&
                     uid.equals(delete.uid) &&
                     versionType == delete.versionType;
         }
@@ -1095,6 +1115,7 @@ public class Translog extends AbstractIndexShardComponent implements IndexShardC
         public int hashCode() {
             int result = uid.hashCode();
             result = 31 * result + Long.hashCode(seqNo);
+            result = 31 * result + Long.hashCode(primaryTerm);
             result = 31 * result + Long.hashCode(version);
             result = 31 * result + versionType.hashCode();
             return result;

core/src/main/java/org/elasticsearch/indices/IndicesModule.java

@@ -45,13 +45,13 @@ import org.elasticsearch.index.mapper.ParentFieldMapper;
 import org.elasticsearch.index.mapper.RangeFieldMapper;
 import org.elasticsearch.index.mapper.RoutingFieldMapper;
 import org.elasticsearch.index.mapper.ScaledFloatFieldMapper;
+import org.elasticsearch.index.mapper.SeqNoFieldMapper;
 import org.elasticsearch.index.mapper.SourceFieldMapper;
 import org.elasticsearch.index.mapper.TextFieldMapper;
 import org.elasticsearch.index.mapper.TokenCountFieldMapper;
 import org.elasticsearch.index.mapper.TypeFieldMapper;
 import org.elasticsearch.index.mapper.UidFieldMapper;
 import org.elasticsearch.index.mapper.VersionFieldMapper;
-import org.elasticsearch.index.mapper.internal.SeqNoFieldMapper;
 import org.elasticsearch.index.seqno.GlobalCheckpointSyncAction;
 import org.elasticsearch.indices.cluster.IndicesClusterStateService;
 import org.elasticsearch.indices.flush.SyncedFlushService;

core/src/main/java/org/elasticsearch/node/service/NodeService.java

@@ -19,9 +19,6 @@
 
 package org.elasticsearch.node.service;
 
-import java.io.Closeable;
-import java.io.IOException;
-
 import org.elasticsearch.Build;
 import org.elasticsearch.Version;
 import org.elasticsearch.action.admin.cluster.node.info.NodeInfo;
@@ -44,6 +41,9 @@ import org.elasticsearch.script.ScriptService;
 import org.elasticsearch.threadpool.ThreadPool;
 import org.elasticsearch.transport.TransportService;
 
+import java.io.Closeable;
+import java.io.IOException;
+
 public class NodeService extends AbstractComponent implements Closeable {
 
     private final ThreadPool threadPool;
@@ -111,7 +111,7 @@ public class NodeService extends AbstractComponent implements Closeable {
                 threadPool ? this.threadPool.stats() : null,
                 fs ? monitorService.fsService().stats() : null,
                 transport ? transportService.stats() : null,
-                http ? httpServer.stats() : null,
+                http ? (httpServer == null ? null : httpServer.stats()) : null,
                 circuitBreaker ? circuitBreakerService.stats() : null,
                 script ? scriptService.stats() : null,
                 discoveryStats ? discovery.stats() : null,
@@ -127,4 +127,5 @@ public class NodeService extends AbstractComponent implements Closeable {
     public void close() throws IOException {
         indicesService.close();
     }
+
 }

core/src/test/java/org/elasticsearch/action/admin/cluster/node/tasks/TasksIT.java

@@ -303,7 +303,9 @@ public class TasksIT extends ESIntegTestCase {
         client().prepareBulk().add(client().prepareIndex("test", "doc", "test_id").setSource("{\"foo\": \"bar\"}")).get();
 
         // the bulk operation should produce one main task
-        assertEquals(1, numberOfEvents(BulkAction.NAME, Tuple::v1));
+        List<TaskInfo> topTask = findEvents(BulkAction.NAME, Tuple::v1);
+        assertEquals(1, topTask.size());
+        assertEquals("requests[1], indices[test]", topTask.get(0).getDescription());
 
         // we should also get 1 or 2 [s] operation with main operation as a parent
         // in case the primary is located on the coordinating node we will have 1 operation, otherwise - 2
@@ -317,17 +319,20 @@ public class TasksIT extends ESIntegTestCase {
             shardTask = shardTasks.get(0);
             // and it should have the main task as a parent
             assertParentTask(shardTask, findEvents(BulkAction.NAME, Tuple::v1).get(0));
+            assertEquals("requests[1], index[test]", shardTask.getDescription());
         } else {
             if (shardTasks.get(0).getParentTaskId().equals(shardTasks.get(1).getTaskId())) {
                 // task 1 is the parent of task 0, that means that task 0 will control [s][p] and [s][r] tasks
                  shardTask = shardTasks.get(0);
                 // in turn the parent of the task 1 should be the main task
                 assertParentTask(shardTasks.get(1), findEvents(BulkAction.NAME, Tuple::v1).get(0));
+                assertEquals("requests[1], index[test]", shardTask.getDescription());
             } else {
                 // otherwise task 1 will control [s][p] and [s][r] tasks
                 shardTask = shardTasks.get(1);
                 // in turn the parent of the task 0 should be the main task
                 assertParentTask(shardTasks.get(0), findEvents(BulkAction.NAME, Tuple::v1).get(0));
+                assertEquals("requests[1], index[test]", shardTask.getDescription());
             }
         }
 

core/src/test/java/org/elasticsearch/index/IndexingSlowLogTests.java

@@ -28,6 +28,7 @@ import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.xcontent.json.JsonXContent;
 import org.elasticsearch.index.IndexingSlowLog.SlowLogParsedDocumentPrinter;
 import org.elasticsearch.index.mapper.ParsedDocument;
+import org.elasticsearch.index.mapper.SeqNoFieldMapper;
 import org.elasticsearch.test.ESTestCase;
 
 import java.io.IOException;
@@ -39,7 +40,7 @@ import static org.hamcrest.Matchers.startsWith;
 public class IndexingSlowLogTests extends ESTestCase {
     public void testSlowLogParsedDocumentPrinterSourceToLog() throws IOException {
         BytesReference source = JsonXContent.contentBuilder().startObject().field("foo", "bar").endObject().bytes();
-        ParsedDocument pd = new ParsedDocument(new NumericDocValuesField("version", 1), new NumericDocValuesField("seqNo", 1), "id",
+        ParsedDocument pd = new ParsedDocument(new NumericDocValuesField("version", 1), SeqNoFieldMapper.SequenceID.emptySeqID(), "id",
                 "test", null, null, source, null);
         Index index = new Index("foo", "123");
         // Turning off document logging doesn't log source[]

core/src/test/java/org/elasticsearch/index/engine/InternalEngineTests.java

@@ -31,6 +31,7 @@ import org.apache.lucene.analysis.Tokenizer;
 import org.apache.lucene.analysis.standard.StandardAnalyzer;
 import org.apache.lucene.codecs.Codec;
 import org.apache.lucene.document.Field;
+import org.apache.lucene.document.LongPoint;
 import org.apache.lucene.document.NumericDocValuesField;
 import org.apache.lucene.document.TextField;
 import org.apache.lucene.index.CorruptIndexException;
@@ -75,7 +76,9 @@ import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.bytes.BytesArray;
 import org.elasticsearch.common.bytes.BytesReference;
+import org.elasticsearch.common.collect.Tuple;
 import org.elasticsearch.common.io.FileSystemUtils;
+import org.elasticsearch.common.lease.Releasables;
 import org.elasticsearch.common.logging.Loggers;
 import org.elasticsearch.common.lucene.Lucene;
 import org.elasticsearch.common.lucene.uid.Versions;
@@ -100,9 +103,9 @@ import org.elasticsearch.index.mapper.MetadataFieldMapper;
 import org.elasticsearch.index.mapper.ParseContext.Document;
 import org.elasticsearch.index.mapper.ParsedDocument;
 import org.elasticsearch.index.mapper.RootObjectMapper;
+import org.elasticsearch.index.mapper.SeqNoFieldMapper;
 import org.elasticsearch.index.mapper.SourceFieldMapper;
 import org.elasticsearch.index.mapper.UidFieldMapper;
-import org.elasticsearch.index.mapper.internal.SeqNoFieldMapper;
 import org.elasticsearch.index.seqno.SequenceNumbersService;
 import org.elasticsearch.index.shard.DocsStats;
 import org.elasticsearch.index.shard.IndexSearcherWrapper;
@@ -268,11 +271,13 @@ public class InternalEngineTests extends ESTestCase {
     private ParsedDocument testParsedDocument(String uid, String id, String type, String routing, Document document, BytesReference source, Mapping mappingUpdate) {
         Field uidField = new Field("_uid", uid, UidFieldMapper.Defaults.FIELD_TYPE);
         Field versionField = new NumericDocValuesField("_version", 0);
-        Field seqNoField = new NumericDocValuesField("_seq_no", 0);
+        SeqNoFieldMapper.SequenceID seqID = SeqNoFieldMapper.SequenceID.emptySeqID();
         document.add(uidField);
         document.add(versionField);
-        document.add(seqNoField);
-        return new ParsedDocument(versionField, seqNoField, id, type, routing, Arrays.asList(document), source, mappingUpdate);
+        document.add(seqID.seqNo);
+        document.add(seqID.seqNoDocValue);
+        document.add(seqID.primaryTerm);
+        return new ParsedDocument(versionField, seqID, id, type, routing, Arrays.asList(document), source, mappingUpdate);
     }
 
     protected Store createStore() throws IOException {
@@ -708,11 +713,11 @@ public class InternalEngineTests extends ESTestCase {
             for (int i = 0; i < ops; i++) {
                 final ParsedDocument doc = testParsedDocument("1", "1", "test", null, testDocumentWithTextField(), SOURCE, null);
                 if (randomBoolean()) {
-                    final Engine.Index operation = new Engine.Index(newUid("test#1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, i, VersionType.EXTERNAL, Engine.Operation.Origin.PRIMARY, System.nanoTime(), -1, false);
+                    final Engine.Index operation = new Engine.Index(newUid("test#1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, i, VersionType.EXTERNAL, Engine.Operation.Origin.PRIMARY, System.nanoTime(), -1, false);
                     operations.add(operation);
                     initialEngine.index(operation);
                 } else {
-                    final Engine.Delete operation = new Engine.Delete("test", "1", newUid("test#1"), SequenceNumbersService.UNASSIGNED_SEQ_NO, i, VersionType.EXTERNAL, Engine.Operation.Origin.PRIMARY, System.nanoTime());
+                    final Engine.Delete operation = new Engine.Delete("test", "1", newUid("test#1"), SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, i, VersionType.EXTERNAL, Engine.Operation.Origin.PRIMARY, System.nanoTime());
                     operations.add(operation);
                     initialEngine.delete(operation);
                 }
@@ -1039,7 +1044,7 @@ public class InternalEngineTests extends ESTestCase {
                 engine.flush();
                 final boolean forceMergeFlushes = randomBoolean();
                 if (forceMergeFlushes) {
-                    engine.index(new Engine.Index(newUid("3"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, Versions.MATCH_ANY, VersionType.INTERNAL, Engine.Operation.Origin.PRIMARY, System.nanoTime() - engine.engineConfig.getFlushMergesAfter().nanos(), -1, false));
+                    engine.index(new Engine.Index(newUid("3"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, Versions.MATCH_ANY, VersionType.INTERNAL, Engine.Operation.Origin.PRIMARY, System.nanoTime() - engine.engineConfig.getFlushMergesAfter().nanos(), -1, false));
                 } else {
                     engine.index(new Engine.Index(newUid("3"), doc));
                 }
@@ -1126,7 +1131,7 @@ public class InternalEngineTests extends ESTestCase {
         Engine.IndexResult indexResult = engine.index(create);
         assertThat(indexResult.getVersion(), equalTo(1L));
 
-        create = new Engine.Index(newUid("1"), doc, indexResult.getSeqNo(), indexResult.getVersion(), create.versionType().versionTypeForReplicationAndRecovery(), REPLICA, 0, -1, false);
+        create = new Engine.Index(newUid("1"), doc, indexResult.getSeqNo(), create.primaryTerm(), indexResult.getVersion(), create.versionType().versionTypeForReplicationAndRecovery(), REPLICA, 0, -1, false);
         indexResult = replicaEngine.index(create);
         assertThat(indexResult.getVersion(), equalTo(1L));
     }
@@ -1137,18 +1142,18 @@ public class InternalEngineTests extends ESTestCase {
         Engine.IndexResult indexResult = engine.index(index);
         assertThat(indexResult.getVersion(), equalTo(1L));
 
-        index = new Engine.Index(newUid("1"), doc, indexResult.getSeqNo(), indexResult.getVersion(), index.versionType().versionTypeForReplicationAndRecovery(), REPLICA, 0, -1, false);
+        index = new Engine.Index(newUid("1"), doc, indexResult.getSeqNo(), index.primaryTerm(), indexResult.getVersion(), index.versionType().versionTypeForReplicationAndRecovery(), REPLICA, 0, -1, false);
         indexResult = replicaEngine.index(index);
         assertThat(indexResult.getVersion(), equalTo(1L));
     }
 
     public void testExternalVersioningNewIndex() {
         ParsedDocument doc = testParsedDocument("1", "1", "test", null, testDocument(), B_1, null);
-        Engine.Index index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 12, VersionType.EXTERNAL, PRIMARY, 0, -1, false);
+        Engine.Index index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 12, VersionType.EXTERNAL, PRIMARY, 0, -1, false);
         Engine.IndexResult indexResult = engine.index(index);
         assertThat(indexResult.getVersion(), equalTo(12L));
 
-        index = new Engine.Index(newUid("1"), doc, indexResult.getSeqNo(), indexResult.getVersion(), index.versionType().versionTypeForReplicationAndRecovery(), REPLICA, 0, -1, false);
+        index = new Engine.Index(newUid("1"), doc, indexResult.getSeqNo(), index.primaryTerm(), indexResult.getVersion(), index.versionType().versionTypeForReplicationAndRecovery(), REPLICA, 0, -1, false);
         indexResult = replicaEngine.index(index);
         assertThat(indexResult.getVersion(), equalTo(12L));
     }
@@ -1163,13 +1168,13 @@ public class InternalEngineTests extends ESTestCase {
         indexResult = engine.index(index);
         assertThat(indexResult.getVersion(), equalTo(2L));
 
-        index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 1L, VersionType.INTERNAL, Engine.Operation.Origin.PRIMARY, 0, -1, false);
+        index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 1L, VersionType.INTERNAL, Engine.Operation.Origin.PRIMARY, 0, -1, false);
         indexResult = engine.index(index);
         assertTrue(indexResult.hasFailure());
         assertThat(indexResult.getFailure(), instanceOf(VersionConflictEngineException.class));
 
         // future versions should not work as well
-        index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 3L, VersionType.INTERNAL, PRIMARY, 0, -1, false);
+        index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 3L, VersionType.INTERNAL, PRIMARY, 0, -1, false);
         indexResult = engine.index(index);
         assertTrue(indexResult.hasFailure());
         assertThat(indexResult.getFailure(), instanceOf(VersionConflictEngineException.class));
@@ -1177,15 +1182,15 @@ public class InternalEngineTests extends ESTestCase {
 
     public void testExternalVersioningIndexConflict() {
         ParsedDocument doc = testParsedDocument("1", "1", "test", null, testDocument(), B_1, null);
-        Engine.Index index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 12, VersionType.EXTERNAL, PRIMARY, 0, -1, false);
+        Engine.Index index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 12, VersionType.EXTERNAL, PRIMARY, 0, -1, false);
         Engine.IndexResult indexResult = engine.index(index);
         assertThat(indexResult.getVersion(), equalTo(12L));
 
-        index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 14, VersionType.EXTERNAL, PRIMARY, 0, -1, false);
+        index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 14, VersionType.EXTERNAL, PRIMARY, 0, -1, false);
         indexResult = engine.index(index);
         assertThat(indexResult.getVersion(), equalTo(14L));
 
-        index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 13, VersionType.EXTERNAL, PRIMARY, 0, -1, false);
+        index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 13, VersionType.EXTERNAL, PRIMARY, 0, -1, false);
         indexResult = engine.index(index);
         assertTrue(indexResult.hasFailure());
         assertThat(indexResult.getFailure(), instanceOf(VersionConflictEngineException.class));
@@ -1193,7 +1198,7 @@ public class InternalEngineTests extends ESTestCase {
 
     public void testForceVersioningNotAllowedExceptForOlderIndices() throws Exception {
         ParsedDocument doc = testParsedDocument("1", "1", "test", null, testDocument(), B_1, null);
-        Engine.Index index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 42, VersionType.FORCE, PRIMARY, 0, -1, false);
+        Engine.Index index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 42, VersionType.FORCE, PRIMARY, 0, -1, false);
 
         Engine.IndexResult indexResult = engine.index(index);
         assertTrue(indexResult.hasFailure());
@@ -1205,13 +1210,13 @@ public class InternalEngineTests extends ESTestCase {
                 .build());
         try (Store store = createStore();
                 Engine engine = createEngine(oldIndexSettings, store, createTempDir(), NoMergePolicy.INSTANCE)) {
-            index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 84, VersionType.FORCE, PRIMARY, 0, -1, false);
+            index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 84, VersionType.FORCE, PRIMARY, 0, -1, false);
             Engine.IndexResult result = engine.index(index);
             assertTrue(result.hasFailure());
             assertThat(result.getFailure(), instanceOf(IllegalArgumentException.class));
             assertThat(result.getFailure().getMessage(), containsString("version type [FORCE] may not be used for non-translog operations"));
 
-            index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 84, VersionType.FORCE,
+            index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 84, VersionType.FORCE,
                     Engine.Operation.Origin.LOCAL_TRANSLOG_RECOVERY, 0, -1, false);
             result = engine.index(index);
             assertThat(result.getVersion(), equalTo(84L));
@@ -1230,13 +1235,13 @@ public class InternalEngineTests extends ESTestCase {
 
         engine.flush();
 
-        index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 1L, VersionType.INTERNAL, PRIMARY, 0, -1, false);
+        index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 1L, VersionType.INTERNAL, PRIMARY, 0, -1, false);
         indexResult = engine.index(index);
         assertTrue(indexResult.hasFailure());
         assertThat(indexResult.getFailure(), instanceOf(VersionConflictEngineException.class));
 
         // future versions should not work as well
-        index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 3L, VersionType.INTERNAL, PRIMARY, 0, -1, false);
+        index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 3L, VersionType.INTERNAL, PRIMARY, 0, -1, false);
         indexResult = engine.index(index);
         assertTrue(indexResult.hasFailure());
         assertThat(indexResult.getFailure(), instanceOf(VersionConflictEngineException.class));
@@ -1244,17 +1249,17 @@ public class InternalEngineTests extends ESTestCase {
 
     public void testExternalVersioningIndexConflictWithFlush() {
         ParsedDocument doc = testParsedDocument("1", "1", "test", null, testDocument(), B_1, null);
-        Engine.Index index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 12, VersionType.EXTERNAL, PRIMARY, 0, -1, false);
+        Engine.Index index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 12, VersionType.EXTERNAL, PRIMARY, 0, -1, false);
         Engine.IndexResult indexResult = engine.index(index);
         assertThat(indexResult.getVersion(), equalTo(12L));
 
-        index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 14, VersionType.EXTERNAL, PRIMARY, 0, -1, false);
+        index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 14, VersionType.EXTERNAL, PRIMARY, 0, -1, false);
         indexResult = engine.index(index);
         assertThat(indexResult.getVersion(), equalTo(14L));
 
         engine.flush();
 
-        index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 13, VersionType.EXTERNAL, PRIMARY, 0, -1, false);
+        index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 13, VersionType.EXTERNAL, PRIMARY, 0, -1, false);
         indexResult = engine.index(index);
         assertTrue(indexResult.hasFailure());
         assertThat(indexResult.getFailure(), instanceOf(VersionConflictEngineException.class));
@@ -1365,24 +1370,24 @@ public class InternalEngineTests extends ESTestCase {
         indexResult = engine.index(index);
         assertThat(indexResult.getVersion(), equalTo(2L));
 
-        Engine.Delete delete = new Engine.Delete("test", "1", newUid("1"), SequenceNumbersService.UNASSIGNED_SEQ_NO, 1L, VersionType.INTERNAL, PRIMARY, 0);
+        Engine.Delete delete = new Engine.Delete("test", "1", newUid("1"), SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 1L, VersionType.INTERNAL, PRIMARY, 0);
         Engine.DeleteResult result = engine.delete(delete);
         assertTrue(result.hasFailure());
         assertThat(result.getFailure(), instanceOf(VersionConflictEngineException.class));
 
         // future versions should not work as well
-        delete = new Engine.Delete("test", "1", newUid("1"), SequenceNumbersService.UNASSIGNED_SEQ_NO, 3L, VersionType.INTERNAL, PRIMARY, 0);
+        delete = new Engine.Delete("test", "1", newUid("1"), SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 3L, VersionType.INTERNAL, PRIMARY, 0);
         result = engine.delete(delete);
         assertTrue(result.hasFailure());
         assertThat(result.getFailure(), instanceOf(VersionConflictEngineException.class));
 
         // now actually delete
-        delete = new Engine.Delete("test", "1", newUid("1"), SequenceNumbersService.UNASSIGNED_SEQ_NO, 2L, VersionType.INTERNAL, PRIMARY, 0);
+        delete = new Engine.Delete("test", "1", newUid("1"), SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 2L, VersionType.INTERNAL, PRIMARY, 0);
         result = engine.delete(delete);
         assertThat(result.getVersion(), equalTo(3L));
 
         // now check if we can index to a delete doc with version
-        index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 2L, VersionType.INTERNAL, PRIMARY, 0, -1, false);
+        index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 2L, VersionType.INTERNAL, PRIMARY, 0, -1, false);
         indexResult = engine.index(index);
         assertTrue(indexResult.hasFailure());
         assertThat(indexResult.getFailure(), instanceOf(VersionConflictEngineException.class));
@@ -1400,13 +1405,13 @@ public class InternalEngineTests extends ESTestCase {
 
         engine.flush();
 
-        Engine.Delete delete = new Engine.Delete("test", "1", newUid("1"), SequenceNumbersService.UNASSIGNED_SEQ_NO, 1L, VersionType.INTERNAL, PRIMARY, 0);
+        Engine.Delete delete = new Engine.Delete("test", "1", newUid("1"), SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 1L, VersionType.INTERNAL, PRIMARY, 0);
         Engine.DeleteResult deleteResult = engine.delete(delete);
         assertTrue(deleteResult.hasFailure());
         assertThat(deleteResult.getFailure(), instanceOf(VersionConflictEngineException.class));
 
         // future versions should not work as well
-        delete = new Engine.Delete("test", "1", newUid("1"), SequenceNumbersService.UNASSIGNED_SEQ_NO, 3L, VersionType.INTERNAL, PRIMARY, 0);
+        delete = new Engine.Delete("test", "1", newUid("1"), SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 3L, VersionType.INTERNAL, PRIMARY, 0);
         deleteResult = engine.delete(delete);
         assertTrue(deleteResult.hasFailure());
         assertThat(deleteResult.getFailure(), instanceOf(VersionConflictEngineException.class));
@@ -1414,14 +1419,14 @@ public class InternalEngineTests extends ESTestCase {
         engine.flush();
 
         // now actually delete
-        delete = new Engine.Delete("test", "1", newUid("1"), SequenceNumbersService.UNASSIGNED_SEQ_NO, 2L, VersionType.INTERNAL, PRIMARY, 0);
+        delete = new Engine.Delete("test", "1", newUid("1"), SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 2L, VersionType.INTERNAL, PRIMARY, 0);
         deleteResult = engine.delete(delete);
         assertThat(deleteResult.getVersion(), equalTo(3L));
 
         engine.flush();
 
         // now check if we can index to a delete doc with version
-        index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 2L, VersionType.INTERNAL, PRIMARY, 0, -1, false);
+        index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 2L, VersionType.INTERNAL, PRIMARY, 0, -1, false);
         indexResult = engine.index(index);
         assertTrue(indexResult.hasFailure());
         assertThat(indexResult.getFailure(), instanceOf(VersionConflictEngineException.class));
@@ -1429,11 +1434,11 @@ public class InternalEngineTests extends ESTestCase {
 
     public void testVersioningCreateExistsException() {
         ParsedDocument doc = testParsedDocument("1", "1", "test", null, testDocument(), B_1, null);
-        Engine.Index create = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, Versions.MATCH_DELETED, VersionType.INTERNAL, PRIMARY, 0, -1, false);
+        Engine.Index create = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, Versions.MATCH_DELETED, VersionType.INTERNAL, PRIMARY, 0, -1, false);
         Engine.IndexResult indexResult = engine.index(create);
         assertThat(indexResult.getVersion(), equalTo(1L));
 
-        create = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, Versions.MATCH_DELETED, VersionType.INTERNAL, PRIMARY, 0, -1, false);
+        create = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, Versions.MATCH_DELETED, VersionType.INTERNAL, PRIMARY, 0, -1, false);
         indexResult = engine.index(create);
         assertTrue(indexResult.hasFailure());
         assertThat(indexResult.getFailure(), instanceOf(VersionConflictEngineException.class));
@@ -1441,13 +1446,13 @@ public class InternalEngineTests extends ESTestCase {
 
     public void testVersioningCreateExistsExceptionWithFlush() {
         ParsedDocument doc = testParsedDocument("1", "1", "test", null, testDocument(), B_1, null);
-        Engine.Index create = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, Versions.MATCH_DELETED, VersionType.INTERNAL, PRIMARY, 0, -1, false);
+        Engine.Index create = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, Versions.MATCH_DELETED, VersionType.INTERNAL, PRIMARY, 0, -1, false);
         Engine.IndexResult indexResult = engine.index(create);
         assertThat(indexResult.getVersion(), equalTo(1L));
 
         engine.flush();
 
-        create = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, Versions.MATCH_DELETED, VersionType.INTERNAL, PRIMARY, 0, -1, false);
+        create = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, Versions.MATCH_DELETED, VersionType.INTERNAL, PRIMARY, 0, -1, false);
         indexResult = engine.index(create);
         assertTrue(indexResult.hasFailure());
         assertThat(indexResult.getFailure(), instanceOf(VersionConflictEngineException.class));
@@ -1464,19 +1469,20 @@ public class InternalEngineTests extends ESTestCase {
         assertThat(indexResult.getVersion(), equalTo(2L));
 
         // apply the second index to the replica, should work fine
-        index = new Engine.Index(newUid("1"), doc, indexResult.getSeqNo(), indexResult.getVersion(), VersionType.INTERNAL.versionTypeForReplicationAndRecovery(), REPLICA,  0, -1, false);
+        index = new Engine.Index(newUid("1"), doc, indexResult.getSeqNo(), index.primaryTerm(), indexResult.getVersion(), VersionType.INTERNAL.versionTypeForReplicationAndRecovery(), REPLICA,  0, -1, false);
         indexResult = replicaEngine.index(index);
         assertThat(indexResult.getVersion(), equalTo(2L));
 
         long seqNo = indexResult.getSeqNo();
+        long primaryTerm = index.primaryTerm();
         // now, the old one should not work
-        index = new Engine.Index(newUid("1"), doc, seqNo, 1L, VersionType.INTERNAL.versionTypeForReplicationAndRecovery(), REPLICA, 0, -1, false);
+        index = new Engine.Index(newUid("1"), doc, seqNo, primaryTerm, 1L, VersionType.INTERNAL.versionTypeForReplicationAndRecovery(), REPLICA, 0, -1, false);
         indexResult = replicaEngine.index(index);
         assertTrue(indexResult.hasFailure());
         assertThat(indexResult.getFailure(), instanceOf(VersionConflictEngineException.class));
 
         // second version on replica should fail as well
-        index = new Engine.Index(newUid("1"), doc, seqNo, 2L
+        index = new Engine.Index(newUid("1"), doc, seqNo, primaryTerm, 2L
                 , VersionType.INTERNAL.versionTypeForReplicationAndRecovery(), REPLICA, 0, -1, false);
         indexResult = replicaEngine.index(index);
         assertThat(indexResult.getVersion(), equalTo(2L));
@@ -1490,8 +1496,8 @@ public class InternalEngineTests extends ESTestCase {
         assertThat(indexResult.getVersion(), equalTo(1L));
 
         // apply the first index to the replica, should work fine
-        index = new Engine.Index(newUid("1"), doc, indexResult.getSeqNo(), 1L
-                , VersionType.INTERNAL.versionTypeForReplicationAndRecovery(), REPLICA, 0, -1, false);
+        index = new Engine.Index(newUid("1"), doc, indexResult.getSeqNo(), index.primaryTerm(), 1L,
+                VersionType.INTERNAL.versionTypeForReplicationAndRecovery(), REPLICA, 0, -1, false);
         indexResult = replicaEngine.index(index);
         assertThat(indexResult.getVersion(), equalTo(1L));
 
@@ -1506,20 +1512,20 @@ public class InternalEngineTests extends ESTestCase {
         assertThat(deleteResult.getVersion(), equalTo(3L));
 
         // apply the delete on the replica (skipping the second index)
-        delete = new Engine.Delete("test", "1", newUid("1"), deleteResult.getSeqNo(), 3L
+        delete = new Engine.Delete("test", "1", newUid("1"), deleteResult.getSeqNo(), delete.primaryTerm(), 3L
                 , VersionType.INTERNAL.versionTypeForReplicationAndRecovery(), REPLICA, 0);
         deleteResult = replicaEngine.delete(delete);
         assertThat(deleteResult.getVersion(), equalTo(3L));
 
         // second time delete with same version should fail
-        delete = new Engine.Delete("test", "1", newUid("1"), deleteResult.getSeqNo(), 3L
+        delete = new Engine.Delete("test", "1", newUid("1"), deleteResult.getSeqNo(), delete.primaryTerm(), 3L
                 , VersionType.INTERNAL.versionTypeForReplicationAndRecovery(), REPLICA, 0);
         deleteResult = replicaEngine.delete(delete);
         assertTrue(deleteResult.hasFailure());
         assertThat(deleteResult.getFailure(), instanceOf(VersionConflictEngineException.class));
 
         // now do the second index on the replica, it should fail
-        index = new Engine.Index(newUid("1"), doc, deleteResult.getSeqNo(), 2L, VersionType.INTERNAL.versionTypeForReplicationAndRecovery(), REPLICA, 0, -1, false);
+        index = new Engine.Index(newUid("1"), doc, deleteResult.getSeqNo(), delete.primaryTerm(), 2L, VersionType.INTERNAL.versionTypeForReplicationAndRecovery(), REPLICA, 0, -1, false);
         indexResult = replicaEngine.index(index);
         assertTrue(indexResult.hasFailure());
         assertThat(indexResult.getFailure(), instanceOf(VersionConflictEngineException.class));
@@ -1638,7 +1644,7 @@ public class InternalEngineTests extends ESTestCase {
                     // we have some docs indexed, so delete one of them
                     id = randomFrom(indexedIds);
                     final Engine.Delete delete = new Engine.Delete(
-                        "test", id, newUid("test#" + id), SequenceNumbersService.UNASSIGNED_SEQ_NO,
+                        "test", id, newUid("test#" + id), SequenceNumbersService.UNASSIGNED_SEQ_NO, 0,
                         rarely() ? 100 : Versions.MATCH_ANY, VersionType.INTERNAL, PRIMARY, 0);
                     final Engine.DeleteResult result = initialEngine.delete(delete);
                     if (!result.hasFailure()) {
@@ -1655,7 +1661,7 @@ public class InternalEngineTests extends ESTestCase {
                     id = randomFrom(ids);
                     ParsedDocument doc = testParsedDocument("test#" + id, id, "test", null, testDocumentWithTextField(), SOURCE, null);
                     final Engine.Index index = new Engine.Index(newUid("test#" + id), doc,
-                        SequenceNumbersService.UNASSIGNED_SEQ_NO,
+                        SequenceNumbersService.UNASSIGNED_SEQ_NO, 0,
                         rarely() ? 100 : Versions.MATCH_ANY, VersionType.INTERNAL,
                         PRIMARY, 0, -1, false);
                     final Engine.IndexResult result = initialEngine.index(index);
@@ -1794,7 +1800,7 @@ public class InternalEngineTests extends ESTestCase {
                 assertThat(localCheckpoint, greaterThanOrEqualTo(prevLocalCheckpoint));
                 assertThat(maxSeqNo, greaterThanOrEqualTo(prevMaxSeqNo));
                 try (IndexReader reader = DirectoryReader.open(commit)) {
-                    FieldStats stats = SeqNoFieldMapper.Defaults.FIELD_TYPE.stats(reader);
+                    FieldStats stats = SeqNoFieldMapper.SeqNoDefaults.FIELD_TYPE.stats(reader);
                     final long highestSeqNo;
                     if (stats != null) {
                         highestSeqNo = (long) stats.getMaxValue();
@@ -1887,10 +1893,10 @@ public class InternalEngineTests extends ESTestCase {
             document.add(new TextField("value", "test1", Field.Store.YES));
 
             ParsedDocument doc = testParsedDocument("1", "1", "test", null, document, B_2, null);
-            engine.index(new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 1, VersionType.EXTERNAL, Engine.Operation.Origin.PRIMARY, System.nanoTime(), -1, false));
+            engine.index(new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 1, VersionType.EXTERNAL, Engine.Operation.Origin.PRIMARY, System.nanoTime(), -1, false));
 
             // Delete document we just added:
-            engine.delete(new Engine.Delete("test", "1", newUid("1"), SequenceNumbersService.UNASSIGNED_SEQ_NO, 10, VersionType.EXTERNAL, Engine.Operation.Origin.PRIMARY, System.nanoTime()));
+            engine.delete(new Engine.Delete("test", "1", newUid("1"), SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 10, VersionType.EXTERNAL, Engine.Operation.Origin.PRIMARY, System.nanoTime()));
 
             // Get should not find the document
             Engine.GetResult getResult = engine.get(new Engine.Get(true, newUid("1")));
@@ -1904,14 +1910,14 @@ public class InternalEngineTests extends ESTestCase {
             }
 
             // Delete non-existent document
-            engine.delete(new Engine.Delete("test", "2", newUid("2"), SequenceNumbersService.UNASSIGNED_SEQ_NO, 10, VersionType.EXTERNAL, Engine.Operation.Origin.PRIMARY, System.nanoTime()));
+            engine.delete(new Engine.Delete("test", "2", newUid("2"), SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 10, VersionType.EXTERNAL, Engine.Operation.Origin.PRIMARY, System.nanoTime()));
 
             // Get should not find the document (we never indexed uid=2):
             getResult = engine.get(new Engine.Get(true, newUid("2")));
             assertThat(getResult.exists(), equalTo(false));
 
             // Try to index uid=1 with a too-old version, should fail:
-            Engine.Index index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 2, VersionType.EXTERNAL, Engine.Operation.Origin.PRIMARY, System.nanoTime(), -1, false);
+            Engine.Index index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 2, VersionType.EXTERNAL, Engine.Operation.Origin.PRIMARY, System.nanoTime(), -1, false);
             Engine.IndexResult indexResult = engine.index(index);
             assertTrue(indexResult.hasFailure());
             assertThat(indexResult.getFailure(), instanceOf(VersionConflictEngineException.class));
@@ -1921,7 +1927,7 @@ public class InternalEngineTests extends ESTestCase {
             assertThat(getResult.exists(), equalTo(false));
 
             // Try to index uid=2 with a too-old version, should fail:
-            Engine.Index index1 = new Engine.Index(newUid("2"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 2, VersionType.EXTERNAL, Engine.Operation.Origin.PRIMARY, System.nanoTime(), -1, false);
+            Engine.Index index1 = new Engine.Index(newUid("2"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 2, VersionType.EXTERNAL, Engine.Operation.Origin.PRIMARY, System.nanoTime(), -1, false);
             indexResult = engine.index(index1);
             assertTrue(indexResult.hasFailure());
             assertThat(indexResult.getFailure(), instanceOf(VersionConflictEngineException.class));
@@ -2019,7 +2025,7 @@ public class InternalEngineTests extends ESTestCase {
         final int numDocs = randomIntBetween(1, 10);
         for (int i = 0; i < numDocs; i++) {
             ParsedDocument doc = testParsedDocument(Integer.toString(i), Integer.toString(i), "test", null, testDocument(), new BytesArray("{}"), null);
-            Engine.Index firstIndexRequest = new Engine.Index(newUid(Integer.toString(i)), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, Versions.MATCH_DELETED, VersionType.INTERNAL, PRIMARY, System.nanoTime(), -1, false);
+            Engine.Index firstIndexRequest = new Engine.Index(newUid(Integer.toString(i)), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, Versions.MATCH_DELETED, VersionType.INTERNAL, PRIMARY, System.nanoTime(), -1, false);
             Engine.IndexResult indexResult = engine.index(firstIndexRequest);
             assertThat(indexResult.getVersion(), equalTo(1L));
         }
@@ -2069,7 +2075,7 @@ public class InternalEngineTests extends ESTestCase {
         final int numDocs = randomIntBetween(1, 10);
         for (int i = 0; i < numDocs; i++) {
             ParsedDocument doc = testParsedDocument(Integer.toString(i), Integer.toString(i), "test", null, testDocument(), new BytesArray("{}"), null);
-            Engine.Index firstIndexRequest = new Engine.Index(newUid(Integer.toString(i)), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, Versions.MATCH_DELETED, VersionType.INTERNAL, PRIMARY, System.nanoTime(), -1, false);
+            Engine.Index firstIndexRequest = new Engine.Index(newUid(Integer.toString(i)), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, Versions.MATCH_DELETED, VersionType.INTERNAL, PRIMARY, System.nanoTime(), -1, false);
             Engine.IndexResult indexResult = engine.index(firstIndexRequest);
             assertThat(indexResult.getVersion(), equalTo(1L));
         }
@@ -2162,7 +2168,7 @@ public class InternalEngineTests extends ESTestCase {
                 final int numExtraDocs = randomIntBetween(1, 10);
                 for (int i = 0; i < numExtraDocs; i++) {
                     ParsedDocument doc = testParsedDocument("extra" + Integer.toString(i), "extra" + Integer.toString(i), "test", null, testDocument(), new BytesArray("{}"), null);
-                    Engine.Index firstIndexRequest = new Engine.Index(newUid(Integer.toString(i)), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, Versions.MATCH_DELETED, VersionType.INTERNAL, PRIMARY, System.nanoTime(), -1, false);
+                    Engine.Index firstIndexRequest = new Engine.Index(newUid(Integer.toString(i)), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, Versions.MATCH_DELETED, VersionType.INTERNAL, PRIMARY, System.nanoTime(), -1, false);
                     Engine.IndexResult indexResult = engine.index(firstIndexRequest);
                     assertThat(indexResult.getVersion(), equalTo(1L));
                 }
@@ -2191,7 +2197,7 @@ public class InternalEngineTests extends ESTestCase {
         final int numDocs = randomIntBetween(1, 10);
         for (int i = 0; i < numDocs; i++) {
             ParsedDocument doc = testParsedDocument(Integer.toString(i), Integer.toString(i), "test", null, testDocument(), new BytesArray("{}"), null);
-            Engine.Index firstIndexRequest = new Engine.Index(newUid(Integer.toString(i)), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, Versions.MATCH_DELETED, VersionType.INTERNAL, PRIMARY, System.nanoTime(), -1, false);
+            Engine.Index firstIndexRequest = new Engine.Index(newUid(Integer.toString(i)), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, Versions.MATCH_DELETED, VersionType.INTERNAL, PRIMARY, System.nanoTime(), -1, false);
             Engine.IndexResult indexResult = engine.index(firstIndexRequest);
             assertThat(indexResult.getVersion(), equalTo(1L));
         }
@@ -2234,7 +2240,7 @@ public class InternalEngineTests extends ESTestCase {
         int randomId = randomIntBetween(numDocs + 1, numDocs + 10);
         String uuidValue = "test#" + Integer.toString(randomId);
         ParsedDocument doc = testParsedDocument(uuidValue, Integer.toString(randomId), "test", null, testDocument(), new BytesArray("{}"), null);
-        Engine.Index firstIndexRequest = new Engine.Index(newUid(uuidValue), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 1, VersionType.EXTERNAL, PRIMARY, System.nanoTime(), -1, false);
+        Engine.Index firstIndexRequest = new Engine.Index(newUid(uuidValue), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 1, VersionType.EXTERNAL, PRIMARY, System.nanoTime(), -1, false);
         Engine.IndexResult indexResult = engine.index(firstIndexRequest);
         assertThat(indexResult.getVersion(), equalTo(1L));
         if (flush) {
@@ -2242,7 +2248,7 @@ public class InternalEngineTests extends ESTestCase {
         }
 
         doc = testParsedDocument(uuidValue, Integer.toString(randomId), "test", null, testDocument(), new BytesArray("{}"), null);
-        Engine.Index idxRequest = new Engine.Index(newUid(uuidValue), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 2, VersionType.EXTERNAL, PRIMARY, System.nanoTime(), -1, false);
+        Engine.Index idxRequest = new Engine.Index(newUid(uuidValue), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, 2, VersionType.EXTERNAL, PRIMARY, System.nanoTime(), -1, false);
         Engine.IndexResult result = engine.index(idxRequest);
         engine.refresh("test");
         assertThat(result.getVersion(), equalTo(2L));
@@ -2308,7 +2314,7 @@ public class InternalEngineTests extends ESTestCase {
         final int numDocs = randomIntBetween(1, 10);
         for (int i = 0; i < numDocs; i++) {
             ParsedDocument doc = testParsedDocument(Integer.toString(i), Integer.toString(i), "test", null, testDocument(), new BytesArray("{}"), null);
-            Engine.Index firstIndexRequest = new Engine.Index(newUid(Integer.toString(i)), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, Versions.MATCH_DELETED, VersionType.INTERNAL, PRIMARY, System.nanoTime(), -1, false);
+            Engine.Index firstIndexRequest = new Engine.Index(newUid(Integer.toString(i)), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, Versions.MATCH_DELETED, VersionType.INTERNAL, PRIMARY, System.nanoTime(), -1, false);
             Engine.IndexResult index = engine.index(firstIndexRequest);
             assertThat(index.getVersion(), equalTo(1L));
         }
@@ -2396,7 +2402,7 @@ public class InternalEngineTests extends ESTestCase {
             // create
             {
                 ParsedDocument doc = testParsedDocument(Integer.toString(0), Integer.toString(0), "test", null, testDocument(), new BytesArray("{}"), null);
-                Engine.Index firstIndexRequest = new Engine.Index(newUid(Integer.toString(0)), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, Versions.MATCH_DELETED, VersionType.INTERNAL, PRIMARY, System.nanoTime(), -1, false);
+                Engine.Index firstIndexRequest = new Engine.Index(newUid(Integer.toString(0)), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, Versions.MATCH_DELETED, VersionType.INTERNAL, PRIMARY, System.nanoTime(), -1, false);
 
                 try (InternalEngine engine = new InternalEngine(copy(config, EngineConfig.OpenMode.CREATE_INDEX_AND_TRANSLOG))){
                     assertFalse(engine.isRecovering());
@@ -2523,7 +2529,7 @@ public class InternalEngineTests extends ESTestCase {
         final int numDocs = randomIntBetween(2, 10); // at least 2 documents otherwise we don't see any deletes below
         for (int i = 0; i < numDocs; i++) {
             ParsedDocument doc = testParsedDocument(Integer.toString(i), Integer.toString(i), "test", null, testDocument(), new BytesArray("{}"), null);
-            Engine.Index firstIndexRequest = new Engine.Index(newUid(Integer.toString(i)), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, Versions.MATCH_ANY, VersionType.INTERNAL, PRIMARY, System.nanoTime(), -1, false);
+            Engine.Index firstIndexRequest = new Engine.Index(newUid(Integer.toString(i)), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, Versions.MATCH_ANY, VersionType.INTERNAL, PRIMARY, System.nanoTime(), -1, false);
             Engine.IndexResult indexResult = engine.index(firstIndexRequest);
             assertThat(indexResult.getVersion(), equalTo(1L));
         }
@@ -2533,7 +2539,7 @@ public class InternalEngineTests extends ESTestCase {
         engine.forceMerge(randomBoolean(), 1, false, false, false);
 
         ParsedDocument doc = testParsedDocument(Integer.toString(0), Integer.toString(0), "test", null, testDocument(), new BytesArray("{}"), null);
-        Engine.Index firstIndexRequest = new Engine.Index(newUid(Integer.toString(0)), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, Versions.MATCH_ANY, VersionType.INTERNAL, PRIMARY, System.nanoTime(), -1, false);
+        Engine.Index firstIndexRequest = new Engine.Index(newUid(Integer.toString(0)), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, Versions.MATCH_ANY, VersionType.INTERNAL, PRIMARY, System.nanoTime(), -1, false);
         Engine.IndexResult index = engine.index(firstIndexRequest);
         assertThat(index.getVersion(), equalTo(2L));
         engine.flush(); // flush - buffered deletes are not counted
@@ -2607,16 +2613,16 @@ public class InternalEngineTests extends ESTestCase {
         boolean isRetry = false;
         long autoGeneratedIdTimestamp = 0;
 
-        Engine.Index index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, Versions.MATCH_ANY, VersionType.INTERNAL, PRIMARY, System.nanoTime(), autoGeneratedIdTimestamp, isRetry);
+        Engine.Index index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, Versions.MATCH_ANY, VersionType.INTERNAL, PRIMARY, System.nanoTime(), autoGeneratedIdTimestamp, isRetry);
         Engine.IndexResult indexResult = engine.index(index);
         assertThat(indexResult.getVersion(), equalTo(1L));
 
-        index = new Engine.Index(newUid("1"), doc, indexResult.getSeqNo(), indexResult.getVersion(), index.versionType().versionTypeForReplicationAndRecovery(), REPLICA, System.nanoTime(), autoGeneratedIdTimestamp, isRetry);
+        index = new Engine.Index(newUid("1"), doc, indexResult.getSeqNo(), index.primaryTerm(), indexResult.getVersion(), index.versionType().versionTypeForReplicationAndRecovery(), REPLICA, System.nanoTime(), autoGeneratedIdTimestamp, isRetry);
         indexResult = replicaEngine.index(index);
         assertThat(indexResult.getVersion(), equalTo(1L));
 
         isRetry = true;
-        index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, Versions.MATCH_ANY, VersionType.INTERNAL, PRIMARY, System.nanoTime(), autoGeneratedIdTimestamp, isRetry);
+        index = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, Versions.MATCH_ANY, VersionType.INTERNAL, PRIMARY, System.nanoTime(), autoGeneratedIdTimestamp, isRetry);
         indexResult = engine.index(index);
         assertThat(indexResult.getVersion(), equalTo(1L));
         engine.refresh("test");
@@ -2625,7 +2631,7 @@ public class InternalEngineTests extends ESTestCase {
             assertEquals(1, topDocs.totalHits);
         }
 
-        index = new Engine.Index(newUid("1"), doc, indexResult.getSeqNo(), indexResult.getVersion(), index.versionType().versionTypeForReplicationAndRecovery(), REPLICA, System.nanoTime(), autoGeneratedIdTimestamp, isRetry);
+        index = new Engine.Index(newUid("1"), doc, indexResult.getSeqNo(), index.primaryTerm(), indexResult.getVersion(), index.versionType().versionTypeForReplicationAndRecovery(), REPLICA, System.nanoTime(), autoGeneratedIdTimestamp, isRetry);
         indexResult = replicaEngine.index(index);
         assertThat(indexResult.hasFailure(), equalTo(false));
         replicaEngine.refresh("test");
@@ -2641,16 +2647,16 @@ public class InternalEngineTests extends ESTestCase {
         boolean isRetry = true;
         long autoGeneratedIdTimestamp = 0;
 
-        Engine.Index firstIndexRequest = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, Versions.MATCH_ANY, VersionType.INTERNAL, PRIMARY, System.nanoTime(), autoGeneratedIdTimestamp, isRetry);
+        Engine.Index firstIndexRequest = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, Versions.MATCH_ANY, VersionType.INTERNAL, PRIMARY, System.nanoTime(), autoGeneratedIdTimestamp, isRetry);
         Engine.IndexResult result = engine.index(firstIndexRequest);
         assertThat(result.getVersion(), equalTo(1L));
 
-        Engine.Index firstIndexRequestReplica = new Engine.Index(newUid("1"), doc, result.getSeqNo(), result.getVersion(), firstIndexRequest.versionType().versionTypeForReplicationAndRecovery(), REPLICA, System.nanoTime(), autoGeneratedIdTimestamp, isRetry);
+        Engine.Index firstIndexRequestReplica = new Engine.Index(newUid("1"), doc, result.getSeqNo(), firstIndexRequest.primaryTerm(), result.getVersion(), firstIndexRequest.versionType().versionTypeForReplicationAndRecovery(), REPLICA, System.nanoTime(), autoGeneratedIdTimestamp, isRetry);
         Engine.IndexResult indexReplicaResult = replicaEngine.index(firstIndexRequestReplica);
         assertThat(indexReplicaResult.getVersion(), equalTo(1L));
 
         isRetry = false;
-        Engine.Index secondIndexRequest = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, Versions.MATCH_ANY, VersionType.INTERNAL, PRIMARY, System.nanoTime(), autoGeneratedIdTimestamp, isRetry);
+        Engine.Index secondIndexRequest = new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, Versions.MATCH_ANY, VersionType.INTERNAL, PRIMARY, System.nanoTime(), autoGeneratedIdTimestamp, isRetry);
         Engine.IndexResult indexResult = engine.index(secondIndexRequest);
         assertTrue(indexResult.isCreated());
         engine.refresh("test");
@@ -2659,7 +2665,7 @@ public class InternalEngineTests extends ESTestCase {
             assertEquals(1, topDocs.totalHits);
         }
 
-        Engine.Index secondIndexRequestReplica = new Engine.Index(newUid("1"), doc, result.getSeqNo(), result.getVersion(), firstIndexRequest.versionType().versionTypeForReplicationAndRecovery(), REPLICA, System.nanoTime(), autoGeneratedIdTimestamp, isRetry);
+        Engine.Index secondIndexRequestReplica = new Engine.Index(newUid("1"), doc, result.getSeqNo(), secondIndexRequest.primaryTerm(), result.getVersion(), firstIndexRequest.versionType().versionTypeForReplicationAndRecovery(), REPLICA, System.nanoTime(), autoGeneratedIdTimestamp, isRetry);
         replicaEngine.index(secondIndexRequestReplica);
         replicaEngine.refresh("test");
         try (Engine.Searcher searcher = replicaEngine.acquireSearcher("test")) {
@@ -2670,9 +2676,9 @@ public class InternalEngineTests extends ESTestCase {
 
     public Engine.Index randomAppendOnly(int docId, ParsedDocument doc, boolean retry) {
         if (randomBoolean()) {
-            return new Engine.Index(newUid(Integer.toString(docId)), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, Versions.MATCH_ANY, VersionType.INTERNAL, Engine.Operation.Origin.PRIMARY, System.nanoTime(), docId, retry);
+            return new Engine.Index(newUid(Integer.toString(docId)), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, Versions.MATCH_ANY, VersionType.INTERNAL, Engine.Operation.Origin.PRIMARY, System.nanoTime(), docId, retry);
         }
-        return new Engine.Index(newUid(Integer.toString(docId)), doc, 0, 1, VersionType.EXTERNAL, Engine.Operation.Origin.REPLICA, System.nanoTime(), docId, retry);
+        return new Engine.Index(newUid(Integer.toString(docId)), doc, 0, 0, 1, VersionType.EXTERNAL, Engine.Operation.Origin.REPLICA, System.nanoTime(), docId, retry);
     }
 
     public void testRetryConcurrently() throws InterruptedException, IOException {
@@ -2857,37 +2863,74 @@ public class InternalEngineTests extends ESTestCase {
         }
     }
 
-    public void testTragicEventErrorBubblesUp() throws IOException {
-        engine.close();
-        final AtomicBoolean failWithFatalError = new AtomicBoolean(true);
-        final VirtualMachineError error = randomFrom(
-            new InternalError(),
-            new OutOfMemoryError(),
-            new StackOverflowError(),
-            new UnknownError());
-        engine = new InternalEngine(copy(engine.config(), EngineConfig.OpenMode.OPEN_INDEX_AND_TRANSLOG, new Analyzer() {
-            @Override
-            protected TokenStreamComponents createComponents(String fieldName) {
-                return new TokenStreamComponents(new Tokenizer() {
-                    @Override
-                    public boolean incrementToken() throws IOException {
-                        if (failWithFatalError.get()) {
-                            throw error;
-                        } else {
-                            throw new AssertionError("should not get to this point");
+    public void testSequenceIDs() throws Exception {
+        Tuple<Long, Long> seqID = getSequenceID(engine, new Engine.Get(false, newUid("1")));
+        // Non-existent doc returns no seqnum and no primary term
+        assertThat(seqID.v1(), equalTo(SequenceNumbersService.UNASSIGNED_SEQ_NO));
+        assertThat(seqID.v2(), equalTo(0L));
+
+        // create a document
+        Document document = testDocumentWithTextField();
+        document.add(new Field(SourceFieldMapper.NAME, BytesReference.toBytes(B_1), SourceFieldMapper.Defaults.FIELD_TYPE));
+        ParsedDocument doc = testParsedDocument("1", "1", "test", null, document, B_1, null);
+        engine.index(new Engine.Index(newUid("1"), doc));
+        engine.refresh("test");
+
+        seqID = getSequenceID(engine, new Engine.Get(false, newUid("1")));
+        logger.info("--> got seqID: {}", seqID);
+        assertThat(seqID.v1(), equalTo(0L));
+        assertThat(seqID.v2(), equalTo(0L));
+
+        // Index the same document again
+        document = testDocumentWithTextField();
+        document.add(new Field(SourceFieldMapper.NAME, BytesReference.toBytes(B_1), SourceFieldMapper.Defaults.FIELD_TYPE));
+        doc = testParsedDocument("1", "1", "test", null, document, B_1, null);
+        engine.index(new Engine.Index(newUid("1"), doc));
+        engine.refresh("test");
+
+        seqID = getSequenceID(engine, new Engine.Get(false, newUid("1")));
+        logger.info("--> got seqID: {}", seqID);
+        assertThat(seqID.v1(), equalTo(1L));
+        assertThat(seqID.v2(), equalTo(0L));
+
+        // Index the same document for the third time, this time changing the primary term
+        document = testDocumentWithTextField();
+        document.add(new Field(SourceFieldMapper.NAME, BytesReference.toBytes(B_1), SourceFieldMapper.Defaults.FIELD_TYPE));
+        doc = testParsedDocument("1", "1", "test", null, document, B_1, null);
+        engine.index(new Engine.Index(newUid("1"), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 1,
+                        Versions.MATCH_ANY, VersionType.INTERNAL, Engine.Operation.Origin.PRIMARY,
+                        System.nanoTime(), -1, false));
+        engine.refresh("test");
+
+        seqID = getSequenceID(engine, new Engine.Get(false, newUid("1")));
+        logger.info("--> got seqID: {}", seqID);
+        assertThat(seqID.v1(), equalTo(2L));
+        assertThat(seqID.v2(), equalTo(1L));
+
+        // we can query by the _seq_no
+        Engine.Searcher searchResult = engine.acquireSearcher("test");
+        MatcherAssert.assertThat(searchResult, EngineSearcherTotalHitsMatcher.engineSearcherTotalHits(1));
+        MatcherAssert.assertThat(searchResult, EngineSearcherTotalHitsMatcher.engineSearcherTotalHits(LongPoint.newExactQuery("_seq_no", 2), 1));
+        searchResult.close();
     }
+
+    /**
+     * Return a tuple representing the sequence ID for the given {@code Get}
+     * operation. The first value in the tuple is the sequence number, the
+     * second is the primary term.
+     */
+    private Tuple<Long, Long> getSequenceID(Engine engine, Engine.Get get) throws EngineException {
+        final Searcher searcher = engine.acquireSearcher("get");
+        try {
+            long seqNum = Versions.loadSeqNo(searcher.reader(), get.uid());
+            long primaryTerm = Versions.loadPrimaryTerm(searcher.reader(), get.uid());
+            return new Tuple(seqNum, primaryTerm);
+        } catch (Exception e) {
+            Releasables.closeWhileHandlingException(searcher);
+            throw new EngineException(shardId, "unable to retrieve sequence id", e);
+        } finally {
+            searcher.close();
         }
-                });
-            }
-        }));
-        final Document document = testDocument();
-        document.add(new TextField("value", "test", Field.Store.YES));
-        final ParsedDocument doc = testParsedDocument("1", "1", "test", null, document, B_1, null);
-        final Engine.Index first = new Engine.Index(newUid("1"), doc);
-        expectThrows(error.getClass(), () -> engine.index(first));
-        failWithFatalError.set(false);
-        expectThrows(error.getClass(), () -> engine.index(first));
-        assertNull(engine.failedEngine.get());
     }
 
 }

core/src/test/java/org/elasticsearch/index/engine/ShadowEngineTests.java

@@ -54,6 +54,7 @@ import org.elasticsearch.index.codec.CodecService;
 import org.elasticsearch.index.mapper.Mapping;
 import org.elasticsearch.index.mapper.ParseContext;
 import org.elasticsearch.index.mapper.ParsedDocument;
+import org.elasticsearch.index.mapper.SeqNoFieldMapper;
 import org.elasticsearch.index.mapper.SourceFieldMapper;
 import org.elasticsearch.index.mapper.UidFieldMapper;
 import org.elasticsearch.index.seqno.SequenceNumbersService;
@@ -174,11 +175,14 @@ public class ShadowEngineTests extends ESTestCase {
     private ParsedDocument testParsedDocument(String uid, String id, String type, String routing, ParseContext.Document document, BytesReference source, Mapping mappingsUpdate) {
         Field uidField = new Field("_uid", uid, UidFieldMapper.Defaults.FIELD_TYPE);
         Field versionField = new NumericDocValuesField("_version", 0);
-        Field seqNoField = new NumericDocValuesField("_seq_no", 0);
+        SeqNoFieldMapper.SequenceID seqID = SeqNoFieldMapper.SequenceID.emptySeqID();
         document.add(uidField);
         document.add(versionField);
+        document.add(seqID.seqNo);
+        document.add(seqID.seqNoDocValue);
+        document.add(seqID.primaryTerm);
         document.add(new LongPoint("point_field", 42)); // so that points report memory/disk usage
-        return new ParsedDocument(versionField, seqNoField, id, type, routing, Arrays.asList(document), source, mappingsUpdate);
+        return new ParsedDocument(versionField, seqID, id, type, routing, Arrays.asList(document), source, mappingsUpdate);
     }
 
     protected Store createStore(Path p) throws IOException {
@@ -984,7 +988,7 @@ public class ShadowEngineTests extends ESTestCase {
         final int numDocs = randomIntBetween(2, 10); // at least 2 documents otherwise we don't see any deletes below
         for (int i = 0; i < numDocs; i++) {
             ParsedDocument doc = testParsedDocument(Integer.toString(i), Integer.toString(i), "test", null, testDocument(), new BytesArray("{}"), null);
-            Engine.Index firstIndexRequest = new Engine.Index(newUid(Integer.toString(i)), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, Versions.MATCH_ANY, VersionType.INTERNAL, PRIMARY, System.nanoTime(), -1, false);
+            Engine.Index firstIndexRequest = new Engine.Index(newUid(Integer.toString(i)), doc, SequenceNumbersService.UNASSIGNED_SEQ_NO, 0, Versions.MATCH_ANY, VersionType.INTERNAL, PRIMARY, System.nanoTime(), -1, false);
             Engine.IndexResult indexResult = primaryEngine.index(firstIndexRequest);
             assertThat(indexResult.getVersion(), equalTo(1L));
         }

core/src/test/java/org/elasticsearch/index/fielddata/AbstractFieldDataImplTestCase.java

@@ -31,6 +31,7 @@ import org.apache.lucene.util.BytesRef;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.search.MultiValueMode;
 
+import java.util.List;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.greaterThanOrEqualTo;
 
@@ -71,7 +72,8 @@ public abstract class AbstractFieldDataImplTestCase extends AbstractFieldDataTes
     public void testDeletedDocs() throws Exception {
         add2SingleValuedDocumentsAndDeleteOneOfThem();
         IndexFieldData indexFieldData = getForField("value");
-        LeafReaderContext readerContext = refreshReader();
+        List<LeafReaderContext> readerContexts = refreshReader();
+        for (LeafReaderContext readerContext : readerContexts) {
             AtomicFieldData fieldData = indexFieldData.load(readerContext);
             SortedBinaryDocValues values = fieldData.getBytesValues();
             for (int i = 0; i < readerContext.reader().maxDoc(); ++i) {
@@ -79,11 +81,13 @@ public abstract class AbstractFieldDataImplTestCase extends AbstractFieldDataTes
                 assertThat(values.count(), greaterThanOrEqualTo(1));
             }
         }
+    }
 
     public void testSingleValueAllSet() throws Exception {
         fillSingleValueAllSet();
         IndexFieldData indexFieldData = getForField("value");
-        LeafReaderContext readerContext = refreshReader();
+        List<LeafReaderContext> readerContexts = refreshReader();
+        for (LeafReaderContext readerContext : readerContexts) {
             AtomicFieldData fieldData = indexFieldData.load(readerContext);
             assertThat(fieldData.ramBytesUsed(), greaterThanOrEqualTo(minRamBytesUsed()));
 
@@ -123,6 +127,7 @@ public abstract class AbstractFieldDataImplTestCase extends AbstractFieldDataTes
             assertThat(topDocs.scoreDocs[1].doc, equalTo(0));
             assertThat(topDocs.scoreDocs[2].doc, equalTo(1));
         }
+    }
 
     protected abstract void fillSingleValueWithMissing() throws Exception;
 
@@ -145,27 +150,33 @@ public abstract class AbstractFieldDataImplTestCase extends AbstractFieldDataTes
     public void testSingleValueWithMissing() throws Exception {
         fillSingleValueWithMissing();
         IndexFieldData indexFieldData = getForField("value");
-        AtomicFieldData fieldData = indexFieldData.load(refreshReader());
+        List<LeafReaderContext> readerContexts = refreshReader();
+        for (LeafReaderContext readerContext : readerContexts) {
+            AtomicFieldData fieldData = indexFieldData.load(readerContext);
             assertThat(fieldData.ramBytesUsed(), greaterThanOrEqualTo(minRamBytesUsed()));
 
-        SortedBinaryDocValues bytesValues = fieldData
-                .getBytesValues();
+            SortedBinaryDocValues bytesValues = fieldData.getBytesValues();
 
             assertValues(bytesValues, 0, two());
             assertValues(bytesValues, 1, Strings.EMPTY_ARRAY);
             assertValues(bytesValues, 2, three());
         }
+    }
 
     protected abstract void fillMultiValueAllSet() throws Exception;
 
     public void testMultiValueAllSet() throws Exception {
         fillMultiValueAllSet();
+        // the segments are force merged to a single segment so that the sorted binary doc values can be asserted within a single segment.
+        // Previously we used the SlowCompositeReaderWrapper but this is an unideal solution so force merging is a better idea.
+        writer.forceMerge(1);
         IndexFieldData indexFieldData = getForField("value");
-        AtomicFieldData fieldData = indexFieldData.load(refreshReader());
+        List<LeafReaderContext> readerContexts = refreshReader();
+        for (LeafReaderContext readerContext : readerContexts) {
+            AtomicFieldData fieldData = indexFieldData.load(readerContext);
             assertThat(fieldData.ramBytesUsed(), greaterThanOrEqualTo(minRamBytesUsed()));
 
             SortedBinaryDocValues bytesValues = fieldData.getBytesValues();
-
             assertValues(bytesValues, 0, two(), four());
             assertValues(bytesValues, 1, one());
             assertValues(bytesValues, 2, three());
@@ -185,13 +196,16 @@ public abstract class AbstractFieldDataImplTestCase extends AbstractFieldDataTes
             assertThat(topDocs.scoreDocs[1].doc, equalTo(2));
             assertThat(topDocs.scoreDocs[2].doc, equalTo(1));
         }
+    }
 
     protected abstract void fillMultiValueWithMissing() throws Exception;
 
     public void testMultiValueWithMissing() throws Exception {
         fillMultiValueWithMissing();
         IndexFieldData indexFieldData = getForField("value");
-        AtomicFieldData fieldData = indexFieldData.load(refreshReader());
+        List<LeafReaderContext> readerContexts = refreshReader();
+        for (LeafReaderContext readerContext : readerContexts) {
+            AtomicFieldData fieldData = indexFieldData.load(readerContext);
             assertThat(fieldData.ramBytesUsed(), greaterThanOrEqualTo(minRamBytesUsed()));
 
             SortedBinaryDocValues bytesValues = fieldData.getBytesValues();
@@ -200,11 +214,14 @@ public abstract class AbstractFieldDataImplTestCase extends AbstractFieldDataTes
             assertValues(bytesValues, 1, Strings.EMPTY_ARRAY);
             assertValues(bytesValues, 2, three());
         }
+    }
 
     public void testMissingValueForAll() throws Exception {
         fillAllMissing();
         IndexFieldData indexFieldData = getForField("value");
-        AtomicFieldData fieldData = indexFieldData.load(refreshReader());
+        List<LeafReaderContext> readerContexts = refreshReader();
+        for (LeafReaderContext readerContext : readerContexts) {
+            AtomicFieldData fieldData = indexFieldData.load(readerContext);
             // Some impls (FST) return size 0 and some (PagedBytes) do take size in the case no actual data is loaded
             assertThat(fieldData.ramBytesUsed(), greaterThanOrEqualTo(0L));
 
@@ -219,6 +236,7 @@ public abstract class AbstractFieldDataImplTestCase extends AbstractFieldDataTes
             assertValues(hashedBytesValues, 1, Strings.EMPTY_ARRAY);
             assertValues(hashedBytesValues, 2, Strings.EMPTY_ARRAY);
         }
+    }
 
     protected abstract void fillAllMissing() throws Exception;
 

core/src/test/java/org/elasticsearch/index/fielddata/AbstractFieldDataTestCase.java

@@ -29,7 +29,6 @@ import org.apache.lucene.index.IndexWriterConfig;
 import org.apache.lucene.index.LeafReader;
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.index.LogByteSizeMergePolicy;
-import org.apache.lucene.index.SlowCompositeReaderWrapper;
 import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.search.Query;
 import org.apache.lucene.store.RAMDirectory;
@@ -61,6 +60,7 @@ import org.junit.Before;
 
 import java.io.IOException;
 import java.util.Collection;
+import java.util.List;
 
 import static org.elasticsearch.index.fielddata.IndexFieldData.XFieldComparatorSource.Nested;
 import static org.hamcrest.Matchers.equalTo;
@@ -73,8 +73,8 @@ public abstract class AbstractFieldDataTestCase extends ESSingleNodeTestCase {
     protected IndexFieldDataService ifdService;
     protected MapperService mapperService;
     protected IndexWriter writer;
-    protected LeafReaderContext readerContext;
-    protected DirectoryReader topLevelReader;
+    protected List<LeafReaderContext> readerContexts = null;
+    protected DirectoryReader topLevelReader = null;
     protected IndicesFieldDataCache indicesFieldDataCache;
     protected abstract String getFieldDataType();
 
@@ -146,22 +146,21 @@ public abstract class AbstractFieldDataTestCase extends ESSingleNodeTestCase {
         writer = new IndexWriter(new RAMDirectory(), new IndexWriterConfig(new StandardAnalyzer()).setMergePolicy(new LogByteSizeMergePolicy()));
     }
 
-    protected final LeafReaderContext refreshReader() throws Exception {
-        if (readerContext != null) {
-            readerContext.reader().close();
+    protected final List<LeafReaderContext> refreshReader() throws Exception {
+        if (readerContexts != null && topLevelReader != null) {
+            topLevelReader.close();
         }
         topLevelReader = ElasticsearchDirectoryReader.wrap(DirectoryReader.open(writer), new ShardId("foo", "_na_", 1));
-        LeafReader reader = SlowCompositeReaderWrapper.wrap(topLevelReader);
-        readerContext = reader.getContext();
-        return readerContext;
+        readerContexts = topLevelReader.leaves();
+        return readerContexts;
     }
 
     @Override
     @After
     public void tearDown() throws Exception {
         super.tearDown();
-        if (readerContext != null) {
-            readerContext.reader().close();
+        if (topLevelReader != null) {
+            topLevelReader.close();
         }
         writer.close();
     }
@@ -179,6 +178,7 @@ public abstract class AbstractFieldDataTestCase extends ESSingleNodeTestCase {
 
         IndexFieldData fieldData = getForField("non_existing_field");
         int max = randomInt(7);
+        for (LeafReaderContext readerContext : readerContexts) {
             AtomicFieldData previous = null;
             for (int i = 0; i < max; i++) {
                 AtomicFieldData current = fieldData.load(readerContext);
@@ -190,3 +190,4 @@ public abstract class AbstractFieldDataTestCase extends ESSingleNodeTestCase {
             }
         }
     }
+}

core/src/test/java/org/elasticsearch/index/fielddata/AbstractStringFieldDataTestCase.java

@@ -557,9 +557,11 @@ public abstract class AbstractStringFieldDataTestCase extends AbstractFieldDataI
 
     public void testTermsEnum() throws Exception {
         fillExtendedMvSet();
-        LeafReaderContext atomicReaderContext = refreshReader();
+        writer.forceMerge(1);
+        List<LeafReaderContext> atomicReaderContexts = refreshReader();
 
         IndexOrdinalsFieldData ifd = getForField("value");
+        for (LeafReaderContext atomicReaderContext : atomicReaderContexts) {
             AtomicOrdinalsFieldData afd = ifd.load(atomicReaderContext);
 
             TermsEnum termsEnum = afd.getOrdinalsValues().termsEnum();
@@ -589,6 +591,7 @@ public abstract class AbstractStringFieldDataTestCase extends AbstractFieldDataI
             }
             assertThat(size, equalTo(3));
         }
+    }
 
     public void testGlobalOrdinalsGetRemovedOnceIndexReaderCloses() throws Exception {
         fillExtendedMvSet();

core/src/test/java/org/elasticsearch/index/fielddata/BinaryDVFieldDataTests.java

@@ -30,6 +30,7 @@ import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.index.mapper.DocumentMapper;
 import org.elasticsearch.index.mapper.ParsedDocument;
 
+import java.util.List;
 import static org.hamcrest.Matchers.equalTo;
 
 public class BinaryDVFieldDataTests extends AbstractFieldDataTestCase {
@@ -75,8 +76,9 @@ public class BinaryDVFieldDataTests extends AbstractFieldDataTestCase {
         d = mapper.parse("test", "test", "4", doc.bytes());
         writer.addDocument(d.rootDoc());
 
-        LeafReaderContext reader = refreshReader();
+        List<LeafReaderContext> readers = refreshReader();
         IndexFieldData<?> indexFieldData = getForField("field");
+        for (LeafReaderContext reader : readers) {
             AtomicFieldData fieldData = indexFieldData.load(reader);
 
             SortedBinaryDocValues bytesValues = fieldData.getBytesValues();
@@ -100,6 +102,7 @@ public class BinaryDVFieldDataTests extends AbstractFieldDataTestCase {
             assertThat(bytesValues.valueAt(0), equalTo(new BytesRef(bytesList2.get(0))));
             assertThat(bytesValues.valueAt(1), equalTo(new BytesRef(bytesList2.get(1))));
         }
+    }
 
     private byte[] randomBytes() {
         int size = randomIntBetween(10, 1000);

core/src/test/java/org/elasticsearch/index/fielddata/FilterFieldDataTests.java

@@ -28,6 +28,7 @@ import org.elasticsearch.index.mapper.MappedFieldType;
 import org.elasticsearch.index.mapper.TextFieldMapper;
 import org.elasticsearch.index.mapper.Mapper.BuilderContext;
 
+import java.util.List;
 import java.util.Random;
 
 import static org.hamcrest.Matchers.equalTo;
@@ -58,7 +59,7 @@ public class FilterFieldDataTests extends AbstractFieldDataTestCase {
             writer.addDocument(d);
         }
         writer.forceMerge(1, true);
-        LeafReaderContext context = refreshReader();
+        List<LeafReaderContext> contexts = refreshReader();
         final BuilderContext builderCtx = new BuilderContext(indexService.getIndexSettings().getSettings(), new ContentPath(1));
 
         {
@@ -68,12 +69,14 @@ public class FilterFieldDataTests extends AbstractFieldDataTestCase {
                     .fielddataFrequencyFilter(0, random.nextBoolean() ? 100 : 0.5d, 0)
                     .build(builderCtx).fieldType();
             IndexOrdinalsFieldData fieldData = ifdService.getForField(ft);
+            for (LeafReaderContext context : contexts) {
                 AtomicOrdinalsFieldData loadDirect = fieldData.loadDirect(context);
                 RandomAccessOrds bytesValues = loadDirect.getOrdinalsValues();
                 assertThat(2L, equalTo(bytesValues.getValueCount()));
                 assertThat(bytesValues.lookupOrd(0).utf8ToString(), equalTo("10"));
                 assertThat(bytesValues.lookupOrd(1).utf8ToString(), equalTo("100"));
             }
+        }
         {
             ifdService.clear();
             MappedFieldType ft = new TextFieldMapper.Builder("high_freq")
@@ -81,11 +84,13 @@ public class FilterFieldDataTests extends AbstractFieldDataTestCase {
                     .fielddataFrequencyFilter(random.nextBoolean() ? 101 : 101d/200.0d, 201, 100)
                     .build(builderCtx).fieldType();
             IndexOrdinalsFieldData fieldData = ifdService.getForField(ft);
+            for (LeafReaderContext context : contexts) {
                 AtomicOrdinalsFieldData loadDirect = fieldData.loadDirect(context);
                 RandomAccessOrds bytesValues = loadDirect.getOrdinalsValues();
                 assertThat(1L, equalTo(bytesValues.getValueCount()));
                 assertThat(bytesValues.lookupOrd(0).utf8ToString(), equalTo("5"));
             }
+        }
 
         {
             ifdService.clear(); // test # docs with value
@@ -94,12 +99,14 @@ public class FilterFieldDataTests extends AbstractFieldDataTestCase {
                     .fielddataFrequencyFilter(random.nextBoolean() ? 101 : 101d/200.0d, Integer.MAX_VALUE, 101)
                     .build(builderCtx).fieldType();
             IndexOrdinalsFieldData fieldData = ifdService.getForField(ft);
+            for (LeafReaderContext context : contexts) {
                 AtomicOrdinalsFieldData loadDirect = fieldData.loadDirect(context);
                 RandomAccessOrds bytesValues = loadDirect.getOrdinalsValues();
                 assertThat(2L, equalTo(bytesValues.getValueCount()));
                 assertThat(bytesValues.lookupOrd(0).utf8ToString(), equalTo("10"));
                 assertThat(bytesValues.lookupOrd(1).utf8ToString(), equalTo("100"));
             }
+        }
 
         {
             ifdService.clear();
@@ -108,12 +115,14 @@ public class FilterFieldDataTests extends AbstractFieldDataTestCase {
                     .fielddataFrequencyFilter(random.nextBoolean() ? 101 : 101d/200.0d, Integer.MAX_VALUE, 101)
                     .build(builderCtx).fieldType();
             IndexOrdinalsFieldData fieldData = ifdService.getForField(ft);
+            for (LeafReaderContext context : contexts) {
                 AtomicOrdinalsFieldData loadDirect = fieldData.loadDirect(context);
                 RandomAccessOrds bytesValues = loadDirect.getOrdinalsValues();
                 assertThat(2L, equalTo(bytesValues.getValueCount()));
                 assertThat(bytesValues.lookupOrd(0).utf8ToString(), equalTo("10"));
                 assertThat(bytesValues.lookupOrd(1).utf8ToString(), equalTo("100"));
             }
+        }
 
     }
 

core/src/test/java/org/elasticsearch/index/fielddata/GeoFieldDataTests.java

@@ -25,6 +25,7 @@ import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.index.Term;
 import org.elasticsearch.index.fielddata.plain.AbstractAtomicGeoPointFieldData;
 
+import java.util.List;
 import static org.hamcrest.Matchers.greaterThanOrEqualTo;
 
 /**
@@ -153,7 +154,8 @@ public class GeoFieldDataTests extends AbstractGeoFieldDataTestCase {
     public void testSingleValueAllSet() throws Exception {
         fillSingleValueAllSet();
         IndexFieldData indexFieldData = getForField("value");
-        LeafReaderContext readerContext = refreshReader();
+        List<LeafReaderContext> readerContexts = refreshReader();
+        for (LeafReaderContext readerContext : readerContexts) {
             AtomicFieldData fieldData = indexFieldData.load(readerContext);
             assertThat(fieldData.ramBytesUsed(), greaterThanOrEqualTo(minRamBytesUsed()));
 
@@ -162,12 +164,14 @@ public class GeoFieldDataTests extends AbstractGeoFieldDataTestCase {
             assertValues(fieldValues, 1);
             assertValues(fieldValues, 2);
         }
+    }
 
     @Override
     public void testSingleValueWithMissing() throws Exception {
         fillSingleValueWithMissing();
         IndexFieldData indexFieldData = getForField("value");
-        LeafReaderContext readerContext = refreshReader();
+        List<LeafReaderContext> readerContexts = refreshReader();
+        for (LeafReaderContext readerContext : readerContexts) {
             AtomicFieldData fieldData = indexFieldData.load(readerContext);
             assertThat(fieldData.ramBytesUsed(), greaterThanOrEqualTo(minRamBytesUsed()));
 
@@ -176,12 +180,14 @@ public class GeoFieldDataTests extends AbstractGeoFieldDataTestCase {
             assertMissing(fieldValues, 1);
             assertValues(fieldValues, 2);
         }
+    }
 
     @Override
     public void testMultiValueAllSet() throws Exception {
         fillMultiValueAllSet();
         IndexFieldData indexFieldData = getForField("value");
-        LeafReaderContext readerContext = refreshReader();
+        List<LeafReaderContext> readerContexts = refreshReader();
+        for (LeafReaderContext readerContext : readerContexts) {
             AtomicFieldData fieldData = indexFieldData.load(readerContext);
             assertThat(fieldData.ramBytesUsed(), greaterThanOrEqualTo(minRamBytesUsed()));
 
@@ -190,12 +196,15 @@ public class GeoFieldDataTests extends AbstractGeoFieldDataTestCase {
             assertValues(fieldValues, 1);
             assertValues(fieldValues, 2);
         }
+    }
 
     @Override
     public void testMultiValueWithMissing() throws Exception {
         fillMultiValueWithMissing();
         IndexFieldData indexFieldData = getForField("value");
-        AtomicFieldData fieldData = indexFieldData.load(refreshReader());
+        List<LeafReaderContext> readerContexts = refreshReader();
+        for (LeafReaderContext readerContext : readerContexts) {
+            AtomicFieldData fieldData = indexFieldData.load(readerContext);
             assertThat(fieldData.ramBytesUsed(), greaterThanOrEqualTo(minRamBytesUsed()));
 
             MultiGeoPointValues fieldValues = ((AbstractAtomicGeoPointFieldData)fieldData).getGeoPointValues();
@@ -205,3 +214,4 @@ public class GeoFieldDataTests extends AbstractGeoFieldDataTestCase {
             assertValues(fieldValues, 2);
         }
     }
+}

core/src/test/java/org/elasticsearch/index/fielddata/ParentChildFieldDataTests.java

@@ -47,6 +47,7 @@ import org.elasticsearch.search.MultiValueMode;
 import org.junit.Before;
 
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicReference;
@@ -124,8 +125,11 @@ public class ParentChildFieldDataTests extends AbstractFieldDataTestCase {
     }
 
     public void testGetBytesValues() throws Exception {
+        writer.forceMerge(1); // force merge to 1 segment so we can iterate through documents
         IndexFieldData indexFieldData = getForField(childType);
-        AtomicFieldData fieldData = indexFieldData.load(refreshReader());
+        List<LeafReaderContext> readerContexts = refreshReader();
+        for (LeafReaderContext readerContext : readerContexts) {
+            AtomicFieldData fieldData = indexFieldData.load(readerContext);
 
             SortedBinaryDocValues bytesValues = fieldData.getBytesValues();
             bytesValues.setDocument(0);
@@ -163,6 +167,7 @@ public class ParentChildFieldDataTests extends AbstractFieldDataTestCase {
             bytesValues.setDocument(7);
             assertThat(bytesValues.count(), equalTo(0));
         }
+    }
 
     public void testSorting() throws Exception {
         IndexFieldData indexFieldData = getForField(parentType);

core/src/test/java/org/elasticsearch/index/mapper/FieldNamesFieldMapperTests.java

@@ -97,7 +97,7 @@ public class FieldNamesFieldMapperTests extends ESSingleNodeTestCase {
                 .endObject()
                 .bytes());
 
-        assertFieldNames(set("a", "a.keyword", "b", "b.c", "_uid", "_type", "_version", "_seq_no", "_source", "_all"), doc);
+        assertFieldNames(set("a", "a.keyword", "b", "b.c", "_uid", "_type", "_version", "_seq_no", "_primary_term", "_source", "_all"), doc);
     }
 
     public void testExplicitEnabled() throws Exception {
@@ -114,7 +114,7 @@ public class FieldNamesFieldMapperTests extends ESSingleNodeTestCase {
             .endObject()
             .bytes());
 
-        assertFieldNames(set("field", "field.keyword", "_uid", "_type", "_version", "_seq_no", "_source", "_all"), doc);
+        assertFieldNames(set("field", "field.keyword", "_uid", "_type", "_version", "_seq_no", "_primary_term", "_source", "_all"), doc);
     }
 
     public void testDisabled() throws Exception {

core/src/test/java/org/elasticsearch/index/shard/IndexShardIT.java

@@ -55,6 +55,7 @@ import org.elasticsearch.index.flush.FlushStats;
 import org.elasticsearch.index.mapper.Mapping;
 import org.elasticsearch.index.mapper.ParseContext;
 import org.elasticsearch.index.mapper.ParsedDocument;
+import org.elasticsearch.index.mapper.SeqNoFieldMapper;
 import org.elasticsearch.index.mapper.UidFieldMapper;
 import org.elasticsearch.index.seqno.SequenceNumbersService;
 import org.elasticsearch.index.translog.Translog;
@@ -102,12 +103,15 @@ public class IndexShardIT extends ESSingleNodeTestCase {
     private ParsedDocument testParsedDocument(String uid, String id, String type, String routing, long seqNo,
                                               ParseContext.Document document, BytesReference source, Mapping mappingUpdate) {
         Field uidField = new Field("_uid", uid, UidFieldMapper.Defaults.FIELD_TYPE);
-        Field seqNoField = new NumericDocValuesField("_seq_no", seqNo);
         Field versionField = new NumericDocValuesField("_version", 0);
+        SeqNoFieldMapper.SequenceID seqID = SeqNoFieldMapper.SequenceID.emptySeqID();
         document.add(uidField);
         document.add(versionField);
-        return new ParsedDocument(versionField, seqNoField, id, type, routing, Collections.singletonList(document), source,
-            mappingUpdate);
+        document.add(seqID.seqNo);
+        document.add(seqID.seqNoDocValue);
+        document.add(seqID.primaryTerm);
+        return new ParsedDocument(versionField, seqID, id, type, routing,
+                Collections.singletonList(document), source, mappingUpdate);
     }
 
     public void testLockTryingToDelete() throws Exception {

core/src/test/java/org/elasticsearch/index/shard/IndexShardTests.java

@@ -70,6 +70,7 @@ import org.elasticsearch.index.mapper.MappedFieldType;
 import org.elasticsearch.index.mapper.Mapping;
 import org.elasticsearch.index.mapper.ParseContext;
 import org.elasticsearch.index.mapper.ParsedDocument;
+import org.elasticsearch.index.mapper.SeqNoFieldMapper;
 import org.elasticsearch.index.mapper.Uid;
 import org.elasticsearch.index.mapper.UidFieldMapper;
 import org.elasticsearch.index.snapshots.IndexShardSnapshotStatus;
@@ -542,10 +543,13 @@ public class IndexShardTests extends IndexShardTestCase {
                                               ParseContext.Document document, BytesReference source, Mapping mappingUpdate) {
         Field uidField = new Field("_uid", uid, UidFieldMapper.Defaults.FIELD_TYPE);
         Field versionField = new NumericDocValuesField("_version", 0);
-        Field seqNoField = new NumericDocValuesField("_seq_no", 0);
+        SeqNoFieldMapper.SequenceID seqID = SeqNoFieldMapper.SequenceID.emptySeqID();
         document.add(uidField);
         document.add(versionField);
-        return new ParsedDocument(versionField, seqNoField, id, type, routing, Arrays.asList(document), source, mappingUpdate);
+        document.add(seqID.seqNo);
+        document.add(seqID.seqNoDocValue);
+        document.add(seqID.primaryTerm);
+        return new ParsedDocument(versionField, seqID, id, type, routing, Arrays.asList(document), source, mappingUpdate);
     }
 
     public void testIndexingOperationsListeners() throws IOException {

core/src/test/java/org/elasticsearch/index/shard/RefreshListenersTests.java

@@ -47,6 +47,7 @@ import org.elasticsearch.index.engine.InternalEngineTests.TranslogHandler;
 import org.elasticsearch.index.fieldvisitor.SingleFieldsVisitor;
 import org.elasticsearch.index.mapper.ParseContext.Document;
 import org.elasticsearch.index.mapper.ParsedDocument;
+import org.elasticsearch.index.mapper.SeqNoFieldMapper;
 import org.elasticsearch.index.mapper.UidFieldMapper;
 import org.elasticsearch.index.store.DirectoryService;
 import org.elasticsearch.index.store.Store;
@@ -273,11 +274,14 @@ public class RefreshListenersTests extends ESTestCase {
         document.add(new TextField("test", testFieldValue, Field.Store.YES));
         Field uidField = new Field("_uid", type + ":" + id, UidFieldMapper.Defaults.FIELD_TYPE);
         Field versionField = new NumericDocValuesField("_version", Versions.MATCH_ANY);
-        Field seqNoField = new NumericDocValuesField("_seq_no", 0);
+        SeqNoFieldMapper.SequenceID seqID = SeqNoFieldMapper.SequenceID.emptySeqID();
         document.add(uidField);
         document.add(versionField);
+        document.add(seqID.seqNo);
+        document.add(seqID.seqNoDocValue);
+        document.add(seqID.primaryTerm);
         BytesReference source = new BytesArray(new byte[] { 1 });
-        ParsedDocument doc = new ParsedDocument(versionField, seqNoField, id, type, null, Arrays.asList(document), source, null);
+        ParsedDocument doc = new ParsedDocument(versionField, seqID, id, type, null, Arrays.asList(document), source, null);
         Engine.Index index = new Engine.Index(new Term("_uid", uid), doc);
         return engine.index(index);
     }

core/src/test/java/org/elasticsearch/index/translog/TranslogTests.java

@@ -301,7 +301,7 @@ public class TranslogTests extends ESTestCase {
         assertThat(stats.estimatedNumberOfOperations(), equalTo(0L));
         assertThat(stats.getTranslogSizeInBytes(), equalTo(firstOperationPosition));
         assertEquals(6, total.estimatedNumberOfOperations());
-        assertEquals(413, total.getTranslogSizeInBytes());
+        assertEquals(419, total.getTranslogSizeInBytes());
 
         BytesStreamOutput out = new BytesStreamOutput();
         total.writeTo(out);
@@ -309,13 +309,13 @@ public class TranslogTests extends ESTestCase {
         copy.readFrom(out.bytes().streamInput());
 
         assertEquals(6, copy.estimatedNumberOfOperations());
-        assertEquals(413, copy.getTranslogSizeInBytes());
+        assertEquals(419, copy.getTranslogSizeInBytes());
 
         try (XContentBuilder builder = XContentFactory.jsonBuilder()) {
             builder.startObject();
             copy.toXContent(builder, ToXContent.EMPTY_PARAMS);
             builder.endObject();
-            assertEquals("{\"translog\":{\"operations\":6,\"size_in_bytes\":413}}", builder.string());
+            assertEquals("{\"translog\":{\"operations\":6,\"size_in_bytes\":419}}", builder.string());
         }
 
         try {
@@ -1137,7 +1137,7 @@ public class TranslogTests extends ESTestCase {
         try (Translog ignored = new Translog(config, translogGeneration, () -> SequenceNumbersService.UNASSIGNED_SEQ_NO)) {
             fail("corrupted");
         } catch (IllegalStateException ex) {
-            assertEquals(ex.getMessage(), "Checkpoint file translog-2.ckp already exists but has corrupted content expected: Checkpoint{offset=2298, numOps=55, translogFileGeneration=2, globalCheckpoint=-2} but got: Checkpoint{offset=0, numOps=0, translogFileGeneration=0, globalCheckpoint=-2}");
+            assertEquals(ex.getMessage(), "Checkpoint file translog-2.ckp already exists but has corrupted content expected: Checkpoint{offset=2353, numOps=55, translogFileGeneration=2, globalCheckpoint=-2} but got: Checkpoint{offset=0, numOps=0, translogFileGeneration=0, globalCheckpoint=-2}");
         }
         Checkpoint.write(FileChannel::open, config.getTranslogPath().resolve(Translog.getCommitCheckpointFileName(read.generation)), read, StandardOpenOption.WRITE, StandardOpenOption.TRUNCATE_EXISTING);
         try (Translog translog = new Translog(config, translogGeneration, () -> SequenceNumbersService.UNASSIGNED_SEQ_NO)) {
@@ -1303,6 +1303,7 @@ public class TranslogTests extends ESTestCase {
                             op = new Translog.Delete(
                                 new Term("_uid", threadId + "_" + opCount),
                                 opCount,
+                                0,
                                 1 + randomInt(100000),
                                 randomFrom(VersionType.values()));
                             break;

core/src/test/java/org/elasticsearch/node/service/NodeServiceTests.java

@@ -0,0 +1,43 @@
+/*
+ * 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.node.service;
+
+import org.elasticsearch.action.admin.cluster.node.stats.NodesStatsRequest;
+import org.elasticsearch.action.admin.cluster.node.stats.NodesStatsResponse;
+import org.elasticsearch.common.network.NetworkModule;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.test.ESSingleNodeTestCase;
+
+import static org.hamcrest.Matchers.hasSize;
+
+public class NodeServiceTests extends ESSingleNodeTestCase {
+
+    @Override
+    protected Settings nodeSettings() {
+        return Settings.builder().put(NetworkModule.HTTP_ENABLED.getKey(), false).build();
+    }
+
+    public void testHttpServerDisabled() {
+        // test for a bug where if HTTP stats were requested but HTTP was disabled, NodeService would hit a NullPointerException
+        NodesStatsResponse response = client().admin().cluster().nodesStats(new NodesStatsRequest().http(true)).actionGet();
+        assertThat(response.getNodes(), hasSize(1));
+    }
+
+}

modules/percolator/src/test/java/org/elasticsearch/percolator/PercolatorFieldMapperTests.java

@@ -359,7 +359,7 @@ public class PercolatorFieldMapperTests extends ESSingleNodeTestCase {
                         .field("query_field2", queryBuilder)
                         .endObject().bytes()
         );
-        assertThat(doc.rootDoc().getFields().size(), equalTo(12)); // also includes all other meta fields
+        assertThat(doc.rootDoc().getFields().size(), equalTo(14)); // also includes all other meta fields
         BytesRef queryBuilderAsBytes = doc.rootDoc().getField("query_field1.query_builder_field").binaryValue();
         assertQueryBuilder(queryBuilderAsBytes, queryBuilder);
 
@@ -389,7 +389,7 @@ public class PercolatorFieldMapperTests extends ESSingleNodeTestCase {
                             .field("query_field", queryBuilder)
                         .endObject().endObject().bytes()
         );
-        assertThat(doc.rootDoc().getFields().size(), equalTo(9)); // also includes all other meta fields
+        assertThat(doc.rootDoc().getFields().size(), equalTo(11)); // also includes all other meta fields
         BytesRef queryBuilderAsBytes = doc.rootDoc().getField("object_field.query_field.query_builder_field").binaryValue();
         assertQueryBuilder(queryBuilderAsBytes, queryBuilder);
 
@@ -400,7 +400,7 @@ public class PercolatorFieldMapperTests extends ESSingleNodeTestCase {
                             .endArray()
                         .endObject().bytes()
         );
-        assertThat(doc.rootDoc().getFields().size(), equalTo(9)); // also includes all other meta fields
+        assertThat(doc.rootDoc().getFields().size(), equalTo(11)); // also includes all other meta fields
         queryBuilderAsBytes = doc.rootDoc().getField("object_field.query_field.query_builder_field").binaryValue();
         assertQueryBuilder(queryBuilderAsBytes, queryBuilder);
 

qa/vagrant/versions

@@ -1,3 +1,4 @@
 5.0.0
 5.0.1
 5.0.2
+5.1.1

rest-api-spec/src/main/resources/rest-api-spec/test/search.aggregation/40_range.yaml

@@ -111,6 +111,9 @@ setup:
 
 ---
 "IP range":
+  - skip:
+      version: " - 5.1.1"
+      reason: IP range queries had an exclusive range bug prior to 5.1.2
   - do:
       index:
         index: test