Make IndexStoreListener a pluggable interface

CHANGELOG.md

@@ -11,7 +11,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Add logic in master service to optimize performance and retain detailed logging for critical cluster operations. ([#14795](https://github.com/opensearch-project/OpenSearch/pull/14795))
 - Add Setting to adjust the primary constraint weights ([#16471](https://github.com/opensearch-project/OpenSearch/pull/16471))
 - Switch from `buildSrc/version.properties` to Gradle version catalog (`gradle/libs.versions.toml`) to enable dependabot to perform automated upgrades on common libs ([#16284](https://github.com/opensearch-project/OpenSearch/pull/16284))
-- Add dynamic setting allowing size > 0 requests to be cached in the request cache ([#16483](https://github.com/opensearch-project/OpenSearch/pull/16483/files))
+- Add dynamic setting allowing size > 0 requests to be cached in the request cache ([#16483](https://github.com/opensearch-project/OpenSearch/pull/16483))
+- Make IndexStoreListener a pluggable interface ([#16583](https://github.com/opensearch-project/OpenSearch/pull/16583))
 
 ### Dependencies
 - Bump `com.azure:azure-storage-common` from 12.25.1 to 12.27.1 ([#16521](https://github.com/opensearch-project/OpenSearch/pull/16521))

server/src/main/java/org/opensearch/env/NodeEnvironment.java

@@ -71,6 +71,7 @@
 import org.opensearch.index.IndexSettings;
 import org.opensearch.index.shard.ShardPath;
 import org.opensearch.index.store.FsDirectoryFactory;
+import org.opensearch.index.store.IndexStoreListener;
 import org.opensearch.monitor.fs.FsInfo;
 import org.opensearch.monitor.fs.FsProbe;
 import org.opensearch.monitor.jvm.JvmInfo;
@@ -1412,18 +1413,4 @@ private static void tryWriteTempFile(Path path) throws IOException {
             }
         }
     }
-
-    /**
-     * A listener that is executed on per-index and per-shard store events, like deleting shard path
-     *
-     * @opensearch.internal
-     */
-    public interface IndexStoreListener {
-        default void beforeShardPathDeleted(ShardId shardId, IndexSettings indexSettings, NodeEnvironment env) {}
-
-        default void beforeIndexPathDeleted(Index index, IndexSettings indexSettings, NodeEnvironment env) {}
-
-        IndexStoreListener EMPTY = new IndexStoreListener() {
-        };
-    }
 }

server/src/main/java/org/opensearch/index/store/IndexStoreListener.java

@@ -0,0 +1,73 @@
+/*
+ * 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.index.store;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.apache.logging.log4j.message.ParameterizedMessage;
+import org.opensearch.common.annotation.PublicApi;
+import org.opensearch.core.index.Index;
+import org.opensearch.core.index.shard.ShardId;
+import org.opensearch.env.NodeEnvironment;
+import org.opensearch.index.IndexSettings;
+
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * A listener that is executed on per-index and per-shard store events, like deleting shard path
+ *
+ * @opensearch.api
+ */
+@PublicApi(since = "2.19.0")
+public interface IndexStoreListener {
+    default void beforeShardPathDeleted(ShardId shardId, IndexSettings indexSettings, NodeEnvironment env) {}
+
+    default void beforeIndexPathDeleted(Index index, IndexSettings indexSettings, NodeEnvironment env) {}
+
+    IndexStoreListener EMPTY = new IndexStoreListener() {
+    };
+
+    /**
+     * A Composite listener that multiplexes calls to each of the listeners methods.
+     *
+     * @opensearch.api
+     */
+    @PublicApi(since = "2.19.0")
+    final class CompositeIndexStoreListener implements IndexStoreListener {
+        private final List<IndexStoreListener> listeners;
+        private final static Logger logger = LogManager.getLogger(CompositeIndexStoreListener.class);
+
+        public CompositeIndexStoreListener(List<IndexStoreListener> listeners) {
+            this.listeners = Collections.unmodifiableList(listeners);
+        }
+
+        @Override
+        public void beforeShardPathDeleted(ShardId shardId, IndexSettings indexSettings, NodeEnvironment env) {
+            for (IndexStoreListener listener : listeners) {
+                try {
+                    listener.beforeShardPathDeleted(shardId, indexSettings, env);
+                } catch (Exception e) {
+                    logger.warn(() -> new ParameterizedMessage("beforeShardPathDeleted listener [{}] failed", listener), e);
+                }
+            }
+        }
+
+        @Override
+        public void beforeIndexPathDeleted(Index index, IndexSettings indexSettings, NodeEnvironment env) {
+            for (IndexStoreListener listener : listeners) {
+                try {
+                    listener.beforeIndexPathDeleted(index, indexSettings, env);
+                } catch (Exception e) {
+                    logger.warn(() -> new ParameterizedMessage("beforeIndexPathDeleted listener [{}] failed", listener), e);
+                }
+            }
+        }
+    }
+}

server/src/main/java/org/opensearch/index/store/remote/filecache/FileCacheCleaner.java

@@ -18,6 +18,7 @@
 import org.opensearch.env.NodeEnvironment;
 import org.opensearch.index.IndexSettings;
 import org.opensearch.index.shard.ShardPath;
+import org.opensearch.index.store.IndexStoreListener;
 
 import java.io.IOException;
 import java.nio.file.DirectoryStream;
@@ -33,7 +34,7 @@
  *
  * @opensearch.internal
  */
-public class FileCacheCleaner implements NodeEnvironment.IndexStoreListener {
+public class FileCacheCleaner implements IndexStoreListener {
     private static final Logger logger = LogManager.getLogger(FileCacheCleaner.class);
 
     private final Provider<FileCache> fileCacheProvider;

server/src/main/java/org/opensearch/node/Node.java

@@ -157,6 +157,7 @@
 import org.opensearch.index.recovery.RemoteStoreRestoreService;
 import org.opensearch.index.remote.RemoteIndexPathUploader;
 import org.opensearch.index.remote.RemoteStoreStatsTrackerFactory;
+import org.opensearch.index.store.IndexStoreListener;
 import org.opensearch.index.store.RemoteSegmentStoreDirectoryFactory;
 import org.opensearch.index.store.remote.filecache.FileCache;
 import org.opensearch.index.store.remote.filecache.FileCacheCleaner;
@@ -548,10 +549,27 @@ protected Node(
              */
             this.environment = new Environment(settings, initialEnvironment.configDir(), Node.NODE_LOCAL_STORAGE_SETTING.get(settings));
             Environment.assertEquivalent(initialEnvironment, this.environment);
+            Stream<IndexStoreListener> indexStoreListenerStream = pluginsService.filterPlugins(IndexStorePlugin.class)
+                .stream()
+                .map(IndexStorePlugin::getIndexStoreListener)
+                .filter(Optional::isPresent)
+                .map(Optional::get);
+            // FileCache is only initialized on search nodes, so we only create FileCacheCleaner on search nodes as well
             if (DiscoveryNode.isSearchNode(settings) == false) {
-                nodeEnvironment = new NodeEnvironment(tmpSettings, environment);
+                nodeEnvironment = new NodeEnvironment(
+                    settings,
+                    environment,
+                    new IndexStoreListener.CompositeIndexStoreListener(indexStoreListenerStream.collect(Collectors.toList()))
+                );
             } else {
-                nodeEnvironment = new NodeEnvironment(settings, environment, new FileCacheCleaner(this::fileCache));
+                nodeEnvironment = new NodeEnvironment(
+                    settings,
+                    environment,
+                    new IndexStoreListener.CompositeIndexStoreListener(
+                        Stream.concat(indexStoreListenerStream, Stream.of(new FileCacheCleaner(this::fileCache)))
+                            .collect(Collectors.toList())
+                    )
+                );
             }
             logger.info(
                 "node name [{}], node ID [{}], cluster name [{}], roles {}",

server/src/main/java/org/opensearch/plugins/IndexStorePlugin.java

@@ -39,11 +39,13 @@
 import org.opensearch.common.annotation.PublicApi;
 import org.opensearch.index.IndexSettings;
 import org.opensearch.index.shard.ShardPath;
+import org.opensearch.index.store.IndexStoreListener;
 import org.opensearch.indices.recovery.RecoveryState;
 
 import java.io.IOException;
 import java.util.Collections;
 import java.util.Map;
+import java.util.Optional;
 
 /**
  * A plugin that provides alternative directory implementations.
@@ -105,4 +107,11 @@ interface RecoveryStateFactory {
     default Map<String, RecoveryStateFactory> getRecoveryStateFactories() {
         return Collections.emptyMap();
     }
+
+    /**
+     * The {@link IndexStoreListener}s for this plugin which are triggered upon shard/index path deletion
+     */
+    default Optional<IndexStoreListener> getIndexStoreListener() {
+        return Optional.empty();
+    }
 }

server/src/test/java/org/opensearch/env/NodeEnvironmentTests.java

@@ -45,6 +45,7 @@
 import org.opensearch.core.index.shard.ShardId;
 import org.opensearch.gateway.MetadataStateFormat;
 import org.opensearch.index.IndexSettings;
+import org.opensearch.index.store.IndexStoreListener;
 import org.opensearch.node.Node;
 import org.opensearch.test.IndexSettingsModule;
 import org.opensearch.test.NodeRoles;
@@ -360,24 +361,39 @@ protected void doRun() throws Exception {
     }
 
     public void testIndexStoreListener() throws Exception {
-        final AtomicInteger shardCounter = new AtomicInteger(0);
-        final AtomicInteger indexCounter = new AtomicInteger(0);
+        final AtomicInteger shardCounter1 = new AtomicInteger(0);
+        final AtomicInteger shardCounter2 = new AtomicInteger(0);
+        final AtomicInteger indexCounter1 = new AtomicInteger(0);
+        final AtomicInteger indexCounter2 = new AtomicInteger(0);
         final Index index = new Index("foo", "fooUUID");
         final ShardId shardId = new ShardId(index, 0);
-        final NodeEnvironment.IndexStoreListener listener = new NodeEnvironment.IndexStoreListener() {
+        final IndexStoreListener listener1 = new IndexStoreListener() {
             @Override
             public void beforeShardPathDeleted(ShardId inShardId, IndexSettings indexSettings, NodeEnvironment env) {
                 assertEquals(shardId, inShardId);
-                shardCounter.incrementAndGet();
+                shardCounter1.incrementAndGet();
             }
 
             @Override
             public void beforeIndexPathDeleted(Index inIndex, IndexSettings indexSettings, NodeEnvironment env) {
                 assertEquals(index, inIndex);
-                indexCounter.incrementAndGet();
+                indexCounter1.incrementAndGet();
             }
         };
-        final NodeEnvironment env = newNodeEnvironment(listener);
+        final IndexStoreListener listener2 = new IndexStoreListener() {
+            @Override
+            public void beforeShardPathDeleted(ShardId inShardId, IndexSettings indexSettings, NodeEnvironment env) {
+                assertEquals(shardId, inShardId);
+                shardCounter2.incrementAndGet();
+            }
+
+            @Override
+            public void beforeIndexPathDeleted(Index inIndex, IndexSettings indexSettings, NodeEnvironment env) {
+                assertEquals(index, inIndex);
+                indexCounter2.incrementAndGet();
+            }
+        };
+        final NodeEnvironment env = newNodeEnvironment(new IndexStoreListener.CompositeIndexStoreListener(List.of(listener1, listener2)));
 
         for (Path path : env.indexPaths(index)) {
             Files.createDirectories(path.resolve("0"));
@@ -386,26 +402,30 @@ public void beforeIndexPathDeleted(Index inIndex, IndexSettings indexSettings, N
         for (Path path : env.indexPaths(index)) {
             assertTrue(Files.exists(path.resolve("0")));
         }
-        assertEquals(0, shardCounter.get());
+        assertEquals(0, shardCounter1.get());
+        assertEquals(0, shardCounter2.get());
 
         env.deleteShardDirectorySafe(new ShardId(index, 0), idxSettings);
 
         for (Path path : env.indexPaths(index)) {
             assertFalse(Files.exists(path.resolve("0")));
         }
-        assertEquals(1, shardCounter.get());
+        assertEquals(1, shardCounter1.get());
+        assertEquals(1, shardCounter2.get());
 
         for (Path path : env.indexPaths(index)) {
             assertTrue(Files.exists(path));
         }
-        assertEquals(0, indexCounter.get());
+        assertEquals(0, indexCounter1.get());
+        assertEquals(0, indexCounter2.get());
 
         env.deleteIndexDirectorySafe(index, 5000, idxSettings);
 
         for (Path path : env.indexPaths(index)) {
             assertFalse(Files.exists(path));
         }
-        assertEquals(1, indexCounter.get());
+        assertEquals(1, indexCounter1.get());
+        assertEquals(1, indexCounter2.get());
         assertTrue("LockedShards: " + env.lockedShards(), env.lockedShards().isEmpty());
         env.close();
     }
@@ -680,7 +700,7 @@ public NodeEnvironment newNodeEnvironment() throws IOException {
         return newNodeEnvironment(Settings.EMPTY);
     }
 
-    public NodeEnvironment newNodeEnvironment(NodeEnvironment.IndexStoreListener listener) throws IOException {
+    public NodeEnvironment newNodeEnvironment(IndexStoreListener listener) throws IOException {
         Settings build = buildEnvSettings(Settings.EMPTY);
         return new NodeEnvironment(build, TestEnvironment.newEnvironment(build), listener);
     }