[Backport 2.x] Introduce cluster default remote translog buffer interval setting (#9584)

CHANGELOG.md

@@ -29,6 +29,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Core crypto library to perform encryption and decryption of source content ([#8466](https://github.com/opensearch-project/OpenSearch/pull/8466))
 - Expose DelimitedTermFrequencyTokenFilter to allow providing term frequencies along with terms ([#9479](https://github.com/opensearch-project/OpenSearch/pull/9479))
 - APIs for performing async blob reads and async downloads from the repository using multiple streams ([#9592](https://github.com/opensearch-project/OpenSearch/issues/9592))
+- Introduce cluster default remote translog buffer interval setting ([#9584](https://github.com/opensearch-project/OpenSearch/pull/9584))
 
 ### Dependencies
 - Bump `org.apache.logging.log4j:log4j-core` from 2.17.1 to 2.20.0 ([#8307](https://github.com/opensearch-project/OpenSearch/pull/8307))

server/src/internalClusterTest/java/org/opensearch/index/shard/IndexShardIT.java

@@ -678,7 +678,8 @@ public static final IndexShard newIndexShard(
             (indexSettings, shardRouting) -> new InternalTranslogFactory(),
             SegmentReplicationCheckpointPublisher.EMPTY,
             null,
-            null
+            null,
+            () -> IndexSettings.DEFAULT_REMOTE_TRANSLOG_BUFFER_INTERVAL
         );
     }
 

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

@@ -9,11 +9,21 @@
 package org.opensearch.remotestore;
 
 import org.opensearch.action.admin.indices.delete.DeleteIndexRequest;
+import org.opensearch.action.admin.indices.get.GetIndexRequest;
+import org.opensearch.action.admin.indices.get.GetIndexResponse;
 import org.opensearch.action.admin.indices.recovery.RecoveryResponse;
+import org.opensearch.action.admin.indices.settings.put.UpdateSettingsRequest;
 import org.opensearch.action.index.IndexResponse;
 import org.opensearch.cluster.metadata.IndexMetadata;
 import org.opensearch.cluster.routing.RecoverySource;
 import org.opensearch.common.settings.Settings;
+import org.opensearch.common.unit.TimeValue;
+import org.opensearch.common.util.concurrent.BufferedAsyncIOProcessor;
+import org.opensearch.core.index.Index;
+import org.opensearch.index.IndexService;
+import org.opensearch.index.IndexSettings;
+import org.opensearch.index.shard.IndexShard;
+import org.opensearch.indices.IndicesService;
 import org.opensearch.indices.recovery.RecoveryState;
 import org.opensearch.plugins.Plugin;
 import org.opensearch.test.OpenSearchIntegTestCase;
@@ -26,9 +36,11 @@
 import java.util.Collection;
 import java.util.Map;
 import java.util.Optional;
+import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 
 import static org.opensearch.index.shard.RemoteStoreRefreshListener.LAST_N_METADATA_FILES_TO_KEEP;
+import static org.opensearch.indices.IndicesService.CLUSTER_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
 import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertHitCount;
 import static org.hamcrest.Matchers.comparesEqualTo;
@@ -184,4 +196,161 @@ public void testStaleCommitDeletionWithoutInvokeFlush() throws Exception {
         // We also allow (numberOfIterations + 1) as index creation also triggers refresh.
         MatcherAssert.assertThat(actualFileCount, is(oneOf(numberOfIterations - 1, numberOfIterations, numberOfIterations + 1)));
     }
+
+    /**
+     * Tests that when the index setting is not passed during index creation, the buffer interval picked up is the cluster
+     * default.
+     */
+    public void testDefaultBufferInterval() throws ExecutionException, InterruptedException {
+        setupRepo();
+        String clusterManagerName = internalCluster().getClusterManagerName();
+        String dataNode = internalCluster().startDataOnlyNodes(1).get(0);
+        createIndex(INDEX_NAME);
+        ensureYellowAndNoInitializingShards(INDEX_NAME);
+        ensureGreen(INDEX_NAME);
+        assertClusterRemoteBufferInterval(IndexSettings.DEFAULT_REMOTE_TRANSLOG_BUFFER_INTERVAL, dataNode);
+
+        IndexShard indexShard = getIndexShard(dataNode);
+        assertTrue(indexShard.getTranslogSyncProcessor() instanceof BufferedAsyncIOProcessor);
+        assertBufferInterval(IndexSettings.DEFAULT_REMOTE_TRANSLOG_BUFFER_INTERVAL, indexShard);
+
+        // Next, we change the default buffer interval and the same should reflect in the buffer interval of the index created
+        TimeValue clusterBufferInterval = TimeValue.timeValueSeconds(randomIntBetween(100, 200));
+        client(clusterManagerName).admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(Settings.builder().put(CLUSTER_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING.getKey(), clusterBufferInterval))
+            .get();
+        assertBufferInterval(clusterBufferInterval, indexShard);
+        clearClusterBufferIntervalSetting(clusterManagerName);
+    }
+
+    /**
+     * This tests multiple cases where the index setting is passed during the index creation with multiple combinations
+     * with and without cluster default.
+     */
+    public void testOverriddenBufferInterval() throws ExecutionException, InterruptedException {
+        setupRepo();
+        String clusterManagerName = internalCluster().getClusterManagerName();
+        String dataNode = internalCluster().startDataOnlyNodes(1).get(0);
+
+        TimeValue bufferInterval = TimeValue.timeValueSeconds(randomIntBetween(0, 100));
+        Settings indexSettings = Settings.builder()
+            .put(indexSettings())
+            .put(IndexSettings.INDEX_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING.getKey(), bufferInterval)
+            .build();
+        createIndex(INDEX_NAME, indexSettings);
+        ensureYellowAndNoInitializingShards(INDEX_NAME);
+        ensureGreen(INDEX_NAME);
+
+        IndexShard indexShard = getIndexShard(dataNode);
+        assertTrue(indexShard.getTranslogSyncProcessor() instanceof BufferedAsyncIOProcessor);
+        assertBufferInterval(bufferInterval, indexShard);
+
+        // Set the cluster default with a different value, validate that the buffer interval is still the overridden value
+        TimeValue clusterBufferInterval = TimeValue.timeValueSeconds(randomIntBetween(100, 200));
+        client(clusterManagerName).admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(Settings.builder().put(CLUSTER_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING.getKey(), clusterBufferInterval))
+            .get();
+        assertBufferInterval(bufferInterval, indexShard);
+
+        // Set the index setting (index.remote_store.translog.buffer_interval) with a different value and validate that
+        // the buffer interval is updated
+        bufferInterval = TimeValue.timeValueSeconds(bufferInterval.seconds() + randomIntBetween(1, 100));
+        client(clusterManagerName).admin()
+            .indices()
+            .updateSettings(
+                new UpdateSettingsRequest(INDEX_NAME).settings(
+                    Settings.builder().put(IndexSettings.INDEX_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING.getKey(), bufferInterval)
+                )
+            )
+            .get();
+        assertBufferInterval(bufferInterval, indexShard);
+
+        // Set the index setting (index.remote_store.translog.buffer_interval) with null and validate the buffer interval
+        // which will be the cluster default now.
+        client(clusterManagerName).admin()
+            .indices()
+            .updateSettings(
+                new UpdateSettingsRequest(INDEX_NAME).settings(
+                    Settings.builder().putNull(IndexSettings.INDEX_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING.getKey())
+                )
+            )
+            .get();
+        assertBufferInterval(clusterBufferInterval, indexShard);
+        clearClusterBufferIntervalSetting(clusterManagerName);
+    }
+
+    /**
+     * This tests validation which kicks in during index creation failing creation if the value is less than minimum allowed value.
+     */
+    public void testOverriddenBufferIntervalValidation() {
+        setupRepo();
+        TimeValue bufferInterval = TimeValue.timeValueSeconds(-1);
+        Settings indexSettings = Settings.builder()
+            .put(indexSettings())
+            .put(IndexSettings.INDEX_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING.getKey(), bufferInterval)
+            .build();
+        IllegalArgumentException exceptionDuringCreateIndex = assertThrows(
+            IllegalArgumentException.class,
+            () -> createIndex(INDEX_NAME, indexSettings)
+        );
+        assertEquals(
+            "failed to parse value [-1] for setting [index.remote_store.translog.buffer_interval], must be >= [0ms]",
+            exceptionDuringCreateIndex.getMessage()
+        );
+    }
+
+    /**
+     * This tests validation of the cluster setting when being set.
+     */
+    public void testClusterBufferIntervalValidation() {
+        String clusterManagerName = internalCluster().startClusterManagerOnlyNode();
+        setupRepo(false);
+        IllegalArgumentException exception = assertThrows(
+            IllegalArgumentException.class,
+            () -> client(clusterManagerName).admin()
+                .cluster()
+                .prepareUpdateSettings()
+                .setTransientSettings(
+                    Settings.builder().put(CLUSTER_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING.getKey(), TimeValue.timeValueSeconds(-1))
+                )
+                .get()
+        );
+        assertEquals(
+            "failed to parse value [-1] for setting [cluster.remote_store.translog.buffer_interval], must be >= [0ms]",
+            exception.getMessage()
+        );
+    }
+
+    private IndexShard getIndexShard(String dataNode) throws ExecutionException, InterruptedException {
+        String clusterManagerName = internalCluster().getClusterManagerName();
+        IndicesService indicesService = internalCluster().getInstance(IndicesService.class, dataNode);
+        GetIndexResponse getIndexResponse = client(clusterManagerName).admin().indices().getIndex(new GetIndexRequest()).get();
+        String uuid = getIndexResponse.getSettings().get(INDEX_NAME).get(IndexMetadata.SETTING_INDEX_UUID);
+        IndexService indexService = indicesService.indexService(new Index(INDEX_NAME, uuid));
+        return indexService.getShard(0);
+    }
+
+    private void assertClusterRemoteBufferInterval(TimeValue expectedBufferInterval, String dataNode) {
+        IndicesService indicesService = internalCluster().getInstance(IndicesService.class, dataNode);
+        assertEquals(expectedBufferInterval, indicesService.getClusterRemoteTranslogBufferInterval());
+    }
+
+    private void assertBufferInterval(TimeValue expectedBufferInterval, IndexShard indexShard) {
+        assertEquals(
+            expectedBufferInterval,
+            ((BufferedAsyncIOProcessor<?>) indexShard.getTranslogSyncProcessor()).getBufferIntervalSupplier().get()
+        );
+    }
+
+    private void clearClusterBufferIntervalSetting(String clusterManagerName) {
+        client(clusterManagerName).admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(Settings.builder().putNull(CLUSTER_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING.getKey()))
+            .get();
+    }
 }

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

@@ -689,7 +689,8 @@ public void apply(Settings value, Settings current, Settings previous) {
         List.of(
             IndicesService.CLUSTER_REMOTE_STORE_ENABLED_SETTING,
             IndicesService.CLUSTER_REMOTE_SEGMENT_STORE_REPOSITORY_SETTING,
-            IndicesService.CLUSTER_REMOTE_TRANSLOG_REPOSITORY_SETTING
+            IndicesService.CLUSTER_REMOTE_TRANSLOG_REPOSITORY_SETTING,
+            IndicesService.CLUSTER_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING
         ),
         List.of(FeatureFlags.CONCURRENT_SEGMENT_SEARCH),
         List.of(

server/src/main/java/org/opensearch/common/util/concurrent/BufferedAsyncIOProcessor.java

@@ -92,4 +92,8 @@
 
     protected abstract String getBufferProcessThreadPoolName();
 
+    // Exclusively for testing, please do not use it elsewhere.
+    public Supplier<TimeValue> getBufferIntervalSupplier() {
+        return bufferIntervalSupplier;
+    }
 }

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

@@ -602,7 +602,8 @@ public IndexService newIndexService(
         ValuesSourceRegistry valuesSourceRegistry,
         IndexStorePlugin.DirectoryFactory remoteDirectoryFactory,
         BiFunction<IndexSettings, ShardRouting, TranslogFactory> translogFactorySupplier,
-        Supplier<TimeValue> clusterDefaultRefreshIntervalSupplier
+        Supplier<TimeValue> clusterDefaultRefreshIntervalSupplier,
+        Supplier<TimeValue> clusterRemoteTranslogBufferIntervalSupplier
     ) throws IOException {
         final IndexEventListener eventListener = freeze();
         Function<IndexService, CheckedFunction<DirectoryReader, DirectoryReader, IOException>> readerWrapperFactory = indexReaderWrapper
@@ -659,7 +660,8 @@ public IndexService newIndexService(
                 valuesSourceRegistry,
                 recoveryStateFactory,
                 translogFactorySupplier,
-                clusterDefaultRefreshIntervalSupplier
+                clusterDefaultRefreshIntervalSupplier,
+                clusterRemoteTranslogBufferIntervalSupplier
             );
             success = true;
             return indexService;

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

@@ -177,6 +177,7 @@ public class IndexService extends AbstractIndexComponent implements IndicesClust
     private final ValuesSourceRegistry valuesSourceRegistry;
     private final BiFunction<IndexSettings, ShardRouting, TranslogFactory> translogFactorySupplier;
     private final Supplier<TimeValue> clusterDefaultRefreshIntervalSupplier;
+    private final Supplier<TimeValue> clusterRemoteTranslogBufferIntervalSupplier;
 
     public IndexService(
         IndexSettings indexSettings,
@@ -210,7 +211,8 @@ public IndexService(
         ValuesSourceRegistry valuesSourceRegistry,
         IndexStorePlugin.RecoveryStateFactory recoveryStateFactory,
         BiFunction<IndexSettings, ShardRouting, TranslogFactory> translogFactorySupplier,
-        Supplier<TimeValue> clusterDefaultRefreshIntervalSupplier
+        Supplier<TimeValue> clusterDefaultRefreshIntervalSupplier,
+        Supplier<TimeValue> clusterRemoteTranslogBufferIntervalSupplier
     ) {
         super(indexSettings);
         this.allowExpensiveQueries = allowExpensiveQueries;
@@ -284,6 +286,7 @@ public IndexService(
         this.globalCheckpointTask = new AsyncGlobalCheckpointTask(this);
         this.retentionLeaseSyncTask = new AsyncRetentionLeaseSyncTask(this);
         this.translogFactorySupplier = translogFactorySupplier;
+        this.clusterRemoteTranslogBufferIntervalSupplier = clusterRemoteTranslogBufferIntervalSupplier;
         updateFsyncTaskIfNecessary();
     }
 
@@ -512,7 +515,8 @@ public synchronized IndexShard createShard(
                 translogFactorySupplier,
                 this.indexSettings.isSegRepEnabled() ? checkpointPublisher : null,
                 remoteStore,
-                remoteStoreStatsTrackerFactory
+                remoteStoreStatsTrackerFactory,
+                clusterRemoteTranslogBufferIntervalSupplier
             );
             eventListener.indexShardStateChanged(indexShard, null, indexShard.state(), "shard created");
             eventListener.afterIndexShardCreated(indexShard);

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

@@ -1196,6 +1196,13 @@ public TimeValue getRemoteTranslogUploadBufferInterval() {
         return remoteTranslogUploadBufferInterval;
     }
 
+    /**
+     * Returns true iff the remote translog buffer interval setting exists or in other words is explicitly set.
+     */
+    public boolean isRemoteTranslogBufferIntervalExplicit() {
+        return INDEX_REMOTE_TRANSLOG_BUFFER_INTERVAL_SETTING.exists(settings);
+    }
+
     public void setRemoteTranslogUploadBufferInterval(TimeValue remoteTranslogUploadBufferInterval) {
         this.remoteTranslogUploadBufferInterval = remoteTranslogUploadBufferInterval;
     }

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

@@ -363,7 +363,8 @@
         final BiFunction<IndexSettings, ShardRouting, TranslogFactory> translogFactorySupplier,
         @Nullable final SegmentReplicationCheckpointPublisher checkpointPublisher,
         @Nullable final Store remoteStore,
-        final RemoteStoreStatsTrackerFactory remoteStoreStatsTrackerFactory
+        final RemoteStoreStatsTrackerFactory remoteStoreStatsTrackerFactory,
+        final Supplier<TimeValue> clusterRemoteTranslogBufferIntervalSupplier
     ) throws IOException {
         super(shardRouting.shardId(), indexSettings);
         assert shardRouting.initializing();
@@ -384,7 +385,7 @@
             threadPool,
             this::getEngine,
             indexSettings.isRemoteTranslogStoreEnabled(),
-            indexSettings::getRemoteTranslogUploadBufferInterval
+            () -> getRemoteTranslogUploadBufferInterval(clusterRemoteTranslogBufferIntervalSupplier)
         );
         this.mapperService = mapperService;
         this.indexCache = indexCache;
@@ -4130,6 +4131,8 @@
         boolean bufferAsyncIoProcessor,
         Supplier<TimeValue> bufferIntervalSupplier
     ) {
+        assert bufferAsyncIoProcessor == false || Objects.nonNull(bufferIntervalSupplier)
+            : "If bufferAsyncIoProcessor is true, then the bufferIntervalSupplier needs to be non null";
         ThreadContext threadContext = threadPool.getThreadContext();
         CheckedConsumer<List<Tuple<Translog.Location, Consumer<Exception>>>, IOException> writeConsumer = candidates -> {
             try {
@@ -4922,4 +4925,17 @@
     public GatedCloseable<SegmentInfos> getSegmentInfosSnapshot() {
         return getEngine().getSegmentInfosSnapshot();
     }
+
+    private TimeValue getRemoteTranslogUploadBufferInterval(Supplier<TimeValue> clusterRemoteTranslogBufferIntervalSupplier) {
+        assert Objects.nonNull(clusterRemoteTranslogBufferIntervalSupplier) : "remote translog buffer interval supplier is null";
+        if (indexSettings().isRemoteTranslogBufferIntervalExplicit()) {
+            return indexSettings().getRemoteTranslogUploadBufferInterval();
+        }
+        return clusterRemoteTranslogBufferIntervalSupplier.get();
+    }
+
+    // Exclusively for testing, please do not use it elsewhere.
+    public AsyncIOProcessor<Translog.Location> getTranslogSyncProcessor() {
+        return translogSyncProcessor;
+    }
 }