Add Changes in Snapshot Clone Flow for remote store interoperability.

server/src/internalClusterTest/java/org/opensearch/snapshots/CloneSnapshotIT.java

@@ -38,11 +38,15 @@
 import org.opensearch.action.support.master.AcknowledgedResponse;
 import org.opensearch.client.Client;
 import org.opensearch.cluster.SnapshotsInProgress;
+import org.opensearch.cluster.metadata.RepositoryMetadata;
+import org.opensearch.common.settings.Settings;
 import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.FeatureFlags;
 import org.opensearch.index.IndexNotFoundException;
 import org.opensearch.repositories.RepositoriesService;
 import org.opensearch.repositories.RepositoryData;
 import org.opensearch.snapshots.mockstore.MockRepository;
+import org.opensearch.test.FeatureFlagSetter;
 import org.opensearch.test.OpenSearchIntegTestCase;
 
 import java.util.ArrayList;
@@ -64,6 +68,7 @@
 import org.opensearch.repositories.blobstore.BlobStoreRepository;
 
 import java.nio.file.Path;
+import java.util.concurrent.ExecutionException;
 
 import static org.hamcrest.Matchers.hasSize;
 import static org.hamcrest.Matchers.is;
@@ -153,6 +158,162 @@ public void testCloneSnapshotIndex() throws Exception {
         assertEquals(status1.getStats().getTotalSize(), status2.getStats().getTotalSize());
     }
 
+    public void testCloneShallowSnapshotIndex() throws Exception {
+        disableRepoConsistencyCheck("This test uses remote store repository");
+        FeatureFlagSetter.set(FeatureFlags.REMOTE_STORE);
+        internalCluster().startClusterManagerOnlyNode();
+        internalCluster().startDataOnlyNode();
+
+        final String snapshotRepoName = "snapshot-repo-name";
+        final Path snapshotRepoPath = randomRepoPath();
+        createRepository(snapshotRepoName, "fs", snapshotRepoPath);
+
+        final String shallowSnapshotRepoName = "shallow-snapshot-repo-name";
+        final Path shallowSnapshotRepoPath = randomRepoPath();
+        createRepository(shallowSnapshotRepoName, "fs", snapshotRepoSettingsForShallowCopy(shallowSnapshotRepoPath));
+
+        final Path remoteStoreRepoPath = randomRepoPath();
+        final String remoteStoreRepoName = "remote-store-repo-name";
+        createRepository(remoteStoreRepoName, "fs", remoteStoreRepoPath);
+
+        final String indexName = "index-1";
+        createIndexWithRandomDocs(indexName, randomIntBetween(5, 10));
+
+        final String remoteStoreEnabledIndexName = "remote-index-1";
+        final Settings remoteStoreEnabledIndexSettings = getRemoteStoreBackedIndexSettings(remoteStoreRepoName);
+        createIndex(remoteStoreEnabledIndexName, remoteStoreEnabledIndexSettings);
+        indexRandomDocs(remoteStoreEnabledIndexName, randomIntBetween(5, 10));
+
+        final String snapshot = "snapshot";
+        createFullSnapshot(snapshotRepoName, snapshot);
+        assert (getLockFilesInRemoteStore(remoteStoreEnabledIndexName, remoteStoreRepoName).length == 0);
+
+        indexRandomDocs(indexName, randomIntBetween(20, 100));
+
+        final String shallowSnapshot = "shallow-snapshot";
+        createFullSnapshot(shallowSnapshotRepoName, shallowSnapshot);
+        assert (getLockFilesInRemoteStore(remoteStoreEnabledIndexName, remoteStoreRepoName).length == 1);
+
+        if (randomBoolean()) {
+            assertAcked(admin().indices().prepareDelete(indexName));
+        }
+
+        final String sourceSnapshot = shallowSnapshot;
+        final String targetSnapshot = "target-snapshot";
+        assertAcked(startClone(shallowSnapshotRepoName, sourceSnapshot, targetSnapshot, indexName, remoteStoreEnabledIndexName).get());
+        logger.info("Lock files count: {}", getLockFilesInRemoteStore(remoteStoreEnabledIndexName, remoteStoreRepoName).length);
+        assert (getLockFilesInRemoteStore(remoteStoreEnabledIndexName, remoteStoreRepoName).length == 2);
+    }
+
+    public void testShallowCloneNameAvailability() throws Exception {
+        disableRepoConsistencyCheck("This test uses remote store repository");
+        FeatureFlagSetter.set(FeatureFlags.REMOTE_STORE);
+        internalCluster().startClusterManagerOnlyNode(LARGE_SNAPSHOT_POOL_SETTINGS);
+        internalCluster().startDataOnlyNode();
+
+        final String shallowSnapshotRepoName = "shallow-snapshot-repo-name";
+        final Path shallowSnapshotRepoPath = randomRepoPath();
+        createRepository(shallowSnapshotRepoName, "fs", snapshotRepoSettingsForShallowCopy(shallowSnapshotRepoPath));
+
+        final Path remoteStoreRepoPath = randomRepoPath();
+        final String remoteStoreRepoName = "remote-store-repo-name";
+        createRepository(remoteStoreRepoName, "fs", remoteStoreRepoPath);
+
+        final String indexName = "index-1";
+        createIndexWithRandomDocs(indexName, randomIntBetween(5, 10));
+
+        final String remoteStoreEnabledIndexName = "remote-index-1";
+        final Settings remoteStoreEnabledIndexSettings = getRemoteStoreBackedIndexSettings(remoteStoreRepoName);
+        createIndex(remoteStoreEnabledIndexName, remoteStoreEnabledIndexSettings);
+        indexRandomDocs(remoteStoreEnabledIndexName, randomIntBetween(5, 10));
+
+        final String shallowSnapshot1 = "snapshot1";
+        createFullSnapshot(shallowSnapshotRepoName, shallowSnapshot1);
+
+        final String shallowSnapshot2 = "snapshot2";
+        createFullSnapshot(shallowSnapshotRepoName, shallowSnapshot2);
+
+        ExecutionException ex = expectThrows(
+            ExecutionException.class,
+            () -> startClone(shallowSnapshotRepoName, shallowSnapshot1, shallowSnapshot2, indexName, remoteStoreEnabledIndexName).get()
+        );
+        assertThat(ex.getMessage(), containsString("snapshot with the same name already exists"));
+    }
+
+    public void testCloneAfterRepoShallowSettingEnabled() throws Exception {
+        disableRepoConsistencyCheck("This test uses remote store repository");
+        FeatureFlagSetter.set(FeatureFlags.REMOTE_STORE);
+        internalCluster().startClusterManagerOnlyNode();
+        internalCluster().startDataOnlyNode();
+
+        final String snapshotRepoName = "snapshot-repo-name";
+        final Path snapshotRepoPath = randomRepoPath();
+        createRepository(snapshotRepoName, "fs", snapshotRepoPath);
+
+        final Path remoteStoreRepoPath = randomRepoPath();
+        final String remoteStoreRepoName = "remote-store-repo-name";
+        createRepository(remoteStoreRepoName, "fs", remoteStoreRepoPath);
+
+        final String indexName = "index-1";
+        createIndexWithRandomDocs(indexName, randomIntBetween(5, 10));
+
+        final String remoteStoreEnabledIndexName = "remote-index-1";
+        final Settings remoteStoreEnabledIndexSettings = getRemoteStoreBackedIndexSettings(remoteStoreRepoName);
+        createIndex(remoteStoreEnabledIndexName, remoteStoreEnabledIndexSettings);
+        indexRandomDocs(remoteStoreEnabledIndexName, randomIntBetween(5, 10));
+
+        final String snapshot = "snapshot";
+        createFullSnapshot(snapshotRepoName, snapshot);
+        assertEquals(getSnapshot(snapshotRepoName, snapshot).state(), SnapshotState.SUCCESS);
+
+        // Updating the snapshot repository flag to enable shallow snapshots
+        createRepository(snapshotRepoName, "fs", snapshotRepoSettingsForShallowCopy(snapshotRepoPath));
+        RepositoryMetadata updatedRepositoryMetadata = clusterAdmin().prepareGetRepositories(snapshotRepoName).get().repositories().get(0);
+        assertTrue(updatedRepositoryMetadata.settings().getAsBoolean(BlobStoreRepository.REMOTE_STORE_INDEX_SHALLOW_COPY.getKey(), false));
+
+        final String targetSnapshot = "target-snapshot";
+        assertAcked(startClone(snapshotRepoName, snapshot, targetSnapshot, indexName, remoteStoreEnabledIndexName).get());
+        assert (getLockFilesInRemoteStore(remoteStoreEnabledIndexName, remoteStoreRepoName).length == 0);
+        assertEquals(getSnapshot(snapshotRepoName, targetSnapshot).isRemoteStoreIndexShallowCopyEnabled(), false);
+    }
+
+    public void testCloneAfterRepoShallowSettingDisabled() throws Exception {
+        disableRepoConsistencyCheck("This test uses remote store repository");
+        FeatureFlagSetter.set(FeatureFlags.REMOTE_STORE);
+        internalCluster().startClusterManagerOnlyNode();
+        internalCluster().startDataOnlyNode();
+
+        final String snapshotRepoName = "snapshot-repo-name";
+        final Path snapshotRepoPath = randomRepoPath();
+        createRepository(snapshotRepoName, "fs", snapshotRepoSettingsForShallowCopy(snapshotRepoPath));
+
+        final Path remoteStoreRepoPath = randomRepoPath();
+        final String remoteStoreRepoName = "remote-store-repo-name";
+        createRepository(remoteStoreRepoName, "fs", remoteStoreRepoPath);
+
+        final String indexName = "index-1";
+        createIndexWithRandomDocs(indexName, randomIntBetween(5, 10));
+
+        final String remoteStoreEnabledIndexName = "remote-index-1";
+        final Settings remoteStoreEnabledIndexSettings = getRemoteStoreBackedIndexSettings(remoteStoreRepoName);
+        createIndex(remoteStoreEnabledIndexName, remoteStoreEnabledIndexSettings);
+        indexRandomDocs(remoteStoreEnabledIndexName, randomIntBetween(5, 10));
+
+        final String snapshot = "snapshot";
+        createFullSnapshot(snapshotRepoName, snapshot);
+        assertEquals(getSnapshot(snapshotRepoName, snapshot).state(), SnapshotState.SUCCESS);
+
+        // Updating the snapshot repository flag to enable shallow snapshots
+        createRepository(snapshotRepoName, "fs", snapshotRepoPath);
+        RepositoryMetadata updatedRepositoryMetadata = clusterAdmin().prepareGetRepositories(snapshotRepoName).get().repositories().get(0);
+        assertFalse(updatedRepositoryMetadata.settings().getAsBoolean(BlobStoreRepository.REMOTE_STORE_INDEX_SHALLOW_COPY.getKey(), false));
+
+        final String targetSnapshot = "target-snapshot";
+        assertAcked(startClone(snapshotRepoName, snapshot, targetSnapshot, indexName, remoteStoreEnabledIndexName).get());
+        assert (getLockFilesInRemoteStore(remoteStoreEnabledIndexName, remoteStoreRepoName).length == 2);
+        assertEquals(getSnapshot(snapshotRepoName, targetSnapshot).isRemoteStoreIndexShallowCopyEnabled(), true);
+    }
+
     public void testClonePreventsSnapshotDelete() throws Exception {
         final String clusterManagerName = internalCluster().startClusterManagerOnlyNode();
         internalCluster().startDataOnlyNode();

server/src/main/java/org/opensearch/cluster/SnapshotsInProgress.java

@@ -167,7 +167,8 @@ public static Entry startClone(
             version,
             source,
             Map.of(),
-            false // TODO: need to pull this value from the original snapshot, use whatever we set during snapshot create.
+            false // initialising to false, will be updated in startCloning method of SnapshotsService while updating entry with
+                  // clone jobs
         );
     }
 
@@ -453,6 +454,26 @@ public Entry withClones(final Map<RepositoryShardId, ShardSnapshotStatus> update
             );
         }
 
+        public Entry withRemoteStoreIndexShallowCopy(final boolean remoteStoreIndexShallowCopy) {
+            return new Entry(
+                snapshot,
+                includeGlobalState,
+                partial,
+                state,
+                indices,
+                dataStreams,
+                startTime,
+                repositoryStateId,
+                shards,
+                failure,
+                userMetadata,
+                version,
+                source,
+                clones,
+                remoteStoreIndexShallowCopy
+            );
+        }
+
         /**
          * Create a new instance by aborting this instance. Moving all in-progress shards to {@link ShardState#ABORTED} if assigned to a
          * data node or to {@link ShardState#FAILED} if not assigned to any data node.

server/src/main/java/org/opensearch/index/snapshots/blobstore/RemoteStoreShardShallowCopySnapshot.java

@@ -408,4 +408,29 @@ private void verifyParameters(
             throw new IllegalArgumentException(exceptionStr);
         }
     }
+
+    /**
+     * Creates a new instance which has a different name and zero incremental file counts but is identical to this instance in terms of the files
+     * it references.
+     *
+     * @param targetSnapshotName target snapshot name
+     * @param startTime          time the clone operation on the repository was started
+     * @param time               time it took to create the clone
+     */
+    public RemoteStoreShardShallowCopySnapshot asClone(String targetSnapshotName, long startTime, long time) {
+        return new RemoteStoreShardShallowCopySnapshot(
+            targetSnapshotName,
+            indexVersion,
+            primaryTerm,
+            commitGeneration,
+            startTime,
+            time,
+            totalFileCount,
+            totalSize,
+            indexUUID,
+            remoteStoreRepository,
+            repositoryBasePath,
+            fileNames
+        );
+    }
 }

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

@@ -8,6 +8,7 @@
 
 package org.opensearch.index.store.lockmanager;
 
+import java.nio.file.NoSuchFileException;
 import java.util.Arrays;
 import java.util.List;
 import java.util.stream.Collectors;
@@ -50,13 +51,21 @@ String getLockPrefix() {
         return fileToLock + RemoteStoreLockManagerUtils.SEPARATOR;
     }
 
-    List<String> getLocksForAcquirer(String[] lockFiles) {
+    String getLockForAcquirer(String[] lockFiles) throws NoSuchFileException {
         if (acquirerId == null || acquirerId.isBlank()) {
             throw new IllegalArgumentException("Acquirer ID should be provided");
         }
-        return Arrays.stream(lockFiles)
+        List<String> locksForAcquirer = Arrays.stream(lockFiles)
             .filter(lockFile -> acquirerId.equals(LockFileUtils.getAcquirerIdFromLock(lockFile)))
             .collect(Collectors.toList());
+
+        if (locksForAcquirer.isEmpty()) {
+            throw new NoSuchFileException("No lock file found for the acquirer: " + acquirerId);
+        }
+        if (locksForAcquirer.size() != 1) {
+            throw new IllegalStateException("Expected single lock file but found [" + locksForAcquirer.size() + "] lock files");
+        }
+        return locksForAcquirer.get(0);
     }
 
     public static LockInfoBuilder getLockInfoBuilder() {

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

@@ -39,6 +39,16 @@ public interface RemoteStoreLockManager {
      */
     Boolean isAcquired(LockInfo lockInfo) throws IOException;
 
+    /**
+     * Acquires lock on the file mentioned in originalLockInfo for acquirer mentioned in clonedLockInfo.
+     * There can occur a race condition where the original file is deleted before we can use it to acquire lock for the new acquirer. Until we have a
+     * fix on LockManager side, Implementors must ensure thread safety for this operation.
+     * @param originalLockInfo lock info instance for original lock.
+     * @param clonedLockInfo lock info instance for which lock needs to be cloned.
+     * @throws IOException throws IOException if originalResource itself do not have any lock.
+     */
+    void cloneLock(LockInfo originalLockInfo, LockInfo clonedLockInfo) throws IOException;
+
     /*
     Deletes all lock related files and directories
      */

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

@@ -15,8 +15,9 @@
 import org.opensearch.index.store.RemoteBufferedOutputDirectory;
 
 import java.io.IOException;
+import java.nio.file.NoSuchFileException;
 import java.util.Collection;
-import java.util.List;
+import java.util.Objects;
 
 /**
  * A Class that implements Remote Store Lock Manager by creating lock files for the remote store files that needs to
@@ -48,6 +49,7 @@ public void acquire(LockInfo lockInfo) throws IOException {
 
     /**
      * Releases Locks acquired by a given acquirer which is passed in LockInfo Instance.
+     * If the lock file doesn't exist for the acquirer, release will be a no-op.
      * Right now this method is only used to release locks for a given acquirer,
      * This can be extended in future to handle other cases as well, like:
      * - release lock for given fileToLock and AcquirerId
@@ -59,15 +61,12 @@ public void acquire(LockInfo lockInfo) throws IOException {
     public void release(LockInfo lockInfo) throws IOException {
         assert lockInfo instanceof FileLockInfo : "lockInfo should be instance of FileLockInfo";
         String[] lockFiles = lockDirectory.listAll();
-
-        // ideally there should be only one lock per acquirer, but just to handle any stale locks,
-        // we try to release all the locks for the acquirer.
-        List<String> locksToRelease = ((FileLockInfo) lockInfo).getLocksForAcquirer(lockFiles);
-        if (locksToRelease.size() > 1) {
-            logger.warn(locksToRelease.size() + " locks found for acquirer " + ((FileLockInfo) lockInfo).getAcquirerId());
-        }
-        for (String lock : locksToRelease) {
-            lockDirectory.deleteFile(lock);
+        try {
+            String lockToRelease = ((FileLockInfo) lockInfo).getLockForAcquirer(lockFiles);
+            lockDirectory.deleteFile(lockToRelease);
+        } catch (NoSuchFileException e) {
+            // Ignoring if the file to be deleted is not present.
+            logger.info("No lock file found for acquirerId: {}", ((FileLockInfo) lockInfo).getAcquirerId());
         }
     }
 
@@ -84,6 +83,27 @@ public Boolean isAcquired(LockInfo lockInfo) throws IOException {
         return !lockFiles.isEmpty();
     }
 
+    /**
+     * Acquires lock on the file mentioned in originalLockInfo for acquirer mentioned in clonedLockInfo.
+     * Snapshot layer enforces thread safety by having checks in place to ensure that the source snapshot is not being deleted before proceeding
+     * with the clone operation. Hence, the original lock file would always be present while acquiring the lock for cloned snapshot.
+     * @param originalLockInfo lock info instance for original lock.
+     * @param clonedLockInfo lock info instance for which lock needs to be cloned.
+     * @throws IOException throws IOException if originalResource itself do not have any lock.
+     */
+    @Override
+    public void cloneLock(LockInfo originalLockInfo, LockInfo clonedLockInfo) throws IOException {
+        assert originalLockInfo instanceof FileLockInfo : "originalLockInfo should be instance of FileLockInfo";
+        assert clonedLockInfo instanceof FileLockInfo : "clonedLockInfo should be instance of FileLockInfo";
+        String originalResourceId = Objects.requireNonNull(((FileLockInfo) originalLockInfo).getAcquirerId());
+        String clonedResourceId = Objects.requireNonNull(((FileLockInfo) clonedLockInfo).getAcquirerId());
+        assert originalResourceId != null && clonedResourceId != null : "provided resourceIds should not be null";
+        String[] lockFiles = lockDirectory.listAll();
+        String lockNameForAcquirer = ((FileLockInfo) originalLockInfo).getLockForAcquirer(lockFiles);
+        String fileToLockName = FileLockInfo.LockFileUtils.getFileToLockNameFromLock(lockNameForAcquirer);
+        acquire(FileLockInfo.getLockInfoBuilder().withFileToLock(fileToLockName).withAcquirerId(clonedResourceId).build());
+    }
+
     public void delete() throws IOException {
         lockDirectory.delete();
     }

server/src/main/java/org/opensearch/repositories/FilterRepository.java

@@ -47,6 +47,7 @@
 import org.opensearch.index.snapshots.IndexShardSnapshotStatus;
 import org.opensearch.index.snapshots.blobstore.RemoteStoreShardShallowCopySnapshot;
 import org.opensearch.index.store.Store;
+import org.opensearch.index.store.lockmanager.RemoteStoreLockManagerFactory;
 import org.opensearch.indices.recovery.RecoveryState;
 import org.opensearch.snapshots.SnapshotId;
 import org.opensearch.snapshots.SnapshotInfo;
@@ -248,6 +249,18 @@ public void executeConsistentStateUpdate(
         in.executeConsistentStateUpdate(createUpdateTask, source, onFailure);
     }
 
+    @Override
+    public void cloneRemoteStoreIndexShardSnapshot(
+        SnapshotId source,
+        SnapshotId target,
+        RepositoryShardId shardId,
+        String shardGeneration,
+        RemoteStoreLockManagerFactory remoteStoreLockManagerFactory,
+        ActionListener<String> listener
+    ) {
+        in.cloneRemoteStoreIndexShardSnapshot(source, target, shardId, shardGeneration, remoteStoreLockManagerFactory, listener);
+    }
+
     @Override
     public void cloneShardSnapshot(
         SnapshotId source,