[Backport 2.x] Upload remote paths during index creation or full cluster upload

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

@@ -0,0 +1,108 @@
+/*
+ * 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.action.admin.indices.delete.DeleteIndexRequest;
+import org.opensearch.cluster.metadata.IndexMetadata;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.core.util.FileSystemUtils;
+import org.opensearch.index.remote.RemoteIndexPath;
+import org.opensearch.index.remote.RemoteStoreEnums;
+import org.opensearch.test.OpenSearchIntegTestCase;
+
+import java.io.IOException;
+import java.util.Locale;
+import java.util.concurrent.ExecutionException;
+
+import static org.opensearch.gateway.remote.RemoteClusterStateService.REMOTE_CLUSTER_STATE_ENABLED_SETTING;
+import static org.opensearch.indices.RemoteStoreSettings.CLUSTER_REMOTE_STORE_PATH_TYPE_SETTING;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
+
+@OpenSearchIntegTestCase.ClusterScope(scope = OpenSearchIntegTestCase.Scope.TEST, numDataNodes = 0)
+public class RemoteStoreUploadIndexPathIT extends RemoteStoreBaseIntegTestCase {
+
+    private final String INDEX_NAME = "remote-store-test-idx-1";
+
+    @Override
+    protected Settings nodeSettings(int nodeOrdinal) {
+        return Settings.builder().put(super.nodeSettings(nodeOrdinal)).put(REMOTE_CLUSTER_STATE_ENABLED_SETTING.getKey(), true).build();
+    }
+
+    /**
+     * Checks that the remote index path file gets created for the intended remote store path type and does not get created
+     * wherever not required.
+     */
+    public void testRemoteIndexPathFileCreation() throws ExecutionException, InterruptedException, IOException {
+        String clusterManagerNode = internalCluster().startClusterManagerOnlyNode();
+        internalCluster().startDataOnlyNodes(2);
+
+        // Case 1 - Hashed_prefix, we would need the remote index path file to be created.
+        client(clusterManagerNode).admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(
+                Settings.builder().put(CLUSTER_REMOTE_STORE_PATH_TYPE_SETTING.getKey(), RemoteStoreEnums.PathType.HASHED_PREFIX)
+            )
+            .get();
+
+        createIndex(INDEX_NAME, remoteStoreIndexSettings(0, 1));
+        validateRemoteIndexPathFile(true);
+        assertAcked(client().admin().indices().delete(new DeleteIndexRequest(INDEX_NAME)).get());
+        FileSystemUtils.deleteSubDirectories(translogRepoPath);
+        FileSystemUtils.deleteSubDirectories(segmentRepoPath);
+
+        // Case 2 - Hashed_infix, we would not have the remote index path file created here.
+        client(clusterManagerNode).admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(
+                Settings.builder().put(CLUSTER_REMOTE_STORE_PATH_TYPE_SETTING.getKey(), RemoteStoreEnums.PathType.HASHED_INFIX)
+            )
+            .get();
+        createIndex(INDEX_NAME, remoteStoreIndexSettings(0, 1));
+        validateRemoteIndexPathFile(false);
+        assertAcked(client().admin().indices().delete(new DeleteIndexRequest(INDEX_NAME)).get());
+
+        // Case 3 - fixed, we would not have the remote index path file created here either.
+        client(clusterManagerNode).admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(Settings.builder().put(CLUSTER_REMOTE_STORE_PATH_TYPE_SETTING.getKey(), RemoteStoreEnums.PathType.FIXED))
+            .get();
+        createIndex(INDEX_NAME, remoteStoreIndexSettings(0, 1));
+        validateRemoteIndexPathFile(false);
+        assertAcked(client().admin().indices().delete(new DeleteIndexRequest(INDEX_NAME)).get());
+
+    }
+
+    private void validateRemoteIndexPathFile(boolean exists) {
+        String indexUUID = client().admin()
+            .indices()
+            .prepareGetSettings(INDEX_NAME)
+            .get()
+            .getSetting(INDEX_NAME, IndexMetadata.SETTING_INDEX_UUID);
+
+        assertEquals(exists, FileSystemUtils.exists(translogRepoPath.resolve(RemoteIndexPath.DIR)));
+        assertEquals(
+            exists,
+            FileSystemUtils.exists(
+                translogRepoPath.resolve(RemoteIndexPath.DIR)
+                    .resolve(String.format(Locale.ROOT, RemoteIndexPath.FILE_NAME_FORMAT, indexUUID))
+            )
+        );
+        assertEquals(exists, FileSystemUtils.exists(segmentRepoPath.resolve(RemoteIndexPath.DIR)));
+        assertEquals(
+            exists,
+            FileSystemUtils.exists(
+                segmentRepoPath.resolve(RemoteIndexPath.DIR)
+                    .resolve(String.format(Locale.ROOT, RemoteIndexPath.FILE_NAME_FORMAT, indexUUID))
+            )
+        );
+    }
+}

server/src/main/java/org/opensearch/common/blobstore/transfer/RemoteTransferContainer.java

@@ -51,7 +51,7 @@ public class RemoteTransferContainer implements Closeable {
     private final String remoteFileName;
     private final boolean failTransferIfFileExists;
     private final WritePriority writePriority;
-    private final long expectedChecksum;
+    private final Long expectedChecksum;
     private final OffsetRangeInputStreamSupplier offsetRangeInputStreamSupplier;
     private final boolean isRemoteDataIntegritySupported;
     private final AtomicBoolean readBlock = new AtomicBoolean();
@@ -77,7 +77,7 @@ public RemoteTransferContainer(
         boolean failTransferIfFileExists,
         WritePriority writePriority,
         OffsetRangeInputStreamSupplier offsetRangeInputStreamSupplier,
-        long expectedChecksum,
+        Long expectedChecksum,
         boolean isRemoteDataIntegritySupported
     ) {
         this.fileName = fileName;
@@ -190,15 +190,15 @@ private LocalStreamSupplier<InputStreamContainer> getMultipartStreamSupplier(
     }
 
     private boolean isRemoteDataIntegrityCheckPossible() {
-        return isRemoteDataIntegritySupported;
+        return isRemoteDataIntegritySupported && Objects.nonNull(expectedChecksum);
     }
 
     private void finalizeUpload(boolean uploadSuccessful) throws IOException {
         if (isRemoteDataIntegrityCheckPossible()) {
             return;
         }
 
-        if (uploadSuccessful) {
+        if (uploadSuccessful && Objects.nonNull(expectedChecksum)) {
             long actualChecksum = getActualChecksum();
             if (actualChecksum != expectedChecksum) {
                 throw new CorruptIndexException(

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

@@ -0,0 +1,49 @@
+/*
+ * 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.cluster.metadata.IndexMetadata;
+import org.opensearch.core.action.ActionListener;
+import org.opensearch.threadpool.ThreadPool;
+
+import java.util.List;
+import java.util.Objects;
+import java.util.concurrent.ExecutorService;
+
+/**
+ * Hook for running code that needs to be executed before the upload of index metadata. Here we have introduced a hook
+ * for index creation (also triggerred after enabling the remote cluster statement for the first time). The listener
+ * is intended to be run in parallel and async with the index metadata upload.
+ *
+ * @opensearch.internal
+ */
+public abstract class IndexMetadataUploadListener {
+
+    private final ExecutorService executorService;
+
+    public IndexMetadataUploadListener(ThreadPool threadPool, String threadPoolName) {
+        Objects.requireNonNull(threadPool);
+        Objects.requireNonNull(threadPoolName);
+        assert ThreadPool.THREAD_POOL_TYPES.containsKey(threadPoolName) && ThreadPool.Names.SAME.equals(threadPoolName) == false;
+        this.executorService = threadPool.executor(threadPoolName);
+    }
+
+    /**
+     * Runs before the new index upload of index metadata (or first time upload). The caller is expected to trigger
+     * onSuccess or onFailure of the {@code ActionListener}.
+     *
+     * @param indexMetadataList list of index metadata of new indexes (or first time index metadata upload).
+     * @param actionListener    listener to be invoked on success or failure.
+     */
+    public final void onNewIndexUpload(List<IndexMetadata> indexMetadataList, ActionListener<Void> actionListener) {
+        executorService.execute(() -> doOnNewIndexUpload(indexMetadataList, actionListener));
+    }
+
+    protected abstract void doOnNewIndexUpload(List<IndexMetadata> indexMetadataList, ActionListener<Void> actionListener);
+}