Fix assertion failures in creation and deletion of remote store backe…

…d index (opensearch-project#5918) (opensearch-project#6039)

* Fix failures in creation and deletion of remote store backed index
Signed-off-by: Sachin Kale <kalsac@amazon.com>
(cherry picked from commit 4f6ac34)
Signed-off-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

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

@@ -0,0 +1,80 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.remotestore;
+
+import org.opensearch.cluster.metadata.IndexMetadata;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.common.util.FeatureFlags;
+import org.opensearch.index.IndexModule;
+import org.opensearch.indices.replication.common.ReplicationType;
+import org.opensearch.plugins.Plugin;
+import org.opensearch.test.OpenSearchIntegTestCase;
+import org.opensearch.test.transport.MockTransportService;
+
+import java.nio.file.Path;
+import java.util.Arrays;
+import java.util.Collection;
+
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
+
+@OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST, numDataNodes = 0)
+public class RemoteStoreIT extends OpenSearchIntegTestCase {
+
+    private static final String REPOSITORY_NAME = "test-remore-store-repo";
+    private static final String INDEX_NAME = "remote-store-test-idx-1";
+    protected static final int SHARD_COUNT = 1;
+    protected static final int REPLICA_COUNT = 1;
+
+    @Override
+    protected Collection<Class<? extends Plugin>> nodePlugins() {
+        return Arrays.asList(MockTransportService.TestPlugin.class);
+    }
+
+    @Override
+    public Settings indexSettings() {
+        return Settings.builder()
+            .put(super.indexSettings())
+            .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, SHARD_COUNT)
+            .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, REPLICA_COUNT)
+            .put(IndexModule.INDEX_QUERY_CACHE_ENABLED_SETTING.getKey(), false)
+            .put(IndexMetadata.SETTING_REPLICATION_TYPE, ReplicationType.SEGMENT)
+            .put(IndexMetadata.SETTING_REMOTE_STORE_ENABLED, true)
+            .put(IndexMetadata.SETTING_REMOTE_STORE_REPOSITORY, REPOSITORY_NAME)
+            .build();
+    }
+
+    @Override
+    protected boolean addMockInternalEngine() {
+        return false;
+    }
+
+    @Override
+    protected Settings featureFlagSettings() {
+        return Settings.builder()
+            .put(super.featureFlagSettings())
+            .put(FeatureFlags.REPLICATION_TYPE, "true")
+            .put(FeatureFlags.REMOTE_STORE, "true")
+            .build();
+    }
+
+    // This is a dummy test to check if create index flow is working as expected.
+    // As index creation is pre-requisite for each integration test in this class, once we add more integ tests,
+    // we can remove this test.
+    public void testIndexCreation() {
+        internalCluster().startNode();
+
+        Path absolutePath = randomRepoPath().toAbsolutePath();
+        assertAcked(
+            clusterAdmin().preparePutRepository(REPOSITORY_NAME).setType("fs").setSettings(Settings.builder().put("location", absolutePath))
+        );
+
+        createIndex(INDEX_NAME);
+        ensureYellowAndNoInitializingShards(INDEX_NAME);
+    }
+}

server/src/main/java/org/opensearch/index/shard/IndexShard.java

@@ -1725,8 +1725,7 @@ public void close(String reason, boolean flushEngine) throws IOException {
                 } finally {
                     // playing safe here and close the engine even if the above succeeds - close can be called multiple times
                     // Also closing refreshListeners to prevent us from accumulating any more listeners
-                    // Closing remoteStore as a part of IndexShard close. null check is handled by IOUtils
-                    IOUtils.close(engine, globalCheckpointListeners, refreshListeners, pendingReplicationActions, remoteStore);
+                    IOUtils.close(engine, globalCheckpointListeners, refreshListeners, pendingReplicationActions);
                     indexShardOperationPermits.close();
                 }
             }

server/src/main/java/org/opensearch/repositories/blobstore/BlobStoreRepository.java

@@ -651,8 +651,6 @@ protected BlobContainer blobContainer() {
      * Public for testing.
      */
     public BlobStore blobStore() {
-        assertSnapshotOrGenericThread();
-
         BlobStore store = blobStore.get();
         if (store == null) {
             synchronized (lock) {