Read the same medata file that is locked during restore of shallow sn…

…apshot (#10979)

Signed-off-by: Sachin Kale <kalsac@amazon.com>

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

@@ -589,4 +589,71 @@ public void testRestoreShallowSnapshotRepository() throws ExecutionException, In
         assertDocsPresentInIndex(client, restoredIndexName1, numDocsInIndex1 + 2);
     }
 
+    public void testRestoreShallowSnapshotIndexAfterSnapshot() throws ExecutionException, InterruptedException {
+        String indexName1 = "testindex1";
+        String snapshotRepoName = "test-restore-snapshot-repo";
+        String remoteStoreRepoNameUpdated = "test-rs-repo-updated" + TEST_REMOTE_STORE_REPO_SUFFIX;
+        String snapshotName1 = "test-restore-snapshot1";
+        Path absolutePath1 = randomRepoPath().toAbsolutePath();
+        Path absolutePath2 = randomRepoPath().toAbsolutePath();
+        String[] pathTokens = absolutePath1.toString().split("/");
+        String basePath = pathTokens[pathTokens.length - 1];
+        Arrays.copyOf(pathTokens, pathTokens.length - 1);
+        Path location = PathUtils.get(String.join("/", pathTokens));
+        pathTokens = absolutePath2.toString().split("/");
+        String basePath2 = pathTokens[pathTokens.length - 1];
+        Arrays.copyOf(pathTokens, pathTokens.length - 1);
+        Path location2 = PathUtils.get(String.join("/", pathTokens));
+        logger.info("Path 1 [{}]", absolutePath1);
+        logger.info("Path 2 [{}]", absolutePath2);
+        String restoredIndexName1 = indexName1 + "-restored";
+
+        createRepository(snapshotRepoName, "fs", getRepositorySettings(location, basePath, true));
+
+        Client client = client();
+        Settings indexSettings = Settings.builder()
+            .put(super.indexSettings())
+            .put(IndexMetadata.SETTING_REPLICATION_TYPE, ReplicationType.SEGMENT)
+            .put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1)
+            .put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 0)
+            .build();
+        createIndex(indexName1, indexSettings);
+
+        int numDocsInIndex1 = randomIntBetween(2, 5);
+        indexDocuments(client, indexName1, numDocsInIndex1);
+
+        ensureGreen(indexName1);
+
+        logger.info("--> snapshot");
+        SnapshotInfo snapshotInfo1 = createSnapshot(snapshotRepoName, snapshotName1, new ArrayList<>(List.of(indexName1)));
+        assertThat(snapshotInfo1.successfulShards(), greaterThan(0));
+        assertThat(snapshotInfo1.successfulShards(), equalTo(snapshotInfo1.totalShards()));
+        assertThat(snapshotInfo1.state(), equalTo(SnapshotState.SUCCESS));
+
+        int extraNumDocsInIndex1 = randomIntBetween(20, 50);
+        indexDocuments(client, indexName1, extraNumDocsInIndex1);
+        refresh(indexName1);
+
+        client().admin().indices().close(Requests.closeIndexRequest(indexName1)).get();
+        createRepository(remoteStoreRepoNameUpdated, "fs", remoteRepoPath);
+        RestoreSnapshotResponse restoreSnapshotResponse2 = client.admin()
+            .cluster()
+            .prepareRestoreSnapshot(snapshotRepoName, snapshotName1)
+            .setWaitForCompletion(true)
+            .setIndices(indexName1)
+            .setRenamePattern(indexName1)
+            .setRenameReplacement(restoredIndexName1)
+            .setSourceRemoteStoreRepository(remoteStoreRepoNameUpdated)
+            .get();
+
+        assertTrue(restoreSnapshotResponse2.getRestoreInfo().failedShards() == 0);
+        ensureGreen(restoredIndexName1);
+        assertDocsPresentInIndex(client, restoredIndexName1, numDocsInIndex1);
+
+        // indexing some new docs and validating
+        indexDocuments(client, restoredIndexName1, numDocsInIndex1, numDocsInIndex1 + 2);
+        ensureGreen(restoredIndexName1);
+        assertDocsPresentInIndex(client, restoredIndexName1, numDocsInIndex1 + 2);
+    }
+
 }

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

@@ -4908,8 +4908,7 @@ public void syncSegmentsFromGivenRemoteSegmentStore(
             remoteStore.incRef();
         }
         Map<String, RemoteSegmentStoreDirectory.UploadedSegmentMetadata> uploadedSegments = sourceRemoteDirectory
-            .initializeToSpecificCommit(primaryTerm, commitGeneration)
-            .getMetadata();
+            .getSegmentsUploadedToRemoteStore();
         final Directory storeDirectory = store.directory();
         store.incRef();
 

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

@@ -410,6 +410,11 @@ void recoverFromSnapshotAndRemoteStore(
                     indexUUID,
                     shardId
                 );
+                sourceRemoteDirectory.initializeToSpecificCommit(
+                    primaryTerm,
+                    commitGeneration,
+                    recoverySource.snapshot().getSnapshotId().getUUID()
+                );
                 indexShard.syncSegmentsFromGivenRemoteSegmentStore(true, sourceRemoteDirectory, primaryTerm, commitGeneration);
                 final Store store = indexShard.store();
                 if (indexShard.indexSettings.isRemoteTranslogStoreEnabled() == false) {

server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectory.java

@@ -34,6 +34,7 @@
 import org.opensearch.index.store.lockmanager.FileLockInfo;
 import org.opensearch.index.store.lockmanager.RemoteStoreCommitLevelLockManager;
 import org.opensearch.index.store.lockmanager.RemoteStoreLockManager;
+import org.opensearch.index.store.lockmanager.RemoteStoreMetadataLockManager;
 import org.opensearch.index.store.remote.metadata.RemoteSegmentMetadata;
 import org.opensearch.index.store.remote.metadata.RemoteSegmentMetadataHandler;
 import org.opensearch.indices.replication.checkpoint.ReplicationCheckpoint;
@@ -160,8 +161,9 @@ public RemoteSegmentMetadata init() throws IOException {
      *
      * @throws IOException if there were any failures in reading the metadata file
      */
-    public RemoteSegmentMetadata initializeToSpecificCommit(long primaryTerm, long commitGeneration) throws IOException {
-        String metadataFile = getMetadataFileForCommit(primaryTerm, commitGeneration);
+    public RemoteSegmentMetadata initializeToSpecificCommit(long primaryTerm, long commitGeneration, String acquirerId) throws IOException {
+        String metadataFilePrefix = MetadataFilenameUtils.getMetadataFilePrefixForCommit(primaryTerm, commitGeneration);
+        String metadataFile = ((RemoteStoreMetadataLockManager) mdLockManager).fetchLock(metadataFilePrefix, acquirerId);
         RemoteSegmentMetadata remoteSegmentMetadata = readMetadataFile(metadataFile);
         if (remoteSegmentMetadata != null) {
             this.segmentsUploadedToRemoteStore = new ConcurrentHashMap<>(remoteSegmentMetadata.getMetadata());

server/src/main/java/org/opensearch/index/store/lockmanager/RemoteStoreMetadataLockManager.java

@@ -14,10 +14,13 @@
 import org.apache.lucene.store.IndexOutput;
 import org.opensearch.index.store.RemoteBufferedOutputDirectory;
 
+import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.nio.file.NoSuchFileException;
 import java.util.Collection;
+import java.util.List;
 import java.util.Objects;
+import java.util.stream.Collectors;
 
 /**
  * A Class that implements Remote Store Lock Manager by creating lock files for the remote store files that needs to
@@ -70,6 +73,19 @@ public void release(LockInfo lockInfo) throws IOException {
         }
     }
 
+    public String fetchLock(String filenamePrefix, String acquirerId) throws IOException {
+        Collection<String> lockFiles = lockDirectory.listFilesByPrefix(filenamePrefix);
+        List<String> lockFilesForAcquirer = lockFiles.stream()
+            .filter(lockFile -> acquirerId.equals(FileLockInfo.LockFileUtils.getAcquirerIdFromLock(lockFile)))
+            .map(FileLockInfo.LockFileUtils::getFileToLockNameFromLock)
+            .collect(Collectors.toList());
+        if (lockFilesForAcquirer.size() == 0) {
+            throw new FileNotFoundException("No lock file found for prefix: " + filenamePrefix + " and acquirerId: " + acquirerId);
+        }
+        assert lockFilesForAcquirer.size() == 1;
+        return lockFilesForAcquirer.get(0);
+    }
+
     /**
      * Checks whether a given file have any lock on it or not.
      * @param lockInfo File Lock Info instance for which we need to check if lock is acquired.