upload translog ckp file as object metadata to translog tlog file

Signed-off-by: Sandeep Kumawat <2025sandeepkumawat@gmail.com>

Author: skumawat2025

server/src/main/java/org/opensearch/cluster/metadata/MetadataCreateIndexService.java

@@ -89,10 +89,11 @@
 import org.opensearch.index.mapper.MapperService;
 import org.opensearch.index.mapper.MapperService.MergeReason;
 import org.opensearch.index.query.QueryShardContext;
+import org.opensearch.index.remote.RemoteStoreCustomMetadataResolver;
+import org.opensearch.index.remote.RemoteStoreEnums;
 import org.opensearch.index.remote.RemoteStoreEnums.PathHashAlgorithm;
 import org.opensearch.index.remote.RemoteStoreEnums.PathType;
 import org.opensearch.index.remote.RemoteStorePathStrategy;
-import org.opensearch.index.remote.RemoteStorePathStrategyResolver;
 import org.opensearch.index.shard.IndexSettingProvider;
 import org.opensearch.index.translog.Translog;
 import org.opensearch.indices.IndexCreationException;
@@ -177,7 +178,7 @@ public class MetadataCreateIndexService {
     private AwarenessReplicaBalance awarenessReplicaBalance;
 
     @Nullable
-    private final RemoteStorePathStrategyResolver remoteStorePathStrategyResolver;
+    private final RemoteStoreCustomMetadataResolver remoteStoreCustomMetadataResolver;
 
     public MetadataCreateIndexService(
         final Settings settings,
@@ -212,8 +213,8 @@ public MetadataCreateIndexService(
         // Task is onboarded for throttling, it will get retried from associated TransportClusterManagerNodeAction.
         createIndexTaskKey = clusterService.registerClusterManagerTask(ClusterManagerTaskKeys.CREATE_INDEX_KEY, true);
         Supplier<Version> minNodeVersionSupplier = () -> clusterService.state().nodes().getMinNodeVersion();
-        remoteStorePathStrategyResolver = isRemoteDataAttributePresent(settings)
-            ? new RemoteStorePathStrategyResolver(remoteStoreSettings, minNodeVersionSupplier)
+        remoteStoreCustomMetadataResolver = isRemoteDataAttributePresent(settings)
+            ? new RemoteStoreCustomMetadataResolver(remoteStoreSettings, minNodeVersionSupplier)
             : null;
     }
 
@@ -562,7 +563,7 @@ IndexMetadata buildAndValidateTemporaryIndexMetadata(
         tmpImdBuilder.setRoutingNumShards(routingNumShards);
         tmpImdBuilder.settings(indexSettings);
         tmpImdBuilder.system(isSystem);
-        addRemoteStorePathStrategyInCustomData(tmpImdBuilder, true);
+        addRemoteStoreCustomMetadata(tmpImdBuilder, true);
 
         // Set up everything, now locally create the index to see that things are ok, and apply
         IndexMetadata tempMetadata = tmpImdBuilder.build();
@@ -572,23 +573,28 @@ IndexMetadata buildAndValidateTemporaryIndexMetadata(
     }
 
     /**
-     * Adds the remote store path type information in custom data of index metadata.
+     * Adds the 1) remote store path type 2) ckp as translog metadata information in custom data of index metadata.
      *
      * @param tmpImdBuilder     index metadata builder.
      * @param assertNullOldType flag to verify that the old remote store path type is null
      */
-    public void addRemoteStorePathStrategyInCustomData(IndexMetadata.Builder tmpImdBuilder, boolean assertNullOldType) {
-        if (remoteStorePathStrategyResolver == null) {
+    public void addRemoteStoreCustomMetadata(IndexMetadata.Builder tmpImdBuilder, boolean assertNullOldType) {
+        if (remoteStoreCustomMetadataResolver == null) {
             return;
         }
         // It is possible that remote custom data exists already. In such cases, we need to only update the path type
         // in the remote store custom data map.
         Map<String, String> existingCustomData = tmpImdBuilder.removeCustom(IndexMetadata.REMOTE_STORE_CUSTOM_KEY);
         assert assertNullOldType == false || Objects.isNull(existingCustomData);
 
-        // Determine the path type for use using the remoteStorePathResolver.
-        RemoteStorePathStrategy newPathStrategy = remoteStorePathStrategyResolver.get();
         Map<String, String> remoteCustomData = new HashMap<>();
+
+        // Determine if the ckp would be stored as translog metadata
+        boolean isCkpAsTranslogMetadata = remoteStoreCustomMetadataResolver.isCkpAsTranslogMetadata();
+        remoteCustomData.put(RemoteStoreEnums.CKP_AS_METADATA, Boolean.toString(isCkpAsTranslogMetadata));
+
+        // Determine the path type for use using the remoteStorePathResolver.
+        RemoteStorePathStrategy newPathStrategy = remoteStoreCustomMetadataResolver.getPathStrategy();
         remoteCustomData.put(PathType.NAME, newPathStrategy.getType().name());
         if (Objects.nonNull(newPathStrategy.getHashAlgorithm())) {
             remoteCustomData.put(PathHashAlgorithm.NAME, newPathStrategy.getHashAlgorithm().name());

server/src/main/java/org/opensearch/cluster/routing/allocation/IndexMetadataUpdater.java

@@ -176,7 +176,7 @@ public Metadata applyChanges(Metadata oldMetadata, RoutingTable newRoutingTable,
                         oldMetadata.settings(),
                         logger
                     );
-                    migrationImdUpdater.maybeUpdateRemoteStorePathStrategy(indexMetadataBuilder, index.getName());
+                    migrationImdUpdater.maybeUpdateRemoteStoreCustomMetadata(indexMetadataBuilder, index.getName());
                     migrationImdUpdater.maybeAddRemoteIndexSettings(indexMetadataBuilder, index.getName());
                 }
             }

server/src/main/java/org/opensearch/common/blobstore/BlobStore.java

@@ -71,6 +71,13 @@ default Map<Metric, Map<String, Long>> extendedStats() {
      */
     default void reload(RepositoryMetadata repositoryMetadata) {}
 
+    /**
+     * Returns a boolean indicating if blobStore support object metadata upload
+     */
+    default boolean isBlobMetadataSupported() {
+        return false;
+    }
+
     /**
      * Metrics for BlobStore interactions
      */

server/src/main/java/org/opensearch/common/settings/ClusterSettings.java

@@ -739,7 +739,8 @@ public void apply(Settings value, Settings current, Settings previous) {
                 RemoteStoreSettings.CLUSTER_REMOTE_TRANSLOG_TRANSFER_TIMEOUT_SETTING,
                 RemoteStoreSettings.CLUSTER_REMOTE_STORE_PATH_TYPE_SETTING,
                 RemoteStoreSettings.CLUSTER_REMOTE_STORE_PATH_HASH_ALGORITHM_SETTING,
-                RemoteStoreSettings.CLUSTER_REMOTE_MAX_TRANSLOG_READERS
+                RemoteStoreSettings.CLUSTER_REMOTE_MAX_TRANSLOG_READERS,
+                RemoteStoreSettings.CLUSTER_REMOTE_STORE_TRANSLOG_CKP_AS_METADATA
             )
         )
     );

server/src/main/java/org/opensearch/index/IndexSettings.java

@@ -763,6 +763,7 @@ public static IndexMergePolicy fromString(String text) {
     private final boolean widenIndexSortType;
     private final boolean assignedOnRemoteNode;
     private final RemoteStorePathStrategy remoteStorePathStrategy;
+    private final boolean ckpAsTranslogMetadata;
 
     /**
      * The maximum age of a retention lease before it is considered expired.
@@ -989,6 +990,8 @@ public IndexSettings(final IndexMetadata indexMetadata, final Settings nodeSetti
         assignedOnRemoteNode = RemoteStoreNodeAttribute.isRemoteDataAttributePresent(this.getNodeSettings());
         remoteStorePathStrategy = RemoteStoreUtils.determineRemoteStorePathStrategy(indexMetadata);
 
+        ckpAsTranslogMetadata = RemoteStoreUtils.determineCkpAsTranslogMetadata(indexMetadata);
+
         setEnableFuzzySetForDocId(scopedSettings.get(INDEX_DOC_ID_FUZZY_SET_ENABLED_SETTING));
         setDocIdFuzzySetFalsePositiveProbability(scopedSettings.get(INDEX_DOC_ID_FUZZY_SET_FALSE_POSITIVE_PROBABILITY_SETTING));
 
@@ -1911,4 +1914,8 @@ public void setDocIdFuzzySetFalsePositiveProbability(double docIdFuzzySetFalsePo
     public RemoteStorePathStrategy getRemoteStorePathStrategy() {
         return remoteStorePathStrategy;
     }
+
+    public boolean isCkpAsTranslogMetadata() {
+        return ckpAsTranslogMetadata;
+    }
 }

server/src/main/java/org/opensearch/index/remote/RemoteMigrationIndexMetadataUpdater.java

@@ -28,7 +28,7 @@
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_REMOTE_STORE_ENABLED;
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_REMOTE_TRANSLOG_STORE_REPOSITORY;
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_REPLICATION_TYPE;
-import static org.opensearch.index.remote.RemoteStoreUtils.determineRemoteStorePathStrategyDuringMigration;
+import static org.opensearch.index.remote.RemoteStoreUtils.determineRemoteStoreCustomMetadataDuringMigration;
 import static org.opensearch.index.remote.RemoteStoreUtils.getRemoteStoreRepoName;
 import static org.opensearch.node.remotestore.RemoteStoreNodeAttribute.REMOTE_STORE_SEGMENT_REPOSITORY_NAME_ATTRIBUTE_KEY;
 import static org.opensearch.node.remotestore.RemoteStoreNodeAttribute.REMOTE_STORE_TRANSLOG_REPOSITORY_NAME_ATTRIBUTE_KEY;
@@ -118,7 +118,7 @@ private boolean needsRemoteIndexSettingsUpdate(
     }
 
     /**
-     * Updates the remote store path strategy metadata for the index when it is migrating to remote.
+     * Updates the remote store custom metadata for the index when it is migrating to remote.
      * This is run during state change of each shard copy when the cluster is in `MIXED` mode and the direction of migration is `REMOTE_STORE`
      * Should not interfere with docrep functionality even if the index is in docrep nodes since this metadata
      * is not used anywhere in the docrep flow
@@ -127,20 +127,20 @@ private boolean needsRemoteIndexSettingsUpdate(
      * @param indexMetadataBuilder Mutated {@link IndexMetadata.Builder} having the previous state updates
      * @param index                index name
      */
-    public void maybeUpdateRemoteStorePathStrategy(IndexMetadata.Builder indexMetadataBuilder, String index) {
-        if (indexHasRemotePathMetadata(indexMetadata) == false) {
-            logger.info("Adding remote store path strategy for index [{}] during migration", index);
+    public void maybeUpdateRemoteStoreCustomMetadata(IndexMetadata.Builder indexMetadataBuilder, String index) {
+        if (indexHasRemoteCustomMetadata(indexMetadata) == false) {
+            logger.info("Adding remote store custom data for index [{}] during migration", index);
             indexMetadataBuilder.putCustom(
                 REMOTE_STORE_CUSTOM_KEY,
-                determineRemoteStorePathStrategyDuringMigration(clusterSettings, discoveryNodes)
+                determineRemoteStoreCustomMetadataDuringMigration(clusterSettings, discoveryNodes)
             );
         } else {
-            logger.debug("Index {} already has remote store path strategy", index);
+            logger.debug("Index {} already has remote store custom data", index);
         }
     }
 
     public static boolean indexHasAllRemoteStoreRelatedMetadata(IndexMetadata indexMetadata) {
-        return indexHasRemoteStoreSettings(indexMetadata.getSettings()) && indexHasRemotePathMetadata(indexMetadata);
+        return indexHasRemoteStoreSettings(indexMetadata.getSettings()) && indexHasRemoteCustomMetadata(indexMetadata);
     }
 
     /**
@@ -167,9 +167,11 @@ public static boolean indexHasRemoteStoreSettings(Settings indexSettings) {
      * @param indexMetadata Current index metadata
      * @return <code>true</code> if all above conditions match. <code>false</code> otherwise
      */
-    public static boolean indexHasRemotePathMetadata(IndexMetadata indexMetadata) {
+    public static boolean indexHasRemoteCustomMetadata(IndexMetadata indexMetadata) {
         Map<String, String> customMetadata = indexMetadata.getCustomData(REMOTE_STORE_CUSTOM_KEY);
-        return Objects.nonNull(customMetadata) && Objects.nonNull(customMetadata.get(PathType.NAME));
+        return Objects.nonNull(customMetadata)
+            && Objects.nonNull(customMetadata.get(PathType.NAME))
+            && Objects.nonNull(customMetadata.get(RemoteStoreEnums.CKP_AS_METADATA));
     }
 
     public static void updateRemoteStoreSettings(Settings.Builder settingsBuilder, String segmentRepository, String translogRepository) {

server/src/main/java/org/opensearch/index/remote/RemoteStorePathStrategyResolver.java renamed to server/src/main/java/org/opensearch/index/remote/RemoteStoreCustomMetadataResolver.java

@@ -22,17 +22,17 @@
  * @opensearch.internal
  */
 @ExperimentalApi
-public class RemoteStorePathStrategyResolver {
+public class RemoteStoreCustomMetadataResolver {
 
     private final RemoteStoreSettings remoteStoreSettings;
     private final Supplier<Version> minNodeVersionSupplier;
 
-    public RemoteStorePathStrategyResolver(RemoteStoreSettings remoteStoreSettings, Supplier<Version> minNodeVersionSupplier) {
+    public RemoteStoreCustomMetadataResolver(RemoteStoreSettings remoteStoreSettings, Supplier<Version> minNodeVersionSupplier) {
         this.remoteStoreSettings = remoteStoreSettings;
         this.minNodeVersionSupplier = minNodeVersionSupplier;
     }
 
-    public RemoteStorePathStrategy get() {
+    public RemoteStorePathStrategy getPathStrategy() {
         PathType pathType;
         PathHashAlgorithm pathHashAlgorithm;
         // Min node version check ensures that we are enabling the new prefix type only when all the nodes understand it.
@@ -41,4 +41,9 @@ public RemoteStorePathStrategy get() {
         pathHashAlgorithm = pathType == PathType.FIXED ? null : remoteStoreSettings.getPathHashAlgorithm();
         return new RemoteStorePathStrategy(pathType, pathHashAlgorithm);
     }
+
+    public boolean isCkpAsTranslogMetadata() {
+        return Version.CURRENT.compareTo(minNodeVersionSupplier.get()) <= 0 && remoteStoreSettings.isCkpAsTranslogMetadata();
+    }
+
 }

server/src/main/java/org/opensearch/index/remote/RemoteStoreEnums.java

@@ -36,6 +36,8 @@
 @ExperimentalApi
 public class RemoteStoreEnums {
 
+    public static final String CKP_AS_METADATA = "ckp-as-metadata";
+
     /**
      * Categories of the data in Remote store.
      */

server/src/main/java/org/opensearch/index/remote/RemoteStoreUtils.java

@@ -32,6 +32,7 @@
 
 import static org.opensearch.indices.RemoteStoreSettings.CLUSTER_REMOTE_STORE_PATH_HASH_ALGORITHM_SETTING;
 import static org.opensearch.indices.RemoteStoreSettings.CLUSTER_REMOTE_STORE_PATH_TYPE_SETTING;
+import static org.opensearch.indices.RemoteStoreSettings.CLUSTER_REMOTE_STORE_TRANSLOG_CKP_AS_METADATA;
 
 /**
  * Utils for remote store
@@ -181,25 +182,42 @@ public static RemoteStorePathStrategy determineRemoteStorePathStrategy(IndexMeta
         return new RemoteStorePathStrategy(RemoteStoreEnums.PathType.FIXED);
     }
 
+    /**
+     * Determines whether translog ckp upload as metadata allowed or not
+     */
+    public static boolean determineCkpAsTranslogMetadata(IndexMetadata indexMetadata) {
+        Map<String, String> remoteCustomData = indexMetadata.getCustomData(IndexMetadata.REMOTE_STORE_CUSTOM_KEY);
+        assert remoteCustomData == null || remoteCustomData.containsKey(RemoteStoreEnums.CKP_AS_METADATA);
+        if (remoteCustomData != null && remoteCustomData.containsKey(RemoteStoreEnums.CKP_AS_METADATA)) {
+            return Boolean.parseBoolean(remoteCustomData.get(RemoteStoreEnums.CKP_AS_METADATA));
+        }
+        return false;
+    }
+
     /**
      * Generates the remote store path type information to be added to custom data of index metadata during migration
      *
      * @param clusterSettings Current Cluster settings from {@link ClusterState}
-     * @param discoveryNodes Current {@link DiscoveryNodes} from the cluster state
+     * @param discoveryNodes  Current {@link DiscoveryNodes} from the cluster state
      * @return {@link Map} to be added as custom data in index metadata
      */
-    public static Map<String, String> determineRemoteStorePathStrategyDuringMigration(
+    public static Map<String, String> determineRemoteStoreCustomMetadataDuringMigration(
         Settings clusterSettings,
         DiscoveryNodes discoveryNodes
     ) {
+        Map<String, String> remoteCustomData = new HashMap<>();
         Version minNodeVersion = discoveryNodes.getMinNodeVersion();
+
+        boolean ckpAsMetadata = Version.CURRENT.compareTo(minNodeVersion) <= 0
+            && CLUSTER_REMOTE_STORE_TRANSLOG_CKP_AS_METADATA.get(clusterSettings);
+        remoteCustomData.put(RemoteStoreEnums.CKP_AS_METADATA, Boolean.toString(ckpAsMetadata));
+
         RemoteStoreEnums.PathType pathType = Version.CURRENT.compareTo(minNodeVersion) <= 0
             ? CLUSTER_REMOTE_STORE_PATH_TYPE_SETTING.get(clusterSettings)
             : RemoteStoreEnums.PathType.FIXED;
         RemoteStoreEnums.PathHashAlgorithm pathHashAlgorithm = pathType == RemoteStoreEnums.PathType.FIXED
             ? null
             : CLUSTER_REMOTE_STORE_PATH_HASH_ALGORITHM_SETTING.get(clusterSettings);
-        Map<String, String> remoteCustomData = new HashMap<>();
         remoteCustomData.put(RemoteStoreEnums.PathType.NAME, pathType.name());
         if (Objects.nonNull(pathHashAlgorithm)) {
             remoteCustomData.put(RemoteStoreEnums.PathHashAlgorithm.NAME, pathHashAlgorithm.name());

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

@@ -4976,7 +4976,14 @@ public void deleteTranslogFilesFromRemoteTranslog() throws IOException {
         TranslogFactory translogFactory = translogFactorySupplier.apply(indexSettings, shardRouting);
         assert translogFactory instanceof RemoteBlobStoreInternalTranslogFactory;
         Repository repository = ((RemoteBlobStoreInternalTranslogFactory) translogFactory).getRepository();
-        RemoteFsTranslog.cleanup(repository, shardId, getThreadPool(), indexSettings.getRemoteStorePathStrategy(), remoteStoreSettings);
+        RemoteFsTranslog.cleanup(
+            repository,
+            shardId,
+            getThreadPool(),
+            indexSettings.getRemoteStorePathStrategy(),
+            remoteStoreSettings,
+            indexSettings().isCkpAsTranslogMetadata()
+        );
     }
 
     /*
@@ -5001,7 +5008,8 @@ public void syncTranslogFilesFromRemoteTranslog() throws IOException {
             indexSettings.getRemoteStorePathStrategy(),
             remoteStoreSettings,
             logger,
-            shouldSeedRemoteStore()
+            shouldSeedRemoteStore(),
+            indexSettings().isCkpAsTranslogMetadata()
         );
     }