[Backport 2.x] Add POJO classes required for cluster state publication from remote (#14006)

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

@@ -494,6 +494,18 @@
      * @opensearch.internal
      */
     public abstract static class NonDiffableValueSerializer<K, V> implements ValueSerializer<K, V> {
+        private static final NonDiffableValueSerializer ABSTRACT_INSTANCE = new NonDiffableValueSerializer<>() {
+            @Override
+            public void write(Object value, StreamOutput out) {
+                throw new UnsupportedOperationException();
+            }
+
+            @Override
+            public Object read(StreamInput in, Object key) {
+                throw new UnsupportedOperationException();
+            }
+        };
+
         @Override
         public boolean supportsDiffableValues() {
             return false;
@@ -513,6 +525,10 @@
         public Diff<V> readDiff(StreamInput in, K key) throws IOException {
             throw new UnsupportedOperationException();
         }
+
+        public static <K, V> NonDiffableValueSerializer<K, V> getAbstractInstance() {
+            return ABSTRACT_INSTANCE;
+        }
     }
 
     /**

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

@@ -66,7 +66,7 @@ public static DiffableStringMap readFrom(StreamInput in) throws IOException {
         return map.isEmpty() ? EMPTY : new DiffableStringMap(map);
     }
 
-    DiffableStringMap(final Map<String, String> map) {
+    public DiffableStringMap(final Map<String, String> map) {
         this.innerMap = Collections.unmodifiableMap(map);
     }
 

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

@@ -970,6 +970,10 @@ public static boolean isSettingsMetadataEqual(Metadata metadata1, Metadata metad
         return metadata1.persistentSettings.equals(metadata2.persistentSettings);
     }
 
+    public static boolean isTransientSettingsMetadataEqual(Metadata metadata1, Metadata metadata2) {
+        return metadata1.transientSettings.equals(metadata2.transientSettings);
+    }
+
     public static boolean isTemplatesMetadataEqual(Metadata metadata1, Metadata metadata2) {
         return metadata1.templates.equals(metadata2.templates);
     }

server/src/main/java/org/opensearch/cluster/routing/remote/RemoteRoutingTableService.java

@@ -28,7 +28,7 @@
  * Interface for RemoteRoutingTableService. Exposes methods to orchestrate upload and download of routing table from remote store.
  */
 public interface RemoteRoutingTableService extends LifecycleComponent {
-    static final DiffableUtils.NonDiffableValueSerializer<String, IndexRoutingTable> CUSTOM_ROUTING_TABLE_VALUE_SERIALIZER =
+    public static final DiffableUtils.NonDiffableValueSerializer<String, IndexRoutingTable> CUSTOM_ROUTING_TABLE_VALUE_SERIALIZER =
         new DiffableUtils.NonDiffableValueSerializer<String, IndexRoutingTable>() {
             @Override
             public void write(IndexRoutingTable value, StreamOutput out) throws IOException {

server/src/main/java/org/opensearch/gateway/remote/RemoteClusterStateAttributesManager.java

@@ -0,0 +1,118 @@
+/*
+ * 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.gateway.remote;
+
+import org.opensearch.action.LatchedActionListener;
+import org.opensearch.cluster.ClusterState;
+import org.opensearch.cluster.ClusterState.Custom;
+import org.opensearch.cluster.block.ClusterBlocks;
+import org.opensearch.cluster.node.DiscoveryNodes;
+import org.opensearch.common.CheckedRunnable;
+import org.opensearch.common.remote.AbstractRemoteWritableBlobEntity;
+import org.opensearch.core.action.ActionListener;
+import org.opensearch.core.common.io.stream.NamedWriteableRegistry;
+import org.opensearch.core.compress.Compressor;
+import org.opensearch.core.xcontent.NamedXContentRegistry;
+import org.opensearch.core.xcontent.ToXContent;
+import org.opensearch.gateway.remote.model.RemoteClusterBlocks;
+import org.opensearch.gateway.remote.model.RemoteClusterStateBlobStore;
+import org.opensearch.gateway.remote.model.RemoteClusterStateCustoms;
+import org.opensearch.gateway.remote.model.RemoteDiscoveryNodes;
+import org.opensearch.gateway.remote.model.RemoteReadResult;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * A Manager which provides APIs to upload and download attributes of ClusterState to the {@link RemoteClusterStateBlobStore}
+ *
+ * @opensearch.internal
+ */
+public class RemoteClusterStateAttributesManager {
+    public static final String CLUSTER_STATE_ATTRIBUTE = "cluster_state_attribute";
+    public static final String DISCOVERY_NODES = "nodes";
+    public static final String CLUSTER_BLOCKS = "blocks";
+    public static final int CLUSTER_STATE_ATTRIBUTES_CURRENT_CODEC_VERSION = 1;
+    private final RemoteClusterStateBlobStore<ClusterBlocks, RemoteClusterBlocks> clusterBlocksBlobStore;
+    private final RemoteClusterStateBlobStore<DiscoveryNodes, RemoteDiscoveryNodes> discoveryNodesBlobStore;
+    private final RemoteClusterStateBlobStore<Custom, RemoteClusterStateCustoms> customsBlobStore;
+    private final Compressor compressor;
+    private final NamedXContentRegistry namedXContentRegistry;
+    private final NamedWriteableRegistry namedWriteableRegistry;
+
+    RemoteClusterStateAttributesManager(
+        RemoteClusterStateBlobStore<ClusterBlocks, RemoteClusterBlocks> clusterBlocksBlobStore,
+        RemoteClusterStateBlobStore<DiscoveryNodes, RemoteDiscoveryNodes> discoveryNodesBlobStore,
+        RemoteClusterStateBlobStore<Custom, RemoteClusterStateCustoms> customsBlobStore,
+        Compressor compressor,
+        NamedXContentRegistry namedXContentRegistry,
+        NamedWriteableRegistry namedWriteableRegistry
+    ) {
+        this.clusterBlocksBlobStore = clusterBlocksBlobStore;
+        this.discoveryNodesBlobStore = discoveryNodesBlobStore;
+        this.customsBlobStore = customsBlobStore;
+        this.compressor = compressor;
+        this.namedXContentRegistry = namedXContentRegistry;
+        this.namedWriteableRegistry = namedWriteableRegistry;
+    }
+
+    /**
+     * Allows async upload of Cluster State Attribute components to remote
+     */
+    CheckedRunnable<IOException> getAsyncMetadataWriteAction(
+        String component,
+        AbstractRemoteWritableBlobEntity blobEntity,
+        RemoteClusterStateBlobStore remoteEntityStore,
+        LatchedActionListener<ClusterMetadataManifest.UploadedMetadata> latchedActionListener
+    ) {
+        return () -> remoteEntityStore.writeAsync(blobEntity, getActionListener(component, blobEntity, latchedActionListener));
+    }
+
+    private ActionListener<Void> getActionListener(
+        String component,
+        AbstractRemoteWritableBlobEntity remoteObject,
+        LatchedActionListener<ClusterMetadataManifest.UploadedMetadata> latchedActionListener
+    ) {
+        return ActionListener.wrap(
+            resp -> latchedActionListener.onResponse(remoteObject.getUploadedMetadata()),
+            ex -> latchedActionListener.onFailure(new RemoteStateTransferException(component, remoteObject, ex))
+        );
+    }
+
+    public CheckedRunnable<IOException> getAsyncMetadataReadAction(
+        String component,
+        AbstractRemoteWritableBlobEntity blobEntity,
+        RemoteClusterStateBlobStore remoteEntityStore,
+        LatchedActionListener<RemoteReadResult> listener
+    ) {
+        final ActionListener actionListener = ActionListener.wrap(
+            response -> listener.onResponse(new RemoteReadResult((ToXContent) response, CLUSTER_STATE_ATTRIBUTE, component)),
+            listener::onFailure
+        );
+        return () -> remoteEntityStore.readAsync(blobEntity, actionListener);
+    }
+
+    public Map<String, ClusterState.Custom> getUpdatedCustoms(ClusterState clusterState, ClusterState previousClusterState) {
+        Map<String, ClusterState.Custom> updatedCustoms = new HashMap<>();
+        Set<String> currentCustoms = new HashSet<>(clusterState.customs().keySet());
+        for (Map.Entry<String, ClusterState.Custom> entry : previousClusterState.customs().entrySet()) {
+            if (currentCustoms.contains(entry.getKey()) && !entry.getValue().equals(clusterState.customs().get(entry.getKey()))) {
+                updatedCustoms.put(entry.getKey(), clusterState.customs().get(entry.getKey()));
+            }
+            currentCustoms.remove(entry.getKey());
+        }
+        for (String custom : currentCustoms) {
+            updatedCustoms.put(custom, clusterState.customs().get(custom));
+        }
+        return updatedCustoms;
+    }
+}

server/src/main/java/org/opensearch/gateway/remote/RemoteClusterStateService.java

@@ -75,6 +75,7 @@
 
 import static java.util.Objects.requireNonNull;
 import static org.opensearch.gateway.PersistedClusterStateService.SLOW_WRITE_LOGGING_THRESHOLD;
+import static org.opensearch.gateway.remote.model.RemoteClusterMetadataManifest.MANIFEST_CURRENT_CODEC_VERSION;
 import static org.opensearch.node.remotestore.RemoteStoreNodeAttribute.isRemoteStoreClusterStateEnabled;
 
 /**
@@ -171,12 +172,6 @@ public class RemoteClusterStateService implements Closeable {
     /**
      * Manifest format compatible with codec v2, where global metadata file is replaced with multiple metadata attribute files
      */
-    public static final ChecksumBlobStoreFormat<ClusterMetadataManifest> CLUSTER_METADATA_MANIFEST_FORMAT_V2 =
-        new ChecksumBlobStoreFormat<>("cluster-metadata-manifest", METADATA_MANIFEST_NAME_FORMAT, ClusterMetadataManifest::fromXContentV2);
-
-    /**
-     * Manifest format compatible with codec v3, where global metadata file is replaced with multiple metadata attribute files
-     */
     public static final ChecksumBlobStoreFormat<ClusterMetadataManifest> CLUSTER_METADATA_MANIFEST_FORMAT = new ChecksumBlobStoreFormat<>(
         "cluster-metadata-manifest",
         METADATA_MANIFEST_NAME_FORMAT,
@@ -226,7 +221,6 @@ public class RemoteClusterStateService implements Closeable {
         + "indices, coordination metadata updated : [{}], settings metadata updated : [{}], templates metadata "
         + "updated : [{}], custom metadata updated : [{}], indices routing updated : [{}]";
     public static final int INDEX_METADATA_CURRENT_CODEC_VERSION = 1;
-    public static final int MANIFEST_CURRENT_CODEC_VERSION = ClusterMetadataManifest.CODEC_V3;
     public static final int GLOBAL_METADATA_CURRENT_CODEC_VERSION = 2;
 
     // ToXContent Params with gateway mode.
@@ -836,26 +830,25 @@ private RemoteClusterStateManifestInfo uploadManifest(
                 committed,
                 MANIFEST_CURRENT_CODEC_VERSION
             );
-            final ClusterMetadataManifest manifest = new ClusterMetadataManifest(
-                clusterState.term(),
-                clusterState.getVersion(),
-                clusterState.metadata().clusterUUID(),
-                clusterState.stateUUID(),
-                Version.CURRENT,
-                nodeId,
-                committed,
-                MANIFEST_CURRENT_CODEC_VERSION,
-                null,
-                uploadedIndexMetadata,
-                previousClusterUUID,
-                clusterState.metadata().clusterUUIDCommitted(),
-                uploadedCoordinationMetadata,
-                uploadedSettingsMetadata,
-                uploadedTemplatesMetadata,
-                uploadedCustomMetadataMap,
-                clusterState.routingTable().version(),
-                uploadedIndicesRouting
-            );
+            final ClusterMetadataManifest manifest = ClusterMetadataManifest.builder()
+                .clusterTerm(clusterState.term())
+                .stateVersion(clusterState.getVersion())
+                .clusterUUID(clusterState.metadata().clusterUUID())
+                .stateUUID(clusterState.stateUUID())
+                .opensearchVersion(Version.CURRENT)
+                .nodeId(nodeId)
+                .committed(committed)
+                .codecVersion(MANIFEST_CURRENT_CODEC_VERSION)
+                .indices(uploadedIndexMetadata)
+                .previousClusterUUID(previousClusterUUID)
+                .clusterUUIDCommitted(clusterState.metadata().clusterUUIDCommitted())
+                .coordinationMetadata(uploadedCoordinationMetadata)
+                .settingMetadata(uploadedSettingsMetadata)
+                .templatesMetadata(uploadedTemplatesMetadata)
+                .customMetadataMap(uploadedCustomMetadataMap)
+                .routingTableVersion(clusterState.routingTable().version())
+                .indicesRouting(uploadedIndicesRouting)
+                .build();
             writeMetadataManifest(clusterState.getClusterName().value(), clusterState.metadata().clusterUUID(), manifest, manifestFileName);
             return new RemoteClusterStateManifestInfo(manifest, manifestFileName);
         }
@@ -1540,8 +1533,6 @@ private ChecksumBlobStoreFormat<ClusterMetadataManifest> getClusterMetadataManif
         long codecVersion = getManifestCodecVersion(fileName);
         if (codecVersion == MANIFEST_CURRENT_CODEC_VERSION) {
             return CLUSTER_METADATA_MANIFEST_FORMAT;
-        } else if (codecVersion == ClusterMetadataManifest.CODEC_V2) {
-            return CLUSTER_METADATA_MANIFEST_FORMAT_V2;
         } else if (codecVersion == ClusterMetadataManifest.CODEC_V1) {
             return CLUSTER_METADATA_MANIFEST_FORMAT_V1;
         } else if (codecVersion == ClusterMetadataManifest.CODEC_V0) {

server/src/main/java/org/opensearch/gateway/remote/RemoteClusterStateUtils.java

@@ -9,10 +9,17 @@
 package org.opensearch.gateway.remote;
 
 import org.opensearch.cluster.metadata.Metadata;
+import org.opensearch.common.blobstore.BlobContainer;
+import org.opensearch.common.blobstore.BlobPath;
 import org.opensearch.core.xcontent.ToXContent;
+import org.opensearch.repositories.blobstore.BlobStoreRepository;
 
 import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
 import java.util.Base64;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 
 /**
@@ -21,19 +28,99 @@
 public class RemoteClusterStateUtils {
 
     public static final String DELIMITER = "__";
-    public static final String PATH_DELIMITER = "/";
-    public static final String GLOBAL_METADATA_PATH_TOKEN = "global-metadata";
     public static final String METADATA_NAME_FORMAT = "%s.dat";
-    public static final String METADATA_NAME_PLAIN_FORMAT = "%s";
+    public static final String CLUSTER_STATE_PATH_TOKEN = "cluster-state";
+    public static final String GLOBAL_METADATA_PATH_TOKEN = "global-metadata";
+    public static final String CLUSTER_STATE_EPHEMERAL_PATH_TOKEN = "ephemeral";
     public static final int GLOBAL_METADATA_CURRENT_CODEC_VERSION = 1;
+    public static final String CUSTOM_DELIMITER = "--";
+    public static final String PATH_DELIMITER = "/";
+    public static final String METADATA_NAME_PLAIN_FORMAT = "%s";
 
     // ToXContent Params with gateway mode.
     // We are using gateway context mode to persist all custom metadata.
     public static final ToXContent.Params FORMAT_PARAMS = new ToXContent.MapParams(
         Map.of(Metadata.CONTEXT_MODE_PARAM, Metadata.CONTEXT_MODE_GATEWAY)
     );
 
+    public static BlobPath getCusterMetadataBasePath(BlobStoreRepository blobStoreRepository, String clusterName, String clusterUUID) {
+        return blobStoreRepository.basePath().add(encodeString(clusterName)).add(CLUSTER_STATE_PATH_TOKEN).add(clusterUUID);
+    }
+
     public static String encodeString(String content) {
         return Base64.getUrlEncoder().withoutPadding().encodeToString(content.getBytes(StandardCharsets.UTF_8));
     }
+
+    public static String getFormattedFileName(String fileName, int codecVersion) {
+        if (codecVersion < ClusterMetadataManifest.CODEC_V2) {
+            return String.format(Locale.ROOT, METADATA_NAME_FORMAT, fileName);
+        }
+        return fileName;
+    }
+
+    static BlobContainer clusterUUIDContainer(BlobStoreRepository blobStoreRepository, String clusterName) {
+        return blobStoreRepository.blobStore()
+            .blobContainer(
+                blobStoreRepository.basePath()
+                    .add(Base64.getUrlEncoder().withoutPadding().encodeToString(clusterName.getBytes(StandardCharsets.UTF_8)))
+                    .add(CLUSTER_STATE_PATH_TOKEN)
+            );
+    }
+
+    /**
+     * Container class to keep metadata of all uploaded attributes
+     */
+    public static class UploadedMetadataResults {
+        List<ClusterMetadataManifest.UploadedIndexMetadata> uploadedIndexMetadata;
+        Map<String, ClusterMetadataManifest.UploadedMetadataAttribute> uploadedCustomMetadataMap;
+        Map<String, ClusterMetadataManifest.UploadedMetadataAttribute> uploadedClusterStateCustomMetadataMap;
+        ClusterMetadataManifest.UploadedMetadataAttribute uploadedCoordinationMetadata;
+        ClusterMetadataManifest.UploadedMetadataAttribute uploadedSettingsMetadata;
+        ClusterMetadataManifest.UploadedMetadataAttribute uploadedTransientSettingsMetadata;
+        ClusterMetadataManifest.UploadedMetadataAttribute uploadedTemplatesMetadata;
+        ClusterMetadataManifest.UploadedMetadataAttribute uploadedDiscoveryNodes;
+        ClusterMetadataManifest.UploadedMetadataAttribute uploadedClusterBlocks;
+        List<ClusterMetadataManifest.UploadedIndexMetadata> uploadedIndicesRoutingMetadata;
+        ClusterMetadataManifest.UploadedMetadataAttribute uploadedHashesOfConsistentSettings;
+
+        public UploadedMetadataResults(
+            List<ClusterMetadataManifest.UploadedIndexMetadata> uploadedIndexMetadata,
+            Map<String, ClusterMetadataManifest.UploadedMetadataAttribute> uploadedCustomMetadataMap,
+            ClusterMetadataManifest.UploadedMetadataAttribute uploadedCoordinationMetadata,
+            ClusterMetadataManifest.UploadedMetadataAttribute uploadedSettingsMetadata,
+            ClusterMetadataManifest.UploadedMetadataAttribute uploadedTransientSettingsMetadata,
+            ClusterMetadataManifest.UploadedMetadataAttribute uploadedTemplatesMetadata,
+            ClusterMetadataManifest.UploadedMetadataAttribute uploadedDiscoveryNodes,
+            ClusterMetadataManifest.UploadedMetadataAttribute uploadedClusterBlocks,
+            List<ClusterMetadataManifest.UploadedIndexMetadata> uploadedIndicesRoutingMetadata,
+            ClusterMetadataManifest.UploadedMetadataAttribute uploadedHashesOfConsistentSettings,
+            Map<String, ClusterMetadataManifest.UploadedMetadataAttribute> uploadedClusterStateCustomMap
+        ) {
+            this.uploadedIndexMetadata = uploadedIndexMetadata;
+            this.uploadedCustomMetadataMap = uploadedCustomMetadataMap;
+            this.uploadedCoordinationMetadata = uploadedCoordinationMetadata;
+            this.uploadedSettingsMetadata = uploadedSettingsMetadata;
+            this.uploadedTransientSettingsMetadata = uploadedTransientSettingsMetadata;
+            this.uploadedTemplatesMetadata = uploadedTemplatesMetadata;
+            this.uploadedDiscoveryNodes = uploadedDiscoveryNodes;
+            this.uploadedClusterBlocks = uploadedClusterBlocks;
+            this.uploadedIndicesRoutingMetadata = uploadedIndicesRoutingMetadata;
+            this.uploadedHashesOfConsistentSettings = uploadedHashesOfConsistentSettings;
+            this.uploadedClusterStateCustomMetadataMap = uploadedClusterStateCustomMap;
+        }
+
+        public UploadedMetadataResults() {
+            this.uploadedIndexMetadata = new ArrayList<>();
+            this.uploadedCustomMetadataMap = new HashMap<>();
+            this.uploadedCoordinationMetadata = null;
+            this.uploadedSettingsMetadata = null;
+            this.uploadedTransientSettingsMetadata = null;
+            this.uploadedTemplatesMetadata = null;
+            this.uploadedDiscoveryNodes = null;
+            this.uploadedClusterBlocks = null;
+            this.uploadedIndicesRoutingMetadata = new ArrayList<>();
+            this.uploadedHashesOfConsistentSettings = null;
+            this.uploadedClusterStateCustomMetadataMap = new HashMap<>();
+        }
+    }
 }