iter

Author: lkts

server/src/main/java/module-info.java

@@ -55,6 +55,7 @@
     requires org.apache.lucene.queryparser;
     requires org.apache.lucene.sandbox;
     requires org.apache.lucene.suggest;
+    requires org.elasticsearch.server;
 
     exports org.elasticsearch;
     exports org.elasticsearch.action;

server/src/main/java/org/elasticsearch/action/search/TransportSearchAction.java

@@ -41,6 +41,7 @@
 import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver.ResolvedExpression;
+import org.elasticsearch.cluster.metadata.IndexReshardingMetadata;
 import org.elasticsearch.cluster.metadata.ProjectMetadata;
 import org.elasticsearch.cluster.node.DiscoveryNode;
 import org.elasticsearch.cluster.node.DiscoveryNodes;
@@ -1243,7 +1244,9 @@ static List<SearchShardIterator> getRemoteShardsIterator(
                     null,
                     searchShardsGroup.preFiltered(),
                     searchShardsGroup.skipped(),
-                    0 // TODO
+                    // This parameter is specific to the resharding feature.
+                    // Resharding is currently not supported with CCS.
+                    IndexReshardingMetadata.NOOP_RESHARD_SPLIT_SHARD_COUNT_SUMMARY
                 );
                 remoteShardIterators.add(shardIterator);
             }
@@ -1297,7 +1300,9 @@ static List<SearchShardIterator> getRemoteShardsIteratorFromPointInTime(
                     searchContextKeepAlive,
                     false,
                     false,
-                    0 // TODO
+                    // This parameter is specific to the resharding feature.
+                    // Resharding is currently not supported with CCS.
+                    IndexReshardingMetadata.NOOP_RESHARD_SPLIT_SHARD_COUNT_SUMMARY
                 );
                 remoteShardIterators.add(shardIterator);
             }
@@ -1980,7 +1985,15 @@ static List<SearchShardIterator> getLocalShardsIteratorFromPointInTime(
                         keepAlive,
                         false,
                         false,
-                        0 // TODO
+                        // This parameter is specific to the resharding feature.
+                        // It is used when creating a searcher to apply filtering needed to have correct search results
+                        // while resharding is in progress.
+                        // In context of PIT the searcher is reused or can be recreated only in read-only scenarios.
+                        // If a searcher is reused, this value won't be used
+                        // (it was calculated and used when PIT was created).
+                        // In read-only scenarios (e.g. searchable snapshots) we don't expect resharding to happen
+                        // so the value doesn't matter.
+                        IndexReshardingMetadata.NOOP_RESHARD_SPLIT_SHARD_COUNT_SUMMARY
                     )
                 );
             }
@@ -2005,7 +2018,7 @@ List<SearchShardIterator> getLocalShardsIterator(
             searchRequest.routing(),
             searchRequest.indices()
         );
-        List<SearchShardRouting> shardRoutings = clusterService.operationRouting()
+        List<SearchShardRouting> searchShards = clusterService.operationRouting()
             .searchShards(
                 projectState,
                 concreteIndices,
@@ -2020,18 +2033,19 @@ List<SearchShardIterator> getLocalShardsIterator(
             concreteIndices,
             searchRequest.indicesOptions()
         );
-        SearchShardIterator[] list = new SearchShardIterator[shardRoutings.size()];
+        SearchShardIterator[] list = new SearchShardIterator[searchShards.size()];
         int i = 0;
-        for (SearchShardRouting shardRouting : shardRoutings) {
-            final ShardId shardId = shardRouting.iterator().shardId();
+        for (SearchShardRouting shardInfo : searchShards) {
+            ShardIterator iterator = shardInfo.iterator();
+            final ShardId shardId = iterator.shardId();
             OriginalIndices finalIndices = originalIndices.get(shardId.getIndex().getName());
             assert finalIndices != null;
             list[i++] = new SearchShardIterator(
                 clusterAlias,
                 shardId,
-                shardRouting.iterator().getShardRoutings(),
+                iterator.getShardRoutings(),
                 finalIndices,
-                shardRouting.reshardSplitShardCountSummary()
+                shardInfo.reshardSplitShardCountSummary()
             );
         }
         // the returned list must support in-place sorting, so this is the most memory efficient we can do here

server/src/main/java/org/elasticsearch/cluster/metadata/IndexReshardingMetadata.java

@@ -89,6 +89,12 @@
  * to beginning another resharding operation.
  */
 public class IndexReshardingMetadata implements ToXContentFragment, Writeable {
+    /**
+     * A value of `reshardSplitShardCountSummary` ({@link IndexMetadata#getReshardSplitShardCountSummaryForSearch(int)})
+     * that is used when it is known that this value won't affect the correctness of the operation.
+     */
+    public static int NOOP_RESHARD_SPLIT_SHARD_COUNT_SUMMARY = 0;
+
     private static final String SPLIT_FIELD_NAME = "split";
     private static final ParseField SPLIT_FIELD = new ParseField(SPLIT_FIELD_NAME);
     // This exists only so that tests can verify that IndexReshardingMetadata supports more than one kind of operation.

server/src/main/java/org/elasticsearch/search/internal/ShardSearchRequest.java

@@ -19,6 +19,7 @@
 import org.elasticsearch.action.support.IndicesOptions;
 import org.elasticsearch.cluster.metadata.AliasMetadata;
 import org.elasticsearch.cluster.metadata.IndexMetadata;
+import org.elasticsearch.cluster.metadata.IndexReshardingMetadata;
 import org.elasticsearch.common.CheckedBiConsumer;
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.bytes.BytesArray;
@@ -233,8 +234,10 @@ public ShardSearchRequest(ShardId shardId, long nowInMillis, AliasFilter aliasFi
             SequenceNumbers.UNASSIGNED_SEQ_NO,
             SearchService.NO_TIMEOUT,
             false,
-            // TODO (resharding) take as a parameter
-            0
+            // This parameter is specific to the resharding feature.
+            // TODO
+            // It is currently only supported in _search API and is stubbed here as a result.
+            IndexReshardingMetadata.NOOP_RESHARD_SPLIT_SHARD_COUNT_SUMMARY
         );
     }