Aggregations Refactor: Refactor Terms Aggregation

35 files changed, 1831 insertions, 747 deletions

diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/Aggregator.java b/core/src/main/java/org/elasticsearch/search/aggregations/Aggregator.java
index 99c23fc744..0e6387b1b7 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/Aggregator.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/Aggregator.java
@@ -22,6 +22,9 @@ package org.elasticsearch.search.aggregations;
 import org.elasticsearch.ElasticsearchParseException;
 import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.ParseFieldMatcher;
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.io.stream.StreamOutput;
+import org.elasticsearch.common.io.stream.Writeable;
 import org.elasticsearch.common.lease.Releasable;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.search.aggregations.bucket.BucketsAggregator;
@@ -112,7 +115,7 @@ public abstract class Aggregator extends BucketCollector implements Releasable {
     public abstract InternalAggregation buildEmptyAggregation();
 
     /** Aggregation mode for sub aggregations. */
-    public enum SubAggCollectionMode {
+    public enum SubAggCollectionMode implements Writeable<SubAggCollectionMode> {
 
         /**
          * Creates buckets and delegates to child aggregators in a single pass over
@@ -148,5 +151,19 @@ public abstract class Aggregator extends BucketCollector implements Releasable {
             }
             throw new ElasticsearchParseException("no [{}] found for value [{}]", KEY.getPreferredName(), value);
         }
+
+        @Override
+        public SubAggCollectionMode readFrom(StreamInput in) throws IOException {
+            int ordinal = in.readVInt();
+            if (ordinal < 0 || ordinal >= values().length) {
+                throw new IOException("Unknown SubAggCollectionMode ordinal [" + ordinal + "]");
+            }
+            return values()[ordinal];
+        }
+
+        @Override
+        public void writeTo(StreamOutput out) throws IOException {
+            out.writeVInt(ordinal());
+        }
     }
 }
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantLongTerms.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantLongTerms.java
index 9e8ad33476..226c6d5b3b 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantLongTerms.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantLongTerms.java
@@ -228,7 +228,7 @@ public class SignificantLongTerms extends InternalSignificantTerms<SignificantLo
         out.writeVLong(minDocCount);
         out.writeVLong(subsetSize);
         out.writeVLong(supersetSize);
-        significanceHeuristic.writeTo(out);
+        SignificanceHeuristicStreams.writeTo(significanceHeuristic, out);
         out.writeVInt(buckets.size());
         for (InternalSignificantTerms.Bucket bucket : buckets) {
 
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantStringTerms.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantStringTerms.java
index 6c1ca0a11a..b0479475d8 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantStringTerms.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantStringTerms.java
@@ -214,7 +214,7 @@ public class SignificantStringTerms extends InternalSignificantTerms<Significant
         out.writeVLong(minDocCount);
         out.writeVLong(subsetSize);
         out.writeVLong(supersetSize);
-        significanceHeuristic.writeTo(out);
+        SignificanceHeuristicStreams.writeTo(significanceHeuristic, out);
         out.writeVInt(buckets.size());
         for (InternalSignificantTerms.Bucket bucket : buckets) {
             bucket.writeTo(out);
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantTermsAggregatorFactory.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantTermsAggregatorFactory.java
index 0ad7389a5f..bb927c9cec 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantTermsAggregatorFactory.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantTermsAggregatorFactory.java
@@ -26,34 +26,51 @@ import org.apache.lucene.util.BytesRef;
 import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.ParseFieldMatcher;
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.lease.Releasable;
 import org.elasticsearch.common.lucene.index.FilterableTermsEnum;
 import org.elasticsearch.common.lucene.index.FreqTermsEnum;
+import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.index.mapper.MappedFieldType;
+import org.elasticsearch.index.query.QueryBuilder;
 import org.elasticsearch.search.aggregations.AggregationExecutionException;
 import org.elasticsearch.search.aggregations.Aggregator;
 import org.elasticsearch.search.aggregations.AggregatorFactories;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.NonCollectingAggregator;
+import org.elasticsearch.search.aggregations.bucket.BucketUtils;
+import org.elasticsearch.search.aggregations.bucket.significant.heuristics.JLHScore;
 import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristic;
+import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristicStreams;
 import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregator;
+import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregator.BucketCountThresholds;
+import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregatorFactory;
 import org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude;
 import org.elasticsearch.search.aggregations.pipeline.PipelineAggregator;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
+import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
-import org.elasticsearch.search.aggregations.support.ValuesSourceParser;
+import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 import org.elasticsearch.search.internal.SearchContext;
 
 import java.io.IOException;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 
 /**
  *
  */
 public class SignificantTermsAggregatorFactory extends ValuesSourceAggregatorFactory<ValuesSource> implements Releasable {
 
+    static final ParseField BACKGROUND_FILTER = new ParseField("background_filter");
+    static final ParseField HEURISTIC = new ParseField("significance_heuristic");
+
+    static final TermsAggregator.BucketCountThresholds DEFAULT_BUCKET_COUNT_THRESHOLDS = new TermsAggregator.BucketCountThresholds(
+            3, 0, 10, -1);
+
     public SignificanceHeuristic getSignificanceHeuristic() {
         return significanceHeuristic;
     }
@@ -98,9 +115,8 @@ public class SignificantTermsAggregatorFactory extends ValuesSourceAggregatorFac
                     List<PipelineAggregator> pipelineAggregators, Map<String, Object> metaData) throws IOException {
                 final IncludeExclude.OrdinalsFilter filter = includeExclude == null ? null : includeExclude.convertToOrdinalsFilter();
                 return new GlobalOrdinalsSignificantTermsAggregator.WithHash(name, factories,
-                        (ValuesSource.Bytes.WithOrdinals.FieldData) valuesSource, bucketCountThresholds, filter,
- aggregationContext,
-                        parent, termsAggregatorFactory, pipelineAggregators, metaData);
+                        (ValuesSource.Bytes.WithOrdinals.FieldData) valuesSource, bucketCountThresholds, filter, aggregationContext, parent,
+                        termsAggregatorFactory, pipelineAggregators, metaData);
             }
         };
 
@@ -129,36 +145,82 @@ public class SignificantTermsAggregatorFactory extends ValuesSourceAggregatorFac
             return parseField.getPreferredName();
         }
     }
-    private final IncludeExclude includeExclude;
-    private final String executionHint;
+
+    private IncludeExclude includeExclude = null;
+    private String executionHint = null;
     private String indexedFieldName;
     private MappedFieldType fieldType;
     private FilterableTermsEnum termsEnum;
     private int numberOfAggregatorsCreated = 0;
-    private final Query filter;
-    private final TermsAggregator.BucketCountThresholds bucketCountThresholds;
-    private final SignificanceHeuristic significanceHeuristic;
+    private QueryBuilder<?> filterBuilder = null;
+    private TermsAggregator.BucketCountThresholds bucketCountThresholds = new BucketCountThresholds(DEFAULT_BUCKET_COUNT_THRESHOLDS);
+    private SignificanceHeuristic significanceHeuristic = JLHScore.PROTOTYPE;
 
     protected TermsAggregator.BucketCountThresholds getBucketCountThresholds() {
         return new TermsAggregator.BucketCountThresholds(bucketCountThresholds);
     }
 
-    public SignificantTermsAggregatorFactory(String name, ValuesSourceParser.Input valueSourceInput,
-            TermsAggregator.BucketCountThresholds bucketCountThresholds, IncludeExclude includeExclude,
-                                             String executionHint, Query filter, SignificanceHeuristic significanceHeuristic) {
+    public SignificantTermsAggregatorFactory(String name, ValuesSourceType valuesSourceType, ValueType valueType) {
+        super(name, SignificantStringTerms.TYPE, valuesSourceType, valueType);
+    }
+
+    public TermsAggregator.BucketCountThresholds bucketCountThresholds() {
+        return bucketCountThresholds;
+    }
 
-        super(name, SignificantStringTerms.TYPE, valueSourceInput);
+    public void bucketCountThresholds(TermsAggregator.BucketCountThresholds bucketCountThresholds) {
         this.bucketCountThresholds = bucketCountThresholds;
-        this.includeExclude = includeExclude;
+    }
+
+    /**
+     * Expert: sets an execution hint to the aggregation.
+     */
+    public void executionHint(String executionHint) {
         this.executionHint = executionHint;
+    }
+
+    /**
+     * Expert: gets an execution hint to the aggregation.
+     */
+    public String executionHint() {
+        return executionHint;
+    }
+
+    public void backgroundFilter(QueryBuilder<?> filterBuilder) {
+        this.filterBuilder = filterBuilder;
+    }
+
+    public QueryBuilder<?> backgroundFilter() {
+        return filterBuilder;
+    }
+
+    /**
+     * Set terms to include and exclude from the aggregation results
+     */
+    public void includeExclude(IncludeExclude includeExclude) {
+        this.includeExclude = includeExclude;
+    }
+
+    /**
+     * Get terms to include and exclude from the aggregation results
+     */
+    public IncludeExclude includeExclude() {
+        return includeExclude;
+    }
+
+    public void significanceHeuristic(SignificanceHeuristic significanceHeuristic) {
         this.significanceHeuristic = significanceHeuristic;
-        this.filter = filter;
+    }
+
+    public SignificanceHeuristic significanceHeuristic() {
+        return significanceHeuristic;
     }
 
     @Override
     public void doInit(AggregationContext context) {
         super.doInit(context);
         setFieldInfo();
+        significanceHeuristic.initialize(context.searchContext());
     }
 
     private void setFieldInfo() {
@@ -191,6 +253,18 @@ public class SignificantTermsAggregatorFactory extends ValuesSourceAggregatorFac
         }
 
         numberOfAggregatorsCreated++;
+        BucketCountThresholds bucketCountThresholds = new BucketCountThresholds(this.bucketCountThresholds);
+        if (bucketCountThresholds.getShardSize() == DEFAULT_BUCKET_COUNT_THRESHOLDS.getShardSize()) {
+            //The user has not made a shardSize selection .
+            //Use default heuristic to avoid any wrong-ranking caused by distributed counting
+            //but request double the usual amount.
+            //We typically need more than the number of "top" terms requested by other aggregations
+            //as the significance algorithm is in less of a position to down-select at shard-level -
+            //some of the things we want to find have only one occurrence on each shard and as
+            // such are impossible to differentiate from non-significant terms at that early stage.
+            bucketCountThresholds.setShardSize(2 * BucketUtils.suggestShardSideQueueSize(bucketCountThresholds.getRequiredSize(),
+                    aggregationContext.searchContext().numberOfShards()));
+        }
 
         if (valuesSource instanceof ValuesSource.Bytes) {
             ExecutionMode execution = null;
@@ -247,6 +321,14 @@ public class SignificantTermsAggregatorFactory extends ValuesSourceAggregatorFac
         }
         SearchContext searchContext = context.searchContext();
         IndexReader reader = searchContext.searcher().getIndexReader();
+        Query filter = null;
+        try {
+            if (filterBuilder != null) {
+                filter = filterBuilder.toFilter(context.searchContext().indexShard().getQueryShardContext());
+            }
+        } catch (IOException e) {
+            throw new ElasticsearchException("failed to create filter: " + filterBuilder.toString(), e);
+        }
         try {
             if (numberOfAggregatorsCreated == 1) {
                 // Setup a termsEnum for sole use by one aggregator
@@ -291,4 +373,68 @@ public class SignificantTermsAggregatorFactory extends ValuesSourceAggregatorFac
             termsEnum = null;
         }
     }
+
+    @Override
+    protected XContentBuilder doXContentBody(XContentBuilder builder, Params params) throws IOException {
+        bucketCountThresholds.toXContent(builder, params);
+        if (executionHint != null) {
+            builder.field(TermsAggregatorFactory.EXECUTION_HINT_FIELD_NAME.getPreferredName(), executionHint);
+        }
+        if (filterBuilder != null) {
+            builder.field(BACKGROUND_FILTER.getPreferredName(), filterBuilder);
+        }
+        if (includeExclude != null) {
+            includeExclude.toXContent(builder, params);
+        }
+        significanceHeuristic.toXContent(builder, params);
+        return builder;
+    }
+
+    @Override
+    protected ValuesSourceAggregatorFactory<ValuesSource> innerReadFrom(String name, ValuesSourceType valuesSourceType,
+            ValueType targetValueType, StreamInput in) throws IOException {
+        SignificantTermsAggregatorFactory factory = new SignificantTermsAggregatorFactory(name, valuesSourceType, targetValueType);
+        factory.bucketCountThresholds = BucketCountThresholds.readFromStream(in);
+        factory.executionHint = in.readOptionalString();
+        if (in.readBoolean()) {
+            factory.filterBuilder = in.readQuery();
+        }
+        if (in.readBoolean()) {
+            factory.includeExclude = IncludeExclude.readFromStream(in);
+        }
+        factory.significanceHeuristic = SignificanceHeuristicStreams.read(in);
+        return factory;
+    }
+
+    @Override
+    protected void innerWriteTo(StreamOutput out) throws IOException {
+        bucketCountThresholds.writeTo(out);
+        out.writeOptionalString(executionHint);
+        boolean hasfilterBuilder = filterBuilder != null;
+        out.writeBoolean(hasfilterBuilder);
+        if (hasfilterBuilder) {
+            out.writeQuery(filterBuilder);
+        }
+        boolean hasIncExc = includeExclude != null;
+        out.writeBoolean(hasIncExc);
+        if (hasIncExc) {
+            includeExclude.writeTo(out);
+        }
+        SignificanceHeuristicStreams.writeTo(significanceHeuristic, out);
+    }
+
+    @Override
+    protected int innerHashCode() {
+        return Objects.hash(bucketCountThresholds, executionHint, filterBuilder, includeExclude, significanceHeuristic);
+    }
+
+    @Override
+    protected boolean innerEquals(Object obj) {
+        SignificantTermsAggregatorFactory other = (SignificantTermsAggregatorFactory) obj;
+        return Objects.equals(bucketCountThresholds, other.bucketCountThresholds)
+                && Objects.equals(executionHint, other.executionHint)
+                && Objects.equals(filterBuilder, other.filterBuilder)
+                && Objects.equals(includeExclude, other.includeExclude)
+                && Objects.equals(significanceHeuristic, other.significanceHeuristic);
+    }
 }
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantTermsBuilder.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantTermsBuilder.java
index b67ce2a1f9..6bbb3348b7 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantTermsBuilder.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantTermsBuilder.java
@@ -24,8 +24,8 @@ import org.elasticsearch.index.query.QueryBuilder;
 import org.elasticsearch.search.aggregations.AggregationBuilder;
 import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristic;
 import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristicBuilder;
-import org.elasticsearch.search.aggregations.bucket.terms.AbstractTermsParametersParser;
 import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregator;
+import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregatorFactory;
 
 import java.io.IOException;
 
@@ -88,7 +88,7 @@ public class SignificantTermsBuilder extends AggregationBuilder<SignificantTerms
         bucketCountThresholds.setMinDocCount(minDocCount);
         return this;
     }
-    
+
     /**
      * Set the background filter to compare to. Defaults to the whole index.
      */
@@ -96,7 +96,7 @@ public class SignificantTermsBuilder extends AggregationBuilder<SignificantTerms
         this.filterBuilder = filter;
         return this;
     }
-    
+
     /**
      * Expert: set the minimum number of documents that a term should match to
      * be retrieved from a shard.
@@ -138,7 +138,7 @@ public class SignificantTermsBuilder extends AggregationBuilder<SignificantTerms
         this.includeFlags = flags;
         return this;
     }
-    
+
     /**
      * Define a set of terms that should be aggregated.
      */
@@ -148,8 +148,8 @@ public class SignificantTermsBuilder extends AggregationBuilder<SignificantTerms
         }
         this.includeTerms = terms;
         return this;
-    }    
-    
+    }
+
     /**
      * Define a set of terms that should be aggregated.
      */
@@ -159,16 +159,16 @@ public class SignificantTermsBuilder extends AggregationBuilder<SignificantTerms
         }
         this.includeTerms = longsArrToStringArr(terms);
         return this;
-    }     
-    
+    }
+
     private String[] longsArrToStringArr(long[] terms) {
         String[] termsAsString = new String[terms.length];
         for (int i = 0; i < terms.length; i++) {
             termsAsString[i] = Long.toString(terms[i]);
         }
         return termsAsString;
-    }      
-    
+    }
+
 
     /**
      * Define a regular expression that will filter out terms that should be excluded from the aggregation. The regular
@@ -194,7 +194,7 @@ public class SignificantTermsBuilder extends AggregationBuilder<SignificantTerms
         this.excludeFlags = flags;
         return this;
     }
-    
+
     /**
      * Define a set of terms that should not be aggregated.
      */
@@ -204,9 +204,9 @@ public class SignificantTermsBuilder extends AggregationBuilder<SignificantTerms
         }
         this.excludeTerms = terms;
         return this;
-    }    
-    
-    
+    }
+
+
     /**
      * Define a set of terms that should not be aggregated.
      */
@@ -224,9 +224,9 @@ public class SignificantTermsBuilder extends AggregationBuilder<SignificantTerms
         if (field != null) {
             builder.field("field", field);
         }
-        bucketCountThresholds.toXContent(builder);
+        bucketCountThresholds.toXContent(builder, params);
         if (executionHint != null) {
-            builder.field(AbstractTermsParametersParser.EXECUTION_HINT_FIELD_NAME.getPreferredName(), executionHint);
+            builder.field(TermsAggregatorFactory.EXECUTION_HINT_FIELD_NAME.getPreferredName(), executionHint);
         }
         if (includePattern != null) {
             if (includeFlags == 0) {
@@ -241,7 +241,7 @@ public class SignificantTermsBuilder extends AggregationBuilder<SignificantTerms
         if (includeTerms != null) {
             builder.array("include", includeTerms);
         }
-        
+
         if (excludePattern != null) {
             if (excludeFlags == 0) {
                 builder.field("exclude", excludePattern);
@@ -255,10 +255,10 @@ public class SignificantTermsBuilder extends AggregationBuilder<SignificantTerms
         if (excludeTerms != null) {
             builder.array("exclude", excludeTerms);
         }
-        
+
         if (filterBuilder != null) {
-            builder.field(SignificantTermsParametersParser.BACKGROUND_FILTER.getPreferredName());
-            filterBuilder.toXContent(builder, params); 
+            builder.field(SignificantTermsAggregatorFactory.BACKGROUND_FILTER.getPreferredName());
+            filterBuilder.toXContent(builder, params);
         }
         if (significanceHeuristicBuilder != null) {
             significanceHeuristicBuilder.toXContent(builder, params);
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantTermsParametersParser.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantTermsParametersParser.java
deleted file mode 100644
index 020229867f..0000000000
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantTermsParametersParser.java
+++ /dev/null
@@ -1,83 +0,0 @@
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-
-package org.elasticsearch.search.aggregations.bucket.significant;
-
-import org.apache.lucene.search.Query;
-import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.xcontent.XContentParser;
-import org.elasticsearch.search.SearchParseException;
-import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristic;
-import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristicParser;
-import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristicParserMapper;
-import org.elasticsearch.search.aggregations.bucket.terms.AbstractTermsParametersParser;
-import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregator;
-import org.elasticsearch.search.internal.SearchContext;
-
-import java.io.IOException;
-
-
-public class SignificantTermsParametersParser extends AbstractTermsParametersParser {
-
-    private static final TermsAggregator.BucketCountThresholds DEFAULT_BUCKET_COUNT_THRESHOLDS = new TermsAggregator.BucketCountThresholds(3, 0, 10, -1);
-    private final SignificanceHeuristicParserMapper significanceHeuristicParserMapper;
-
-    public SignificantTermsParametersParser(SignificanceHeuristicParserMapper significanceHeuristicParserMapper) {
-        this.significanceHeuristicParserMapper = significanceHeuristicParserMapper;
-    }
-
-    public Query getFilter() {
-        return filter;
-    }
-
-    private Query filter = null;
-
-    private SignificanceHeuristic significanceHeuristic;
-
-    @Override
-    public TermsAggregator.BucketCountThresholds getDefaultBucketCountThresholds() {
-        return new TermsAggregator.BucketCountThresholds(DEFAULT_BUCKET_COUNT_THRESHOLDS);
-    }
-
-    static final ParseField BACKGROUND_FILTER = new ParseField("background_filter");
-
-    @Override
-    public void parseSpecial(String aggregationName, XContentParser parser, SearchContext context, XContentParser.Token token, String currentFieldName) throws IOException {
-
-        if (token == XContentParser.Token.START_OBJECT) {
-            SignificanceHeuristicParser significanceHeuristicParser = significanceHeuristicParserMapper.get(currentFieldName);
-            if (significanceHeuristicParser != null) {
-                significanceHeuristic = significanceHeuristicParser.parse(parser, context.parseFieldMatcher(), context);
-            } else if (context.parseFieldMatcher().match(currentFieldName, BACKGROUND_FILTER)) {
-                filter = context.indexShard().getQueryShardContext().parseInnerFilter(parser).query();
-            } else {
-                throw new SearchParseException(context, "Unknown key for a " + token + " in [" + aggregationName + "]: ["
-                        + currentFieldName + "].", parser.getTokenLocation());
-            }
-        } else {
-            throw new SearchParseException(context, "Unknown key for a " + token + " in [" + aggregationName + "]: [" + currentFieldName
-                    + "].", parser.getTokenLocation());
-        }
-    }
-
-    public SignificanceHeuristic getSignificanceHeuristic() {
-        return significanceHeuristic;
-    }
-}
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantTermsParser.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantTermsParser.java
index bcd9bdd4cb..6b44309ad8 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantTermsParser.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantTermsParser.java
@@ -18,31 +18,43 @@
  */
 package org.elasticsearch.search.aggregations.bucket.significant;
 
+import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.xcontent.XContentParser;
-import org.elasticsearch.search.aggregations.Aggregator;
+import org.elasticsearch.common.xcontent.XContentParser.Token;
+import org.elasticsearch.index.query.QueryBuilder;
+import org.elasticsearch.index.query.QueryParseContext;
+import org.elasticsearch.indices.query.IndicesQueriesRegistry;
+import org.elasticsearch.search.aggregations.Aggregator.SubAggCollectionMode;
 import org.elasticsearch.search.aggregations.AggregatorFactory;
-import org.elasticsearch.search.aggregations.bucket.BucketUtils;
-import org.elasticsearch.search.aggregations.bucket.significant.heuristics.JLHScore;
 import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristic;
+import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristicParser;
 import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristicParserMapper;
+import org.elasticsearch.search.aggregations.bucket.terms.AbstractTermsParser;
 import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregator;
+import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregator.BucketCountThresholds;
 import org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude;
-import org.elasticsearch.search.aggregations.support.ValuesSourceParser;
-import org.elasticsearch.search.internal.SearchContext;
+import org.elasticsearch.search.aggregations.support.ValueType;
+import org.elasticsearch.search.aggregations.support.ValuesSource;
+import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
+import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
 import java.io.IOException;
+import java.util.Map;
 
 /**
  *
  */
-public class SignificantTermsParser implements Aggregator.Parser {
-
+public class SignificantTermsParser extends AbstractTermsParser {
     private final SignificanceHeuristicParserMapper significanceHeuristicParserMapper;
+    private final IndicesQueriesRegistry queriesRegistry;
 
     @Inject
-    public SignificantTermsParser(SignificanceHeuristicParserMapper significanceHeuristicParserMapper) {
+    public SignificantTermsParser(SignificanceHeuristicParserMapper significanceHeuristicParserMapper,
+            IndicesQueriesRegistry queriesRegistry) {
         this.significanceHeuristicParserMapper = significanceHeuristicParserMapper;
+        this.queriesRegistry = queriesRegistry;
     }
 
     @Override
@@ -51,39 +63,59 @@ public class SignificantTermsParser implements Aggregator.Parser {
     }
 
     @Override
-    public AggregatorFactory parse(String aggregationName, XContentParser parser, SearchContext context) throws IOException {
-        SignificantTermsParametersParser aggParser = new SignificantTermsParametersParser(significanceHeuristicParserMapper);
-        ValuesSourceParser vsParser = ValuesSourceParser.any(aggregationName, SignificantStringTerms.TYPE, context)
-                .scriptable(false)
-                .formattable(true)
-                .build();
-        IncludeExclude.Parser incExcParser = new IncludeExclude.Parser();
-        aggParser.parse(aggregationName, parser, context, vsParser, incExcParser);
-
-        TermsAggregator.BucketCountThresholds bucketCountThresholds = aggParser.getBucketCountThresholds();
-        if (bucketCountThresholds.getShardSize() == aggParser.getDefaultBucketCountThresholds().getShardSize()) {
-            //The user has not made a shardSize selection .
-            //Use default heuristic to avoid any wrong-ranking caused by distributed counting
-            //but request double the usual amount.
-            //We typically need more than the number of "top" terms requested by other aggregations
-            //as the significance algorithm is in less of a position to down-select at shard-level -
-            //some of the things we want to find have only one occurrence on each shard and as
-            // such are impossible to differentiate from non-significant terms at that early stage.
-            bucketCountThresholds.setShardSize(2 * BucketUtils.suggestShardSideQueueSize(bucketCountThresholds.getRequiredSize(), context.numberOfShards()));
+    protected ValuesSourceAggregatorFactory<ValuesSource> doCreateFactory(String aggregationName, ValuesSourceType valuesSourceType,
+            ValueType targetValueType, BucketCountThresholds bucketCountThresholds, SubAggCollectionMode collectMode, String executionHint,
+            IncludeExclude incExc, Map<ParseField, Object> otherOptions) {
+        SignificantTermsAggregatorFactory factory = new SignificantTermsAggregatorFactory(aggregationName, valuesSourceType,
+                targetValueType);
+        if (bucketCountThresholds != null) {
+            factory.bucketCountThresholds(bucketCountThresholds);
+        }
+        if (executionHint != null) {
+            factory.executionHint(executionHint);
+        }
+        if (incExc != null) {
+            factory.includeExclude(incExc);
+        }
+        QueryBuilder<?> backgroundFilter = (QueryBuilder<?>) otherOptions.get(SignificantTermsAggregatorFactory.BACKGROUND_FILTER);
+        if (backgroundFilter != null) {
+            factory.backgroundFilter(backgroundFilter);
+        }
+        SignificanceHeuristic significanceHeuristic = (SignificanceHeuristic) otherOptions.get(SignificantTermsAggregatorFactory.HEURISTIC);
+        if (significanceHeuristic != null) {
+            factory.significanceHeuristic(significanceHeuristic);
         }
+        return factory;
+    }
 
-        bucketCountThresholds.ensureValidity();
-        SignificanceHeuristic significanceHeuristic = aggParser.getSignificanceHeuristic();
-        if (significanceHeuristic == null) {
-            significanceHeuristic = JLHScore.INSTANCE;
+    @Override
+    public boolean parseSpecial(String aggregationName, XContentParser parser, ParseFieldMatcher parseFieldMatcher, Token token,
+            String currentFieldName, Map<ParseField, Object> otherOptions) throws IOException {
+        if (token == XContentParser.Token.START_OBJECT) {
+            SignificanceHeuristicParser significanceHeuristicParser = significanceHeuristicParserMapper.get(currentFieldName);
+            if (significanceHeuristicParser != null) {
+                SignificanceHeuristic significanceHeuristic = significanceHeuristicParser.parse(parser, parseFieldMatcher);
+                otherOptions.put(SignificantTermsAggregatorFactory.HEURISTIC, significanceHeuristic);
+                return true;
+            } else if (parseFieldMatcher.match(currentFieldName, SignificantTermsAggregatorFactory.BACKGROUND_FILTER)) {
+                QueryParseContext queryParseContext = new QueryParseContext(queriesRegistry);
+                queryParseContext.reset(parser);
+                queryParseContext.parseFieldMatcher(parseFieldMatcher);
+                QueryBuilder<?> filter = queryParseContext.parseInnerQueryBuilder();
+                otherOptions.put(SignificantTermsAggregatorFactory.BACKGROUND_FILTER, filter);
+                return true;
+            }
         }
-        return new SignificantTermsAggregatorFactory(aggregationName, vsParser.input(), bucketCountThresholds,
-                aggParser.getIncludeExclude(), aggParser.getExecutionHint(), aggParser.getFilter(), significanceHeuristic);
+        return false;
     }
 
-    // NORELEASE implement this method when refactoring this aggregation
     @Override
     public AggregatorFactory[] getFactoryPrototypes() {
-        return null;
+        return new AggregatorFactory[] { new SignificantTermsAggregatorFactory(null, null, null) };
+    }
+
+    @Override
+    protected BucketCountThresholds getDefaultBucketCountThresholds() {
+        return new TermsAggregator.BucketCountThresholds(SignificantTermsAggregatorFactory.DEFAULT_BUCKET_COUNT_THRESHOLDS);
     }
 }
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/UnmappedSignificantTerms.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/UnmappedSignificantTerms.java
index c7569db612..bcad058f2e 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/UnmappedSignificantTerms.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/UnmappedSignificantTerms.java
@@ -58,9 +58,9 @@ public class UnmappedSignificantTerms extends InternalSignificantTerms<UnmappedS
     UnmappedSignificantTerms() {} // for serialization
 
     public UnmappedSignificantTerms(String name, int requiredSize, long minDocCount, List<PipelineAggregator> pipelineAggregators, Map<String, Object> metaData) {
-        //We pass zero for index/subset sizes because for the purpose of significant term analysis 
-        // we assume an unmapped index's size is irrelevant to the proceedings. 
-        super(0, 0, name, requiredSize, minDocCount, JLHScore.INSTANCE, BUCKETS, pipelineAggregators, metaData);
+        //We pass zero for index/subset sizes because for the purpose of significant term analysis
+        // we assume an unmapped index's size is irrelevant to the proceedings.
+        super(0, 0, name, requiredSize, minDocCount, JLHScore.PROTOTYPE, BUCKETS, pipelineAggregators, metaData);
     }
 
     @Override
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/ChiSquare.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/ChiSquare.java
index cc9303a635..c68e47acb7 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/ChiSquare.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/ChiSquare.java
@@ -23,13 +23,14 @@ package org.elasticsearch.search.aggregations.bucket.significant.heuristics;
 
 import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.io.stream.StreamInput;
-import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 
 import java.io.IOException;
 
 public class ChiSquare extends NXYSignificanceHeuristic {
 
+    static final ChiSquare PROTOTYPE = new ChiSquare(false, false);
+
     protected static final ParseField NAMES_FIELD = new ParseField("chi_square");
 
     public ChiSquare(boolean includeNegatives, boolean backgroundIsSuperset) {
@@ -51,18 +52,6 @@ public class ChiSquare extends NXYSignificanceHeuristic {
         return result;
     }
 
-    public static final SignificanceHeuristicStreams.Stream STREAM = new SignificanceHeuristicStreams.Stream() {
-        @Override
-        public SignificanceHeuristic readResult(StreamInput in) throws IOException {
-            return new ChiSquare(in.readBoolean(), in.readBoolean());
-        }
-
-        @Override
-        public String getName() {
-            return NAMES_FIELD.getPreferredName();
-        }
-    };
-
     /**
      * Calculates Chi^2
      * see "Information Retrieval", Manning et al., Eq. 13.19
@@ -80,9 +69,21 @@ public class ChiSquare extends NXYSignificanceHeuristic {
     }
 
     @Override
-    public void writeTo(StreamOutput out) throws IOException {
-        out.writeString(STREAM.getName());
-        super.writeTo(out);
+    public String getWriteableName() {
+        return NAMES_FIELD.getPreferredName();
+    }
+
+    @Override
+    public SignificanceHeuristic readFrom(StreamInput in) throws IOException {
+        return new ChiSquare(in.readBoolean(), in.readBoolean());
+    }
+
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.startObject(NAMES_FIELD.getPreferredName());
+        super.build(builder);
+        builder.endObject();
+        return builder;
     }
 
     public static class ChiSquareParser extends NXYParser {
@@ -106,7 +107,7 @@ public class ChiSquare extends NXYSignificanceHeuristic {
 
         @Override
         public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
-            builder.startObject(STREAM.getName());
+            builder.startObject(NAMES_FIELD.getPreferredName());
             super.build(builder);
             builder.endObject();
             return builder;
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/GND.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/GND.java
index 99ee7c73b2..6da05eddb5 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/GND.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/GND.java
@@ -29,12 +29,13 @@ import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.query.QueryShardException;
-import org.elasticsearch.search.internal.SearchContext;
 
 import java.io.IOException;
 
 public class GND extends NXYSignificanceHeuristic {
 
+    static final GND PROTOTYPE = new GND(false);
+
     protected static final ParseField NAMES_FIELD = new ParseField("gnd");
 
     public GND(boolean backgroundIsSuperset) {
@@ -57,18 +58,6 @@ public class GND extends NXYSignificanceHeuristic {
         return result;
     }
 
-    public static final SignificanceHeuristicStreams.Stream STREAM = new SignificanceHeuristicStreams.Stream() {
-        @Override
-        public SignificanceHeuristic readResult(StreamInput in) throws IOException {
-            return new GND(in.readBoolean());
-        }
-
-        @Override
-        public String getName() {
-            return NAMES_FIELD.getPreferredName();
-        }
-    };
-
     /**
      * Calculates Google Normalized Distance, as described in "The Google Similarity Distance", Cilibrasi and Vitanyi, 2007
      * link: http://arxiv.org/pdf/cs/0412098v3.pdf
@@ -98,11 +87,28 @@ public class GND extends NXYSignificanceHeuristic {
     }
 
     @Override
+    public String getWriteableName() {
+        return NAMES_FIELD.getPreferredName();
+    }
+
+    @Override
+    public SignificanceHeuristic readFrom(StreamInput in) throws IOException {
+        return new GND(in.readBoolean());
+    }
+
+    @Override
     public void writeTo(StreamOutput out) throws IOException {
-        out.writeString(STREAM.getName());
         out.writeBoolean(backgroundIsSuperset);
     }
 
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.startObject(NAMES_FIELD.getPreferredName());
+        builder.field(BACKGROUND_IS_SUPERSET.getPreferredName(), backgroundIsSuperset);
+        builder.endObject();
+        return builder;
+    }
+
     public static class GNDParser extends NXYParser {
 
         @Override
@@ -116,7 +122,7 @@ public class GND extends NXYSignificanceHeuristic {
         }
 
         @Override
-        public SignificanceHeuristic parse(XContentParser parser, ParseFieldMatcher parseFieldMatcher, SearchContext context)
+        public SignificanceHeuristic parse(XContentParser parser, ParseFieldMatcher parseFieldMatcher)
                 throws IOException, QueryShardException {
             String givenName = parser.currentName();
             boolean backgroundIsSuperset = true;
@@ -143,7 +149,7 @@ public class GND extends NXYSignificanceHeuristic {
 
         @Override
         public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
-            builder.startObject(STREAM.getName());
+            builder.startObject(NAMES_FIELD.getPreferredName());
             builder.field(BACKGROUND_IS_SUPERSET.getPreferredName(), backgroundIsSuperset);
             builder.endObject();
             return builder;
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/JLHScore.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/JLHScore.java
index 97264e7d53..753c9ccb3e 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/JLHScore.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/JLHScore.java
@@ -22,38 +22,42 @@ package org.elasticsearch.search.aggregations.bucket.significant.heuristics;
 
 
 import org.elasticsearch.ElasticsearchParseException;
+import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.query.QueryShardException;
-import org.elasticsearch.search.internal.SearchContext;
 
 import java.io.IOException;
 
 public class JLHScore extends SignificanceHeuristic {
 
-    public static final JLHScore INSTANCE = new JLHScore();
+    public static final JLHScore PROTOTYPE = new JLHScore();
 
-    protected static final String[] NAMES = {"jlh"};
+    protected static final ParseField NAMES_FIELD = new ParseField("jlh");
 
     private JLHScore() {}
 
-    public static final SignificanceHeuristicStreams.Stream STREAM = new SignificanceHeuristicStreams.Stream() {
-        @Override
-        public SignificanceHeuristic readResult(StreamInput in) throws IOException {
-            return readFrom(in);
-        }
+    @Override
+    public String getWriteableName() {
+        return NAMES_FIELD.getPreferredName();
+    }
 
-        @Override
-        public String getName() {
-            return NAMES[0];
-        }
-    };
+    @Override
+    public SignificanceHeuristic readFrom(StreamInput in) throws IOException {
+        return PROTOTYPE;
+    }
 
-    public static SignificanceHeuristic readFrom(StreamInput in) throws IOException {
-        return INSTANCE;
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+    }
+
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.startObject(NAMES_FIELD.getPreferredName()).endObject();
+        return builder;
     }
 
     /**
@@ -101,26 +105,21 @@ public class JLHScore extends SignificanceHeuristic {
         return absoluteProbabilityChange * relativeProbabilityChange;
     }
 
-    @Override
-    public void writeTo(StreamOutput out) throws IOException {
-        out.writeString(STREAM.getName());
-    }
-
     public static class JLHScoreParser implements SignificanceHeuristicParser {
 
         @Override
-        public SignificanceHeuristic parse(XContentParser parser, ParseFieldMatcher parseFieldMatcher, SearchContext context)
+        public SignificanceHeuristic parse(XContentParser parser, ParseFieldMatcher parseFieldMatcher)
                 throws IOException, QueryShardException {
             // move to the closing bracket
             if (!parser.nextToken().equals(XContentParser.Token.END_OBJECT)) {
                 throw new ElasticsearchParseException("failed to parse [jhl] significance heuristic. expected an empty object, but found [{}] instead", parser.currentToken());
             }
-            return new JLHScore();
+            return PROTOTYPE;
         }
 
         @Override
         public String[] getNames() {
-            return NAMES;
+            return NAMES_FIELD.getAllNamesIncludedDeprecated();
         }
     }
 
@@ -128,7 +127,7 @@ public class JLHScore extends SignificanceHeuristic {
 
         @Override
         public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
-            builder.startObject(STREAM.getName()).endObject();
+            builder.startObject(NAMES_FIELD.getPreferredName()).endObject();
             return builder;
         }
     }
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/MutualInformation.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/MutualInformation.java
index b4529b8267..d20b5f3544 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/MutualInformation.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/MutualInformation.java
@@ -23,13 +23,14 @@ package org.elasticsearch.search.aggregations.bucket.significant.heuristics;
 
 import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.io.stream.StreamInput;
-import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 
 import java.io.IOException;
 
 public class MutualInformation extends NXYSignificanceHeuristic {
 
+    static final MutualInformation PROTOTYPE = new MutualInformation(false, false);
+
     protected static final ParseField NAMES_FIELD = new ParseField("mutual_information");
 
     private static final double log2 = Math.log(2.0);
@@ -53,18 +54,6 @@ public class MutualInformation extends NXYSignificanceHeuristic {
         return result;
     }
 
-    public static final SignificanceHeuristicStreams.Stream STREAM = new SignificanceHeuristicStreams.Stream() {
-        @Override
-        public SignificanceHeuristic readResult(StreamInput in) throws IOException {
-            return new MutualInformation(in.readBoolean(), in.readBoolean());
-        }
-
-        @Override
-        public String getName() {
-            return NAMES_FIELD.getPreferredName();
-        }
-    };
-
     /**
      * Calculates mutual information
      * see "Information Retrieval", Manning et al., Eq. 13.17
@@ -113,9 +102,21 @@ public class MutualInformation extends NXYSignificanceHeuristic {
     }
 
     @Override
-    public void writeTo(StreamOutput out) throws IOException {
-        out.writeString(STREAM.getName());
-        super.writeTo(out);
+    public String getWriteableName() {
+        return NAMES_FIELD.getPreferredName();
+    }
+
+    @Override
+    public SignificanceHeuristic readFrom(StreamInput in) throws IOException {
+        return new MutualInformation(in.readBoolean(), in.readBoolean());
+    }
+
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.startObject(NAMES_FIELD.getPreferredName());
+        super.build(builder);
+        builder.endObject();
+        return builder;
     }
 
     public static class MutualInformationParser extends NXYParser {
@@ -139,7 +140,7 @@ public class MutualInformation extends NXYSignificanceHeuristic {
 
         @Override
         public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
-            builder.startObject(STREAM.getName());
+            builder.startObject(NAMES_FIELD.getPreferredName());
             super.build(builder);
             builder.endObject();
             return builder;
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/NXYSignificanceHeuristic.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/NXYSignificanceHeuristic.java
index c6a6924108..d3f98f23b9 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/NXYSignificanceHeuristic.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/NXYSignificanceHeuristic.java
@@ -28,7 +28,6 @@ import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.query.QueryShardException;
-import org.elasticsearch.search.internal.SearchContext;
 
 import java.io.IOException;
 
@@ -136,10 +135,15 @@ public abstract class NXYSignificanceHeuristic extends SignificanceHeuristic {
         }
     }
 
+    protected void build(XContentBuilder builder) throws IOException {
+        builder.field(INCLUDE_NEGATIVES_FIELD.getPreferredName(), includeNegatives).field(BACKGROUND_IS_SUPERSET.getPreferredName(),
+                backgroundIsSuperset);
+    }
+
     public static abstract class NXYParser implements SignificanceHeuristicParser {
 
         @Override
-        public SignificanceHeuristic parse(XContentParser parser, ParseFieldMatcher parseFieldMatcher, SearchContext context)
+        public SignificanceHeuristic parse(XContentParser parser, ParseFieldMatcher parseFieldMatcher)
                 throws IOException, QueryShardException {
             String givenName = parser.currentName();
             boolean includeNegatives = false;
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/PercentageScore.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/PercentageScore.java
index aceae8c251..e6cfe9a9bf 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/PercentageScore.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/PercentageScore.java
@@ -22,38 +22,42 @@ package org.elasticsearch.search.aggregations.bucket.significant.heuristics;
 
 
 import org.elasticsearch.ElasticsearchParseException;
+import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.query.QueryShardException;
-import org.elasticsearch.search.internal.SearchContext;
 
 import java.io.IOException;
 
 public class PercentageScore extends SignificanceHeuristic {
 
-    public static final PercentageScore INSTANCE = new PercentageScore();
+    public static final PercentageScore PROTOTYPE = new PercentageScore();
 
-    protected static final String[] NAMES = {"percentage"};
+    protected static final ParseField NAMES_FIELD = new ParseField("percentage");
 
     private PercentageScore() {}
 
-    public static final SignificanceHeuristicStreams.Stream STREAM = new SignificanceHeuristicStreams.Stream() {
-        @Override
-        public SignificanceHeuristic readResult(StreamInput in) throws IOException {
-            return readFrom(in);
-        }
+    @Override
+    public String getWriteableName() {
+        return NAMES_FIELD.getPreferredName();
+    }
 
-        @Override
-        public String getName() {
-            return NAMES[0];
-        }
-    };
+    @Override
+    public SignificanceHeuristic readFrom(StreamInput in) throws IOException {
+        return PROTOTYPE;
+    }
 
-    public static SignificanceHeuristic readFrom(StreamInput in) throws IOException {
-        return INSTANCE;
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+    }
+
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.startObject(NAMES_FIELD.getPreferredName()).endObject();
+        return builder;
     }
 
     /**
@@ -70,26 +74,21 @@ public class PercentageScore extends SignificanceHeuristic {
         return (double) subsetFreq / (double) supersetFreq;
    }
 
-    @Override
-    public void writeTo(StreamOutput out) throws IOException {
-        out.writeString(STREAM.getName());
-    }
-
     public static class PercentageScoreParser implements SignificanceHeuristicParser {
 
         @Override
-        public SignificanceHeuristic parse(XContentParser parser, ParseFieldMatcher parseFieldMatcher, SearchContext context)
+        public SignificanceHeuristic parse(XContentParser parser, ParseFieldMatcher parseFieldMatcher)
                 throws IOException, QueryShardException {
             // move to the closing bracket
             if (!parser.nextToken().equals(XContentParser.Token.END_OBJECT)) {
                 throw new ElasticsearchParseException("failed to parse [percentage] significance heuristic. expected an empty object, but got [{}] instead", parser.currentToken());
             }
-            return new PercentageScore();
+            return PROTOTYPE;
         }
 
         @Override
         public String[] getNames() {
-            return NAMES;
+            return NAMES_FIELD.getAllNamesIncludedDeprecated();
         }
     }
 
@@ -97,7 +96,7 @@ public class PercentageScore extends SignificanceHeuristic {
 
         @Override
         public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
-            builder.startObject(STREAM.getName()).endObject();
+            builder.startObject(NAMES_FIELD.getPreferredName()).endObject();
             return builder;
         }
     }
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/ScriptHeuristic.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/ScriptHeuristic.java
index 9efea00051..9dd3d0796b 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/ScriptHeuristic.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/ScriptHeuristic.java
@@ -22,6 +22,7 @@ package org.elasticsearch.search.aggregations.bucket.significant.heuristics;
 
 
 import org.elasticsearch.ElasticsearchParseException;
+import org.elasticsearch.common.HasContextAndHeaders;
 import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.io.stream.StreamInput;
@@ -44,9 +45,12 @@ import java.io.IOException;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Objects;
 
 public class ScriptHeuristic extends SignificanceHeuristic {
 
+    static final ScriptHeuristic PROTOTYPE = new ScriptHeuristic(null);
+
     protected static final ParseField NAMES_FIELD = new ParseField("script_heuristic");
     private final LongAccessor subsetSizeHolder;
     private final LongAccessor supersetSizeHolder;
@@ -55,31 +59,11 @@ public class ScriptHeuristic extends SignificanceHeuristic {
     ExecutableScript searchScript = null;
     Script script;
 
-    public static final SignificanceHeuristicStreams.Stream STREAM = new SignificanceHeuristicStreams.Stream() {
-        @Override
-        public SignificanceHeuristic readResult(StreamInput in) throws IOException {
-            Script script = Script.readScript(in);
-            return new ScriptHeuristic(null, script);
-        }
-
-        @Override
-        public String getName() {
-            return NAMES_FIELD.getPreferredName();
-        }
-    };
-
-    public ScriptHeuristic(ExecutableScript searchScript, Script script) {
+    public ScriptHeuristic(Script script) {
         subsetSizeHolder = new LongAccessor();
         supersetSizeHolder = new LongAccessor();
         subsetDfHolder = new LongAccessor();
         supersetDfHolder = new LongAccessor();
-        this.searchScript = searchScript;
-        if (searchScript != null) {
-            searchScript.setNextVar("_subset_freq", subsetDfHolder);
-            searchScript.setNextVar("_subset_size", subsetSizeHolder);
-            searchScript.setNextVar("_superset_freq", supersetDfHolder);
-            searchScript.setNextVar("_superset_size", supersetSizeHolder);
-        }
         this.script = script;
 
 
@@ -87,7 +71,16 @@ public class ScriptHeuristic extends SignificanceHeuristic {
 
     @Override
     public void initialize(InternalAggregation.ReduceContext context) {
-        searchScript = context.scriptService().executable(script, ScriptContext.Standard.AGGS, context, Collections.emptyMap());
+        initialize(context.scriptService(), context);
+    }
+
+    @Override
+    public void initialize(SearchContext context) {
+        initialize(context.scriptService(), context);
+    }
+
+    public void initialize(ScriptService scriptService, HasContextAndHeaders hasContextAndHeaders) {
+        searchScript = scriptService.executable(script, ScriptContext.Standard.AGGS, hasContextAndHeaders, Collections.emptyMap());
         searchScript.setNextVar("_subset_freq", subsetDfHolder);
         searchScript.setNextVar("_subset_size", subsetSizeHolder);
         searchScript.setNextVar("_superset_freq", supersetDfHolder);
@@ -121,11 +114,47 @@ public class ScriptHeuristic extends SignificanceHeuristic {
     }
 
     @Override
+    public String getWriteableName() {
+        return NAMES_FIELD.getPreferredName();
+    }
+
+    @Override
+    public SignificanceHeuristic readFrom(StreamInput in) throws IOException {
+        Script script = Script.readScript(in);
+        return new ScriptHeuristic(script);
+    }
+
+    @Override
     public void writeTo(StreamOutput out) throws IOException {
-        out.writeString(STREAM.getName());
         script.writeTo(out);
     }
 
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params builderParams) throws IOException {
+        builder.startObject(NAMES_FIELD.getPreferredName());
+        builder.field(ScriptField.SCRIPT.getPreferredName());
+        script.toXContent(builder, builderParams);
+        builder.endObject();
+        return builder;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(script);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj == null) {
+            return false;
+        }
+        if (getClass() != obj.getClass()) {
+            return false;
+        }
+        ScriptHeuristic other = (ScriptHeuristic) obj;
+        return Objects.equals(script, other.script);
+    }
+
     public static class ScriptHeuristicParser implements SignificanceHeuristicParser {
         private final ScriptService scriptService;
 
@@ -134,7 +163,7 @@ public class ScriptHeuristic extends SignificanceHeuristic {
         }
 
         @Override
-        public SignificanceHeuristic parse(XContentParser parser, ParseFieldMatcher parseFieldMatcher, SearchContext context)
+        public SignificanceHeuristic parse(XContentParser parser, ParseFieldMatcher parseFieldMatcher)
                 throws IOException, QueryShardException {
             String heuristicName = parser.currentName();
             Script script = null;
@@ -173,13 +202,7 @@ public class ScriptHeuristic extends SignificanceHeuristic {
             if (script == null) {
                 throw new ElasticsearchParseException("failed to parse [{}] significance heuristic. no script found in script_heuristic", heuristicName);
             }
-            ExecutableScript searchScript;
-            try {
-                searchScript = scriptService.executable(script, ScriptContext.Standard.AGGS, context, Collections.emptyMap());
-            } catch (Exception e) {
-                throw new ElasticsearchParseException("failed to parse [{}] significance heuristic. the script [{}] could not be loaded", e, script, heuristicName);
-            }
-            return new ScriptHeuristic(searchScript, script);
+            return new ScriptHeuristic(script);
         }
 
         @Override
@@ -199,7 +222,7 @@ public class ScriptHeuristic extends SignificanceHeuristic {
 
         @Override
         public XContentBuilder toXContent(XContentBuilder builder, Params builderParams) throws IOException {
-            builder.startObject(STREAM.getName());
+            builder.startObject(NAMES_FIELD.getPreferredName());
             builder.field(ScriptField.SCRIPT.getPreferredName());
             script.toXContent(builder, builderParams);
             builder.endObject();
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/SignificanceHeuristic.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/SignificanceHeuristic.java
index 4f12277ca0..972696ba99 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/SignificanceHeuristic.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/SignificanceHeuristic.java
@@ -20,12 +20,12 @@
 package org.elasticsearch.search.aggregations.bucket.significant.heuristics;
 
 
-import org.elasticsearch.common.io.stream.StreamOutput;
+import org.elasticsearch.common.io.stream.NamedWriteable;
+import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.search.aggregations.InternalAggregation;
+import org.elasticsearch.search.internal.SearchContext;
 
-import java.io.IOException;
-
-public abstract class SignificanceHeuristic {
+public abstract class SignificanceHeuristic implements NamedWriteable<SignificanceHeuristic>, ToXContent {
     /**
      * @param subsetFreq   The frequency of the term in the selected sample
      * @param subsetSize   The size of the selected sample (typically number of docs)
@@ -35,8 +35,6 @@ public abstract class SignificanceHeuristic {
      */
     public abstract double getScore(long subsetFreq, long subsetSize, long supersetFreq, long supersetSize);
 
-    abstract public void writeTo(StreamOutput out) throws IOException;
-
     protected void checkFrequencyValidity(long subsetFreq, long subsetSize, long supersetFreq, long supersetSize, String scoreFunctionName) {
         if (subsetFreq < 0 || subsetSize < 0 || supersetFreq < 0 || supersetSize < 0) {
             throw new IllegalArgumentException("Frequencies of subset and superset must be positive in " + scoreFunctionName + ".getScore()");
@@ -52,4 +50,8 @@ public abstract class SignificanceHeuristic {
     public void initialize(InternalAggregation.ReduceContext reduceContext) {
 
     }
+
+    public void initialize(SearchContext context) {
+
+    }
 }
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/SignificanceHeuristicParser.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/SignificanceHeuristicParser.java
index 92baa43e6b..aa430dc251 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/SignificanceHeuristicParser.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/SignificanceHeuristicParser.java
@@ -23,13 +23,12 @@ package org.elasticsearch.search.aggregations.bucket.significant.heuristics;
 import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.ParsingException;
 import org.elasticsearch.common.xcontent.XContentParser;
-import org.elasticsearch.search.internal.SearchContext;
 
 import java.io.IOException;
 
 public interface SignificanceHeuristicParser {
 
-    SignificanceHeuristic parse(XContentParser parser, ParseFieldMatcher parseFieldMatcher, SearchContext context) throws IOException,
+    SignificanceHeuristic parse(XContentParser parser, ParseFieldMatcher parseFieldMatcher) throws IOException,
             ParsingException;
 
     String[] getNames();
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/SignificanceHeuristicStreams.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/SignificanceHeuristicStreams.java
index 198f129c28..2ffe5ecc70 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/SignificanceHeuristicStreams.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/heuristics/SignificanceHeuristicStreams.java
@@ -19,6 +19,7 @@
 package org.elasticsearch.search.aggregations.bucket.significant.heuristics;
 
 import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.io.stream.StreamOutput;
 
 import java.io.IOException;
 import java.util.Collections;
@@ -31,21 +32,26 @@ import java.util.Map;
  */
 public class SignificanceHeuristicStreams {
 
-    private static Map<String, Stream> STREAMS = Collections.emptyMap();
+    private static Map<String, SignificanceHeuristic> STREAMS = Collections.emptyMap();
 
     static {
-        HashMap<String, Stream> map = new HashMap<>();
-        map.put(JLHScore.STREAM.getName(), JLHScore.STREAM);
-        map.put(PercentageScore.STREAM.getName(), PercentageScore.STREAM);
-        map.put(MutualInformation.STREAM.getName(), MutualInformation.STREAM);
-        map.put(GND.STREAM.getName(), GND.STREAM);
-        map.put(ChiSquare.STREAM.getName(), ChiSquare.STREAM);
-        map.put(ScriptHeuristic.STREAM.getName(), ScriptHeuristic.STREAM);
+        HashMap<String, SignificanceHeuristic> map = new HashMap<>();
+        map.put(JLHScore.NAMES_FIELD.getPreferredName(), JLHScore.PROTOTYPE);
+        map.put(PercentageScore.NAMES_FIELD.getPreferredName(), PercentageScore.PROTOTYPE);
+        map.put(MutualInformation.NAMES_FIELD.getPreferredName(), MutualInformation.PROTOTYPE);
+        map.put(GND.NAMES_FIELD.getPreferredName(), GND.PROTOTYPE);
+        map.put(ChiSquare.NAMES_FIELD.getPreferredName(), ChiSquare.PROTOTYPE);
+        map.put(ScriptHeuristic.NAMES_FIELD.getPreferredName(), ScriptHeuristic.PROTOTYPE);
         STREAMS = Collections.unmodifiableMap(map);
     }
 
     public static SignificanceHeuristic read(StreamInput in) throws IOException {
-        return stream(in.readString()).readResult(in);
+        return stream(in.readString()).readFrom(in);
+    }
+
+    public static void writeTo(SignificanceHeuristic significanceHeuristic, StreamOutput out) throws IOException {
+        out.writeString(significanceHeuristic.getWriteableName());
+        significanceHeuristic.writeTo(out);
     }
 
     /**
@@ -59,17 +65,18 @@ public class SignificanceHeuristicStreams {
     }
 
     /**
-     * Registers the given stream and associate it with the given types.
+     * Registers the given prototype.
      *
-     * @param stream The stream to register
+     * @param prototype
+     *            The prototype to register
      */
-    public static synchronized void registerStream(Stream stream) {
-        if (STREAMS.containsKey(stream.getName())) {
-            throw new IllegalArgumentException("Can't register stream with name [" + stream.getName() + "] more than once");
+    public static synchronized void registerPrototype(SignificanceHeuristic prototype) {
+        if (STREAMS.containsKey(prototype.getWriteableName())) {
+            throw new IllegalArgumentException("Can't register stream with name [" + prototype.getWriteableName() + "] more than once");
         }
-        HashMap<String, Stream> map = new HashMap<>();
+        HashMap<String, SignificanceHeuristic> map = new HashMap<>();
         map.putAll(STREAMS);
-        map.put(stream.getName(), stream);
+        map.put(prototype.getWriteableName(), prototype);
         STREAMS = Collections.unmodifiableMap(map);
     }
 
@@ -79,7 +86,7 @@ public class SignificanceHeuristicStreams {
      * @param name The given name
      * @return The associated stream
      */
-    private static synchronized Stream stream(String name) {
+    private static synchronized SignificanceHeuristic stream(String name) {
         return STREAMS.get(name);
     }
 
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/AbstractTermsParametersParser.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/AbstractTermsParametersParser.java
deleted file mode 100644
index 891526c33c..0000000000
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/AbstractTermsParametersParser.java
+++ /dev/null
@@ -1,111 +0,0 @@
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-
-package org.elasticsearch.search.aggregations.bucket.terms;
-import org.elasticsearch.common.ParseField;
-import org.elasticsearch.common.xcontent.XContentParser;
-import org.elasticsearch.search.aggregations.Aggregator.SubAggCollectionMode;
-import org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude;
-import org.elasticsearch.search.aggregations.support.ValuesSourceParser;
-import org.elasticsearch.search.internal.SearchContext;
-
-import java.io.IOException;
-
-public abstract class AbstractTermsParametersParser {
-
-    public static final ParseField EXECUTION_HINT_FIELD_NAME = new ParseField("execution_hint");
-    public static final ParseField SHARD_SIZE_FIELD_NAME = new ParseField("shard_size");
-    public static final ParseField MIN_DOC_COUNT_FIELD_NAME = new ParseField("min_doc_count");
-    public static final ParseField SHARD_MIN_DOC_COUNT_FIELD_NAME = new ParseField("shard_min_doc_count");
-    public static final ParseField REQUIRED_SIZE_FIELD_NAME = new ParseField("size");
-    public static final ParseField SHOW_TERM_DOC_COUNT_ERROR = new ParseField("show_term_doc_count_error");
-    
-
-    //These are the results of the parsing.
-    private TermsAggregator.BucketCountThresholds bucketCountThresholds = new TermsAggregator.BucketCountThresholds();
-
-    private String executionHint = null;
-    
-    private SubAggCollectionMode collectMode = SubAggCollectionMode.DEPTH_FIRST;
-
-
-    IncludeExclude includeExclude;
-
-    public TermsAggregator.BucketCountThresholds getBucketCountThresholds() {return bucketCountThresholds;}
-
-    //These are the results of the parsing.
-
-    public String getExecutionHint() {
-        return executionHint;
-    }
-
-    public IncludeExclude getIncludeExclude() {
-        return includeExclude;
-    }
-    
-    public SubAggCollectionMode getCollectionMode() {
-        return collectMode;
-    }
-
-    public void parse(String aggregationName, XContentParser parser, SearchContext context, ValuesSourceParser vsParser, IncludeExclude.Parser incExcParser) throws IOException {
-        bucketCountThresholds = getDefaultBucketCountThresholds();
-        XContentParser.Token token;
-        String currentFieldName = null;
-
-        while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
-            if (token == XContentParser.Token.FIELD_NAME) {
-                currentFieldName = parser.currentName();
-            } else if (vsParser.token(currentFieldName, token, parser)) {
-                continue;
-            } else if (incExcParser.token(currentFieldName, token, parser)) {
-                continue;
-            } else if (token == XContentParser.Token.VALUE_STRING) {
-                if (context.parseFieldMatcher().match(currentFieldName, EXECUTION_HINT_FIELD_NAME)) {
-                    executionHint = parser.text();
-                } else if(context.parseFieldMatcher().match(currentFieldName, SubAggCollectionMode.KEY)){
-                    collectMode = SubAggCollectionMode.parse(parser.text(), context.parseFieldMatcher());
-                } else if (context.parseFieldMatcher().match(currentFieldName, REQUIRED_SIZE_FIELD_NAME)) {
-                    bucketCountThresholds.setRequiredSize(parser.intValue());
-                } else {
-                    parseSpecial(aggregationName, parser, context, token, currentFieldName);
-                }
-            } else if (token == XContentParser.Token.VALUE_NUMBER) {
-                if (context.parseFieldMatcher().match(currentFieldName, REQUIRED_SIZE_FIELD_NAME)) {
-                    bucketCountThresholds.setRequiredSize(parser.intValue());
-                } else if (context.parseFieldMatcher().match(currentFieldName, SHARD_SIZE_FIELD_NAME)) {
-                    bucketCountThresholds.setShardSize(parser.intValue());
-                } else if (context.parseFieldMatcher().match(currentFieldName, MIN_DOC_COUNT_FIELD_NAME)) {
-                    bucketCountThresholds.setMinDocCount(parser.intValue());
-                } else if (context.parseFieldMatcher().match(currentFieldName, SHARD_MIN_DOC_COUNT_FIELD_NAME)) {
-                    bucketCountThresholds.setShardMinDocCount(parser.longValue());
-                } else {
-                    parseSpecial(aggregationName, parser, context, token, currentFieldName);
-                }
-            } else {
-                parseSpecial(aggregationName, parser, context, token, currentFieldName);
-            }
-        }
-        includeExclude = incExcParser.includeExclude();
-    }
-
-    public abstract void parseSpecial(String aggregationName, XContentParser parser, SearchContext context, XContentParser.Token token, String currentFieldName) throws IOException;
-
-    protected abstract TermsAggregator.BucketCountThresholds getDefaultBucketCountThresholds();
-}
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/AbstractTermsParser.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/AbstractTermsParser.java
new file mode 100644
index 0000000000..16ec4ab9de
--- /dev/null
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/AbstractTermsParser.java
@@ -0,0 +1,130 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.search.aggregations.bucket.terms;
+
+import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.ParseFieldMatcher;
+import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.common.xcontent.XContentParser.Token;
+import org.elasticsearch.search.aggregations.Aggregator.SubAggCollectionMode;
+import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregator.BucketCountThresholds;
+import org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude;
+import org.elasticsearch.search.aggregations.support.AbstractValuesSourceParser.AnyValuesSourceParser;
+import org.elasticsearch.search.aggregations.support.ValueType;
+import org.elasticsearch.search.aggregations.support.ValuesSource;
+import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
+import org.elasticsearch.search.aggregations.support.ValuesSourceType;
+
+import java.io.IOException;
+import java.util.Map;
+
+public abstract class AbstractTermsParser extends AnyValuesSourceParser {
+
+    public static final ParseField EXECUTION_HINT_FIELD_NAME = new ParseField("execution_hint");
+    public static final ParseField SHARD_SIZE_FIELD_NAME = new ParseField("shard_size");
+    public static final ParseField MIN_DOC_COUNT_FIELD_NAME = new ParseField("min_doc_count");
+    public static final ParseField SHARD_MIN_DOC_COUNT_FIELD_NAME = new ParseField("shard_min_doc_count");
+    public static final ParseField REQUIRED_SIZE_FIELD_NAME = new ParseField("size");
+
+    public IncludeExclude.Parser incExcParser = new IncludeExclude.Parser();
+
+    protected AbstractTermsParser() {
+        super(true, true);
+    }
+
+    @Override
+    protected final ValuesSourceAggregatorFactory<ValuesSource> createFactory(String aggregationName, ValuesSourceType valuesSourceType,
+            ValueType targetValueType, Map<ParseField, Object> otherOptions) {
+        BucketCountThresholds bucketCountThresholds = getDefaultBucketCountThresholds();
+        Integer requiredSize = (Integer) otherOptions.get(REQUIRED_SIZE_FIELD_NAME);
+        if (requiredSize != null && requiredSize != -1) {
+            bucketCountThresholds.setRequiredSize(requiredSize);
+        }
+        Integer shardSize = (Integer) otherOptions.get(SHARD_SIZE_FIELD_NAME);
+        if (shardSize != null && shardSize != -1) {
+            bucketCountThresholds.setShardSize(shardSize);
+        }
+        Long minDocCount = (Long) otherOptions.get(MIN_DOC_COUNT_FIELD_NAME);
+        if (minDocCount != null && minDocCount != -1) {
+            bucketCountThresholds.setMinDocCount(minDocCount);
+        }
+        Long shardMinDocCount = (Long) otherOptions.get(SHARD_MIN_DOC_COUNT_FIELD_NAME);
+        if (shardMinDocCount != null && shardMinDocCount != -1) {
+            bucketCountThresholds.setShardMinDocCount(shardMinDocCount);
+        }
+        SubAggCollectionMode collectMode = (SubAggCollectionMode) otherOptions.get(SubAggCollectionMode.KEY);
+        String executionHint = (String) otherOptions.get(EXECUTION_HINT_FIELD_NAME);
+        IncludeExclude incExc = incExcParser.createIncludeExclude(otherOptions);
+        return doCreateFactory(aggregationName, valuesSourceType, targetValueType, bucketCountThresholds, collectMode, executionHint,
+                incExc,
+                otherOptions);
+    }
+
+    protected abstract ValuesSourceAggregatorFactory<ValuesSource> doCreateFactory(String aggregationName,
+            ValuesSourceType valuesSourceType,
+            ValueType targetValueType, BucketCountThresholds bucketCountThresholds, SubAggCollectionMode collectMode, String executionHint,
+            IncludeExclude incExc, Map<ParseField, Object> otherOptions);
+
+    @Override
+    protected boolean token(String aggregationName, String currentFieldName, Token token, XContentParser parser,
+            ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException {
+        if (incExcParser.token(currentFieldName, token, parser, parseFieldMatcher, otherOptions)) {
+            return true;
+        } else if (token == XContentParser.Token.VALUE_STRING) {
+            if (parseFieldMatcher.match(currentFieldName, EXECUTION_HINT_FIELD_NAME)) {
+                otherOptions.put(EXECUTION_HINT_FIELD_NAME, parser.text());
+                return true;
+            } else if (parseFieldMatcher.match(currentFieldName, SubAggCollectionMode.KEY)) {
+                otherOptions.put(SubAggCollectionMode.KEY, SubAggCollectionMode.parse(parser.text(), parseFieldMatcher));
+                return true;
+            } else if (parseFieldMatcher.match(currentFieldName, REQUIRED_SIZE_FIELD_NAME)) {
+                otherOptions.put(REQUIRED_SIZE_FIELD_NAME, parser.intValue());
+                return true;
+            } else if (parseSpecial(aggregationName, parser, parseFieldMatcher, token, currentFieldName, otherOptions)) {
+                return true;
+            }
+        } else if (token == XContentParser.Token.VALUE_NUMBER) {
+            if (parseFieldMatcher.match(currentFieldName, REQUIRED_SIZE_FIELD_NAME)) {
+                otherOptions.put(REQUIRED_SIZE_FIELD_NAME, parser.intValue());
+                return true;
+            } else if (parseFieldMatcher.match(currentFieldName, SHARD_SIZE_FIELD_NAME)) {
+                otherOptions.put(SHARD_SIZE_FIELD_NAME, parser.intValue());
+                return true;
+            } else if (parseFieldMatcher.match(currentFieldName, MIN_DOC_COUNT_FIELD_NAME)) {
+                otherOptions.put(MIN_DOC_COUNT_FIELD_NAME, parser.longValue());
+                return true;
+            } else if (parseFieldMatcher.match(currentFieldName, SHARD_MIN_DOC_COUNT_FIELD_NAME)) {
+                otherOptions.put(SHARD_MIN_DOC_COUNT_FIELD_NAME, parser.longValue());
+                return true;
+            } else if (parseSpecial(aggregationName, parser, parseFieldMatcher, token, currentFieldName, otherOptions)) {
+                return true;
+            }
+        } else if (parseSpecial(aggregationName, parser, parseFieldMatcher, token, currentFieldName, otherOptions)) {
+            return true;
+        }
+        return false;
+    }
+
+    public abstract boolean parseSpecial(String aggregationName, XContentParser parser, ParseFieldMatcher parseFieldMatcher,
+            XContentParser.Token token, String currentFieldName, Map<ParseField, Object> otherOptions) throws IOException;
+
+    protected abstract TermsAggregator.BucketCountThresholds getDefaultBucketCountThresholds();
+
+}
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/InternalOrder.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/InternalOrder.java
index 4e3e28a1b3..b5e1e81479 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/InternalOrder.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/InternalOrder.java
@@ -38,6 +38,7 @@ import java.util.Comparator;
 import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Objects;
 
 /**
  *
@@ -263,6 +264,23 @@ class InternalOrder extends Terms.Order {
             return new CompoundOrderComparator(orderElements, aggregator);
         }
 
+        @Override
+        public int hashCode() {
+            return Objects.hash(orderElements);
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (obj == null) {
+                return false;
+            }
+            if (getClass() != obj.getClass()) {
+                return false;
+            }
+            CompoundOrder other = (CompoundOrder) obj;
+            return Objects.equals(orderElements, other.orderElements);
+        }
+
         public static class CompoundOrderComparator implements Comparator<Terms.Bucket> {
 
             private List<Terms.Order> compoundOrder;
@@ -306,7 +324,7 @@ class InternalOrder extends Terms.Order {
         }
 
         public static Terms.Order readOrder(StreamInput in) throws IOException {
-            return readOrder(in, true);
+            return readOrder(in, false);
         }
 
         public static Terms.Order readOrder(StreamInput in, boolean absoluteOrder) throws IOException {
@@ -332,4 +350,22 @@ class InternalOrder extends Terms.Order {
             }
         }
     }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id, asc);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj == null) {
+            return false;
+        }
+        if (getClass() != obj.getClass()) {
+            return false;
+        }
+        InternalOrder other = (InternalOrder) obj;
+        return Objects.equals(id, other.id)
+                && Objects.equals(asc, other.asc);
+    }
 }
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/Terms.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/Terms.java
index 224e42cb7f..16fb7f1d81 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/Terms.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/Terms.java
@@ -82,7 +82,7 @@ public interface Terms extends MultiBucketsAggregation {
      * Get the bucket for the given term, or null if there is no such bucket.
      */
     Bucket getBucketByKey(String term);
-    
+
     /**
      * Get an upper bound of the error on document counts in this aggregation.
      */
@@ -166,5 +166,11 @@ public interface Terms extends MultiBucketsAggregation {
 
         abstract byte id();
 
+        @Override
+        public abstract int hashCode();
+
+        @Override
+        public abstract boolean equals(Object obj);
+
     }
 }
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsAggregator.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsAggregator.java
index 7971d1f5ae..7ea88c9a10 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsAggregator.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsAggregator.java
@@ -21,7 +21,10 @@
 package org.elasticsearch.search.aggregations.bucket.terms;
 
 import org.elasticsearch.ElasticsearchException;
-import org.elasticsearch.common.Explicit;
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.io.stream.StreamOutput;
+import org.elasticsearch.common.io.stream.Writeable;
+import org.elasticsearch.common.xcontent.ToXContent;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.search.aggregations.Aggregator;
 import org.elasticsearch.search.aggregations.AggregatorFactories;
@@ -36,99 +39,136 @@ import java.io.IOException;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 
 public abstract class TermsAggregator extends BucketsAggregator {
 
-    public static class BucketCountThresholds {
-        private Explicit<Long> minDocCount;
-        private Explicit<Long> shardMinDocCount;
-        private Explicit<Integer> requiredSize;
-        private Explicit<Integer> shardSize;
+    public static class BucketCountThresholds implements Writeable<BucketCountThresholds>, ToXContent {
 
-        public BucketCountThresholds(long minDocCount, long shardMinDocCount, int requiredSize, int shardSize) {
-            this.minDocCount = new Explicit<>(minDocCount, false);
-            this.shardMinDocCount =  new Explicit<>(shardMinDocCount, false);
-            this.requiredSize = new Explicit<>(requiredSize, false);
-            this.shardSize = new Explicit<>(shardSize, false);
+        private static final BucketCountThresholds PROTOTYPE = new BucketCountThresholds(-1, -1, -1, -1);
+
+        private long minDocCount;
+        private long shardMinDocCount;
+        private int requiredSize;
+        private int shardSize;
+
+        public static BucketCountThresholds readFromStream(StreamInput in) throws IOException {
+            return PROTOTYPE.readFrom(in);
         }
-        public BucketCountThresholds() {
-            this(-1, -1, -1, -1);
+
+        public BucketCountThresholds(long minDocCount, long shardMinDocCount, int requiredSize, int shardSize) {
+            this.minDocCount = minDocCount;
+            this.shardMinDocCount = shardMinDocCount;
+            this.requiredSize = requiredSize;
+            this.shardSize = shardSize;
         }
 
         public BucketCountThresholds(BucketCountThresholds bucketCountThresholds) {
-            this(bucketCountThresholds.minDocCount.value(), bucketCountThresholds.shardMinDocCount.value(), bucketCountThresholds.requiredSize.value(), bucketCountThresholds.shardSize.value());
+            this(bucketCountThresholds.minDocCount, bucketCountThresholds.shardMinDocCount, bucketCountThresholds.requiredSize,
+                    bucketCountThresholds.shardSize);
         }
 
         public void ensureValidity() {
 
-            if (shardSize.value() == 0) {
+            if (shardSize == 0) {
                 setShardSize(Integer.MAX_VALUE);
             }
 
-            if (requiredSize.value() == 0) {
+            if (requiredSize == 0) {
                 setRequiredSize(Integer.MAX_VALUE);
             }
             // shard_size cannot be smaller than size as we need to at least fetch <size> entries from every shards in order to return <size>
-            if (shardSize.value() < requiredSize.value()) {
-                setShardSize(requiredSize.value());
+            if (shardSize < requiredSize) {
+                setShardSize(requiredSize);
             }
 
             // shard_min_doc_count should not be larger than min_doc_count because this can cause buckets to be removed that would match the min_doc_count criteria
-            if (shardMinDocCount.value() > minDocCount.value()) {
-                setShardMinDocCount(minDocCount.value());
+            if (shardMinDocCount > minDocCount) {
+                setShardMinDocCount(minDocCount);
             }
 
-            if (requiredSize.value() < 0 || minDocCount.value() < 0) {
+            if (requiredSize < 0 || minDocCount < 0) {
                 throw new ElasticsearchException("parameters [requiredSize] and [minDocCount] must be >=0 in terms aggregation.");
             }
         }
 
         public long getShardMinDocCount() {
-            return shardMinDocCount.value();
+            return shardMinDocCount;
         }
 
         public void setShardMinDocCount(long shardMinDocCount) {
-            this.shardMinDocCount = new Explicit<>(shardMinDocCount, true);
+            this.shardMinDocCount = shardMinDocCount;
         }
 
         public long getMinDocCount() {
-            return minDocCount.value();
+            return minDocCount;
         }
 
         public void setMinDocCount(long minDocCount) {
-            this.minDocCount = new Explicit<>(minDocCount, true);
+            this.minDocCount = minDocCount;
         }
 
         public int getRequiredSize() {
-            return requiredSize.value();
+            return requiredSize;
         }
 
         public void setRequiredSize(int requiredSize) {
-            this.requiredSize = new Explicit<>(requiredSize, true);
+            this.requiredSize = requiredSize;
         }
 
         public int getShardSize() {
-            return shardSize.value();
+            return shardSize;
         }
 
         public void setShardSize(int shardSize) {
-            this.shardSize = new Explicit<>(shardSize, true);
+            this.shardSize = shardSize;
         }
 
-        public void toXContent(XContentBuilder builder) throws IOException {
-            if (requiredSize.explicit()) {
-                builder.field(AbstractTermsParametersParser.REQUIRED_SIZE_FIELD_NAME.getPreferredName(), requiredSize.value());
-            }
-            if (shardSize.explicit()) {
-                builder.field(AbstractTermsParametersParser.SHARD_SIZE_FIELD_NAME.getPreferredName(), shardSize.value());
-            }
-            if (minDocCount.explicit()) {
-                builder.field(AbstractTermsParametersParser.MIN_DOC_COUNT_FIELD_NAME.getPreferredName(), minDocCount.value());
+        @Override
+        public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+            builder.field(TermsAggregatorFactory.REQUIRED_SIZE_FIELD_NAME.getPreferredName(), requiredSize);
+            builder.field(TermsAggregatorFactory.SHARD_SIZE_FIELD_NAME.getPreferredName(), shardSize);
+            builder.field(TermsAggregatorFactory.MIN_DOC_COUNT_FIELD_NAME.getPreferredName(), minDocCount);
+            builder.field(TermsAggregatorFactory.SHARD_MIN_DOC_COUNT_FIELD_NAME.getPreferredName(), shardMinDocCount);
+            return builder;
+        }
+
+        @Override
+        public BucketCountThresholds readFrom(StreamInput in) throws IOException {
+            int requiredSize = in.readInt();
+            int shardSize = in.readInt();
+            long minDocCount = in.readLong();
+            long shardMinDocCount = in.readLong();
+            return new BucketCountThresholds(minDocCount, shardMinDocCount, requiredSize, shardSize);
+        }
+
+        @Override
+        public void writeTo(StreamOutput out) throws IOException {
+            out.writeInt(requiredSize);
+            out.writeInt(shardSize);
+            out.writeLong(minDocCount);
+            out.writeLong(shardMinDocCount);
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(requiredSize, shardSize, minDocCount, shardMinDocCount);
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (obj == null) {
+                return false;
             }
-            if (shardMinDocCount.explicit()) {
-                builder.field(AbstractTermsParametersParser.SHARD_MIN_DOC_COUNT_FIELD_NAME.getPreferredName(), shardMinDocCount.value());
+            if (getClass() != obj.getClass()) {
+                return false;
             }
+            BucketCountThresholds other = (BucketCountThresholds) obj;
+            return Objects.equals(requiredSize, other.requiredSize)
+                    && Objects.equals(shardSize, other.shardSize)
+                    && Objects.equals(minDocCount, other.minDocCount)
+                    && Objects.equals(shardMinDocCount, other.shardMinDocCount);
         }
     }
 
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsAggregatorFactory.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsAggregatorFactory.java
index f668e3ad99..29fbe3bae1 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsAggregatorFactory.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsAggregatorFactory.java
@@ -21,28 +21,52 @@ package org.elasticsearch.search.aggregations.bucket.terms;
 import org.apache.lucene.search.IndexSearcher;
 import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.ParseFieldMatcher;
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.io.stream.StreamOutput;
+import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.search.aggregations.AggregationExecutionException;
 import org.elasticsearch.search.aggregations.Aggregator;
 import org.elasticsearch.search.aggregations.Aggregator.SubAggCollectionMode;
 import org.elasticsearch.search.aggregations.AggregatorFactories;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.NonCollectingAggregator;
+import org.elasticsearch.search.aggregations.bucket.BucketUtils;
+import org.elasticsearch.search.aggregations.bucket.terms.Terms.Order;
+import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregator.BucketCountThresholds;
 import org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude;
 import org.elasticsearch.search.aggregations.pipeline.PipelineAggregator;
 import org.elasticsearch.search.aggregations.support.AggregationContext;
+import org.elasticsearch.search.aggregations.support.ValueType;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
-import org.elasticsearch.search.aggregations.support.ValuesSourceParser;
+import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 
 /**
  *
  */
+/**
+ *
+ */
 public class TermsAggregatorFactory extends ValuesSourceAggregatorFactory<ValuesSource> {
 
+    public static final ParseField EXECUTION_HINT_FIELD_NAME = new ParseField("execution_hint");
+    public static final ParseField SHARD_SIZE_FIELD_NAME = new ParseField("shard_size");
+    public static final ParseField MIN_DOC_COUNT_FIELD_NAME = new ParseField("min_doc_count");
+    public static final ParseField SHARD_MIN_DOC_COUNT_FIELD_NAME = new ParseField("shard_min_doc_count");
+    public static final ParseField REQUIRED_SIZE_FIELD_NAME = new ParseField("size");
+
+    static final TermsAggregator.BucketCountThresholds DEFAULT_BUCKET_COUNT_THRESHOLDS = new TermsAggregator.BucketCountThresholds(1, 0, 10,
+            -1);
+    public static final ParseField SHOW_TERM_DOC_COUNT_ERROR = new ParseField("show_term_doc_count_error");
+    public static final ParseField ORDER_FIELD = new ParseField("order");
+
     public enum ExecutionMode {
 
         MAP(new ParseField("map")) {
@@ -155,28 +179,100 @@ public class TermsAggregatorFactory extends ValuesSourceAggregatorFactory<Values
         }
     }
 
-    private final Terms.Order order;
-    private final IncludeExclude includeExclude;
-    private final String executionHint;
-    private final SubAggCollectionMode collectMode;
-    private final TermsAggregator.BucketCountThresholds bucketCountThresholds;
-    private final boolean showTermDocCountError;
-
-    public TermsAggregatorFactory(String name, ValuesSourceParser.Input input, Terms.Order order,
-            TermsAggregator.BucketCountThresholds bucketCountThresholds, IncludeExclude includeExclude, String executionHint,
-            SubAggCollectionMode executionMode, boolean showTermDocCountError) {
-        super(name, StringTerms.TYPE, input);
-        this.order = order;
-        this.includeExclude = includeExclude;
-        this.executionHint = executionHint;
+    private List<Terms.Order> orders = Collections.singletonList(Terms.Order.count(false));
+    private IncludeExclude includeExclude = null;
+    private String executionHint = null;
+    private SubAggCollectionMode collectMode = SubAggCollectionMode.DEPTH_FIRST;
+    private TermsAggregator.BucketCountThresholds bucketCountThresholds = new TermsAggregator.BucketCountThresholds(
+            DEFAULT_BUCKET_COUNT_THRESHOLDS);
+    private boolean showTermDocCountError = false;
+
+    public TermsAggregatorFactory(String name, ValuesSourceType valuesSourceType, ValueType valueType) {
+        super(name, StringTerms.TYPE, valuesSourceType, valueType);
+    }
+
+    public TermsAggregator.BucketCountThresholds bucketCountThresholds() {
+        return bucketCountThresholds;
+    }
+
+    public void bucketCountThresholds(TermsAggregator.BucketCountThresholds bucketCountThresholds) {
         this.bucketCountThresholds = bucketCountThresholds;
-        this.collectMode = executionMode;
+    }
+
+    /**
+     * Sets the order in which the buckets will be returned.
+     */
+    public void order(List<Terms.Order> order) {
+        this.orders = order;
+    }
+
+    /**
+     * Gets the order in which the buckets will be returned.
+     */
+    public List<Terms.Order> order() {
+        return orders;
+    }
+
+    /**
+     * Expert: sets an execution hint to the aggregation.
+     */
+    public void executionHint(String executionHint) {
+        this.executionHint = executionHint;
+    }
+
+    /**
+     * Expert: gets an execution hint to the aggregation.
+     */
+    public String executionHint() {
+        return executionHint;
+    }
+
+    /**
+     * Expert: set the collection mode.
+     */
+    public void collectMode(SubAggCollectionMode mode) {
+        this.collectMode = mode;
+    }
+
+    /**
+     * Expert: get the collection mode.
+     */
+    public SubAggCollectionMode collectMode() {
+        return collectMode;
+    }
+
+    /**
+     * Set terms to include and exclude from the aggregation results
+     */
+    public void includeExclude(IncludeExclude includeExclude) {
+        this.includeExclude = includeExclude;
+    }
+
+    /**
+     * Get terms to include and exclude from the aggregation results
+     */
+    public IncludeExclude includeExclude() {
+        return includeExclude;
+    }
+
+    /**
+     * Get whether doc count error will be return for individual terms
+     */
+    public boolean showTermDocCountError() {
+        return showTermDocCountError;
+    }
+
+    /**
+     * Set whether doc count error will be return for individual terms
+     */
+    public void showTermDocCountError(boolean showTermDocCountError) {
         this.showTermDocCountError = showTermDocCountError;
     }
 
     @Override
     protected Aggregator createUnmapped(AggregationContext aggregationContext, Aggregator parent,
             List<PipelineAggregator> pipelineAggregators, Map<String, Object> metaData) throws IOException {
+        Terms.Order order = resolveOrder(orders);
         final InternalAggregation aggregation = new UnmappedTerms(name, order, bucketCountThresholds.getRequiredSize(),
                 bucketCountThresholds.getShardSize(), bucketCountThresholds.getMinDocCount(), pipelineAggregators, metaData);
         return new NonCollectingAggregator(name, aggregationContext, parent, factories, pipelineAggregators, metaData) {
@@ -192,13 +288,38 @@ public class TermsAggregatorFactory extends ValuesSourceAggregatorFactory<Values
         };
     }
 
+    private Order resolveOrder(List<Order> orders) {
+        Terms.Order order;
+        if (orders.size() == 1 && (orders.get(0) == InternalOrder.TERM_ASC || orders.get(0) == InternalOrder.TERM_DESC)) {
+            // If order is only terms order then we don't need compound
+            // ordering
+            order = orders.get(0);
+        } else {
+            // for all other cases we need compound order so term order asc
+            // can be added to make the order deterministic
+            order = Order.compound(orders);
+        }
+        return order;
+    }
+
     @Override
     protected Aggregator doCreateInternal(ValuesSource valuesSource, AggregationContext aggregationContext, Aggregator parent,
             boolean collectsFromSingleBucket, List<PipelineAggregator> pipelineAggregators, Map<String, Object> metaData)
             throws IOException {
+        Terms.Order order = resolveOrder(orders);
         if (collectsFromSingleBucket == false) {
             return asMultiBucketAggregator(this, aggregationContext, parent);
         }
+        BucketCountThresholds bucketCountThresholds = new BucketCountThresholds(this.bucketCountThresholds);
+        if (!(order == InternalOrder.TERM_ASC || order == InternalOrder.TERM_DESC)
+                && bucketCountThresholds.getShardSize() == DEFAULT_BUCKET_COUNT_THRESHOLDS.getShardSize()) {
+            // The user has not made a shardSize selection. Use default
+            // heuristic to avoid any wrong-ranking caused by distributed
+            // counting
+            bucketCountThresholds.setShardSize(BucketUtils.suggestShardSideQueueSize(bucketCountThresholds.getRequiredSize(),
+                    aggregationContext.searchContext().numberOfShards()));
+        }
+        bucketCountThresholds.ensureValidity();
         if (valuesSource instanceof ValuesSource.Bytes) {
             ExecutionMode execution = null;
             if (executionHint != null) {
@@ -278,4 +399,76 @@ public class TermsAggregatorFactory extends ValuesSourceAggregatorFactory<Values
                 + "]. It can only be applied to numeric or string fields.");
     }
 
+    @Override
+    protected XContentBuilder doXContentBody(XContentBuilder builder, Params params) throws IOException {
+        bucketCountThresholds.toXContent(builder, params);
+        builder.field(SHOW_TERM_DOC_COUNT_ERROR.getPreferredName(), showTermDocCountError);
+        if (executionHint != null) {
+            builder.field(TermsAggregatorFactory.EXECUTION_HINT_FIELD_NAME.getPreferredName(), executionHint);
+        }
+        builder.startArray(ORDER_FIELD.getPreferredName());
+        for (Terms.Order order : orders) {
+            order.toXContent(builder, params);
+        }
+        builder.endArray();
+        builder.field(SubAggCollectionMode.KEY.getPreferredName(), collectMode.parseField().getPreferredName());
+        if (includeExclude != null) {
+            includeExclude.toXContent(builder, params);
+        }
+        return builder;
+    }
+
+    @Override
+    protected ValuesSourceAggregatorFactory<ValuesSource> innerReadFrom(String name, ValuesSourceType valuesSourceType,
+            ValueType targetValueType, StreamInput in) throws IOException {
+        TermsAggregatorFactory factory = new TermsAggregatorFactory(name, valuesSourceType, targetValueType);
+        factory.bucketCountThresholds = BucketCountThresholds.readFromStream(in);
+        factory.collectMode = SubAggCollectionMode.BREADTH_FIRST.readFrom(in);
+        factory.executionHint = in.readOptionalString();
+        if (in.readBoolean()) {
+            factory.includeExclude = IncludeExclude.readFromStream(in);
+        }
+        int numOrders = in.readVInt();
+        List<Terms.Order> orders = new ArrayList<>(numOrders);
+        for (int i = 0; i < numOrders; i++) {
+            orders.add(InternalOrder.Streams.readOrder(in));
+        }
+        factory.orders = orders;
+        factory.showTermDocCountError = in.readBoolean();
+        return factory;
+    }
+
+    @Override
+    protected void innerWriteTo(StreamOutput out) throws IOException {
+        bucketCountThresholds.writeTo(out);
+        collectMode.writeTo(out);
+        out.writeOptionalString(executionHint);
+        boolean hasIncExc = includeExclude != null;
+        out.writeBoolean(hasIncExc);
+        if (hasIncExc) {
+            includeExclude.writeTo(out);
+        }
+        out.writeVInt(orders.size());
+        for (Terms.Order order : orders) {
+            InternalOrder.Streams.writeOrder(order, out);
+        }
+        out.writeBoolean(showTermDocCountError);
+    }
+
+    @Override
+    protected int innerHashCode() {
+        return Objects.hash(bucketCountThresholds, collectMode, executionHint, includeExclude, orders, showTermDocCountError);
+    }
+
+    @Override
+    protected boolean innerEquals(Object obj) {
+        TermsAggregatorFactory other = (TermsAggregatorFactory) obj;
+        return Objects.equals(bucketCountThresholds, other.bucketCountThresholds)
+                && Objects.equals(collectMode, other.collectMode)
+                && Objects.equals(executionHint, other.executionHint)
+                && Objects.equals(includeExclude, other.includeExclude)
+                && Objects.equals(orders, other.orders)
+                && Objects.equals(showTermDocCountError, other.showTermDocCountError);
+    }
+
 }
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsBuilder.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsBuilder.java
index 9bc1f7a9a6..3d8aff9b24 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsBuilder.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsBuilder.java
@@ -97,7 +97,7 @@ public class TermsBuilder extends ValuesSourceAggregationBuilder<TermsBuilder> {
         this.includePattern = regex;
         return this;
     }
-    
+
     /**
      * Define a set of terms that should be aggregated.
      */
@@ -107,8 +107,8 @@ public class TermsBuilder extends ValuesSourceAggregationBuilder<TermsBuilder> {
         }
         this.includeTerms = terms;
         return this;
-    }    
-    
+    }
+
     /**
      * Define a set of terms that should be aggregated.
      */
@@ -118,16 +118,16 @@ public class TermsBuilder extends ValuesSourceAggregationBuilder<TermsBuilder> {
         }
         this.includeTerms = longsArrToStringArr(terms);
         return this;
-    }     
-    
+    }
+
     private String[] longsArrToStringArr(long[] terms) {
         String[] termsAsString = new String[terms.length];
         for (int i = 0; i < terms.length; i++) {
             termsAsString[i] = Long.toString(terms[i]);
         }
         return termsAsString;
-    }      
-    
+    }
+
 
     /**
      * Define a set of terms that should be aggregated.
@@ -146,7 +146,7 @@ public class TermsBuilder extends ValuesSourceAggregationBuilder<TermsBuilder> {
             termsAsString[i] = Double.toString(terms[i]);
         }
         return termsAsString;
-    }    
+    }
 
     /**
      * Define a regular expression that will filter out terms that should be excluded from the aggregation. The regular
@@ -161,7 +161,7 @@ public class TermsBuilder extends ValuesSourceAggregationBuilder<TermsBuilder> {
         this.excludePattern = regex;
         return this;
     }
-    
+
     /**
      * Define a set of terms that should not be aggregated.
      */
@@ -171,9 +171,9 @@ public class TermsBuilder extends ValuesSourceAggregationBuilder<TermsBuilder> {
         }
         this.excludeTerms = terms;
         return this;
-    }    
-    
-    
+    }
+
+
     /**
      * Define a set of terms that should not be aggregated.
      */
@@ -194,9 +194,9 @@ public class TermsBuilder extends ValuesSourceAggregationBuilder<TermsBuilder> {
         }
         this.excludeTerms = doubleArrToStringArr(terms);
         return this;
-    }    
-    
-    
+    }
+
+
 
     /**
      * When using scripts, the value type indicates the types of the values the script is generating.
@@ -241,13 +241,13 @@ public class TermsBuilder extends ValuesSourceAggregationBuilder<TermsBuilder> {
     @Override
     protected XContentBuilder doInternalXContent(XContentBuilder builder, Params params) throws IOException {
 
-        bucketCountThresholds.toXContent(builder);
+        bucketCountThresholds.toXContent(builder, params);
 
         if (showTermDocCountError != null) {
-            builder.field(AbstractTermsParametersParser.SHOW_TERM_DOC_COUNT_ERROR.getPreferredName(), showTermDocCountError);
+            builder.field(TermsAggregatorFactory.SHOW_TERM_DOC_COUNT_ERROR.getPreferredName(), showTermDocCountError);
         }
         if (executionHint != null) {
-            builder.field(AbstractTermsParametersParser.EXECUTION_HINT_FIELD_NAME.getPreferredName(), executionHint);
+            builder.field(TermsAggregatorFactory.EXECUTION_HINT_FIELD_NAME.getPreferredName(), executionHint);
         }
         if (valueType != null) {
             builder.field("value_type", valueType.name().toLowerCase(Locale.ROOT));
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsParametersParser.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsParametersParser.java
deleted file mode 100644
index c8138b7b45..0000000000
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsParametersParser.java
+++ /dev/null
@@ -1,144 +0,0 @@
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-
-package org.elasticsearch.search.aggregations.bucket.terms;
-
-import org.elasticsearch.common.xcontent.XContentParser;
-import org.elasticsearch.search.SearchParseException;
-import org.elasticsearch.search.internal.SearchContext;
-
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-
-
-public class TermsParametersParser extends AbstractTermsParametersParser {
-
-    private static final TermsAggregator.BucketCountThresholds DEFAULT_BUCKET_COUNT_THRESHOLDS = new TermsAggregator.BucketCountThresholds(1, 0, 10, -1);
-
-    public List<OrderElement> getOrderElements() {
-        return orderElements;
-    }
-    
-    public boolean showTermDocCountError() {
-        return showTermDocCountError;
-    }
-
-    List<OrderElement> orderElements;
-    private boolean showTermDocCountError = false;
-
-    public TermsParametersParser() {
-        orderElements = new ArrayList<>(1);
-        orderElements.add(new OrderElement("_count", false));
-    }
-
-    @Override
-    public void parseSpecial(String aggregationName, XContentParser parser, SearchContext context, XContentParser.Token token, String currentFieldName) throws IOException {
-        if (token == XContentParser.Token.START_OBJECT) {
-            if ("order".equals(currentFieldName)) {
-                this.orderElements = Collections.singletonList(parseOrderParam(aggregationName, parser, context));
-            } else {
-                throw new SearchParseException(context, "Unknown key for a " + token + " in [" + aggregationName + "]: ["
-                        + currentFieldName + "].", parser.getTokenLocation());
-            }
-        } else if (token == XContentParser.Token.START_ARRAY) {
-            if ("order".equals(currentFieldName)) {
-                orderElements = new ArrayList<>();
-                while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
-                    if (token == XContentParser.Token.START_OBJECT) {
-                        OrderElement orderParam = parseOrderParam(aggregationName, parser, context);
-                        orderElements.add(orderParam);
-                    } else {
-                        throw new SearchParseException(context, "Order elements must be of type object in [" + aggregationName + "].",
-                                parser.getTokenLocation());
-                    }
-                }
-            } else {
-                throw new SearchParseException(context, "Unknown key for a " + token + " in [" + aggregationName + "]: ["
-                        + currentFieldName + "].", parser.getTokenLocation());
-            }
-        } else if (token == XContentParser.Token.VALUE_BOOLEAN) {
-            if (context.parseFieldMatcher().match(currentFieldName, SHOW_TERM_DOC_COUNT_ERROR)) {
-                showTermDocCountError = parser.booleanValue();
-            }
-        } else {
-            throw new SearchParseException(context, "Unknown key for a " + token + " in [" + aggregationName + "]: [" + currentFieldName
-                    + "].", parser.getTokenLocation());
-        }
-    }
-
-    private OrderElement parseOrderParam(String aggregationName, XContentParser parser, SearchContext context) throws IOException {
-        XContentParser.Token token;
-        OrderElement orderParam = null;
-        String orderKey = null;
-        boolean orderAsc = false;
-        while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
-            if (token == XContentParser.Token.FIELD_NAME) {
-                orderKey = parser.currentName();
-            } else if (token == XContentParser.Token.VALUE_STRING) {
-                String dir = parser.text();
-                if ("asc".equalsIgnoreCase(dir)) {
-                    orderAsc = true;
-                } else if ("desc".equalsIgnoreCase(dir)) {
-                    orderAsc = false;
-                } else {
-                    throw new SearchParseException(context, "Unknown terms order direction [" + dir + "] in terms aggregation ["
-                            + aggregationName + "]", parser.getTokenLocation());
-                }
-            } else {
-                throw new SearchParseException(context, "Unexpected token " + token + " for [order] in [" + aggregationName + "].",
-                        parser.getTokenLocation());
-            }
-        }
-        if (orderKey == null) {
-            throw new SearchParseException(context, "Must specify at least one field for [order] in [" + aggregationName + "].",
-                    parser.getTokenLocation());
-        } else {
-            orderParam = new OrderElement(orderKey, orderAsc);
-        }
-        return orderParam;
-    }
-
-    static class OrderElement {
-        private final String key;
-        private final boolean asc;
-
-        public OrderElement(String key, boolean asc) {
-            this.key = key;
-            this.asc = asc;
-        }
-
-        public String key() {
-            return key;
-        }
-
-        public boolean asc() {
-            return asc;
-        }
-
-        
-    }
-
-    @Override
-    public TermsAggregator.BucketCountThresholds getDefaultBucketCountThresholds() {
-        return new TermsAggregator.BucketCountThresholds(DEFAULT_BUCKET_COUNT_THRESHOLDS);
-    }
-}
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsParser.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsParser.java
index 4398ec655b..4a40816ab2 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsParser.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/TermsParser.java
@@ -18,24 +18,32 @@
  */
 package org.elasticsearch.search.aggregations.bucket.terms;
 
+import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.ParseFieldMatcher;
+import org.elasticsearch.common.ParsingException;
 import org.elasticsearch.common.xcontent.XContentParser;
-import org.elasticsearch.search.aggregations.Aggregator;
+import org.elasticsearch.common.xcontent.XContentParser.Token;
+import org.elasticsearch.search.aggregations.Aggregator.SubAggCollectionMode;
 import org.elasticsearch.search.aggregations.AggregatorFactory;
-import org.elasticsearch.search.aggregations.bucket.BucketUtils;
 import org.elasticsearch.search.aggregations.bucket.terms.Terms.Order;
-import org.elasticsearch.search.aggregations.bucket.terms.TermsParametersParser.OrderElement;
+import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregator.BucketCountThresholds;
 import org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude;
-import org.elasticsearch.search.aggregations.support.ValuesSourceParser;
-import org.elasticsearch.search.internal.SearchContext;
+import org.elasticsearch.search.aggregations.support.ValueType;
+import org.elasticsearch.search.aggregations.support.ValuesSource;
+import org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory;
+import org.elasticsearch.search.aggregations.support.ValuesSourceType;
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
+import java.util.Map;
 
 /**
  *
  */
-public class TermsParser implements Aggregator.Parser {
+public class TermsParser extends AbstractTermsParser {
+
 
     @Override
     public String type() {
@@ -43,38 +51,123 @@ public class TermsParser implements Aggregator.Parser {
     }
 
     @Override
-    public AggregatorFactory parse(String aggregationName, XContentParser parser, SearchContext context) throws IOException {
-        TermsParametersParser aggParser = new TermsParametersParser();
-        ValuesSourceParser vsParser = ValuesSourceParser.any(aggregationName, StringTerms.TYPE, context).scriptable(true).formattable(true).build();
-        IncludeExclude.Parser incExcParser = new IncludeExclude.Parser();
-        aggParser.parse(aggregationName, parser, context, vsParser, incExcParser);
-
-        List<OrderElement> orderElements = aggParser.getOrderElements();
-        List<Terms.Order> orders = new ArrayList<>(orderElements.size());
-        for (OrderElement orderElement : orderElements) {
-            orders.add(resolveOrder(orderElement.key(), orderElement.asc()));
+    protected ValuesSourceAggregatorFactory<ValuesSource> doCreateFactory(String aggregationName, ValuesSourceType valuesSourceType,
+            ValueType targetValueType, BucketCountThresholds bucketCountThresholds, SubAggCollectionMode collectMode, String executionHint,
+            IncludeExclude incExc, Map<ParseField, Object> otherOptions) {
+        TermsAggregatorFactory factory = new TermsAggregatorFactory(aggregationName, valuesSourceType, targetValueType);
+        List<OrderElement> orderElements = (List<OrderElement>) otherOptions.get(TermsAggregatorFactory.ORDER_FIELD);
+        if (orderElements != null) {
+            List<Terms.Order> orders = new ArrayList<>(orderElements.size());
+            for (OrderElement orderElement : orderElements) {
+                orders.add(resolveOrder(orderElement.key(), orderElement.asc()));
+            }
+            factory.order(orders);
+        }
+        if (bucketCountThresholds != null) {
+            factory.bucketCountThresholds(bucketCountThresholds);
+        }
+        if (collectMode != null) {
+            factory.collectMode(collectMode);
+        }
+        if (executionHint != null) {
+            factory.executionHint(executionHint);
+        }
+        if (incExc != null) {
+            factory.includeExclude(incExc);
+        }
+        Boolean showTermDocCountError = (Boolean) otherOptions.get(TermsAggregatorFactory.SHOW_TERM_DOC_COUNT_ERROR);
+        if (showTermDocCountError != null) {
+            factory.showTermDocCountError(showTermDocCountError);
         }
-        Terms.Order order;
-        if (orders.size() == 1 && (orders.get(0) == InternalOrder.TERM_ASC || orders.get(0) == InternalOrder.TERM_DESC))
-        {
-            // If order is only terms order then we don't need compound ordering
-            order = orders.get(0);
+        return factory;
+    }
+
+    @Override
+    public boolean parseSpecial(String aggregationName, XContentParser parser, ParseFieldMatcher parseFieldMatcher, Token token,
+            String currentFieldName, Map<ParseField, Object> otherOptions) throws IOException {
+        if (token == XContentParser.Token.START_OBJECT) {
+            if (parseFieldMatcher.match(currentFieldName, TermsAggregatorFactory.ORDER_FIELD)) {
+                otherOptions.put(TermsAggregatorFactory.ORDER_FIELD, Collections.singletonList(parseOrderParam(aggregationName, parser)));
+                return true;
+            }
+        } else if (token == XContentParser.Token.START_ARRAY) {
+            if (parseFieldMatcher.match(currentFieldName, TermsAggregatorFactory.ORDER_FIELD)) {
+                List<OrderElement> orderElements = new ArrayList<>();
+                while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
+                    if (token == XContentParser.Token.START_OBJECT) {
+                        OrderElement orderParam = parseOrderParam(aggregationName, parser);
+                        orderElements.add(orderParam);
+                    } else {
+                        throw new ParsingException(parser.getTokenLocation(),
+                                "Order elements must be of type object in [" + aggregationName + "].");
+                    }
+                }
+                otherOptions.put(TermsAggregatorFactory.ORDER_FIELD, orderElements);
+                return true;
+            }
+        } else if (token == XContentParser.Token.VALUE_BOOLEAN) {
+            if (parseFieldMatcher.match(currentFieldName, TermsAggregatorFactory.SHOW_TERM_DOC_COUNT_ERROR)) {
+                otherOptions.put(TermsAggregatorFactory.SHOW_TERM_DOC_COUNT_ERROR, parser.booleanValue());
+                return true;
+            }
         }
-        else
-        {
-            // for all other cases we need compound order so term order asc can be added to make the order deterministic
-            order = Order.compound(orders);
+        return false;
+    }
+
+    private OrderElement parseOrderParam(String aggregationName, XContentParser parser) throws IOException {
+        XContentParser.Token token;
+        OrderElement orderParam = null;
+        String orderKey = null;
+        boolean orderAsc = false;
+        while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
+            if (token == XContentParser.Token.FIELD_NAME) {
+                orderKey = parser.currentName();
+            } else if (token == XContentParser.Token.VALUE_STRING) {
+                String dir = parser.text();
+                if ("asc".equalsIgnoreCase(dir)) {
+                    orderAsc = true;
+                } else if ("desc".equalsIgnoreCase(dir)) {
+                    orderAsc = false;
+                } else {
+                    throw new ParsingException(parser.getTokenLocation(),
+                            "Unknown terms order direction [" + dir + "] in terms aggregation [" + aggregationName + "]");
+                }
+            } else {
+                throw new ParsingException(parser.getTokenLocation(),
+                        "Unexpected token " + token + " for [order] in [" + aggregationName + "].");
+            }
         }
-        TermsAggregator.BucketCountThresholds bucketCountThresholds = aggParser.getBucketCountThresholds();
-        if (!(order == InternalOrder.TERM_ASC || order == InternalOrder.TERM_DESC)
-                && bucketCountThresholds.getShardSize() == aggParser.getDefaultBucketCountThresholds().getShardSize()) {
-            // The user has not made a shardSize selection. Use default heuristic to avoid any wrong-ranking caused by distributed counting
-            bucketCountThresholds.setShardSize(BucketUtils.suggestShardSideQueueSize(bucketCountThresholds.getRequiredSize(),
-                    context.numberOfShards()));
+        if (orderKey == null) {
+            throw new ParsingException(parser.getTokenLocation(),
+                    "Must specify at least one field for [order] in [" + aggregationName + "].");
+        } else {
+            orderParam = new OrderElement(orderKey, orderAsc);
         }
-        bucketCountThresholds.ensureValidity();
-        return new TermsAggregatorFactory(aggregationName, vsParser.input(), order, bucketCountThresholds, aggParser.getIncludeExclude(),
-                aggParser.getExecutionHint(), aggParser.getCollectionMode(), aggParser.showTermDocCountError());
+        return orderParam;
+    }
+
+    static class OrderElement {
+        private final String key;
+        private final boolean asc;
+
+        public OrderElement(String key, boolean asc) {
+            this.key = key;
+            this.asc = asc;
+        }
+
+        public String key() {
+            return key;
+        }
+
+        public boolean asc() {
+            return asc;
+        }
+
+    }
+
+    @Override
+    public TermsAggregator.BucketCountThresholds getDefaultBucketCountThresholds() {
+        return new TermsAggregator.BucketCountThresholds(TermsAggregatorFactory.DEFAULT_BUCKET_COUNT_THRESHOLDS);
     }
 
     static Terms.Order resolveOrder(String key, boolean asc) {
@@ -87,10 +180,9 @@ public class TermsParser implements Aggregator.Parser {
         return Order.aggregation(key, asc);
     }
 
-    // NORELEASE implement this method when refactoring this aggregation
     @Override
     public AggregatorFactory[] getFactoryPrototypes() {
-        return null;
+        return new AggregatorFactory[] { new TermsAggregatorFactory(null, null, null) };
     }
 
 }
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/support/IncludeExclude.java b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/support/IncludeExclude.java
index 9c33a987a9..f6df150a4c 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/support/IncludeExclude.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/support/IncludeExclude.java
@@ -34,12 +34,22 @@ import org.apache.lucene.util.automaton.CompiledAutomaton;
 import org.apache.lucene.util.automaton.Operations;
 import org.apache.lucene.util.automaton.RegExp;
 import org.elasticsearch.ElasticsearchParseException;
+import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.ParseFieldMatcher;
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.io.stream.StreamOutput;
+import org.elasticsearch.common.io.stream.Writeable;
+import org.elasticsearch.common.xcontent.ToXContent;
+import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.search.aggregations.support.ValuesSource;
 import org.elasticsearch.search.aggregations.support.ValuesSource.Bytes.WithOrdinals;
 
 import java.io.IOException;
+import java.util.Collections;
 import java.util.HashSet;
+import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 import java.util.SortedSet;
 import java.util.TreeSet;
@@ -48,7 +58,16 @@ import java.util.TreeSet;
  * Defines the include/exclude regular expression filtering for string terms aggregation. In this filtering logic,
  * exclusion has precedence, where the {@code include} is evaluated first and then the {@code exclude}.
  */
-public class IncludeExclude {
+public class IncludeExclude implements Writeable<IncludeExclude>, ToXContent {
+
+    private static final IncludeExclude PROTOTYPE = new IncludeExclude(Collections.emptySortedSet(), Collections.emptySortedSet());
+    private static final ParseField INCLUDE_FIELD = new ParseField("include");
+    private static final ParseField EXCLUDE_FIELD = new ParseField("exclude");
+    private static final ParseField PATTERN_FIELD = new ParseField("pattern");
+
+    public static IncludeExclude readFromStream(StreamInput in) throws IOException {
+        return PROTOTYPE.readFrom(in);
+    }
 
     // The includeValue and excludeValue ByteRefs which are the result of the parsing
     // process are converted into a LongFilter when used on numeric fields
@@ -283,18 +302,14 @@ public class IncludeExclude {
 
     public static class Parser {
 
-        String include = null;
-        String exclude = null;
-        SortedSet<BytesRef> includeValues;
-        SortedSet<BytesRef> excludeValues;
-
-        public boolean token(String currentFieldName, XContentParser.Token token, XContentParser parser) throws IOException {
+        public boolean token(String currentFieldName, XContentParser.Token token, XContentParser parser,
+                ParseFieldMatcher parseFieldMatcher, Map<ParseField, Object> otherOptions) throws IOException {
 
             if (token == XContentParser.Token.VALUE_STRING) {
-                if ("include".equals(currentFieldName)) {
-                    include = parser.text();
-                } else if ("exclude".equals(currentFieldName)) {
-                    exclude = parser.text();
+                if (parseFieldMatcher.match(currentFieldName, INCLUDE_FIELD)) {
+                    otherOptions.put(INCLUDE_FIELD, parser.text());
+                } else if (parseFieldMatcher.match(currentFieldName, EXCLUDE_FIELD)) {
+                    otherOptions.put(EXCLUDE_FIELD, parser.text());
                 } else {
                     return false;
                 }
@@ -302,35 +317,35 @@ public class IncludeExclude {
             }
 
             if (token == XContentParser.Token.START_ARRAY) {
-                if ("include".equals(currentFieldName)) {
-                     includeValues = new TreeSet<>(parseArrayToSet(parser));
+                if (parseFieldMatcher.match(currentFieldName, INCLUDE_FIELD)) {
+                    otherOptions.put(INCLUDE_FIELD, new TreeSet<>(parseArrayToSet(parser)));
                      return true;
                 }
-                if ("exclude".equals(currentFieldName)) {
-                      excludeValues = new TreeSet<>(parseArrayToSet(parser));
+                if (parseFieldMatcher.match(currentFieldName, EXCLUDE_FIELD)) {
+                    otherOptions.put(EXCLUDE_FIELD, new TreeSet<>(parseArrayToSet(parser)));
                       return true;
                 }
                 return false;
             }
 
             if (token == XContentParser.Token.START_OBJECT) {
-                if ("include".equals(currentFieldName)) {
+                if (parseFieldMatcher.match(currentFieldName, INCLUDE_FIELD)) {
                     while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
                         if (token == XContentParser.Token.FIELD_NAME) {
                             currentFieldName = parser.currentName();
                         } else if (token == XContentParser.Token.VALUE_STRING) {
-                            if ("pattern".equals(currentFieldName)) {
-                                include = parser.text();
+                            if (parseFieldMatcher.match(currentFieldName, PATTERN_FIELD)) {
+                                otherOptions.put(INCLUDE_FIELD, parser.text());
                             }
                         }
                     }
-                } else if ("exclude".equals(currentFieldName)) {
+                } else if (parseFieldMatcher.match(currentFieldName, EXCLUDE_FIELD)) {
                     while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
                         if (token == XContentParser.Token.FIELD_NAME) {
                             currentFieldName = parser.currentName();
                         } else if (token == XContentParser.Token.VALUE_STRING) {
-                            if ("pattern".equals(currentFieldName)) {
-                                exclude = parser.text();
+                            if (parseFieldMatcher.match(currentFieldName, PATTERN_FIELD)) {
+                                otherOptions.put(EXCLUDE_FIELD, parser.text());
                             }
                         }
                     }
@@ -342,6 +357,7 @@ public class IncludeExclude {
 
             return false;
         }
+
         private Set<BytesRef> parseArrayToSet(XContentParser parser) throws IOException {
             final Set<BytesRef> set = new HashSet<>();
             if (parser.currentToken() != XContentParser.Token.START_ARRAY) {
@@ -356,7 +372,27 @@ public class IncludeExclude {
             return set;
         }
 
-        public IncludeExclude includeExclude() {
+        public IncludeExclude createIncludeExclude(Map<ParseField, Object> otherOptions) {
+            Object includeObject = otherOptions.get(INCLUDE_FIELD);
+            String include = null;
+            SortedSet<BytesRef> includeValues = null;
+            if (includeObject != null) {
+                if (includeObject instanceof String) {
+                    include = (String) includeObject;
+                } else if (includeObject instanceof SortedSet) {
+                    includeValues = (SortedSet<BytesRef>) includeObject;
+                }
+            }
+            Object excludeObject = otherOptions.get(EXCLUDE_FIELD);
+            String exclude = null;
+            SortedSet<BytesRef> excludeValues = null;
+            if (excludeObject != null) {
+                if (excludeObject instanceof String) {
+                    exclude = (String) excludeObject;
+                } else if (excludeObject instanceof SortedSet) {
+                    excludeValues = (SortedSet<BytesRef>) excludeObject;
+                }
+            }
             RegExp includePattern =  include != null ? new RegExp(include) : null;
             RegExp excludePattern = exclude != null ? new RegExp(exclude) : null;
             if (includePattern != null || excludePattern != null) {
@@ -444,4 +480,111 @@ public class IncludeExclude {
         return result;
     }
 
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        if (include != null) {
+            builder.field(INCLUDE_FIELD.getPreferredName(), include.getOriginalString());
+        }
+        if (includeValues != null) {
+            builder.startArray(INCLUDE_FIELD.getPreferredName());
+            for (BytesRef value : includeValues) {
+                builder.value(value.utf8ToString());
+            }
+            builder.endArray();
+        }
+        if (exclude != null) {
+            builder.field(EXCLUDE_FIELD.getPreferredName(), exclude.getOriginalString());
+        }
+        if (excludeValues != null) {
+            builder.startArray(EXCLUDE_FIELD.getPreferredName());
+            for (BytesRef value : excludeValues) {
+                builder.value(value.utf8ToString());
+            }
+            builder.endArray();
+        }
+        return builder;
+    }
+
+    @Override
+    public IncludeExclude readFrom(StreamInput in) throws IOException {
+        if (in.readBoolean()) {
+            String includeString = in.readOptionalString();
+            RegExp include = null;
+            if (includeString != null) {
+                include = new RegExp(includeString);
+            }
+            String excludeString = in.readOptionalString();
+            RegExp exclude = null;
+            if (excludeString != null) {
+                exclude = new RegExp(excludeString);
+            }
+            return new IncludeExclude(include, exclude);
+        } else {
+            SortedSet<BytesRef> includes = null;
+            if (in.readBoolean()) {
+                int size = in.readVInt();
+                includes = new TreeSet<>();
+                for (int i = 0; i < size; i++) {
+                    includes.add(in.readBytesRef());
+                }
+            }
+            SortedSet<BytesRef> excludes = null;
+            if (in.readBoolean()) {
+                int size = in.readVInt();
+                excludes = new TreeSet<>();
+                for (int i = 0; i < size; i++) {
+                    excludes.add(in.readBytesRef());
+                }
+            }
+            return new IncludeExclude(includes, excludes);
+        }
+    }
+
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+        boolean regexBased = isRegexBased();
+        out.writeBoolean(regexBased);
+        if (regexBased) {
+            out.writeOptionalString(include == null ? null : include.getOriginalString());
+            out.writeOptionalString(exclude == null ? null : exclude.getOriginalString());
+        } else {
+            boolean hasIncludes = includeValues != null;
+            out.writeBoolean(hasIncludes);
+            if (hasIncludes) {
+                out.writeVInt(includeValues.size());
+                for (BytesRef value : includeValues) {
+                    out.writeBytesRef(value);
+                }
+            }
+            boolean hasExcludes = excludeValues != null;
+            out.writeBoolean(hasExcludes);
+            if (hasExcludes) {
+                out.writeVInt(excludeValues.size());
+                for (BytesRef value : excludeValues) {
+                    out.writeBytesRef(value);
+                }
+            }
+        }
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(include == null ? null : include.getOriginalString(), exclude == null ? null : exclude.getOriginalString(),
+                includeValues, excludeValues);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj == null) {
+            return false;
+        } if (getClass() != obj.getClass()) {
+            return false;
+        }
+        IncludeExclude other = (IncludeExclude) obj;
+        return Objects.equals(include == null ? null : include.getOriginalString(), other.include == null ? null : other.include.getOriginalString())
+                && Objects.equals(exclude == null ? null : exclude.getOriginalString(), other.exclude == null ? null : other.exclude.getOriginalString())
+                && Objects.equals(includeValues, other.includeValues)
+                && Objects.equals(excludeValues, other.excludeValues);
+    }
+
 }
diff --git a/core/src/main/java/org/elasticsearch/search/aggregations/support/ValuesSourceAggregatorFactory.java b/core/src/main/java/org/elasticsearch/search/aggregations/support/ValuesSourceAggregatorFactory.java
index 0084e634a1..931863dcef 100644
--- a/core/src/main/java/org/elasticsearch/search/aggregations/support/ValuesSourceAggregatorFactory.java
+++ b/core/src/main/java/org/elasticsearch/search/aggregations/support/ValuesSourceAggregatorFactory.java
@@ -343,7 +343,7 @@ public abstract class ValuesSourceAggregatorFactory<VS extends ValuesSource> ext
     }
 
     @Override
-    public void doWriteTo(StreamOutput out) throws IOException {
+    protected final void doWriteTo(StreamOutput out) throws IOException {
         valuesSourceType.writeTo(out);
         boolean hasTargetValueType = targetValueType != null;
         out.writeBoolean(hasTargetValueType);
@@ -376,7 +376,7 @@ public abstract class ValuesSourceAggregatorFactory<VS extends ValuesSource> ext
     }
 
     @Override
-    protected ValuesSourceAggregatorFactory<VS> doReadFrom(String name, StreamInput in) throws IOException {
+    protected final ValuesSourceAggregatorFactory<VS> doReadFrom(String name, StreamInput in) throws IOException {
         ValuesSourceType valuesSourceType = ValuesSourceType.ANY.readFrom(in);
         ValueType targetValueType = null;
         if (in.readBoolean()) {
@@ -433,7 +433,7 @@ public abstract class ValuesSourceAggregatorFactory<VS extends ValuesSource> ext
     }
 
     @Override
-    public int doHashCode() {
+    public final int doHashCode() {
         return Objects.hash(field, format, missing, script, targetValueType, timeZone, valueType, valuesSourceType,
                 innerHashCode());
     }
@@ -446,7 +446,7 @@ public abstract class ValuesSourceAggregatorFactory<VS extends ValuesSource> ext
     }
 
     @Override
-    public boolean doEquals(Object obj) {
+    public final boolean doEquals(Object obj) {
         ValuesSourceAggregatorFactory<?> other = (ValuesSourceAggregatorFactory<?>) obj;
         if (!Objects.equals(field, other.field))
             return false;
diff --git a/core/src/test/java/org/elasticsearch/search/aggregations/SubAggCollectionModeTests.java b/core/src/test/java/org/elasticsearch/search/aggregations/SubAggCollectionModeTests.java
new file mode 100644
index 0000000000..131144dc5d
--- /dev/null
+++ b/core/src/test/java/org/elasticsearch/search/aggregations/SubAggCollectionModeTests.java
@@ -0,0 +1,82 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.search.aggregations;
+
+import org.elasticsearch.common.io.stream.BytesStreamOutput;
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.search.aggregations.Aggregator.SubAggCollectionMode;
+import org.elasticsearch.test.ESTestCase;
+
+import java.io.IOException;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.equalTo;
+
+public class SubAggCollectionModeTests extends ESTestCase {
+
+    public void testValidOrdinals() {
+        assertThat(SubAggCollectionMode.DEPTH_FIRST.ordinal(), equalTo(0));
+        assertThat(SubAggCollectionMode.BREADTH_FIRST.ordinal(), equalTo(1));
+    }
+
+    public void testwriteTo() throws Exception {
+        try (BytesStreamOutput out = new BytesStreamOutput()) {
+            SubAggCollectionMode.DEPTH_FIRST.writeTo(out);
+            try (StreamInput in = StreamInput.wrap(out.bytes())) {
+                assertThat(in.readVInt(), equalTo(0));
+            }
+        }
+
+        try (BytesStreamOutput out = new BytesStreamOutput()) {
+            SubAggCollectionMode.BREADTH_FIRST.writeTo(out);
+            try (StreamInput in = StreamInput.wrap(out.bytes())) {
+                assertThat(in.readVInt(), equalTo(1));
+            }
+        }
+    }
+
+    public void testReadFrom() throws Exception {
+        try (BytesStreamOutput out = new BytesStreamOutput()) {
+            out.writeVInt(0);
+            try (StreamInput in = StreamInput.wrap(out.bytes())) {
+                assertThat(SubAggCollectionMode.BREADTH_FIRST.readFrom(in), equalTo(SubAggCollectionMode.DEPTH_FIRST));
+            }
+        }
+        try (BytesStreamOutput out = new BytesStreamOutput()) {
+            out.writeVInt(1);
+            try (StreamInput in = StreamInput.wrap(out.bytes())) {
+                assertThat(SubAggCollectionMode.BREADTH_FIRST.readFrom(in), equalTo(SubAggCollectionMode.BREADTH_FIRST));
+            }
+        }
+    }
+
+    public void testInvalidReadFrom() throws Exception {
+        try (BytesStreamOutput out = new BytesStreamOutput()) {
+            out.writeVInt(randomIntBetween(2, Integer.MAX_VALUE));
+            try (StreamInput in = StreamInput.wrap(out.bytes())) {
+                SubAggCollectionMode.BREADTH_FIRST.readFrom(in);
+                fail("Expected IOException");
+            } catch(IOException e) {
+                assertThat(e.getMessage(), containsString("Unknown SubAggCollectionMode ordinal ["));
+            }
+
+        }
+    }
+}
diff --git a/core/src/test/java/org/elasticsearch/search/aggregations/bucket/SignificantTermsSignificanceScoreIT.java b/core/src/test/java/org/elasticsearch/search/aggregations/bucket/SignificantTermsSignificanceScoreIT.java
index 6c1e7dfcab..173f9ddfef 100644
--- a/core/src/test/java/org/elasticsearch/search/aggregations/bucket/SignificantTermsSignificanceScoreIT.java
+++ b/core/src/test/java/org/elasticsearch/search/aggregations/bucket/SignificantTermsSignificanceScoreIT.java
@@ -20,6 +20,7 @@ package org.elasticsearch.search.aggregations.bucket;
 
 import org.elasticsearch.action.index.IndexRequestBuilder;
 import org.elasticsearch.action.search.SearchResponse;
+import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.ParseFieldMatcher;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
@@ -52,7 +53,6 @@ import org.elasticsearch.search.aggregations.bucket.significant.heuristics.Signi
 import org.elasticsearch.search.aggregations.bucket.terms.StringTerms;
 import org.elasticsearch.search.aggregations.bucket.terms.Terms;
 import org.elasticsearch.search.aggregations.bucket.terms.TermsBuilder;
-import org.elasticsearch.search.internal.SearchContext;
 import org.elasticsearch.test.ESIntegTestCase;
 import org.elasticsearch.test.search.aggregations.bucket.SharedSignificantTermsTestMethods;
 
@@ -163,7 +163,7 @@ public class SignificantTermsSignificanceScoreIT extends ESIntegTestCase {
     public static class CustomSignificanceHeuristicPlugin extends Plugin {
 
         static {
-            SignificanceHeuristicStreams.registerStream(SimpleHeuristic.STREAM);
+            SignificanceHeuristicStreams.registerPrototype(SimpleHeuristic.PROTOTYPE);
         }
 
         @Override
@@ -187,24 +187,30 @@ public class SignificantTermsSignificanceScoreIT extends ESIntegTestCase {
 
     public static class SimpleHeuristic extends SignificanceHeuristic {
 
-        protected static final String[] NAMES = {"simple"};
+        static final SimpleHeuristic PROTOTYPE = new SimpleHeuristic();
 
-        public static final SignificanceHeuristicStreams.Stream STREAM = new SignificanceHeuristicStreams.Stream() {
-            @Override
-            public SignificanceHeuristic readResult(StreamInput in) throws IOException {
-                return readFrom(in);
-            }
+        protected static final ParseField NAMES_FIELD = new ParseField("simple");
 
-            @Override
-            public String getName() {
-                return NAMES[0];
-            }
-        };
+        @Override
+        public String getWriteableName() {
+            return NAMES_FIELD.getPreferredName();
+        }
 
-        public static SignificanceHeuristic readFrom(StreamInput in) throws IOException {
+        @Override
+        public SignificanceHeuristic readFrom(StreamInput in) throws IOException {
             return new SimpleHeuristic();
         }
 
+        @Override
+        public void writeTo(StreamOutput out) throws IOException {
+        }
+
+        @Override
+        public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+            builder.startObject(NAMES_FIELD.getPreferredName()).endObject();
+            return builder;
+        }
+
         /**
          * @param subsetFreq   The frequency of the term in the selected sample
          * @param subsetSize   The size of the selected sample (typically number of docs)
@@ -217,15 +223,10 @@ public class SignificantTermsSignificanceScoreIT extends ESIntegTestCase {
             return subsetFreq / subsetSize > supersetFreq / supersetSize ? 2.0 : 1.0;
         }
 
-        @Override
-        public void writeTo(StreamOutput out) throws IOException {
-            out.writeString(STREAM.getName());
-        }
-
         public static class SimpleHeuristicParser implements SignificanceHeuristicParser {
 
             @Override
-            public SignificanceHeuristic parse(XContentParser parser, ParseFieldMatcher parseFieldMatcher, SearchContext context)
+            public SignificanceHeuristic parse(XContentParser parser, ParseFieldMatcher parseFieldMatcher)
                     throws IOException, QueryShardException {
                 parser.nextToken();
                 return new SimpleHeuristic();
@@ -233,7 +234,7 @@ public class SignificantTermsSignificanceScoreIT extends ESIntegTestCase {
 
             @Override
             public String[] getNames() {
-                return NAMES;
+                return NAMES_FIELD.getAllNamesIncludedDeprecated();
             }
         }
 
@@ -241,7 +242,7 @@ public class SignificantTermsSignificanceScoreIT extends ESIntegTestCase {
 
             @Override
             public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
-                builder.startObject(STREAM.getName()).endObject();
+                builder.startObject(NAMES_FIELD.getPreferredName()).endObject();
                 return builder;
             }
         }
diff --git a/core/src/test/java/org/elasticsearch/search/aggregations/bucket/SignificantTermsTests.java b/core/src/test/java/org/elasticsearch/search/aggregations/bucket/SignificantTermsTests.java
new file mode 100644
index 0000000000..8ad928e5ed
--- /dev/null
+++ b/core/src/test/java/org/elasticsearch/search/aggregations/bucket/SignificantTermsTests.java
@@ -0,0 +1,226 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.search.aggregations.bucket;
+
+import org.apache.lucene.util.BytesRef;
+import org.apache.lucene.util.automaton.RegExp;
+import org.elasticsearch.index.query.QueryBuilders;
+import org.elasticsearch.script.Script;
+import org.elasticsearch.search.aggregations.BaseAggregationTestCase;
+import org.elasticsearch.search.aggregations.bucket.significant.SignificantTermsAggregatorFactory;
+import org.elasticsearch.search.aggregations.bucket.significant.heuristics.ChiSquare;
+import org.elasticsearch.search.aggregations.bucket.significant.heuristics.GND;
+import org.elasticsearch.search.aggregations.bucket.significant.heuristics.JLHScore;
+import org.elasticsearch.search.aggregations.bucket.significant.heuristics.MutualInformation;
+import org.elasticsearch.search.aggregations.bucket.significant.heuristics.PercentageScore;
+import org.elasticsearch.search.aggregations.bucket.significant.heuristics.ScriptHeuristic;
+import org.elasticsearch.search.aggregations.bucket.significant.heuristics.SignificanceHeuristic;
+import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregatorFactory.ExecutionMode;
+import org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude;
+import org.elasticsearch.search.aggregations.support.ValuesSourceType;
+
+import java.util.SortedSet;
+import java.util.TreeSet;
+
+public class SignificantTermsTests extends BaseAggregationTestCase<SignificantTermsAggregatorFactory> {
+
+    private static final String[] executionHints;
+
+    static {
+        ExecutionMode[] executionModes = ExecutionMode.values();
+        executionHints = new String[executionModes.length];
+        for (int i = 0; i < executionModes.length; i++) {
+            executionHints[i] = executionModes[i].toString();
+        }
+    }
+
+    @Override
+    protected SignificantTermsAggregatorFactory createTestAggregatorFactory() {
+        String name = randomAsciiOfLengthBetween(3, 20);
+        SignificantTermsAggregatorFactory factory = new SignificantTermsAggregatorFactory(name, ValuesSourceType.ANY, null);
+        String field = randomAsciiOfLengthBetween(3, 20);
+        int randomFieldBranch = randomInt(2);
+        switch (randomFieldBranch) {
+        case 0:
+            factory.field(field);
+            break;
+        case 1:
+            factory.field(field);
+            factory.script(new Script("_value + 1"));
+            break;
+        case 2:
+            factory.script(new Script("doc[" + field + "] + 1"));
+            break;
+        default:
+            fail();
+        }
+        if (randomBoolean()) {
+            factory.missing("MISSING");
+        }
+        if (randomBoolean()) {
+            int size = randomInt(4);
+            switch (size) {
+            case 0:
+                break;
+            case 1:
+            case 2:
+            case 3:
+            case 4:
+                size = randomInt();
+                break;
+            default:
+                fail();
+            }
+            factory.bucketCountThresholds().setRequiredSize(size);
+
+        }
+        if (randomBoolean()) {
+            int shardSize = randomInt(4);
+            switch (shardSize) {
+            case 0:
+                break;
+            case 1:
+            case 2:
+            case 3:
+            case 4:
+                shardSize = randomInt();
+                break;
+            default:
+                fail();
+            }
+            factory.bucketCountThresholds().setShardSize(shardSize);
+        }
+        if (randomBoolean()) {
+            int minDocCount = randomInt(4);
+            switch (minDocCount) {
+            case 0:
+                break;
+            case 1:
+            case 2:
+            case 3:
+            case 4:
+                minDocCount = randomInt();
+                break;
+            }
+            factory.bucketCountThresholds().setMinDocCount(minDocCount);
+        }
+        if (randomBoolean()) {
+            int shardMinDocCount = randomInt(4);
+            switch (shardMinDocCount) {
+            case 0:
+                break;
+            case 1:
+            case 2:
+            case 3:
+            case 4:
+                shardMinDocCount = randomInt();
+                break;
+            default:
+                fail();
+            }
+            factory.bucketCountThresholds().setShardMinDocCount(shardMinDocCount);
+        }
+        if (randomBoolean()) {
+            factory.executionHint(randomFrom(executionHints));
+        }
+        if (randomBoolean()) {
+            factory.format("###.##");
+        }
+        if (randomBoolean()) {
+            IncludeExclude incExc = null;
+            switch (randomInt(5)) {
+            case 0:
+                incExc = new IncludeExclude(new RegExp("foobar"), null);
+                break;
+            case 1:
+                incExc = new IncludeExclude(null, new RegExp("foobaz"));
+                break;
+            case 2:
+                incExc = new IncludeExclude(new RegExp("foobar"), new RegExp("foobaz"));
+                break;
+            case 3:
+                SortedSet<BytesRef> includeValues = new TreeSet<>();
+                int numIncs = randomIntBetween(1, 20);
+                for (int i = 0; i < numIncs; i++) {
+                    includeValues.add(new BytesRef(randomAsciiOfLengthBetween(1, 30)));
+                }
+                SortedSet<BytesRef> excludeValues = null;
+                incExc = new IncludeExclude(includeValues, excludeValues);
+                break;
+            case 4:
+                SortedSet<BytesRef> includeValues2 = null;
+                SortedSet<BytesRef> excludeValues2 = new TreeSet<>();
+                int numExcs2 = randomIntBetween(1, 20);
+                for (int i = 0; i < numExcs2; i++) {
+                    excludeValues2.add(new BytesRef(randomAsciiOfLengthBetween(1, 30)));
+                }
+                incExc = new IncludeExclude(includeValues2, excludeValues2);
+                break;
+            case 5:
+                SortedSet<BytesRef> includeValues3 = new TreeSet<>();
+                int numIncs3 = randomIntBetween(1, 20);
+                for (int i = 0; i < numIncs3; i++) {
+                    includeValues3.add(new BytesRef(randomAsciiOfLengthBetween(1, 30)));
+                }
+                SortedSet<BytesRef> excludeValues3 = new TreeSet<>();
+                int numExcs3 = randomIntBetween(1, 20);
+                for (int i = 0; i < numExcs3; i++) {
+                    excludeValues3.add(new BytesRef(randomAsciiOfLengthBetween(1, 30)));
+                }
+                incExc = new IncludeExclude(includeValues3, excludeValues3);
+                break;
+            default:
+                fail();
+            }
+            factory.includeExclude(incExc);
+        }
+        if (randomBoolean()) {
+            SignificanceHeuristic significanceHeuristic = null;
+            switch (randomInt(5)) {
+            case 0:
+                significanceHeuristic = PercentageScore.PROTOTYPE;
+                break;
+            case 1:
+                significanceHeuristic = new ChiSquare(randomBoolean(), randomBoolean());
+                break;
+            case 2:
+                significanceHeuristic = new GND(randomBoolean());
+                break;
+            case 3:
+                significanceHeuristic = new MutualInformation(randomBoolean(), randomBoolean());
+                break;
+            case 4:
+                significanceHeuristic = new ScriptHeuristic(new Script("foo"));
+                break;
+            case 5:
+                significanceHeuristic = JLHScore.PROTOTYPE;
+                break;
+            default:
+                fail();
+            }
+            factory.significanceHeuristic(significanceHeuristic);
+        }
+        if (randomBoolean()) {
+            factory.backgroundFilter(QueryBuilders.termsQuery("foo", "bar"));
+        }
+        return factory;
+    }
+
+}
diff --git a/core/src/test/java/org/elasticsearch/search/aggregations/bucket/TermsTests.java b/core/src/test/java/org/elasticsearch/search/aggregations/bucket/TermsTests.java
new file mode 100644
index 0000000000..fb57b6d1b2
--- /dev/null
+++ b/core/src/test/java/org/elasticsearch/search/aggregations/bucket/TermsTests.java
@@ -0,0 +1,232 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.search.aggregations.bucket;
+
+import org.apache.lucene.util.BytesRef;
+import org.apache.lucene.util.automaton.RegExp;
+import org.elasticsearch.script.Script;
+import org.elasticsearch.search.aggregations.Aggregator.SubAggCollectionMode;
+import org.elasticsearch.search.aggregations.BaseAggregationTestCase;
+import org.elasticsearch.search.aggregations.bucket.terms.Terms;
+import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregatorFactory;
+import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregatorFactory.ExecutionMode;
+import org.elasticsearch.search.aggregations.bucket.terms.support.IncludeExclude;
+import org.elasticsearch.search.aggregations.support.ValuesSourceType;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.SortedSet;
+import java.util.TreeSet;
+
+public class TermsTests extends BaseAggregationTestCase<TermsAggregatorFactory> {
+
+    private static final String[] executionHints;
+
+    static {
+        ExecutionMode[] executionModes = ExecutionMode.values();
+        executionHints = new String[executionModes.length];
+        for (int i = 0; i < executionModes.length; i++) {
+            executionHints[i] = executionModes[i].toString();
+        }
+    }
+
+    @Override
+    protected TermsAggregatorFactory createTestAggregatorFactory() {
+        String name = randomAsciiOfLengthBetween(3, 20);
+        TermsAggregatorFactory factory = new TermsAggregatorFactory(name, ValuesSourceType.ANY, null);
+        String field = randomAsciiOfLengthBetween(3, 20);
+        int randomFieldBranch = randomInt(2);
+        switch (randomFieldBranch) {
+        case 0:
+            factory.field(field);
+            break;
+        case 1:
+            factory.field(field);
+            factory.script(new Script("_value + 1"));
+            break;
+        case 2:
+            factory.script(new Script("doc[" + field + "] + 1"));
+            break;
+        default:
+            fail();
+        }
+        if (randomBoolean()) {
+            factory.missing("MISSING");
+        }
+        if (randomBoolean()) {
+            int size = randomInt(4);
+            switch (size) {
+            case 0:
+                break;
+            case 1:
+            case 2:
+            case 3:
+            case 4:
+                size = randomInt();
+                break;
+            default:
+                fail();
+            }
+            factory.bucketCountThresholds().setRequiredSize(size);
+
+        }
+        if (randomBoolean()) {
+            int shardSize = randomInt(4);
+            switch (shardSize) {
+            case 0:
+                break;
+            case 1:
+            case 2:
+            case 3:
+            case 4:
+                shardSize = randomInt();
+                break;
+            default:
+                fail();
+            }
+            factory.bucketCountThresholds().setShardSize(shardSize);
+        }
+        if (randomBoolean()) {
+            int minDocCount = randomInt(4);
+            switch (minDocCount) {
+            case 0:
+                break;
+            case 1:
+            case 2:
+            case 3:
+            case 4:
+                minDocCount = randomInt();
+                break;
+            default:
+                fail();
+            }
+            factory.bucketCountThresholds().setMinDocCount(minDocCount);
+        }
+        if (randomBoolean()) {
+            int shardMinDocCount = randomInt(4);
+            switch (shardMinDocCount) {
+            case 0:
+                break;
+            case 1:
+            case 2:
+            case 3:
+            case 4:
+                shardMinDocCount = randomInt();
+                break;
+            default:
+                fail();
+            }
+            factory.bucketCountThresholds().setShardMinDocCount(shardMinDocCount);
+        }
+        if (randomBoolean()) {
+            factory.collectMode(randomFrom(SubAggCollectionMode.values()));
+        }
+        if (randomBoolean()) {
+            factory.executionHint(randomFrom(executionHints));
+        }
+        if (randomBoolean()) {
+            factory.format("###.##");
+        }
+        if (randomBoolean()) {
+            IncludeExclude incExc = null;
+            switch (randomInt(5)) {
+            case 0:
+                incExc = new IncludeExclude(new RegExp("foobar"), null);
+                break;
+            case 1:
+                incExc = new IncludeExclude(null, new RegExp("foobaz"));
+                break;
+            case 2:
+                incExc = new IncludeExclude(new RegExp("foobar"), new RegExp("foobaz"));
+                break;
+            case 3:
+                SortedSet<BytesRef> includeValues = new TreeSet<>();
+                int numIncs = randomIntBetween(1, 20);
+                for (int i = 0; i < numIncs; i++) {
+                    includeValues.add(new BytesRef(randomAsciiOfLengthBetween(1, 30)));
+                }
+                SortedSet<BytesRef> excludeValues = null;
+                incExc = new IncludeExclude(includeValues, excludeValues);
+                break;
+            case 4:
+                SortedSet<BytesRef> includeValues2 = null;
+                SortedSet<BytesRef> excludeValues2 = new TreeSet<>();
+                int numExcs2 = randomIntBetween(1, 20);
+                for (int i = 0; i < numExcs2; i++) {
+                    excludeValues2.add(new BytesRef(randomAsciiOfLengthBetween(1, 30)));
+                }
+                incExc = new IncludeExclude(includeValues2, excludeValues2);
+                break;
+            case 5:
+                SortedSet<BytesRef> includeValues3 = new TreeSet<>();
+                int numIncs3 = randomIntBetween(1, 20);
+                for (int i = 0; i < numIncs3; i++) {
+                    includeValues3.add(new BytesRef(randomAsciiOfLengthBetween(1, 30)));
+                }
+                SortedSet<BytesRef> excludeValues3 = new TreeSet<>();
+                int numExcs3 = randomIntBetween(1, 20);
+                for (int i = 0; i < numExcs3; i++) {
+                    excludeValues3.add(new BytesRef(randomAsciiOfLengthBetween(1, 30)));
+                }
+                incExc = new IncludeExclude(includeValues3, excludeValues3);
+                break;
+            default:
+                fail();
+            }
+            factory.includeExclude(incExc);
+        }
+        if (randomBoolean()) {
+            List<Terms.Order> order = randomOrder();
+            factory.order(order);
+        }
+        if (randomBoolean()) {
+            factory.showTermDocCountError(randomBoolean());
+        }
+        return factory;
+    }
+
+    private List<Terms.Order> randomOrder() {
+        List<Terms.Order> orders = new ArrayList<>();
+        switch (randomInt(4)) {
+        case 0:
+            orders.add(Terms.Order.term(randomBoolean()));
+            break;
+        case 1:
+            orders.add(Terms.Order.count(randomBoolean()));
+            break;
+        case 2:
+            orders.add(Terms.Order.aggregation(randomAsciiOfLengthBetween(3, 20), randomBoolean()));
+            break;
+        case 3:
+            orders.add(Terms.Order.aggregation(randomAsciiOfLengthBetween(3, 20), randomAsciiOfLengthBetween(3, 20), randomBoolean()));
+            break;
+        case 4:
+            int numOrders = randomIntBetween(1, 3);
+            for (int i = 0; i < numOrders; i++) {
+                orders.addAll(randomOrder());
+            }
+            break;
+        default:
+            fail();
+        }
+        return orders;
+    }
+
+}
diff --git a/core/src/test/java/org/elasticsearch/search/aggregations/bucket/significant/SignificanceHeuristicTests.java b/core/src/test/java/org/elasticsearch/search/aggregations/bucket/significant/SignificanceHeuristicTests.java
index 0fe9113e8f..166efe27a3 100644
--- a/core/src/test/java/org/elasticsearch/search/aggregations/bucket/significant/SignificanceHeuristicTests.java
+++ b/core/src/test/java/org/elasticsearch/search/aggregations/bucket/significant/SignificanceHeuristicTests.java
@@ -22,11 +22,14 @@ import org.apache.lucene.util.BytesRef;
 import org.elasticsearch.ElasticsearchParseException;
 import org.elasticsearch.Version;
 import org.elasticsearch.common.io.stream.InputStreamStreamInput;
+import org.elasticsearch.common.io.stream.NamedWriteableRegistry;
 import org.elasticsearch.common.io.stream.OutputStreamStreamOutput;
+import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.common.xcontent.json.JsonXContent;
+import org.elasticsearch.indices.query.IndicesQueriesRegistry;
 import org.elasticsearch.search.SearchShardTarget;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.InternalAggregations;
@@ -127,7 +130,7 @@ public class SignificanceHeuristicTests extends ESTestCase {
 
     SignificanceHeuristic getRandomSignificanceheuristic() {
         List<SignificanceHeuristic> heuristics = new ArrayList<>();
-        heuristics.add(JLHScore.INSTANCE);
+        heuristics.add(JLHScore.PROTOTYPE);
         heuristics.add(new MutualInformation(randomBoolean(), randomBoolean()));
         heuristics.add(new GND(randomBoolean()));
         heuristics.add(new ChiSquare(randomBoolean(), randomBoolean()));
@@ -227,11 +230,14 @@ public class SignificanceHeuristicTests extends ESTestCase {
         checkParseException(heuristicParserMapper, searchContext, faultyHeuristicdefinition, expectedError);
     }
 
-    protected void checkParseException(SignificanceHeuristicParserMapper heuristicParserMapper, SearchContext searchContext, String faultyHeuristicDefinition, String expectedError) throws IOException {
+    protected void checkParseException(SignificanceHeuristicParserMapper heuristicParserMapper, SearchContext searchContext,
+            String faultyHeuristicDefinition, String expectedError) throws IOException {
+
+        IndicesQueriesRegistry registry = new IndicesQueriesRegistry(Settings.EMPTY, new HashSet<>(), new NamedWriteableRegistry());
         try {
             XContentParser stParser = JsonXContent.jsonXContent.createParser("{\"field\":\"text\", " + faultyHeuristicDefinition + ",\"min_doc_count\":200}");
             stParser.nextToken();
-            new SignificantTermsParser(heuristicParserMapper).parse("testagg", stParser, searchContext);
+            new SignificantTermsParser(heuristicParserMapper, registry).parse("testagg", stParser, searchContext);
             fail();
         } catch (ElasticsearchParseException e) {
             assertTrue(e.getMessage().contains(expectedError));
@@ -247,9 +253,12 @@ public class SignificanceHeuristicTests extends ESTestCase {
         return parseSignificanceHeuristic(heuristicParserMapper, searchContext, stParser);
     }
 
-    private SignificanceHeuristic parseSignificanceHeuristic(SignificanceHeuristicParserMapper heuristicParserMapper, SearchContext searchContext, XContentParser stParser) throws IOException {
+    private SignificanceHeuristic parseSignificanceHeuristic(SignificanceHeuristicParserMapper heuristicParserMapper,
+            SearchContext searchContext, XContentParser stParser) throws IOException {
+        IndicesQueriesRegistry registry = new IndicesQueriesRegistry(Settings.EMPTY, new HashSet<>(), new NamedWriteableRegistry());
         stParser.nextToken();
-        SignificantTermsAggregatorFactory aggregatorFactory = (SignificantTermsAggregatorFactory) new SignificantTermsParser(heuristicParserMapper).parse("testagg", stParser, searchContext);
+        SignificantTermsAggregatorFactory aggregatorFactory = (SignificantTermsAggregatorFactory) new SignificantTermsParser(
+                heuristicParserMapper, registry).parse("testagg", stParser, searchContext);
         stParser.nextToken();
         assertThat(aggregatorFactory.getBucketCountThresholds().getMinDocCount(), equalTo(200l));
         assertThat(stParser.currentToken(), equalTo(null));
@@ -365,14 +374,14 @@ public class SignificanceHeuristicTests extends ESTestCase {
         testBackgroundAssertions(new MutualInformation(true, true), new MutualInformation(true, false));
         testBackgroundAssertions(new ChiSquare(true, true), new ChiSquare(true, false));
         testBackgroundAssertions(new GND(true), new GND(false));
-        testAssertions(PercentageScore.INSTANCE);
-        testAssertions(JLHScore.INSTANCE);
+        testAssertions(PercentageScore.PROTOTYPE);
+        testAssertions(JLHScore.PROTOTYPE);
     }
 
     public void testBasicScoreProperties() {
-        basicScoreProperties(JLHScore.INSTANCE, true);
+        basicScoreProperties(JLHScore.PROTOTYPE, true);
         basicScoreProperties(new GND(true), true);
-        basicScoreProperties(PercentageScore.INSTANCE, true);
+        basicScoreProperties(PercentageScore.PROTOTYPE, true);
         basicScoreProperties(new MutualInformation(true, true), false);
         basicScoreProperties(new ChiSquare(true, true), false);
     }
diff --git a/core/src/test/java/org/elasticsearch/test/search/aggregations/bucket/SharedSignificantTermsTestMethods.java b/core/src/test/java/org/elasticsearch/test/search/aggregations/bucket/SharedSignificantTermsTestMethods.java
index 1df965968a..a120b63c82 100644
--- a/core/src/test/java/org/elasticsearch/test/search/aggregations/bucket/SharedSignificantTermsTestMethods.java
+++ b/core/src/test/java/org/elasticsearch/test/search/aggregations/bucket/SharedSignificantTermsTestMethods.java
@@ -57,13 +57,9 @@ public class SharedSignificantTermsTestMethods {
     }
 
     private static void checkSignificantTermsAggregationCorrect(ESIntegTestCase testCase) {
-
-        SearchResponse response = client().prepareSearch(INDEX_NAME).setTypes(DOC_TYPE)
-                .addAggregation(new TermsBuilder("class").field(CLASS_FIELD).subAggregation(
-                        new SignificantTermsBuilder("sig_terms")
-                                .field(TEXT_FIELD)))
-                .execute()
-                .actionGet();
+        SearchResponse response = client().prepareSearch(INDEX_NAME).setTypes(DOC_TYPE).addAggregation(
+                new TermsBuilder("class").field(CLASS_FIELD).subAggregation(new SignificantTermsBuilder("sig_terms").field(TEXT_FIELD)))
+                .execute().actionGet();
         assertSearchResponse(response);
         StringTerms classes = response.getAggregations().get("class");
         Assert.assertThat(classes.getBuckets().size(), equalTo(2));