Remove single shard optimization when suggesting shard_size

server/src/main/java/org/elasticsearch/search/aggregations/bucket/BucketUtils.java

@@ -31,18 +31,12 @@ private BucketUtils() {}
      * 
      * @param finalSize
      *            The number of terms required in the final reduce phase.
-     * @param singleShard
-     *            whether a single shard is being queried, or multiple shards
      * @return A suggested default for the size of any shard-side PriorityQueues
      */
-    public static int suggestShardSideQueueSize(int finalSize, boolean singleShard) {
+    public static int suggestShardSideQueueSize(int finalSize) {
         if (finalSize < 1) {
             throw new IllegalArgumentException("size must be positive, got " + finalSize);
         }
-        if (singleShard) {
-            // In the case of a single shard, we do not need to over-request
-            return finalSize;
-        }
         // Request 50% more buckets on the shards in order to improve accuracy
         // as well as a small constant that should help with small values of 'size'
         final long shardSampleSize = (long) (finalSize * 1.5 + 10);

server/src/main/java/org/elasticsearch/search/aggregations/bucket/geogrid/GeoGridAggregationBuilder.java

@@ -157,7 +157,7 @@ public int shardSize() {
         if (shardSize < 0) {
             // Use default heuristic to avoid any wrong-ranking caused by
             // distributed counting
-            shardSize = BucketUtils.suggestShardSideQueueSize(requiredSize, context.numberOfShards() == 1);
+            shardSize = BucketUtils.suggestShardSideQueueSize(requiredSize);
         }
 
         if (requiredSize <= 0 || shardSize <= 0) {

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

@@ -195,8 +195,7 @@ protected Aggregator doCreateInternal(ValuesSource valuesSource, Aggregator pare
             // 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() == 1));
+            bucketCountThresholds.setShardSize(2 * BucketUtils.suggestShardSideQueueSize(bucketCountThresholds.getRequiredSize()));
         }
 
         if (valuesSource instanceof ValuesSource.Bytes) {

server/src/main/java/org/elasticsearch/search/aggregations/bucket/significant/SignificantTextAggregatorFactory.java

@@ -175,8 +175,7 @@ protected Aggregator createInternal(Aggregator parent, boolean collectsFromSingl
             // 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() == 1));
+            bucketCountThresholds.setShardSize(2 * BucketUtils.suggestShardSideQueueSize(bucketCountThresholds.getRequiredSize()));
         }
 
 //        TODO - need to check with mapping that this is indeed a text field....

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

@@ -121,8 +121,7 @@ protected Aggregator doCreateInternal(ValuesSource valuesSource, Aggregator pare
             // 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() == 1));
+            bucketCountThresholds.setShardSize(BucketUtils.suggestShardSideQueueSize(bucketCountThresholds.getRequiredSize()));
         }
         bucketCountThresholds.ensureValidity();
         if (valuesSource instanceof ValuesSource.Bytes) {

server/src/test/java/org/elasticsearch/search/aggregations/bucket/BucketUtilsTests.java

@@ -27,31 +27,22 @@ public class BucketUtilsTests extends ESTestCase {
 
     public void testBadInput() {
         IllegalArgumentException e = expectThrows(IllegalArgumentException.class,
-                () -> BucketUtils.suggestShardSideQueueSize(0, randomBoolean()));
+                () -> BucketUtils.suggestShardSideQueueSize(0));
         assertEquals(e.getMessage(), "size must be positive, got 0");
     }
 
-    public void testOptimizesSingleShard() {
-        for (int iter = 0; iter < 10; ++iter) {
-            final int size = randomIntBetween(1, Integer.MAX_VALUE);
-            assertEquals(size, BucketUtils.suggestShardSideQueueSize( size, true));
-        }
-    }
-
     public void testOverFlow() {
         for (int iter = 0; iter < 10; ++iter) {
             final int size = Integer.MAX_VALUE - randomInt(10);
-            final int numberOfShards = randomIntBetween(1, 10);
-            final int shardSize = BucketUtils.suggestShardSideQueueSize( size, numberOfShards == 1);
+            final int shardSize = BucketUtils.suggestShardSideQueueSize( size);
             assertThat(shardSize, greaterThanOrEqualTo(shardSize));
         }
     }
 
     public void testShardSizeIsGreaterThanGlobalSize() {
         for (int iter = 0; iter < 10; ++iter) {
             final int size = randomIntBetween(1, Integer.MAX_VALUE);
-            final int numberOfShards = randomIntBetween(1, 10);
-            final int shardSize = BucketUtils.suggestShardSideQueueSize( size, numberOfShards == 1);
+            final int shardSize = BucketUtils.suggestShardSideQueueSize( size);
             assertThat(shardSize, greaterThanOrEqualTo(size));
         }
     }