PR feedback.

Signed-off-by: Marc Handalian <handalm@amazon.com>

server/src/internalClusterTest/java/org/opensearch/indices/replication/SegmentReplicationIT.java

@@ -1419,4 +1419,23 @@ public void testIndexWhileRecoveringReplica() throws Exception {
             .get();
         assertNoFailures(response);
     }
+
+    public void testRestartPrimary_NoReplicas() throws Exception {
+        final String primary = internalCluster().startDataOnlyNode();
+        createIndex(INDEX_NAME);
+        ensureYellow(INDEX_NAME);
+
+        assertEquals(getNodeContainingPrimaryShard().getName(), primary);
+
+        client().prepareIndex(INDEX_NAME).setId("1").setSource("foo", "bar").setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE).get();
+        if (randomBoolean()) {
+            flush(INDEX_NAME);
+        } else {
+            refresh(INDEX_NAME);
+        }
+
+        internalCluster().restartNode(primary);
+        ensureYellow(INDEX_NAME);
+        assertDocCounts(1, primary);
+    }
 }

server/src/internalClusterTest/java/org/opensearch/remotestore/SegmentReplicationUsingRemoteStoreIT.java

@@ -10,7 +10,6 @@
 
 import org.junit.After;
 import org.junit.Before;
-import org.opensearch.action.support.WriteRequest;
 import org.opensearch.common.settings.Settings;
 import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.indices.replication.SegmentReplicationIT;
@@ -68,23 +67,4 @@ public void teardown() {
     public void testPressureServiceStats() throws Exception {
         super.testPressureServiceStats();
     }
-
-    public void testRestartPrimary_NoReplicas() throws Exception {
-        final String primary = internalCluster().startDataOnlyNode();
-        createIndex(INDEX_NAME);
-        ensureYellow(INDEX_NAME);
-
-        assertEquals(getNodeContainingPrimaryShard().getName(), primary);
-
-        client().prepareIndex(INDEX_NAME).setId("1").setSource("foo", "bar").setRefreshPolicy(WriteRequest.RefreshPolicy.IMMEDIATE).get();
-        if (randomBoolean()) {
-            flush(INDEX_NAME);
-        } else {
-            refresh(INDEX_NAME);
-        }
-
-        internalCluster().restartNode(primary);
-        ensureYellow(INDEX_NAME);
-        assertDocCounts(1, primary);
-    }
 }

server/src/main/java/org/opensearch/index/engine/NRTReplicationEngine.java

@@ -394,6 +394,8 @@ protected final void closeNoLock(String reason, CountDownLatch closedLatch) {
                  This is a workaround solution which decreases the chances of conflict on replica nodes when same file is copied
                  from two different primaries during failover. Increasing counter helps in avoiding this conflict as counter is
                  used to generate new segment file names. The ideal solution is to identify the counter from previous primary.
+                 This is not required for remote store implementations given on failover the replica re-syncs with the store
+                 during promotion.
                  */
                 if (engineConfig.getIndexSettings().isRemoteStoreEnabled() == false) {
                     latestSegmentInfos.counter = latestSegmentInfos.counter + SI_COUNTER_INCREMENT;

server/src/main/java/org/opensearch/indices/replication/RemoteStoreReplicationSource.java

@@ -61,8 +61,9 @@ public void getCheckpointMetadata(
         // TODO: Need to figure out a way to pass this information for segment metadata via remote store.
         try (final GatedCloseable<SegmentInfos> segmentInfosSnapshot = indexShard.getSegmentInfosSnapshot()) {
             final Version version = segmentInfosSnapshot.get().getCommitLuceneVersion();
-            RemoteSegmentMetadata mdFile = remoteDirectory.init();            // During initial recovery flow, the remote store might not
-                                                                              // have metadata as primary hasn't uploaded anything yet.
+            RemoteSegmentMetadata mdFile = remoteDirectory.init();
+            // During initial recovery flow, the remote store might not
+            // have metadata as primary hasn't uploaded anything yet.
             if (mdFile == null && indexShard.state().equals(IndexShardState.STARTED) == false) {
                 listener.onResponse(new CheckpointInfoResponse(checkpoint, Collections.emptyMap(), null));
                 return;

server/src/test/java/org/opensearch/index/shard/RemoteIndexShardTests.java

@@ -252,33 +252,6 @@ public void testReplicaCommitsInfosBytesOnRecovery() throws Exception {
         }
     }
 
-    public void testPrimaryRestart() throws Exception {
-        final Path remotePath = createTempDir();
-        try (ReplicationGroup shards = createGroup(0, getIndexSettings(), indexMapping, new NRTReplicationEngineFactory(), remotePath)) {
-            shards.startAll();
-            // ensure primary has uploaded something
-            shards.indexDocs(10);
-            IndexShard primary = shards.getPrimary();
-            if (randomBoolean()) {
-                flushShard(primary);
-            } else {
-                primary.refresh("test");
-            }
-            assertDocCount(primary, 10);
-            // get a metadata map - we'll use segrep diff to ensure segments on reader are identical after restart.
-            final Map<String, StoreFileMetadata> metadataBeforeRestart = primary.getSegmentMetadataMap();
-            // restart the primary
-            shards.reinitPrimaryShard(remotePath);
-            // the store is open at this point but the shard has not yet run through recovery
-            primary = shards.getPrimary();
-            shards.startPrimary();
-            assertDocCount(primary, 10);
-            final Store.RecoveryDiff diff = Store.segmentReplicationDiff(metadataBeforeRestart, primary.getSegmentMetadataMap());
-            assertTrue(diff.missing.isEmpty());
-            assertTrue(diff.different.isEmpty());
-        }
-    }
-
     public void testPrimaryRestart_PrimaryHasExtraCommits() throws Exception {
         final Path remotePath = createTempDir();
         try (ReplicationGroup shards = createGroup(0, getIndexSettings(), indexMapping, new NRTReplicationEngineFactory(), remotePath)) {

server/src/test/java/org/opensearch/index/shard/SegmentReplicationIndexShardTests.java

@@ -62,6 +62,7 @@
 import org.opensearch.transport.TransportService;
 
 import java.io.IOException;
+import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -774,6 +775,33 @@ public void testNoDuplicateSeqNo() throws Exception {
         }
     }
 
+    public void testPrimaryRestart() throws Exception {
+        final Path remotePath = createTempDir();
+        try (ReplicationGroup shards = createGroup(0, getIndexSettings(), indexMapping, new NRTReplicationEngineFactory(), remotePath)) {
+            shards.startAll();
+            // ensure primary has uploaded something
+            shards.indexDocs(10);
+            IndexShard primary = shards.getPrimary();
+            if (randomBoolean()) {
+                flushShard(primary);
+            } else {
+                primary.refresh("test");
+            }
+            assertDocCount(primary, 10);
+            // get a metadata map - we'll use segrep diff to ensure segments on reader are identical after restart.
+            final Map<String, StoreFileMetadata> metadataBeforeRestart = primary.getSegmentMetadataMap();
+            // restart the primary
+            shards.reinitPrimaryShard(remotePath);
+            // the store is open at this point but the shard has not yet run through recovery
+            primary = shards.getPrimary();
+            shards.startPrimary();
+            assertDocCount(primary, 10);
+            final Store.RecoveryDiff diff = Store.segmentReplicationDiff(metadataBeforeRestart, primary.getSegmentMetadataMap());
+            assertTrue(diff.missing.isEmpty());
+            assertTrue(diff.different.isEmpty());
+        }
+    }
+
     /**
      * Assert persisted and searchable doc counts.  This method should not be used while docs are concurrently indexed because
      * it asserts point in time seqNos are relative to the doc counts.