Add per-field Similarity support

src/main/java/org/elasticsearch/index/engine/robin/RobinEngine.java

@@ -1331,7 +1331,7 @@ public class RobinEngine extends AbstractIndexShardComponent implements Engine {
             config.setIndexDeletionPolicy(deletionPolicy);
             config.setMergeScheduler(mergeScheduler.newMergeScheduler());
             config.setMergePolicy(mergePolicyProvider.newMergePolicy());
-            config.setSimilarity(similarityService.defaultIndexSimilarity());
+            config.setSimilarity(similarityService.similarity());
             config.setRAMBufferSizeMB(indexingBufferSize.mbFrac());
             config.setTermIndexInterval(termIndexInterval);
             config.setReaderTermsIndexDivisor(termIndexDivisor);
@@ -1478,7 +1478,7 @@ public class RobinEngine extends AbstractIndexShardComponent implements Engine {
         @Override
         public IndexSearcher newSearcher(IndexReader reader) throws IOException {
             IndexSearcher searcher = new IndexSearcher(reader);
-            searcher.setSimilarity(similarityService.defaultSearchSimilarity());
+            searcher.setSimilarity(similarityService.similarity());
             if (warmer != null) {
                 // we need to pass a custom searcher that does not release anything on Engine.Search Release,
                 // we will release explicitly

src/main/java/org/elasticsearch/index/mapper/DocumentMapperParser.java

@@ -45,6 +45,7 @@ import org.elasticsearch.index.mapper.multifield.MultiFieldMapper;
 import org.elasticsearch.index.mapper.object.ObjectMapper;
 import org.elasticsearch.index.mapper.object.RootObjectMapper;
 import org.elasticsearch.index.settings.IndexSettings;
+import org.elasticsearch.index.similarity.SimilarityLookupService;
 
 import java.io.IOException;
 import java.util.Map;
@@ -58,6 +59,7 @@ public class DocumentMapperParser extends AbstractIndexComponent {
 
     final AnalysisService analysisService;
     private final PostingsFormatService postingsFormatService;
+    private final SimilarityLookupService similarityLookupService;
 
     private final RootObjectMapper.TypeParser rootObjectTypeParser = new RootObjectMapper.TypeParser();
 
@@ -66,14 +68,17 @@ public class DocumentMapperParser extends AbstractIndexComponent {
     private volatile ImmutableMap<String, Mapper.TypeParser> typeParsers;
     private volatile ImmutableMap<String, Mapper.TypeParser> rootTypeParsers;
 
-    public DocumentMapperParser(Index index, AnalysisService analysisService, PostingsFormatService postingsFormatService) {
+    public DocumentMapperParser(Index index, AnalysisService analysisService, PostingsFormatService postingsFormatService,
-        this(index, ImmutableSettings.Builder.EMPTY_SETTINGS, analysisService, postingsFormatService);
+                                SimilarityLookupService similarityLookupService) {
+        this(index, ImmutableSettings.Builder.EMPTY_SETTINGS, analysisService, postingsFormatService, similarityLookupService);
     }
 
-    public DocumentMapperParser(Index index, @IndexSettings Settings indexSettings, AnalysisService analysisService, PostingsFormatService postingsFormatService) {
+    public DocumentMapperParser(Index index, @IndexSettings Settings indexSettings, AnalysisService analysisService,
+                                PostingsFormatService postingsFormatService, SimilarityLookupService similarityLookupService) {
         super(index, indexSettings);
         this.analysisService = analysisService;
         this.postingsFormatService = postingsFormatService;
+        this.similarityLookupService = similarityLookupService;
         MapBuilder<String, Mapper.TypeParser> typeParsersBuilder = new MapBuilder<String, Mapper.TypeParser>()
                 .put(ByteFieldMapper.CONTENT_TYPE, new ByteFieldMapper.TypeParser())
                 .put(ShortFieldMapper.CONTENT_TYPE, new ShortFieldMapper.TypeParser())
@@ -132,7 +137,7 @@ public class DocumentMapperParser extends AbstractIndexComponent {
     }
 
     public Mapper.TypeParser.ParserContext parserContext() {
-        return new Mapper.TypeParser.ParserContext(postingsFormatService, analysisService, typeParsers);
+        return new Mapper.TypeParser.ParserContext(postingsFormatService, analysisService, similarityLookupService, typeParsers);
     }
 
     public DocumentMapper parse(String source) throws MapperParsingException {
@@ -166,7 +171,7 @@ public class DocumentMapperParser extends AbstractIndexComponent {
             }
         }
 
-        Mapper.TypeParser.ParserContext parserContext = new Mapper.TypeParser.ParserContext(postingsFormatService, analysisService, typeParsers);
+        Mapper.TypeParser.ParserContext parserContext = new Mapper.TypeParser.ParserContext(postingsFormatService, analysisService, similarityLookupService, typeParsers);
 
         DocumentMapper.Builder docBuilder = doc(index.name(), indexSettings, (RootObjectMapper.Builder) rootObjectTypeParser.parse(type, mapping, parserContext));
 

src/main/java/org/elasticsearch/index/mapper/FieldMapper.java

@@ -30,6 +30,7 @@ import org.elasticsearch.common.Nullable;
 import org.elasticsearch.index.codec.postingsformat.PostingsFormatProvider;
 import org.elasticsearch.index.field.data.FieldDataType;
 import org.elasticsearch.index.query.QueryParseContext;
+import org.elasticsearch.index.similarity.SimilarityProvider;
 
 /**
  *
@@ -157,6 +158,11 @@ public interface FieldMapper<T> {
      */
     Analyzer searchQuoteAnalyzer();
 
+    /**
+     * Similarity used for scoring queries on the field
+     */
+    SimilarityProvider similarity();
+
     /**
      * Returns the value that will be used as a result for search. Can be only of specific types... .
      */

src/main/java/org/elasticsearch/index/mapper/Mapper.java

@@ -26,6 +26,7 @@ import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.index.analysis.AnalysisService;
 import org.elasticsearch.index.codec.postingsformat.PostingsFormatService;
+import org.elasticsearch.index.similarity.SimilarityLookupService;
 
 import java.io.IOException;
 import java.util.Map;
@@ -81,11 +82,15 @@ public interface Mapper extends ToXContent {
 
             private final AnalysisService analysisService;
 
+            private final SimilarityLookupService similarityLookupService;
+
             private final ImmutableMap<String, TypeParser> typeParsers;
 
-            public ParserContext(PostingsFormatService postingsFormatService, AnalysisService analysisService, ImmutableMap<String, TypeParser> typeParsers) {
+            public ParserContext(PostingsFormatService postingsFormatService, AnalysisService analysisService,
+                                 SimilarityLookupService similarityLookupService, ImmutableMap<String, TypeParser> typeParsers) {
                 this.postingsFormatService = postingsFormatService;
                 this.analysisService = analysisService;
+                this.similarityLookupService = similarityLookupService;
                 this.typeParsers = typeParsers;
             }
 
@@ -97,6 +102,10 @@ public interface Mapper extends ToXContent {
                 return postingsFormatService;
             }
 
+            public SimilarityLookupService similarityLookupService() {
+                return similarityLookupService;
+            }
+
             public TypeParser typeParser(String type) {
                 return typeParsers.get(Strings.toUnderscoreCase(type));
             }

src/main/java/org/elasticsearch/index/mapper/MapperService.java

@@ -49,6 +49,7 @@ import org.elasticsearch.index.mapper.internal.TypeFieldMapper;
 import org.elasticsearch.index.mapper.object.ObjectMapper;
 import org.elasticsearch.index.search.nested.NonNestedDocsFilter;
 import org.elasticsearch.index.settings.IndexSettings;
+import org.elasticsearch.index.similarity.SimilarityLookupService;
 import org.elasticsearch.indices.InvalidTypeNameException;
 import org.elasticsearch.indices.TypeMissingException;
 
@@ -99,11 +100,12 @@ public class MapperService extends AbstractIndexComponent implements Iterable<Do
     private final SmartIndexNameSearchQuoteAnalyzer searchQuoteAnalyzer;
 
     @Inject
-    public MapperService(Index index, @IndexSettings Settings indexSettings, Environment environment, AnalysisService analysisService, PostingsFormatService postingsFormatService) {
+    public MapperService(Index index, @IndexSettings Settings indexSettings, Environment environment, AnalysisService analysisService,
+                         PostingsFormatService postingsFormatService, SimilarityLookupService similarityLookupService) {
         super(index, indexSettings);
         this.analysisService = analysisService;
         this.postingsFormatService = postingsFormatService;
-        this.documentParser = new DocumentMapperParser(index, indexSettings, analysisService, postingsFormatService);
+        this.documentParser = new DocumentMapperParser(index, indexSettings, analysisService, postingsFormatService, similarityLookupService);
         this.searchAnalyzer = new SmartIndexNameSearchAnalyzer(analysisService.defaultSearchAnalyzer());
         this.searchQuoteAnalyzer = new SmartIndexNameSearchQuoteAnalyzer(analysisService.defaultSearchQuoteAnalyzer());
 

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

@@ -37,6 +37,7 @@ import org.elasticsearch.index.codec.postingsformat.PostingsFormatProvider;
 import org.elasticsearch.index.field.data.FieldDataType;
 import org.elasticsearch.index.mapper.*;
 import org.elasticsearch.index.query.QueryParseContext;
+import org.elasticsearch.index.similarity.SimilarityProvider;
 
 import java.io.IOException;
 
@@ -131,6 +132,11 @@ public abstract class AbstractFieldMapper<T> implements FieldMapper<T>, Mapper {
         public T searchAnalyzer(NamedAnalyzer searchAnalyzer) {
             return super.searchAnalyzer(searchAnalyzer);
         }
+
+        @Override
+        public T similarity(SimilarityProvider similarity) {
+            return super.similarity(similarity);
+        }
     }
 
     public abstract static class Builder<T extends Builder, Y extends AbstractFieldMapper> extends Mapper.Builder<T, Y> {
@@ -144,6 +150,7 @@ public abstract class AbstractFieldMapper<T> implements FieldMapper<T>, Mapper {
         protected Boolean includeInAll;
         protected boolean indexOptionsSet = false;
         protected PostingsFormatProvider provider;
+        protected SimilarityProvider similarity;
 
         protected Builder(String name, FieldType fieldType) {
             super(name);
@@ -230,6 +237,11 @@ public abstract class AbstractFieldMapper<T> implements FieldMapper<T>, Mapper {
             return builder;
         }
 
+        protected T similarity(SimilarityProvider similarity) {
+            this.similarity = similarity;
+            return builder;
+        }
+
         protected Names buildNames(BuilderContext context) {
             return new Names(name, buildIndexName(context), indexName == null ? name : indexName, buildFullName(context), context.path().sourcePath());
         }
@@ -250,9 +262,10 @@ public abstract class AbstractFieldMapper<T> implements FieldMapper<T>, Mapper {
     protected final NamedAnalyzer indexAnalyzer;
     protected final NamedAnalyzer searchAnalyzer;
     protected PostingsFormatProvider postingsFormat;
+    protected final SimilarityProvider similarity;
 
     protected AbstractFieldMapper(Names names, float boost, FieldType fieldType, NamedAnalyzer indexAnalyzer,
-                                  NamedAnalyzer searchAnalyzer, PostingsFormatProvider postingsFormat) {
+                                  NamedAnalyzer searchAnalyzer, PostingsFormatProvider postingsFormat, SimilarityProvider similarity) {
         this.names = names;
         this.boost = boost;
         this.fieldType = fieldType;
@@ -276,6 +289,7 @@ public abstract class AbstractFieldMapper<T> implements FieldMapper<T>, Mapper {
             }
         }
         this.postingsFormat = postingsFormat;
+        this.similarity = similarity;
     }
 
     @Nullable
@@ -358,6 +372,11 @@ public abstract class AbstractFieldMapper<T> implements FieldMapper<T>, Mapper {
         return this.searchAnalyzer;
     }
 
+    @Override
+    public SimilarityProvider similarity() {
+        return similarity;
+    }
+
     @Override
     public void parse(ParseContext context) throws IOException {
         try {
@@ -524,6 +543,17 @@ public abstract class AbstractFieldMapper<T> implements FieldMapper<T>, Mapper {
         } else if (!this.searchAnalyzer.name().equals(fieldMergeWith.searchAnalyzer.name())) {
             mergeContext.addConflict("mapper [" + names.fullName() + "] has different search_analyzer");
         }
+
+        if (this.similarity == null) {
+            if (fieldMergeWith.similarity() != null) {
+                mergeContext.addConflict("mapper [" + names.fullName() + "] has different similarity");
+            }
+        } else if (fieldMergeWith.similarity() == null) {
+            mergeContext.addConflict("mapper [" + names.fullName() + "] has different similarity");
+        } else if (!this.similarity().equals(fieldMergeWith.similarity())) {
+            mergeContext.addConflict("mapper [" + names.fullName() + "] has different similarity");
+        }
+
         if (!mergeContext.mergeFlags().simulate()) {
             // apply changeable values
             this.boost = fieldMergeWith.boost;

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

@@ -120,7 +120,7 @@ public class BinaryFieldMapper extends AbstractFieldMapper<byte[]> {
     private long compressThreshold;
 
     protected BinaryFieldMapper(Names names, FieldType fieldType, Boolean compress, long compressThreshold, PostingsFormatProvider provider) {
-        super(names, 1.0f, fieldType, null, null, provider);
+        super(names, 1.0f, fieldType, null, null, provider, null);
         this.compress = compress;
         this.compressThreshold = compressThreshold;
     }

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

@@ -32,6 +32,7 @@ import org.elasticsearch.index.codec.postingsformat.PostingsFormatProvider;
 import org.elasticsearch.index.mapper.Mapper;
 import org.elasticsearch.index.mapper.MapperParsingException;
 import org.elasticsearch.index.mapper.ParseContext;
+import org.elasticsearch.index.similarity.SimilarityProvider;
 
 import java.io.IOException;
 import java.util.Map;
@@ -113,10 +114,14 @@ public class BooleanFieldMapper extends AbstractFieldMapper<Boolean> {
             return super.indexName(indexName);
         }
 
+        @Override
+        public Builder similarity(SimilarityProvider similarity) {
+            return super.similarity(similarity);
+        }
 
         @Override
         public BooleanFieldMapper build(BuilderContext context) {
-            return new BooleanFieldMapper(buildNames(context), boost, fieldType, nullValue, provider);
+            return new BooleanFieldMapper(buildNames(context), boost, fieldType, nullValue, provider, similarity);
         }
     }
 
@@ -138,8 +143,8 @@ public class BooleanFieldMapper extends AbstractFieldMapper<Boolean> {
 
     private Boolean nullValue;
 
-    protected BooleanFieldMapper(Names names, float boost, FieldType fieldType, Boolean nullValue, PostingsFormatProvider provider) {
+    protected BooleanFieldMapper(Names names, float boost, FieldType fieldType, Boolean nullValue, PostingsFormatProvider provider, SimilarityProvider similarity) {
-        super(names, boost, fieldType, Lucene.KEYWORD_ANALYZER, Lucene.KEYWORD_ANALYZER, provider);
+        super(names, boost, fieldType, Lucene.KEYWORD_ANALYZER, Lucene.KEYWORD_ANALYZER, provider, similarity);
         this.nullValue = nullValue;
     }
 
@@ -238,6 +243,9 @@ public class BooleanFieldMapper extends AbstractFieldMapper<Boolean> {
         if (indexOptions() != Defaults.BOOLEAN_FIELD_TYPE.indexOptions()) {
             builder.field("index_options", indexOptionToString(indexOptions()));
         }
+        if (similarity() != null) {
+            builder.field("similarity", similarity().name());
+        }
         if (nullValue != null) {
             builder.field("null_value", nullValue);
         }

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

@@ -42,6 +42,7 @@ import org.elasticsearch.index.field.data.FieldDataType;
 import org.elasticsearch.index.mapper.*;
 import org.elasticsearch.index.query.QueryParseContext;
 import org.elasticsearch.index.search.NumericRangeFieldDataFilter;
+import org.elasticsearch.index.similarity.SimilarityProvider;
 
 import java.io.IOException;
 import java.util.Map;
@@ -86,7 +87,7 @@ public class ByteFieldMapper extends NumberFieldMapper<Byte> {
             fieldType.setOmitNorms(fieldType.omitNorms() && boost == 1.0f);
             ByteFieldMapper fieldMapper = new ByteFieldMapper(buildNames(context),
                     precisionStep, fuzzyFactor, boost, fieldType, nullValue, ignoreMalformed(context),
-                    provider);
+                    provider, similarity);
             fieldMapper.includeInAll(includeInAll);
             return fieldMapper;
         }
@@ -113,10 +114,10 @@ public class ByteFieldMapper extends NumberFieldMapper<Byte> {
     private String nullValueAsString;
 
     protected ByteFieldMapper(Names names, int precisionStep, String fuzzyFactor, float boost, FieldType fieldType,
-                              Byte nullValue, Explicit<Boolean> ignoreMalformed, PostingsFormatProvider provider) {
+                              Byte nullValue, Explicit<Boolean> ignoreMalformed, PostingsFormatProvider provider, SimilarityProvider similarity) {
         super(names, precisionStep, fuzzyFactor, boost, fieldType,
                 ignoreMalformed, new NamedAnalyzer("_byte/" + precisionStep, new NumericIntegerAnalyzer(precisionStep)),
-                new NamedAnalyzer("_byte/max", new NumericIntegerAnalyzer(Integer.MAX_VALUE)), provider);
+                new NamedAnalyzer("_byte/max", new NumericIntegerAnalyzer(Integer.MAX_VALUE)), provider, similarity);
         this.nullValue = nullValue;
         this.nullValueAsString = nullValue == null ? null : nullValue.toString();
     }
@@ -354,6 +355,9 @@ public class ByteFieldMapper extends NumberFieldMapper<Byte> {
         if (fuzzyFactor != Defaults.FUZZY_FACTOR) {
             builder.field("fuzzy_factor", fuzzyFactor);
         }
+        if (similarity() != null) {
+            builder.field("similarity", similarity().name());
+        }
         if (nullValue != null) {
             builder.field("null_value", nullValue);
         }

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

@@ -45,6 +45,7 @@ import org.elasticsearch.index.field.data.FieldDataType;
 import org.elasticsearch.index.mapper.*;
 import org.elasticsearch.index.query.QueryParseContext;
 import org.elasticsearch.index.search.NumericRangeFieldDataFilter;
+import org.elasticsearch.index.similarity.SimilarityProvider;
 
 import java.io.IOException;
 import java.util.Map;
@@ -113,7 +114,7 @@ public class DateFieldMapper extends NumberFieldMapper<Long> {
             fieldType.setOmitNorms(fieldType.omitNorms() && boost == 1.0f);
             DateFieldMapper fieldMapper = new DateFieldMapper(buildNames(context), dateTimeFormatter,
                     precisionStep, fuzzyFactor, boost, fieldType, nullValue,
-                    timeUnit, parseUpperInclusive, ignoreMalformed(context), provider);
+                    timeUnit, parseUpperInclusive, ignoreMalformed(context), provider, similarity);
             fieldMapper.includeInAll(includeInAll);
             return fieldMapper;
         }
@@ -152,12 +153,12 @@ public class DateFieldMapper extends NumberFieldMapper<Long> {
     protected DateFieldMapper(Names names, FormatDateTimeFormatter dateTimeFormatter, int precisionStep, String fuzzyFactor,
                               float boost, FieldType fieldType,
                               String nullValue, TimeUnit timeUnit, boolean parseUpperInclusive, Explicit<Boolean> ignoreMalformed,
-                              PostingsFormatProvider provider) {
+                              PostingsFormatProvider provider, SimilarityProvider similarity) {
         super(names, precisionStep, fuzzyFactor, boost, fieldType,
                 ignoreMalformed, new NamedAnalyzer("_date/" + precisionStep,
                 new NumericDateAnalyzer(precisionStep, dateTimeFormatter.parser())),
                 new NamedAnalyzer("_date/max", new NumericDateAnalyzer(Integer.MAX_VALUE, dateTimeFormatter.parser())),
-                provider);
+                provider, similarity);
         this.dateTimeFormatter = dateTimeFormatter;
         this.nullValue = nullValue;
         this.timeUnit = timeUnit;
@@ -428,6 +429,9 @@ public class DateFieldMapper extends NumberFieldMapper<Long> {
             builder.field("fuzzy_factor", fuzzyFactor);
         }
         builder.field("format", dateTimeFormatter.format());
+        if (similarity() != null) {
+            builder.field("similarity", similarity().name());
+        }
         if (nullValue != null) {
             builder.field("null_value", nullValue);
         }

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

@@ -42,6 +42,7 @@ import org.elasticsearch.index.field.data.FieldDataType;
 import org.elasticsearch.index.mapper.*;
 import org.elasticsearch.index.query.QueryParseContext;
 import org.elasticsearch.index.search.NumericRangeFieldDataFilter;
+import org.elasticsearch.index.similarity.SimilarityProvider;
 
 import java.io.IOException;
 import java.util.Map;
@@ -86,7 +87,7 @@ public class DoubleFieldMapper extends NumberFieldMapper<Double> {
             fieldType.setOmitNorms(fieldType.omitNorms() && boost == 1.0f);
             DoubleFieldMapper fieldMapper = new DoubleFieldMapper(buildNames(context),
                     precisionStep, fuzzyFactor, boost, fieldType, nullValue,
-                    ignoreMalformed(context), provider);
+                    ignoreMalformed(context), provider, similarity);
             fieldMapper.includeInAll(includeInAll);
             return fieldMapper;
         }
@@ -116,10 +117,10 @@ public class DoubleFieldMapper extends NumberFieldMapper<Double> {
     protected DoubleFieldMapper(Names names, int precisionStep, String fuzzyFactor,
                                 float boost, FieldType fieldType,
                                 Double nullValue, Explicit<Boolean> ignoreMalformed,
-                                PostingsFormatProvider provider) {
+                                PostingsFormatProvider provider, SimilarityProvider similarity) {
         super(names, precisionStep, fuzzyFactor, boost, fieldType,
                 ignoreMalformed, new NamedAnalyzer("_double/" + precisionStep, new NumericDoubleAnalyzer(precisionStep)),
-                new NamedAnalyzer("_double/max", new NumericDoubleAnalyzer(Integer.MAX_VALUE)), provider);
+                new NamedAnalyzer("_double/max", new NumericDoubleAnalyzer(Integer.MAX_VALUE)), provider, similarity);
         this.nullValue = nullValue;
         this.nullValueAsString = nullValue == null ? null : nullValue.toString();
     }
@@ -358,6 +359,9 @@ public class DoubleFieldMapper extends NumberFieldMapper<Double> {
         if (fuzzyFactor != Defaults.FUZZY_FACTOR) {
             builder.field("fuzzy_factor", fuzzyFactor);
         }
+        if (similarity() != null) {
+            builder.field("similarity", similarity().name());
+        }
         if (nullValue != null) {
             builder.field("null_value", nullValue);
         }

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

@@ -43,6 +43,7 @@ import org.elasticsearch.index.field.data.FieldDataType;
 import org.elasticsearch.index.mapper.*;
 import org.elasticsearch.index.query.QueryParseContext;
 import org.elasticsearch.index.search.NumericRangeFieldDataFilter;
+import org.elasticsearch.index.similarity.SimilarityProvider;
 
 import java.io.IOException;
 import java.util.Map;
@@ -87,7 +88,7 @@ public class FloatFieldMapper extends NumberFieldMapper<Float> {
             fieldType.setOmitNorms(fieldType.omitNorms() && boost == 1.0f);
             FloatFieldMapper fieldMapper = new FloatFieldMapper(buildNames(context),
                     precisionStep, fuzzyFactor, boost, fieldType, nullValue,
-                    ignoreMalformed(context), provider);
+                    ignoreMalformed(context), provider, similarity);
             fieldMapper.includeInAll(includeInAll);
             return fieldMapper;
         }
@@ -114,10 +115,10 @@ public class FloatFieldMapper extends NumberFieldMapper<Float> {
     private String nullValueAsString;
 
     protected FloatFieldMapper(Names names, int precisionStep, String fuzzyFactor, float boost, FieldType fieldType,
-                               Float nullValue, Explicit<Boolean> ignoreMalformed, PostingsFormatProvider provider) {
+                               Float nullValue, Explicit<Boolean> ignoreMalformed, PostingsFormatProvider provider, SimilarityProvider similarity) {
         super(names, precisionStep, fuzzyFactor, boost, fieldType,
                 ignoreMalformed, new NamedAnalyzer("_float/" + precisionStep, new NumericFloatAnalyzer(precisionStep)),
-                new NamedAnalyzer("_float/max", new NumericFloatAnalyzer(Integer.MAX_VALUE)), provider);
+                new NamedAnalyzer("_float/max", new NumericFloatAnalyzer(Integer.MAX_VALUE)), provider, similarity);
         this.nullValue = nullValue;
         this.nullValueAsString = nullValue == null ? null : nullValue.toString();
     }
@@ -353,6 +354,9 @@ public class FloatFieldMapper extends NumberFieldMapper<Float> {
         if (fuzzyFactor != Defaults.FUZZY_FACTOR) {
             builder.field("fuzzy_factor", fuzzyFactor);
         }
+        if (similarity() != null) {
+            builder.field("similarity", similarity().name());
+        }
         if (nullValue != null) {
             builder.field("null_value", nullValue);
         }

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

@@ -43,6 +43,7 @@ import org.elasticsearch.index.field.data.FieldDataType;
 import org.elasticsearch.index.mapper.*;
 import org.elasticsearch.index.query.QueryParseContext;
 import org.elasticsearch.index.search.NumericRangeFieldDataFilter;
+import org.elasticsearch.index.similarity.SimilarityProvider;
 
 import java.io.IOException;
 import java.util.Map;
@@ -87,7 +88,7 @@ public class IntegerFieldMapper extends NumberFieldMapper<Integer> {
             fieldType.setOmitNorms(fieldType.omitNorms() && boost == 1.0f);
             IntegerFieldMapper fieldMapper = new IntegerFieldMapper(buildNames(context),
                     precisionStep, fuzzyFactor, boost, fieldType,
-                    nullValue, ignoreMalformed(context), provider);
+                    nullValue, ignoreMalformed(context), provider, similarity);
             fieldMapper.includeInAll(includeInAll);
             return fieldMapper;
         }
@@ -116,10 +117,10 @@ public class IntegerFieldMapper extends NumberFieldMapper<Integer> {
     protected IntegerFieldMapper(Names names, int precisionStep, String fuzzyFactor,
                                  float boost, FieldType fieldType,
                                  Integer nullValue, Explicit<Boolean> ignoreMalformed,
-                                 PostingsFormatProvider provider) {
+                                 PostingsFormatProvider provider, SimilarityProvider similarity) {
         super(names, precisionStep, fuzzyFactor, boost, fieldType,
                 ignoreMalformed, new NamedAnalyzer("_int/" + precisionStep, new NumericIntegerAnalyzer(precisionStep)),
-                new NamedAnalyzer("_int/max", new NumericIntegerAnalyzer(Integer.MAX_VALUE)), provider);
+                new NamedAnalyzer("_int/max", new NumericIntegerAnalyzer(Integer.MAX_VALUE)), provider, similarity);
         this.nullValue = nullValue;
         this.nullValueAsString = nullValue == null ? null : nullValue.toString();
     }
@@ -358,6 +359,9 @@ public class IntegerFieldMapper extends NumberFieldMapper<Integer> {
         if (fuzzyFactor != Defaults.FUZZY_FACTOR) {
             builder.field("fuzzy_factor", fuzzyFactor);
         }
+        if (similarity() != null) {
+            builder.field("similarity", similarity().name());
+        }
         if (nullValue != null) {
             builder.field("null_value", nullValue);
         }

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

@@ -43,6 +43,7 @@ import org.elasticsearch.index.field.data.FieldDataType;
 import org.elasticsearch.index.mapper.*;
 import org.elasticsearch.index.query.QueryParseContext;
 import org.elasticsearch.index.search.NumericRangeFieldDataFilter;
+import org.elasticsearch.index.similarity.SimilarityProvider;
 
 import java.io.IOException;
 import java.util.Map;
@@ -87,7 +88,7 @@ public class LongFieldMapper extends NumberFieldMapper<Long> {
             fieldType.setOmitNorms(fieldType.omitNorms() && boost != 1.0f);
             LongFieldMapper fieldMapper = new LongFieldMapper(buildNames(context),
                     precisionStep, fuzzyFactor, boost, fieldType, nullValue,
-                    ignoreMalformed(context), provider);
+                    ignoreMalformed(context), provider, similarity);
             fieldMapper.includeInAll(includeInAll);
             return fieldMapper;
         }
@@ -116,10 +117,10 @@ public class LongFieldMapper extends NumberFieldMapper<Long> {
     protected LongFieldMapper(Names names, int precisionStep, String fuzzyFactor,
                               float boost, FieldType fieldType,
                               Long nullValue, Explicit<Boolean> ignoreMalformed,
-                              PostingsFormatProvider provider) {
+                              PostingsFormatProvider provider, SimilarityProvider similarity) {
         super(names, precisionStep, fuzzyFactor, boost, fieldType,
                 ignoreMalformed, new NamedAnalyzer("_long/" + precisionStep, new NumericLongAnalyzer(precisionStep)),
-                new NamedAnalyzer("_long/max", new NumericLongAnalyzer(Integer.MAX_VALUE)), provider);
+                new NamedAnalyzer("_long/max", new NumericLongAnalyzer(Integer.MAX_VALUE)), provider, similarity);
         this.nullValue = nullValue;
         this.nullValueAsString = nullValue == null ? null : nullValue.toString();
     }
@@ -357,6 +358,9 @@ public class LongFieldMapper extends NumberFieldMapper<Long> {
         if (fuzzyFactor != Defaults.FUZZY_FACTOR) {
             builder.field("fuzzy_factor", fuzzyFactor);
         }
+        if (similarity() != null) {
+            builder.field("similarity", similarity().name());
+        }
         if (nullValue != null) {
             builder.field("null_value", nullValue);
         }

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

@@ -37,6 +37,7 @@ import org.elasticsearch.index.field.data.FieldDataType;
 import org.elasticsearch.index.mapper.*;
 import org.elasticsearch.index.mapper.internal.AllFieldMapper;
 import org.elasticsearch.index.query.QueryParseContext;
+import org.elasticsearch.index.similarity.SimilarityProvider;
 
 import java.io.IOException;
 import java.io.Reader;
@@ -141,9 +142,9 @@ public abstract class NumberFieldMapper<T extends Number> extends AbstractFieldM
     protected NumberFieldMapper(Names names, int precisionStep, @Nullable String fuzzyFactor,
                                 float boost, FieldType fieldType,
                                 Explicit<Boolean> ignoreMalformed, NamedAnalyzer indexAnalyzer,
-                                NamedAnalyzer searchAnalyzer, PostingsFormatProvider provider) {
+                                NamedAnalyzer searchAnalyzer, PostingsFormatProvider provider, SimilarityProvider similarity) {
         // LUCENE 4 UPGRADE: Since we can't do anything before the super call, we have to push the boost check down to subclasses
-        super(names, boost, fieldType, indexAnalyzer, searchAnalyzer, provider);
+        super(names, boost, fieldType, indexAnalyzer, searchAnalyzer, provider, similarity);
         if (precisionStep <= 0 || precisionStep >= maxPrecisionStep()) {
             this.precisionStep = Integer.MAX_VALUE;
         } else {

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

@@ -43,6 +43,7 @@ import org.elasticsearch.index.field.data.FieldDataType;
 import org.elasticsearch.index.mapper.*;
 import org.elasticsearch.index.query.QueryParseContext;
 import org.elasticsearch.index.search.NumericRangeFieldDataFilter;
+import org.elasticsearch.index.similarity.SimilarityProvider;
 
 import java.io.IOException;
 import java.util.Map;
@@ -87,7 +88,7 @@ public class ShortFieldMapper extends NumberFieldMapper<Short> {
             fieldType.setOmitNorms(fieldType.omitNorms() && boost == 1.0f);
             ShortFieldMapper fieldMapper = new ShortFieldMapper(buildNames(context),
                     precisionStep, fuzzyFactor, boost, fieldType, nullValue,
-                    ignoreMalformed(context), provider);
+                    ignoreMalformed(context), provider, similarity);
             fieldMapper.includeInAll(includeInAll);
             return fieldMapper;
         }
@@ -116,10 +117,10 @@ public class ShortFieldMapper extends NumberFieldMapper<Short> {
     protected ShortFieldMapper(Names names, int precisionStep, String fuzzyFactor,
                                float boost, FieldType fieldType,
                                Short nullValue, Explicit<Boolean> ignoreMalformed,
-                               PostingsFormatProvider provider) {
+                               PostingsFormatProvider provider, SimilarityProvider similarity) {
         super(names, precisionStep, fuzzyFactor, boost, fieldType,
                 ignoreMalformed, new NamedAnalyzer("_short/" + precisionStep, new NumericIntegerAnalyzer(precisionStep)),
-                new NamedAnalyzer("_short/max", new NumericIntegerAnalyzer(Integer.MAX_VALUE)), provider);
+                new NamedAnalyzer("_short/max", new NumericIntegerAnalyzer(Integer.MAX_VALUE)), provider, similarity);
         this.nullValue = nullValue;
         this.nullValueAsString = nullValue == null ? null : nullValue.toString();
     }
@@ -357,6 +358,9 @@ public class ShortFieldMapper extends NumberFieldMapper<Short> {
         if (fuzzyFactor != Defaults.FUZZY_FACTOR) {
             builder.field("fuzzy_factor", fuzzyFactor);
         }
+        if (similarity() != null) {
+            builder.field("similarity", similarity().name());
+        }
         if (nullValue != null) {
             builder.field("null_value", nullValue);
         }

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

@@ -33,6 +33,7 @@ import org.elasticsearch.index.analysis.NamedCustomAnalyzer;
 import org.elasticsearch.index.codec.postingsformat.PostingsFormatProvider;
 import org.elasticsearch.index.mapper.*;
 import org.elasticsearch.index.mapper.internal.AllFieldMapper;
+import org.elasticsearch.index.similarity.SimilarityProvider;
 
 import java.io.IOException;
 import java.util.Map;
@@ -130,7 +131,7 @@ public class StringFieldMapper extends AbstractFieldMapper<String> implements Al
             }
             StringFieldMapper fieldMapper = new StringFieldMapper(buildNames(context),
                     boost, fieldType, nullValue, indexAnalyzer, searchAnalyzer, searchQuotedAnalyzer,
-                    positionOffsetGap, ignoreAbove, provider);
+                    positionOffsetGap, ignoreAbove, provider, similarity);
             fieldMapper.includeInAll(includeInAll);
             return fieldMapper;
         }
@@ -185,16 +186,16 @@ public class StringFieldMapper extends AbstractFieldMapper<String> implements Al
 
     protected StringFieldMapper(Names names, float boost, FieldType fieldType,
                                 String nullValue, NamedAnalyzer indexAnalyzer, NamedAnalyzer searchAnalyzer,
-                                PostingsFormatProvider postingsFormat) {
+                                PostingsFormatProvider postingsFormat, SimilarityProvider similarity) {
         this(names, boost, fieldType, nullValue, indexAnalyzer, searchAnalyzer, searchAnalyzer,
-                Defaults.POSITION_OFFSET_GAP, Defaults.IGNORE_ABOVE, postingsFormat);
+                Defaults.POSITION_OFFSET_GAP, Defaults.IGNORE_ABOVE, postingsFormat, similarity);
     }
 
     protected StringFieldMapper(Names names, float boost, FieldType fieldType,
                                 String nullValue, NamedAnalyzer indexAnalyzer, NamedAnalyzer searchAnalyzer,
                                 NamedAnalyzer searchQuotedAnalyzer, int positionOffsetGap, int ignoreAbove,
-                                PostingsFormatProvider postingsFormat) {
+                                PostingsFormatProvider postingsFormat, SimilarityProvider similarity) {
-        super(names, boost, fieldType, indexAnalyzer, searchAnalyzer, postingsFormat);
+        super(names, boost, fieldType, indexAnalyzer, searchAnalyzer, postingsFormat, similarity);
         this.nullValue = nullValue;
         this.positionOffsetGap = positionOffsetGap;
         this.searchQuotedAnalyzer = searchQuotedAnalyzer != null ? searchQuotedAnalyzer : this.searchAnalyzer;
@@ -361,6 +362,9 @@ public class StringFieldMapper extends AbstractFieldMapper<String> implements Al
         if (searchQuotedAnalyzer != null && searchAnalyzer != searchQuotedAnalyzer) {
             builder.field("search_quote_analyzer", searchQuotedAnalyzer.name());
         }
+        if (similarity() != null) {
+            builder.field("similarity", similarity().name());
+        }
         if (ignoreAbove != Defaults.IGNORE_ABOVE) {
             builder.field("ignore_above", ignoreAbove);
         }

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

@@ -55,6 +55,8 @@ public class TypeParsers {
                 builder.ignoreMalformed(nodeBooleanValue(propNode));
             } else if (propName.equals("omit_norms")) {
                 builder.omitNorms(nodeBooleanValue(propNode));
+            } else if (propName.equals("similarity")) {
+                builder.similarity(parserContext.similarityLookupService().similarity(propNode.toString()));
             }
         }
     }
@@ -114,6 +116,8 @@ public class TypeParsers {
             } else if (propName.equals("postings_format")) {
                 String postingFormatName = propNode.toString();
                 builder.postingsFormat(parserContext.postingFormatService().get(postingFormatName));
+            } else if (propName.equals("similarity")) {
+                builder.similarity(parserContext.similarityLookupService().similarity(propNode.toString()));
             }
         }
     }

src/main/java/org/elasticsearch/index/mapper/geo/GeoPointFieldMapper.java

@@ -572,7 +572,7 @@ public class GeoPointFieldMapper implements Mapper, ArrayValueMapperParser {
         public GeoStringFieldMapper(Names names, float boost, FieldType fieldType, String nullValue,
                                     NamedAnalyzer indexAnalyzer, NamedAnalyzer searchAnalyzer,
                                     PostingsFormatProvider provider) {
-            super(names, boost, fieldType, nullValue, indexAnalyzer, searchAnalyzer, provider);
+            super(names, boost, fieldType, nullValue, indexAnalyzer, searchAnalyzer, provider, null);
         }
 
         @Override

src/main/java/org/elasticsearch/index/mapper/geo/GeoShapeFieldMapper.java

@@ -138,7 +138,7 @@ public class GeoShapeFieldMapper extends AbstractFieldMapper<String> {
 
     public GeoShapeFieldMapper(FieldMapper.Names names, SpatialPrefixTree prefixTree, double distanceErrorPct,
                                FieldType fieldType, PostingsFormatProvider provider) {
-        super(names, 1, fieldType, null, null, provider);
+        super(names, 1, fieldType, null, null, provider, null);
         this.spatialStrategy = new TermQueryPrefixTreeStrategy(names, prefixTree, distanceErrorPct);
     }
 

src/main/java/org/elasticsearch/index/mapper/internal/AllFieldMapper.java

@@ -36,6 +36,7 @@ import org.elasticsearch.index.codec.postingsformat.PostingsFormatProvider;
 import org.elasticsearch.index.mapper.*;
 import org.elasticsearch.index.mapper.core.AbstractFieldMapper;
 import org.elasticsearch.index.query.QueryParseContext;
+import org.elasticsearch.index.similarity.SimilarityProvider;
 
 import java.io.IOException;
 import java.util.Map;
@@ -98,7 +99,7 @@ public class AllFieldMapper extends AbstractFieldMapper<Void> implements Interna
             fieldType.setIndexed(true);
             fieldType.setTokenized(true);
 
-            return new AllFieldMapper(name, fieldType, indexAnalyzer, searchAnalyzer, enabled, autoBoost, provider);
+            return new AllFieldMapper(name, fieldType, indexAnalyzer, searchAnalyzer, enabled, autoBoost, provider, similarity);
         }
     }
 
@@ -130,12 +131,12 @@ public class AllFieldMapper extends AbstractFieldMapper<Void> implements Interna
     private volatile boolean autoBoost;
 
     public AllFieldMapper() {
-        this(Defaults.NAME, new FieldType(Defaults.ALL_FIELD_TYPE), null, null, Defaults.ENABLED, false, null);
+        this(Defaults.NAME, new FieldType(Defaults.ALL_FIELD_TYPE), null, null, Defaults.ENABLED, false, null, null);
     }
 
     protected AllFieldMapper(String name, FieldType fieldType, NamedAnalyzer indexAnalyzer, NamedAnalyzer searchAnalyzer,
-                             boolean enabled, boolean autoBoost, PostingsFormatProvider provider) {
+                             boolean enabled, boolean autoBoost, PostingsFormatProvider provider, SimilarityProvider similarity) {
-        super(new Names(name, name, name, name), 1.0f, fieldType, indexAnalyzer, searchAnalyzer, provider);
+        super(new Names(name, name, name, name), 1.0f, fieldType, indexAnalyzer, searchAnalyzer, provider, similarity);
         this.enabled = enabled;
         this.autoBoost = autoBoost;
 
@@ -285,6 +286,9 @@ public class AllFieldMapper extends AbstractFieldMapper<Void> implements Interna
                 builder.field("search_analyzer", searchAnalyzer.name());
             }
         }
+        if (similarity() != null) {
+            builder.field("similarity", similarity().name());
+        }
         builder.endObject();
         return builder;
     }

src/main/java/org/elasticsearch/index/mapper/internal/BoostFieldMapper.java

@@ -122,7 +122,7 @@ public class BoostFieldMapper extends NumberFieldMapper<Float> implements Intern
                                Float nullValue, PostingsFormatProvider provider) {
         super(new Names(name, indexName, indexName, name), precisionStep, null, boost, fieldType,
                 Defaults.IGNORE_MALFORMED, new NamedAnalyzer("_float/" + precisionStep, new NumericFloatAnalyzer(precisionStep)),
-                new NamedAnalyzer("_float/max", new NumericFloatAnalyzer(Integer.MAX_VALUE)), provider);
+                new NamedAnalyzer("_float/max", new NumericFloatAnalyzer(Integer.MAX_VALUE)), provider, null);
         this.nullValue = nullValue;
     }
 

src/main/java/org/elasticsearch/index/mapper/internal/IdFieldMapper.java

@@ -125,7 +125,7 @@ public class IdFieldMapper extends AbstractFieldMapper<String> implements Intern
     protected IdFieldMapper(String name, String indexName, float boost, FieldType fieldType, String path,
                             PostingsFormatProvider provider) {
         super(new Names(name, indexName, indexName, name), boost, fieldType, Lucene.KEYWORD_ANALYZER,
-                Lucene.KEYWORD_ANALYZER, provider);
+                Lucene.KEYWORD_ANALYZER, provider, null);
         this.path = path;
     }
 

src/main/java/org/elasticsearch/index/mapper/internal/IndexFieldMapper.java

@@ -114,7 +114,7 @@ public class IndexFieldMapper extends AbstractFieldMapper<String> implements Int
     public IndexFieldMapper(String name, String indexName, float boost, FieldType fieldType, boolean enabled,
                             PostingsFormatProvider provider) {
         super(new Names(name, indexName, indexName, name), boost, fieldType, Lucene.KEYWORD_ANALYZER,
-                Lucene.KEYWORD_ANALYZER, provider);
+                Lucene.KEYWORD_ANALYZER, provider, null);
         this.enabled = enabled;
     }
 

src/main/java/org/elasticsearch/index/mapper/internal/ParentFieldMapper.java

@@ -116,7 +116,7 @@ public class ParentFieldMapper extends AbstractFieldMapper<Uid> implements Inter
 
     protected ParentFieldMapper(String name, String indexName, String type, PostingsFormatProvider postingsFormat) {
         super(new Names(name, indexName, indexName, name), Defaults.BOOST, new FieldType(Defaults.PARENT_FIELD_TYPE),
-                Lucene.KEYWORD_ANALYZER, Lucene.KEYWORD_ANALYZER, postingsFormat);
+                Lucene.KEYWORD_ANALYZER, Lucene.KEYWORD_ANALYZER, postingsFormat, null);
         this.type = type;
     }
 

src/main/java/org/elasticsearch/index/mapper/internal/RoutingFieldMapper.java

@@ -119,7 +119,7 @@ public class RoutingFieldMapper extends AbstractFieldMapper<String> implements I
 
     protected RoutingFieldMapper(FieldType fieldType, boolean required, String path, PostingsFormatProvider provider) {
         super(new Names(Defaults.NAME, Defaults.NAME, Defaults.NAME, Defaults.NAME), 1.0f, fieldType, Lucene.KEYWORD_ANALYZER,
-                Lucene.KEYWORD_ANALYZER, provider);
+                Lucene.KEYWORD_ANALYZER, provider, null);
         this.required = required;
         this.path = path;
     }

src/main/java/org/elasticsearch/index/mapper/internal/SizeFieldMapper.java

@@ -100,7 +100,7 @@ public class SizeFieldMapper extends IntegerFieldMapper implements RootMapper {
 
     public SizeFieldMapper(boolean enabled, FieldType fieldType, PostingsFormatProvider provider) {
         super(new Names(Defaults.NAME), Defaults.PRECISION_STEP, Defaults.FUZZY_FACTOR,
-                Defaults.BOOST, fieldType, Defaults.NULL_VALUE, Defaults.IGNORE_MALFORMED, provider);
+                Defaults.BOOST, fieldType, Defaults.NULL_VALUE, Defaults.IGNORE_MALFORMED, provider, null);
         this.enabled = enabled;
     }
 

src/main/java/org/elasticsearch/index/mapper/internal/SourceFieldMapper.java

@@ -200,7 +200,7 @@ public class SourceFieldMapper extends AbstractFieldMapper<byte[]> implements In
     protected SourceFieldMapper(String name, boolean enabled, String format, Boolean compress, long compressThreshold,
                                 String[] includes, String[] excludes) {
         super(new Names(name, name, name, name), Defaults.BOOST, new FieldType(Defaults.SOURCE_FIELD_TYPE),
-                Lucene.KEYWORD_ANALYZER, Lucene.KEYWORD_ANALYZER, null); // Only stored.
+                Lucene.KEYWORD_ANALYZER, Lucene.KEYWORD_ANALYZER, null, null); // Only stored.
         this.enabled = enabled;
         this.compress = compress;
         this.compressThreshold = compressThreshold;

src/main/java/org/elasticsearch/index/mapper/internal/TTLFieldMapper.java

@@ -119,7 +119,7 @@ public class TTLFieldMapper extends LongFieldMapper implements InternalMapper, R
                              PostingsFormatProvider provider) {
         super(new Names(Defaults.NAME, Defaults.NAME, Defaults.NAME, Defaults.NAME), Defaults.PRECISION_STEP,
                 Defaults.FUZZY_FACTOR, Defaults.BOOST, fieldType, Defaults.NULL_VALUE, ignoreMalformed,
-                provider);
+                provider, null);
         this.enabled = enabled;
         this.defaultTTL = defaultTTL;
     }

src/main/java/org/elasticsearch/index/mapper/internal/TimestampFieldMapper.java

@@ -138,7 +138,7 @@ public class TimestampFieldMapper extends DateFieldMapper implements InternalMap
         super(new Names(Defaults.NAME, Defaults.NAME, Defaults.NAME, Defaults.NAME), dateTimeFormatter,
                 Defaults.PRECISION_STEP, Defaults.FUZZY_FACTOR, Defaults.BOOST, fieldType,
                 Defaults.NULL_VALUE, TimeUnit.MILLISECONDS /*always milliseconds*/,
-                parseUpperInclusive, ignoreMalformed, provider);
+                parseUpperInclusive, ignoreMalformed, provider, null);
         this.enabled = enabled;
         this.path = path;
     }

src/main/java/org/elasticsearch/index/mapper/internal/TypeFieldMapper.java

@@ -103,7 +103,7 @@ public class TypeFieldMapper extends AbstractFieldMapper<String> implements Inte
 
     public TypeFieldMapper(String name, String indexName, float boost, FieldType fieldType, PostingsFormatProvider provider) {
         super(new Names(name, indexName, indexName, name), boost, fieldType, Lucene.KEYWORD_ANALYZER,
-                Lucene.KEYWORD_ANALYZER, provider);
+                Lucene.KEYWORD_ANALYZER, provider, null);
     }
 
     public String value(Document document) {

src/main/java/org/elasticsearch/index/mapper/internal/UidFieldMapper.java

@@ -109,7 +109,7 @@ public class UidFieldMapper extends AbstractFieldMapper<Uid> implements Internal
 
     protected UidFieldMapper(String name, String indexName, PostingsFormatProvider postingsFormat) {
         super(new Names(name, indexName, indexName, name), Defaults.BOOST, new FieldType(Defaults.UID_FIELD_TYPE),
-                Lucene.KEYWORD_ANALYZER, Lucene.KEYWORD_ANALYZER, postingsFormat);
+                Lucene.KEYWORD_ANALYZER, Lucene.KEYWORD_ANALYZER, postingsFormat, null);
     }
 
     @Override

src/main/java/org/elasticsearch/index/mapper/ip/IpFieldMapper.java

@@ -43,6 +43,7 @@ import org.elasticsearch.index.mapper.core.LongFieldMapper;
 import org.elasticsearch.index.mapper.core.NumberFieldMapper;
 import org.elasticsearch.index.query.QueryParseContext;
 import org.elasticsearch.index.search.NumericRangeFieldDataFilter;
+import org.elasticsearch.index.similarity.SimilarityProvider;
 
 import java.io.IOException;
 import java.io.Reader;
@@ -113,7 +114,7 @@ public class IpFieldMapper extends NumberFieldMapper<Long> {
         public IpFieldMapper build(BuilderContext context) {
             fieldType.setOmitNorms(fieldType.omitNorms() && boost == 1.0f);
             IpFieldMapper fieldMapper = new IpFieldMapper(buildNames(context),
-                    precisionStep, boost, fieldType, nullValue, ignoreMalformed(context), provider);
+                    precisionStep, boost, fieldType, nullValue, ignoreMalformed(context), provider, similarity);
             fieldMapper.includeInAll(includeInAll);
             return fieldMapper;
         }
@@ -140,10 +141,10 @@ public class IpFieldMapper extends NumberFieldMapper<Long> {
     protected IpFieldMapper(Names names, int precisionStep,
                             float boost, FieldType fieldType,
                             String nullValue, Explicit<Boolean> ignoreMalformed,
-                            PostingsFormatProvider provider) {
+                            PostingsFormatProvider provider, SimilarityProvider similarity) {
         super(names, precisionStep, null, boost, fieldType,
                 ignoreMalformed, new NamedAnalyzer("_ip/" + precisionStep, new NumericIpAnalyzer(precisionStep)),
-                new NamedAnalyzer("_ip/max", new NumericIpAnalyzer(Integer.MAX_VALUE)), provider);
+                new NamedAnalyzer("_ip/max", new NumericIpAnalyzer(Integer.MAX_VALUE)), provider, similarity);
         this.nullValue = nullValue;
     }
 
@@ -331,6 +332,9 @@ public class IpFieldMapper extends NumberFieldMapper<Long> {
         if (precisionStep != Defaults.PRECISION_STEP) {
             builder.field("precision_step", precisionStep);
         }
+        if (similarity() != null) {
+            builder.field("similarity", similarity().name());
+        }
         if (nullValue != null) {
             builder.field("null_value", nullValue);
         }

src/main/java/org/elasticsearch/index/query/QueryParseContext.java

@@ -123,7 +123,7 @@ public class QueryParseContext {
     }
 
     public Similarity searchSimilarity() {
-        return indexQueryParser.similarityService != null ? indexQueryParser.similarityService.defaultSearchSimilarity() : null;
+        return indexQueryParser.similarityService != null ? indexQueryParser.similarityService.similarity() : null;
     }
 
     public IndexCache indexCache() {

src/main/java/org/elasticsearch/index/similarity/AbstractSimilarityProvider.java

@@ -19,26 +19,61 @@
 
 package org.elasticsearch.index.similarity;
 
-import org.apache.lucene.search.similarities.Similarity;
+import org.apache.lucene.search.similarities.*;
+import org.elasticsearch.ElasticSearchIllegalArgumentException;
 import org.elasticsearch.common.settings.Settings;
-import org.elasticsearch.index.AbstractIndexComponent;
-import org.elasticsearch.index.Index;
-import org.elasticsearch.index.settings.IndexSettings;
 
 /**
- *
+ * Abstract implemenetation of {@link SimilarityProvider} providing common behaviour
  */
-public abstract class AbstractSimilarityProvider<T extends Similarity> extends AbstractIndexComponent implements SimilarityProvider<T> {
+public abstract class AbstractSimilarityProvider implements SimilarityProvider {
+
+    protected static final Normalization NO_NORMALIZATION = new Normalization.NoNormalization();
 
     private final String name;
 
-    protected AbstractSimilarityProvider(Index index, @IndexSettings Settings indexSettings, String name) {
+    /**
-        super(index, indexSettings);
+     * Creates a new AbstractSimilarityProvider with the given name
+     *
+     * @param name Name of the Provider
+     */
+    protected AbstractSimilarityProvider(String name) {
         this.name = name;
     }
 
+    /**
+     * {@inheritDoc}
+     */
     @Override
     public String name() {
         return this.name;
     }
+
+    /**
+     * Parses the given Settings and creates the appropriate {@link Normalization}
+     *
+     * @param settings Settings to parse
+     * @return {@link Normalization} referred to in the Settings
+     */
+    protected Normalization parseNormalization(Settings settings) {
+        String normalization = settings.get("normalization");
+
+        if ("no".equals(normalization)) {
+            return NO_NORMALIZATION;
+        } else if ("h1".equals(normalization)) {
+            float c = settings.getAsFloat("normalization.h1.c", 1f);
+            return new NormalizationH1(c);
+        } else if ("h2".equals(normalization)) {
+            float c = settings.getAsFloat("normalization.h2.c", 1f);
+            return new NormalizationH2(c);
+        } else if ("h3".equals(normalization)) {
+            float c = settings.getAsFloat("normalization.h3.c", 800f);
+            return new NormalizationH3(c);
+        } else if ("z".equals(normalization)) {
+            float z = settings.getAsFloat("normalization.z.z", 0.30f);
+            return new NormalizationZ(z);
+        } else {
+            throw new ElasticSearchIllegalArgumentException("Unsupported Normalization [" + normalization + "]");
+        }
+    }
 }

src/main/java/org/elasticsearch/index/similarity/BM25SimilarityProvider.java

@@ -0,0 +1,61 @@
+/*
+ * Licensed to ElasticSearch and Shay Banon 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.similarity;
+
+import org.apache.lucene.search.similarities.BM25Similarity;
+import org.apache.lucene.search.similarities.Similarity;
+import org.elasticsearch.common.inject.Inject;
+import org.elasticsearch.common.inject.assistedinject.Assisted;
+import org.elasticsearch.common.settings.Settings;
+
+/**
+ * {@link SimilarityProvider} for the {@link BM25Similarity}.
+ * <p/>
+ * Configuration options available:
+ * <ul>
+ *     <li>k1</li>
+ *     <li>b</li>
+ *     <li>discount_overlaps</li>
+ * </ul>
+ * @see BM25Similarity For more information about configuration
+ */
+public class BM25SimilarityProvider extends AbstractSimilarityProvider {
+
+    private final BM25Similarity similarity;
+
+    @Inject
+    public BM25SimilarityProvider(@Assisted String name, @Assisted Settings settings) {
+        super(name);
+        float k1 = settings.getAsFloat("k1", 1.2f);
+        float b = settings.getAsFloat("b", 0.75f);
+        boolean discountOverlaps = settings.getAsBoolean("discount_overlaps", true);
+
+        this.similarity = new BM25Similarity(k1, b);
+        this.similarity.setDiscountOverlaps(discountOverlaps);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public Similarity get() {
+        return similarity;
+    }
+}

src/main/java/org/elasticsearch/index/similarity/DFRSimilarityProvider.java

@@ -0,0 +1,112 @@
+/*
+ * Licensed to ElasticSearch and Shay Banon 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.similarity;
+
+import com.google.common.collect.ImmutableMap;
+import org.apache.lucene.search.similarities.*;
+import org.elasticsearch.ElasticSearchIllegalArgumentException;
+import org.elasticsearch.common.collect.MapBuilder;
+import org.elasticsearch.common.inject.Inject;
+import org.elasticsearch.common.inject.assistedinject.Assisted;
+import org.elasticsearch.common.settings.Settings;
+
+/**
+ * {@link SimilarityProvider} for {@link DFRSimilarity}.
+ * <p/>
+ * Configuration options available:
+ * <ul>
+ *     <li>basic_model</li>
+ *     <li>after_effect</li>
+ *     <li>normalization</li>
+ * </ul>
+ * @see DFRSimilarity For more information about configuration
+ */
+public class DFRSimilarityProvider extends AbstractSimilarityProvider {
+
+    private static final ImmutableMap<String, BasicModel> MODEL_CACHE;
+    private static final ImmutableMap<String, AfterEffect> EFFECT_CACHE;
+
+    static {
+        MapBuilder<String, BasicModel> models = MapBuilder.newMapBuilder();
+        models.put("be", new BasicModelBE());
+        models.put("d", new BasicModelD());
+        models.put("g", new BasicModelG());
+        models.put("if", new BasicModelIF());
+        models.put("in", new BasicModelIn());
+        models.put("ine", new BasicModelIne());
+        models.put("p", new BasicModelP());
+        MODEL_CACHE = models.immutableMap();
+
+        MapBuilder<String, AfterEffect> effects = MapBuilder.newMapBuilder();
+        effects.put("no", new AfterEffect.NoAfterEffect());
+        effects.put("b", new AfterEffectB());
+        effects.put("l", new AfterEffectL());
+        EFFECT_CACHE = effects.immutableMap();
+    }
+
+    private final DFRSimilarity similarity;
+
+    @Inject
+    public DFRSimilarityProvider(@Assisted String name, @Assisted Settings settings) {
+        super(name);
+        BasicModel basicModel = parseBasicModel(settings);
+        AfterEffect afterEffect = parseAfterEffect(settings);
+        Normalization normalization = parseNormalization(settings);
+        this.similarity = new DFRSimilarity(basicModel, afterEffect, normalization);
+    }
+
+    /**
+     * Parses the given Settings and creates the appropriate {@link BasicModel}
+     *
+     * @param settings Settings to parse
+     * @return {@link BasicModel} referred to in the Settings
+     */
+    protected BasicModel parseBasicModel(Settings settings) {
+        String basicModel = settings.get("basic_model");
+        BasicModel model = MODEL_CACHE.get(basicModel);
+        if (model == null) {
+            throw new ElasticSearchIllegalArgumentException("Unsupported BasicModel [" + basicModel + "]");
+        }
+        return model;
+    }
+
+    /**
+     * Parses the given Settings and creates the appropriate {@link AfterEffect}
+     *
+     * @param settings Settings to parse
+     * @return {@link AfterEffect} referred to in the Settings
+     */
+    protected AfterEffect parseAfterEffect(Settings settings) {
+        String afterEffect = settings.get("after_effect");
+        AfterEffect effect = EFFECT_CACHE.get(afterEffect);
+        if (effect == null) {
+            throw new ElasticSearchIllegalArgumentException("Unsupported AfterEffect [" + afterEffect + "]");
+        }
+        return effect;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public Similarity get() {
+        return similarity;
+    }
+}

src/main/java/org/elasticsearch/index/similarity/DefaultSimilarityProvider.java

@@ -27,18 +27,28 @@ import org.elasticsearch.index.Index;
 import org.elasticsearch.index.settings.IndexSettings;
 
 /**
- *
+ * {@link SimilarityProvider} for {@link DefaultSimilarity}.
+ * <p/>
+ * Configuration options available:
+ * <ul>
+ *     <li>discount_overlaps</li>
+ * </ul>
+ * @see DefaultSimilarity For more information about configuration
  */
-public class DefaultSimilarityProvider extends AbstractSimilarityProvider<DefaultSimilarity> {
+public class DefaultSimilarityProvider extends AbstractSimilarityProvider {
 
-    private DefaultSimilarity similarity;
+    private final DefaultSimilarity similarity = new DefaultSimilarity();
 
     @Inject
-    public DefaultSimilarityProvider(Index index, @IndexSettings Settings indexSettings, @Assisted String name, @Assisted Settings settings) {
+    public DefaultSimilarityProvider(@Assisted String name, @Assisted Settings settings) {
-        super(index, indexSettings, name);
+        super(name);
-        this.similarity = new DefaultSimilarity();
+        boolean discountOverlaps = settings.getAsBoolean("discount_overlaps", true);
+        this.similarity.setDiscountOverlaps(discountOverlaps);
     }
 
+    /**
+     * {@inheritDoc}
+     */
     @Override
     public DefaultSimilarity get() {
         return similarity;

src/main/java/org/elasticsearch/index/similarity/IBSimilarityProvider.java

@@ -0,0 +1,106 @@
+/*
+ * Licensed to ElasticSearch and Shay Banon 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.similarity;
+
+import com.google.common.collect.ImmutableMap;
+import org.apache.lucene.search.similarities.*;
+import org.elasticsearch.ElasticSearchIllegalArgumentException;
+import org.elasticsearch.common.collect.MapBuilder;
+import org.elasticsearch.common.inject.Inject;
+import org.elasticsearch.common.inject.assistedinject.Assisted;
+import org.elasticsearch.common.settings.Settings;
+
+/**
+ * {@link SimilarityProvider} for {@link IBSimilarity}.
+ * <p/>
+ * Configuration options available:
+ * <ul>
+ *     <li>distribution</li>
+ *     <li>lambda</li>
+ *     <li>normalization</li>
+ * </ul>
+ * @see IBSimilarity For more information about configuration
+ */
+public class IBSimilarityProvider extends AbstractSimilarityProvider {
+
+    private static final ImmutableMap<String, Distribution> DISTRIBUTION_CACHE;
+    private static final ImmutableMap<String, Lambda> LAMBDA_CACHE;
+
+    static {
+        MapBuilder<String, Distribution> distributions = MapBuilder.newMapBuilder();
+        distributions.put("ll", new DistributionLL());
+        distributions.put("spl", new DistributionSPL());
+        DISTRIBUTION_CACHE = distributions.immutableMap();
+
+        MapBuilder<String, Lambda> lamdas = MapBuilder.newMapBuilder();
+        lamdas.put("df", new LambdaDF());
+        lamdas.put("ttf", new LambdaTTF());
+        LAMBDA_CACHE = lamdas.immutableMap();
+    }
+
+    private final IBSimilarity similarity;
+
+    @Inject
+    public IBSimilarityProvider(@Assisted String name, @Assisted Settings settings) {
+        super(name);
+        Distribution distribution = parseDistribution(settings);
+        Lambda lambda = parseLambda(settings);
+        Normalization normalization = parseNormalization(settings);
+        this.similarity = new IBSimilarity(distribution, lambda, normalization);
+    }
+
+    /**
+     * Parses the given Settings and creates the appropriate {@link Distribution}
+     *
+     * @param settings Settings to parse
+     * @return {@link Normalization} referred to in the Settings
+     */
+    protected Distribution parseDistribution(Settings settings) {
+        String rawDistribution = settings.get("distribution");
+        Distribution distribution = DISTRIBUTION_CACHE.get(rawDistribution);
+        if (distribution == null) {
+            throw new ElasticSearchIllegalArgumentException("Unsupported Distribution [" + rawDistribution + "]");
+        }
+        return distribution;
+    }
+
+    /**
+     * Parses the given Settings and creates the appropriate {@link Lambda}
+     *
+     * @param settings Settings to parse
+     * @return {@link Normalization} referred to in the Settings
+     */
+    protected Lambda parseLambda(Settings settings) {
+        String rawLambda = settings.get("lambda");
+        Lambda lambda = LAMBDA_CACHE.get(rawLambda);
+        if (lambda == null) {
+            throw new ElasticSearchIllegalArgumentException("Unsupported Lambda [" + rawLambda + "]");
+        }
+        return lambda;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public Similarity get() {
+        return similarity;
+    }
+}

src/main/java/org/elasticsearch/index/similarity/PreBuiltSimilarityProvider.java

@@ -0,0 +1,73 @@
+/*
+ * Licensed to ElasticSearch and Shay Banon 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.similarity;
+
+import org.apache.lucene.search.similarities.Similarity;
+import org.elasticsearch.common.settings.Settings;
+
+/**
+ * {@link SimilarityProvider} for pre-built Similarities
+ */
+public class PreBuiltSimilarityProvider extends AbstractSimilarityProvider {
+
+    public static class Factory implements SimilarityProvider.Factory {
+
+        private final PreBuiltSimilarityProvider similarity;
+
+        public Factory(String name, Similarity similarity) {
+            this.similarity = new PreBuiltSimilarityProvider(name, similarity);
+        }
+
+        @Override
+        public SimilarityProvider create(String name, Settings settings) {
+            return similarity;
+        }
+
+        public String name() {
+            return similarity.name();
+        }
+
+        public SimilarityProvider get() {
+            return similarity;
+        }
+    }
+
+    private final Similarity similarity;
+
+    /**
+     * Creates a new {@link PreBuiltSimilarityProvider} with the given name and given
+     * pre-built Similarity
+     *
+     * @param name Name of the Provider
+     * @param similarity Pre-built Similarity
+     */
+    public PreBuiltSimilarityProvider(String name, Similarity similarity) {
+        super(name);
+        this.similarity = similarity;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public Similarity get() {
+        return similarity;
+    }
+}

src/main/java/org/elasticsearch/index/similarity/Similarities.java

@@ -0,0 +1,53 @@
+/*
+ * Licensed to ElasticSearch and Shay Banon 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.similarity;
+
+import com.google.common.collect.ImmutableCollection;
+import com.google.common.collect.ImmutableMap;
+import org.apache.lucene.search.similarities.*;
+import org.elasticsearch.common.collect.MapBuilder;
+
+/**
+ * Cache of pre-defined Similarities
+ */
+public class Similarities {
+
+    private static final ImmutableMap<String, PreBuiltSimilarityProvider.Factory> PRE_BUILT_SIMILARITIES;
+
+    static {
+        MapBuilder<String, PreBuiltSimilarityProvider.Factory> similarities = MapBuilder.newMapBuilder();
+        similarities.put("default", new PreBuiltSimilarityProvider.Factory("default", new DefaultSimilarity()));
+        similarities.put("BM25", new PreBuiltSimilarityProvider.Factory("BM25", new BM25Similarity()));
+
+        PRE_BUILT_SIMILARITIES = similarities.immutableMap();
+    }
+
+    private Similarities() {
+    }
+
+    /**
+     * Returns the list of pre-defined SimilarityProvider Factories
+     *
+     * @return Pre-defined SimilarityProvider Factories
+     */
+    public static ImmutableCollection<PreBuiltSimilarityProvider.Factory> listFactories() {
+        return PRE_BUILT_SIMILARITIES.values();
+    }
+}

src/main/java/org/elasticsearch/index/similarity/SimilarityLookupService.java

@@ -0,0 +1,84 @@
+/*
+ * Licensed to ElasticSearch and Shay Banon 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.similarity;
+
+import com.google.common.collect.ImmutableMap;
+import org.elasticsearch.common.collect.MapBuilder;
+import org.elasticsearch.common.inject.Inject;
+import org.elasticsearch.common.settings.ImmutableSettings;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.index.AbstractIndexComponent;
+import org.elasticsearch.index.Index;
+import org.elasticsearch.index.settings.IndexSettings;
+
+import java.util.Map;
+
+/**
+ * Service for looking up configured {@link SimilarityProvider} implementations by name.
+ *
+ * The service instantiates the Providers through their Factories using configuration
+ * values found with the {@link SimilarityModule#SIMILARITY_SETTINGS_PREFIX} prefix.
+ */
+public class SimilarityLookupService extends AbstractIndexComponent {
+
+    private final ImmutableMap<String, SimilarityProvider> similarities;
+
+    public SimilarityLookupService(Index index, Settings indexSettings) {
+        this (index, indexSettings, ImmutableMap.<String, SimilarityProvider.Factory>of());
+    }
+
+    @Inject
+    public SimilarityLookupService(Index index, @IndexSettings Settings indexSettings, Map<String, SimilarityProvider.Factory> similarities) {
+        super(index, indexSettings);
+
+        MapBuilder<String, SimilarityProvider> providers = MapBuilder.newMapBuilder();
+
+        Map<String, Settings> similaritySettings = indexSettings.getGroups(SimilarityModule.SIMILARITY_SETTINGS_PREFIX);
+        for (Map.Entry<String, SimilarityProvider.Factory> entry : similarities.entrySet()) {
+            String name = entry.getKey();
+            SimilarityProvider.Factory factory = entry.getValue();
+
+            Settings settings = similaritySettings.get(name);
+            if (settings == null) {
+                settings = ImmutableSettings.Builder.EMPTY_SETTINGS;
+            }
+            providers.put(name, factory.create(name, settings));
+        }
+
+        // For testing
+        for (PreBuiltSimilarityProvider.Factory factory : Similarities.listFactories()) {
+            if (!providers.containsKey(factory.name())) {
+                providers.put(factory.name(), factory.get());
+            }
+        }
+
+        this.similarities = providers.immutableMap();
+    }
+
+    /**
+     * Returns the {@link SimilarityProvider} with the given name
+     *
+     * @param name Name of the SimilarityProvider to find
+     * @return {@link SimilarityProvider} with the given name, or {@code null} if no Provider exists
+     */
+    public SimilarityProvider similarity(String name) {
+        return similarities.get(name);
+    }
+}

src/main/java/org/elasticsearch/index/similarity/SimilarityModule.java

@@ -19,6 +19,8 @@
 
 package org.elasticsearch.index.similarity;
 
+import com.google.common.collect.Maps;
+import org.elasticsearch.ElasticSearchIllegalArgumentException;
 import org.elasticsearch.common.inject.AbstractModule;
 import org.elasticsearch.common.inject.Scopes;
 import org.elasticsearch.common.inject.assistedinject.FactoryProvider;
@@ -28,33 +30,66 @@ import org.elasticsearch.common.settings.Settings;
 import java.util.Map;
 
 /**
+ * {@link SimilarityModule} is responsible gathering registered and configured {@link SimilarityProvider}
+ * implementations and making them available through the {@link SimilarityLookupService} and {@link SimilarityService}.
  *
+ * New {@link SimilarityProvider} implementations can be registered through {@link #addSimilarity(String, Class)}
+ * while existing Providers can be referenced through Settings under the {@link #SIMILARITY_SETTINGS_PREFIX} prefix
+ * along with the "type" value.  For example, to reference the {@link BM25SimilarityProvider}, the configuration
+ * <tt>"index.similarity.my_similarity.type : "BM25"</tt> can be used.
  */
 public class SimilarityModule extends AbstractModule {
 
+    public static final String SIMILARITY_SETTINGS_PREFIX = "index.similarity";
+
     private final Settings settings;
+    private final Map<String, Class<? extends SimilarityProvider>> similarities = Maps.newHashMap();
 
     public SimilarityModule(Settings settings) {
         this.settings = settings;
     }
 
+    /**
+     * Registers the given {@link SimilarityProvider} with the given name
+     *
+     * @param name Name of the SimilarityProvider
+     * @param similarity SimilarityProvider to register
+     */
+    public void addSimilarity(String name, Class<? extends SimilarityProvider> similarity) {
+        similarities.put(name, similarity);
+    }
+
     @Override
     protected void configure() {
-        MapBinder<String, SimilarityProviderFactory> similarityBinder
+        Map<String, Class<? extends SimilarityProvider>> providers = Maps.newHashMap(similarities);
-                = MapBinder.newMapBinder(binder(), String.class, SimilarityProviderFactory.class);
 
-        Map<String, Settings> similarityProvidersSettings = settings.getGroups("index.similarity");
+        Map<String, Settings> similaritySettings = settings.getGroups(SIMILARITY_SETTINGS_PREFIX);
-        for (Map.Entry<String, Settings> entry : similarityProvidersSettings.entrySet()) {
+        for (Map.Entry<String, Settings> entry : similaritySettings.entrySet()) {
             String name = entry.getKey();
             Settings settings = entry.getValue();
 
-            Class<? extends SimilarityProvider> type = settings.getAsClass("type", null, "org.elasticsearch.index.similarity.", "SimilarityProvider");
+            Class<? extends SimilarityProvider> type =
+                    settings.getAsClass("type", null, "org.elasticsearch.index.similarity.", "SimilarityProvider");
             if (type == null) {
-                throw new IllegalArgumentException("Similarity [" + name + "] must have a type associated with it");
+                throw new ElasticSearchIllegalArgumentException("SimilarityProvider [" + name + "] must have an associated type");
             }
-            similarityBinder.addBinding(name).toProvider(FactoryProvider.newFactory(SimilarityProviderFactory.class, type)).in(Scopes.SINGLETON);
+            providers.put(name, type);
         }
 
-        bind(SimilarityService.class).in(Scopes.SINGLETON);
+        MapBinder<String, SimilarityProvider.Factory> similarityBinder =
+                MapBinder.newMapBinder(binder(), String.class, SimilarityProvider.Factory.class);
+
+        for (Map.Entry<String, Class<? extends SimilarityProvider>> entry : providers.entrySet()) {
+            similarityBinder.addBinding(entry.getKey()).toProvider(FactoryProvider.newFactory(SimilarityProvider.Factory.class, entry.getValue())).in(Scopes.SINGLETON);
+        }
+
+        for (PreBuiltSimilarityProvider.Factory factory : Similarities.listFactories()) {
+            if (!providers.containsKey(factory.name())) {
+                similarityBinder.addBinding(factory.name()).toInstance(factory);
+            }
+        }
+
+        bind(SimilarityLookupService.class).asEagerSingleton();
+        bind(SimilarityService.class).asEagerSingleton();
     }
 }

src/main/java/org/elasticsearch/index/similarity/SimilarityProvider.java

@@ -21,14 +21,40 @@ package org.elasticsearch.index.similarity;
 
 import org.apache.lucene.search.similarities.Similarity;
 import org.elasticsearch.common.inject.Provider;
+import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.index.IndexComponent;
 
 /**
- *
+ * Provider for {@link Similarity} instances
  */
-public interface SimilarityProvider<T extends Similarity> extends IndexComponent, Provider<T> {
+public interface SimilarityProvider {
 
+    /**
+     * Returns the name associated with the Provider
+     *
+     * @return Name of the Provider
+     */
     String name();
 
-    T get();
+    /**
+     * Returns the {@link Similarity} the Provider is for
+     *
+     * @return Provided {@link Similarity}
+     */
+    Similarity get();
+
+    /**
+     * Factory for creating {@link SimilarityProvider} instances
+     */
+    public static interface Factory {
+
+        /**
+         * Creates a new {@link SimilarityProvider} instance
+         *
+         * @param name Name of the provider
+         * @param settings Settings to be used by the Provider
+         * @return {@link SimilarityProvider} instance created by the Factory
+         */
+        SimilarityProvider create(String name, Settings settings);
+    }
 }

src/main/java/org/elasticsearch/index/similarity/SimilarityProviderFactory.java

@@ -1,30 +0,0 @@
-/*
- * Licensed to ElasticSearch and Shay Banon 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.similarity;
-
-import org.elasticsearch.common.settings.Settings;
-
-/**
- *
- */
-public interface SimilarityProviderFactory {
-
-    SimilarityProvider create(String name, Settings settings);
-}

src/main/java/org/elasticsearch/index/similarity/SimilarityService.java

@@ -19,81 +19,90 @@
 
 package org.elasticsearch.index.similarity;
 
-import com.google.common.collect.ImmutableMap;
+import org.apache.lucene.search.similarities.PerFieldSimilarityWrapper;
 import org.apache.lucene.search.similarities.Similarity;
-import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.inject.Inject;
+import org.elasticsearch.common.inject.name.Named;
 import org.elasticsearch.common.settings.ImmutableSettings;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.index.AbstractIndexComponent;
 import org.elasticsearch.index.Index;
+import org.elasticsearch.index.mapper.FieldMapper;
+import org.elasticsearch.index.mapper.MapperService;
 import org.elasticsearch.index.settings.IndexSettings;
 
-import java.util.Map;
-
-import static com.google.common.collect.Maps.newHashMap;
-
 /**
  *
  */
 public class SimilarityService extends AbstractIndexComponent {
 
-    private final ImmutableMap<String, SimilarityProvider> similarityProviders;
+    private final SimilarityLookupService similarityLookupService;
+    private final MapperService mapperService;
 
-    private final ImmutableMap<String, Similarity> similarities;
+    private final Similarity perFieldSimilarity;
 
     public SimilarityService(Index index) {
-        this(index, ImmutableSettings.Builder.EMPTY_SETTINGS, null);
+        this(index, ImmutableSettings.Builder.EMPTY_SETTINGS);
+    }
+
+    public SimilarityService(Index index, Settings settings) {
+        this (index, settings, new SimilarityLookupService(index, settings), null);
     }
 
     @Inject
     public SimilarityService(Index index, @IndexSettings Settings indexSettings,
-                             @Nullable Map<String, SimilarityProviderFactory> providerFactories) {
+                             final SimilarityLookupService similarityLookupService, final MapperService mapperService) {
         super(index, indexSettings);
+        this.similarityLookupService = similarityLookupService;
+        this.mapperService = mapperService;
 
-        Map<String, SimilarityProvider> similarityProviders = newHashMap();
+        Similarity defaultSimilarity = similarityLookupService.similarity("default").get();
-        if (providerFactories != null) {
+        // Expert users can configure the base type as being different to default, but out-of-box we use default.
-            Map<String, Settings> providersSettings = indexSettings.getGroups("index.similarity");
+        Similarity baseSimilarity = (similarityLookupService.similarity("base") != null) ? similarityLookupService.similarity("base").get() :
-            for (Map.Entry<String, SimilarityProviderFactory> entry : providerFactories.entrySet()) {
+                defaultSimilarity;
-                String similarityName = entry.getKey();
-                SimilarityProviderFactory similarityProviderFactory = entry.getValue();
 
-                Settings similaritySettings = providersSettings.get(similarityName);
+        this.perFieldSimilarity = (mapperService != null) ? new PerFieldSimilarity(defaultSimilarity, baseSimilarity, mapperService) :
-                if (similaritySettings == null) {
+                defaultSimilarity;
-                    similaritySettings = ImmutableSettings.Builder.EMPTY_SETTINGS;
-                }
-
-                SimilarityProvider similarityProvider = similarityProviderFactory.create(similarityName, similaritySettings);
-                similarityProviders.put(similarityName, similarityProvider);
-            }
-        }
-
-        // add defaults
-        if (!similarityProviders.containsKey("index")) {
-            similarityProviders.put("index", new DefaultSimilarityProvider(index, indexSettings, "index", ImmutableSettings.Builder.EMPTY_SETTINGS));
-        }
-        if (!similarityProviders.containsKey("search")) {
-            similarityProviders.put("search", new DefaultSimilarityProvider(index, indexSettings, "search", ImmutableSettings.Builder.EMPTY_SETTINGS));
-        }
-        this.similarityProviders = ImmutableMap.copyOf(similarityProviders);
-
-
-        Map<String, Similarity> similarities = newHashMap();
-        for (SimilarityProvider provider : similarityProviders.values()) {
-            similarities.put(provider.name(), provider.get());
-        }
-        this.similarities = ImmutableMap.copyOf(similarities);
     }
 
-    public Similarity similarity(String name) {
+    public Similarity similarity() {
-        return similarities.get(name);
+        return perFieldSimilarity;
     }
 
-    public Similarity defaultIndexSimilarity() {
+    public SimilarityLookupService similarityLookupService() {
-        return similarities.get("index");
+        return similarityLookupService;
     }
 
-    public Similarity defaultSearchSimilarity() {
+    public MapperService mapperService() {
-        return similarities.get("search");
+        return mapperService;
+    }
+
+    static class PerFieldSimilarity extends PerFieldSimilarityWrapper {
+
+        private final Similarity defaultSimilarity;
+        private final Similarity baseSimilarity;
+        private final MapperService mapperService;
+
+        PerFieldSimilarity(Similarity defaultSimilarity, Similarity baseSimilarity, MapperService mapperService) {
+            this.defaultSimilarity = defaultSimilarity;
+            this.baseSimilarity = baseSimilarity;
+            this.mapperService = mapperService;
+        }
+
+        @Override
+        public float coord(int overlap, int maxOverlap) {
+            return baseSimilarity.coord(overlap, maxOverlap);
+        }
+
+        @Override
+        public float queryNorm(float valueForNormalization) {
+            return baseSimilarity.queryNorm(valueForNormalization);
+        }
+
+        @Override
+        public Similarity get(String name) {
+            FieldMapper mapper = mapperService.smartNameFieldMapper(name);
+            return (mapper != null && mapper.similarity() != null) ? mapper.similarity().get() : defaultSimilarity;
+        }
     }
 }

src/main/java/org/elasticsearch/search/SearchService.java

@@ -282,7 +282,7 @@ public class SearchService extends AbstractLifecycleComponent<SearchService> {
         SearchContext context = findContext(request.id());
         contextProcessing(context);
         try {
-            context.searcher().dfSource(new CachedDfSource(context.searcher().getIndexReader(), request.dfs(), context.similarityService().defaultSearchSimilarity()));
+            context.searcher().dfSource(new CachedDfSource(context.searcher().getIndexReader(), request.dfs(), context.similarityService().similarity()));
         } catch (IOException e) {
             freeContext(context);
             cleanContext(context);
@@ -348,7 +348,7 @@ public class SearchService extends AbstractLifecycleComponent<SearchService> {
         SearchContext context = findContext(request.id());
         contextProcessing(context);
         try {
-            context.searcher().dfSource(new CachedDfSource(context.searcher().getIndexReader(), request.dfs(), context.similarityService().defaultSearchSimilarity()));
+            context.searcher().dfSource(new CachedDfSource(context.searcher().getIndexReader(), request.dfs(), context.similarityService().similarity()));
         } catch (IOException e) {
             freeContext(context);
             cleanContext(context);

src/main/java/org/elasticsearch/search/internal/ContextIndexSearcher.java

@@ -61,6 +61,7 @@ public class ContextIndexSearcher extends IndexSearcher {
         super(searcher.reader());
         this.searchContext = searchContext;
         this.reader = searcher.reader();
+        setSimilarity(searcher.searcher().getSimilarity());
     }
 
     public void dfSource(CachedDfSource dfSource) {

src/test/java/org/elasticsearch/test/integration/similarity/SimilarityTests.java

@@ -0,0 +1,103 @@
+/*
+ * Licensed to ElasticSearch and Shay Banon 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.test.integration.similarity;
+
+import org.elasticsearch.action.search.SearchResponse;
+import org.elasticsearch.client.Client;
+import org.elasticsearch.common.settings.ImmutableSettings;
+import org.elasticsearch.test.integration.AbstractNodesTests;
+import org.testng.annotations.AfterClass;
+import org.testng.annotations.BeforeClass;
+import org.testng.annotations.Test;
+
+import static org.elasticsearch.common.xcontent.XContentFactory.jsonBuilder;
+import static org.elasticsearch.index.query.FilterBuilders.numericRangeFilter;
+import static org.elasticsearch.index.query.QueryBuilders.filteredQuery;
+import static org.elasticsearch.index.query.QueryBuilders.matchQuery;
+import static org.elasticsearch.index.query.QueryBuilders.queryString;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.not;
+
+public class SimilarityTests extends AbstractNodesTests {
+
+    private Client client;
+
+    @BeforeClass
+    public void createNodes() throws Exception {
+        startNode("node1");
+        client = getClient();
+    }
+
+    @AfterClass
+    public void closeNodes() {
+        client.close();
+        closeAllNodes();
+    }
+
+    protected Client getClient() {
+        return client("node1");
+    }
+
+    @Test
+    public void testCustomBM25Similarity() throws Exception {
+        try {
+            client.admin().indices().prepareDelete("test").execute().actionGet();
+        } catch (Exception e) {
+            // ignore
+        }
+
+        client.admin().indices().prepareCreate("test")
+                .addMapping("type1", jsonBuilder().startObject()
+                        .startObject("type1")
+                            .startObject("properties")
+                                .startObject("field1")
+                                    .field("similarity", "custom")
+                                    .field("type", "string")
+                                .endObject()
+                                .startObject("field2")
+                                    .field("similarity", "default")
+                                    .field("type", "string")
+                            .endObject()
+                        .endObject()
+                    .endObject())
+                .setSettings(ImmutableSettings.settingsBuilder()
+                        .put("number_of_shards", 1)
+                        .put("number_of_replicas", 0)
+                        .put("similarity.custom.type", "BM25")
+                        .put("similarity.custom.k1", 2.0f)
+                        .put("similarity.custom.b", 1.5f)
+                ).execute().actionGet();
+
+        client.prepareIndex("test", "type1", "1").setSource("field1", "the quick brown fox jumped over the lazy dog",
+                                                            "field2", "the quick brown fox jumped over the lazy dog")
+                .setRefresh(true).execute().actionGet();
+
+        SearchResponse bm25SearchResponse = client.prepareSearch().setQuery(matchQuery("field1", "quick brown fox")).execute().actionGet();
+        assertThat(bm25SearchResponse.hits().totalHits(), equalTo(1l));
+        float bm25Score = bm25SearchResponse.hits().hits()[0].score();
+
+        SearchResponse defaultSearchResponse = client.prepareSearch().setQuery(matchQuery("field2", "quick brown fox")).execute().actionGet();
+        assertThat(defaultSearchResponse.hits().totalHits(), equalTo(1l));
+        float defaultScore = defaultSearchResponse.hits().hits()[0].score();
+
+        assertThat(bm25Score, not(equalTo(defaultScore)));
+    }
+}

src/test/java/org/elasticsearch/test/unit/index/codec/CodecTests.java

@@ -44,6 +44,7 @@ import org.elasticsearch.index.codec.postingsformat.*;
 import org.elasticsearch.index.mapper.DocumentMapper;
 import org.elasticsearch.index.mapper.MapperServiceModule;
 import org.elasticsearch.index.settings.IndexSettingsModule;
+import org.elasticsearch.index.similarity.SimilarityModule;
 import org.testng.annotations.Test;
 
 import static org.hamcrest.MatcherAssert.assertThat;
@@ -245,6 +246,7 @@ public class CodecTests {
                 .add(new SettingsModule(settings))
                 .add(new IndexNameModule(index))
                 .add(new IndexSettingsModule(index, settings))
+                .add(new SimilarityModule(settings))
                 .add(new CodecModule(settings))
                 .add(new MapperServiceModule())
                 .add(new AnalysisModule(settings))

src/test/java/org/elasticsearch/test/unit/index/engine/robin/SimpleRobinEngineTests.java

@@ -19,6 +19,7 @@
 
 package org.elasticsearch.test.unit.index.engine.robin;
 
+import org.apache.lucene.search.similarities.DefaultSimilarity;
 import org.elasticsearch.index.analysis.AnalysisService;
 import org.elasticsearch.index.codec.CodecService;
 import org.elasticsearch.index.engine.Engine;

src/test/java/org/elasticsearch/test/unit/index/mapper/MapperTests.java

@@ -19,6 +19,8 @@
 
 package org.elasticsearch.test.unit.index.mapper;
 
+import com.google.common.collect.Maps;
+import org.apache.lucene.search.similarities.Similarity;
 import org.elasticsearch.common.inject.Injector;
 import org.elasticsearch.common.inject.ModulesBuilder;
 import org.elasticsearch.common.settings.ImmutableSettings;
@@ -34,25 +36,31 @@ import org.elasticsearch.index.codec.postingsformat.PostingsFormatService;
 import org.elasticsearch.index.mapper.DocumentMapperParser;
 import org.elasticsearch.index.mapper.MapperService;
 import org.elasticsearch.index.settings.IndexSettingsModule;
+import org.elasticsearch.index.similarity.SimilarityLookupService;
 import org.elasticsearch.indices.analysis.IndicesAnalysisModule;
 import org.elasticsearch.indices.analysis.IndicesAnalysisService;
 
+import java.util.HashMap;
+import java.util.Map;
+
 /**
  *
  */
 public class MapperTests {
 
     public static DocumentMapperParser newParser() {
-        return new DocumentMapperParser(new Index("test"), newAnalysisService(), new PostingsFormatService(new Index("test")));
+        return new DocumentMapperParser(new Index("test"), newAnalysisService(), new PostingsFormatService(new Index("test")),
+                newSimilarityLookupService());
     }
 
     public static DocumentMapperParser newParser(Settings indexSettings) {
-        return new DocumentMapperParser(new Index("test"), indexSettings, newAnalysisService(), new PostingsFormatService(new Index("test")));
+        return new DocumentMapperParser(new Index("test"), indexSettings, newAnalysisService(), new PostingsFormatService(new Index("test")),
+                newSimilarityLookupService());
     }
 
     public static MapperService newMapperService() {
         return new MapperService(new Index("test"), ImmutableSettings.Builder.EMPTY_SETTINGS, new Environment(), newAnalysisService(),
-                new PostingsFormatService(new Index("test")));
+                new PostingsFormatService(new Index("test")), newSimilarityLookupService());
     }
 
     public static AnalysisService newAnalysisService() {
@@ -64,4 +72,8 @@ public class MapperTests {
 
         return injector.getInstance(AnalysisService.class);
     }
+
+    public static SimilarityLookupService newSimilarityLookupService() {
+        return new SimilarityLookupService(new Index("test"), ImmutableSettings.Builder.EMPTY_SETTINGS);
+    }
 }

src/test/java/org/elasticsearch/test/unit/index/similarity/SimilarityTests.java

@@ -0,0 +1,169 @@
+/*
+ * Licensed to ElasticSearch and Shay Banon 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.test.unit.index.similarity;
+
+import org.apache.lucene.search.similarities.*;
+import org.elasticsearch.common.inject.Injector;
+import org.elasticsearch.common.inject.ModulesBuilder;
+import org.elasticsearch.common.settings.ImmutableSettings;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.settings.SettingsModule;
+import org.elasticsearch.common.xcontent.XContentFactory;
+import org.elasticsearch.index.Index;
+import org.elasticsearch.index.IndexNameModule;
+import org.elasticsearch.index.analysis.AnalysisModule;
+import org.elasticsearch.index.codec.CodecModule;
+import org.elasticsearch.index.mapper.DocumentMapper;
+import org.elasticsearch.index.mapper.MapperServiceModule;
+import org.elasticsearch.index.settings.IndexSettingsModule;
+import org.elasticsearch.index.similarity.*;
+import org.testng.annotations.Test;
+
+import java.io.IOException;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.CoreMatchers.instanceOf;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+public class SimilarityTests {
+
+    @Test
+    public void testResolveDefaultSimilarities() {
+        SimilarityLookupService similarityLookupService = similarityService().similarityLookupService();
+        assertThat(similarityLookupService.similarity("default"), instanceOf(PreBuiltSimilarityProvider.class));
+        assertThat(similarityLookupService.similarity("default").get(), instanceOf(DefaultSimilarity.class));
+        assertThat(similarityLookupService.similarity("BM25"), instanceOf(PreBuiltSimilarityProvider.class));
+        assertThat(similarityLookupService.similarity("BM25").get(), instanceOf(BM25Similarity.class));
+    }
+
+    @Test
+    public void testResolveSimilaritiesFromMapping_default() throws IOException {
+        String mapping = XContentFactory.jsonBuilder().startObject().startObject("type")
+                .startObject("properties")
+                .startObject("field1").field("type", "string").field("similarity", "my_similarity").endObject()
+                .endObject()
+                .endObject().endObject().string();
+
+        Settings indexSettings = ImmutableSettings.settingsBuilder()
+                .put("index.similarity.my_similarity.type", "default")
+                .put("index.similarity.my_similarity.discount_overlaps", false)
+                .build();
+        SimilarityService similarityService = similarityService(indexSettings);
+        DocumentMapper documentMapper = similarityService.mapperService().documentMapperParser().parse(mapping);
+        assertThat(documentMapper.mappers().name("field1").mapper().similarity(), instanceOf(DefaultSimilarityProvider.class));
+
+        DefaultSimilarity similarity = (DefaultSimilarity) documentMapper.mappers().name("field1").mapper().similarity().get();
+        assertThat(similarity.getDiscountOverlaps(), equalTo(false));
+    }
+
+    @Test
+    public void testResolveSimilaritiesFromMapping_bm25() throws IOException {
+        String mapping = XContentFactory.jsonBuilder().startObject().startObject("type")
+                .startObject("properties")
+                .startObject("field1").field("type", "string").field("similarity", "my_similarity").endObject()
+                .endObject()
+                .endObject().endObject().string();
+
+        Settings indexSettings = ImmutableSettings.settingsBuilder()
+                .put("index.similarity.my_similarity.type", "BM25")
+                .put("index.similarity.my_similarity.k1", 2.0f)
+                .put("index.similarity.my_similarity.b", 1.5f)
+                .put("index.similarity.my_similarity.discount_overlaps", false)
+                .build();
+        SimilarityService similarityService = similarityService(indexSettings);
+        DocumentMapper documentMapper = similarityService.mapperService().documentMapperParser().parse(mapping);
+        assertThat(documentMapper.mappers().name("field1").mapper().similarity(), instanceOf(BM25SimilarityProvider.class));
+
+        BM25Similarity similarity = (BM25Similarity) documentMapper.mappers().name("field1").mapper().similarity().get();
+        assertThat(similarity.getK1(), equalTo(2.0f));
+        assertThat(similarity.getB(), equalTo(1.5f));
+        assertThat(similarity.getDiscountOverlaps(), equalTo(false));
+    }
+
+    @Test
+    public void testResolveSimilaritiesFromMapping_DFR() throws IOException {
+        String mapping = XContentFactory.jsonBuilder().startObject().startObject("type")
+                .startObject("properties")
+                .startObject("field1").field("type", "string").field("similarity", "my_similarity").endObject()
+                .endObject()
+                .endObject().endObject().string();
+
+        Settings indexSettings = ImmutableSettings.settingsBuilder()
+                .put("index.similarity.my_similarity.type", "DFR")
+                .put("index.similarity.my_similarity.basic_model", "g")
+                .put("index.similarity.my_similarity.after_effect", "l")
+                .put("index.similarity.my_similarity.normalization", "h2")
+                .put("index.similarity.my_similarity.normalization.h2.c", 3f)
+                .build();
+        SimilarityService similarityService = similarityService(indexSettings);
+        DocumentMapper documentMapper = similarityService.mapperService().documentMapperParser().parse(mapping);
+        assertThat(documentMapper.mappers().name("field1").mapper().similarity(), instanceOf(DFRSimilarityProvider.class));
+
+        DFRSimilarity similarity = (DFRSimilarity) documentMapper.mappers().name("field1").mapper().similarity().get();
+        assertThat(similarity.getBasicModel(), instanceOf(BasicModelG.class));
+        assertThat(similarity.getAfterEffect(), instanceOf(AfterEffectL.class));
+        assertThat(similarity.getNormalization(), instanceOf(NormalizationH2.class));
+        assertThat(((NormalizationH2) similarity.getNormalization()).getC(), equalTo(3f));
+    }
+
+    @Test
+    public void testResolveSimilaritiesFromMapping_IB() throws IOException {
+        String mapping = XContentFactory.jsonBuilder().startObject().startObject("type")
+                .startObject("properties")
+                .startObject("field1").field("type", "string").field("similarity", "my_similarity").endObject()
+                .endObject()
+                .endObject().endObject().string();
+
+        Settings indexSettings = ImmutableSettings.settingsBuilder()
+                .put("index.similarity.my_similarity.type", "IB")
+                .put("index.similarity.my_similarity.distribution", "spl")
+                .put("index.similarity.my_similarity.lambda", "ttf")
+                .put("index.similarity.my_similarity.normalization", "h2")
+                .put("index.similarity.my_similarity.normalization.h2.c", 3f)
+                .build();
+        SimilarityService similarityService = similarityService(indexSettings);
+        DocumentMapper documentMapper = similarityService.mapperService().documentMapperParser().parse(mapping);
+        assertThat(documentMapper.mappers().name("field1").mapper().similarity(), instanceOf(IBSimilarityProvider.class));
+
+        IBSimilarity similarity = (IBSimilarity) documentMapper.mappers().name("field1").mapper().similarity().get();
+        assertThat(similarity.getDistribution(), instanceOf(DistributionSPL.class));
+        assertThat(similarity.getLambda(), instanceOf(LambdaTTF.class));
+        assertThat(similarity.getNormalization(), instanceOf(NormalizationH2.class));
+        assertThat(((NormalizationH2) similarity.getNormalization()).getC(), equalTo(3f));
+    }
+
+    private static SimilarityService similarityService() {
+        return similarityService(ImmutableSettings.Builder.EMPTY_SETTINGS);
+    }
+
+    private static SimilarityService similarityService(Settings settings) {
+        Index index = new Index("test");
+        Injector injector = new ModulesBuilder()
+                .add(new SettingsModule(settings))
+                .add(new IndexNameModule(index))
+                .add(new IndexSettingsModule(index, settings))
+                .add(new CodecModule(settings))
+                .add(new MapperServiceModule())
+                .add(new AnalysisModule(settings))
+                .add(new SimilarityModule(settings))
+                .createInjector();
+        return injector.getInstance(SimilarityService.class);
+    }
+}