Add filecache support in clear indices cache API

CHANGELOG.md

@@ -92,6 +92,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Adds ExtensionsManager.lookupExtensionSettingsById ([#7466](https://github.com/opensearch-project/OpenSearch/pull/7466))
 - SegRep with Remote: Add hook for publishing checkpoint notifications after segment upload to remote store ([#7394](https://github.com/opensearch-project/OpenSearch/pull/7394))
 - Provide mechanism to configure XContent parsing constraints (after update to Jackson 2.15.0 and above) ([#7550](https://github.com/opensearch-project/OpenSearch/pull/7550))
+- Support to clear filecache using clear indices cache API ([#7498](https://github.com/opensearch-project/OpenSearch/pull/7498))
 
 ### Dependencies
 - Bump `com.netflix.nebula:gradle-info-plugin` from 12.0.0 to 12.1.3 (#7564)

client/rest-high-level/src/main/java/org/opensearch/client/IndicesRequestConverters.java

@@ -261,6 +261,7 @@ static Request clearCache(ClearIndicesCacheRequest clearIndicesCacheRequest) {
         parameters.withIndicesOptions(clearIndicesCacheRequest.indicesOptions());
         parameters.putParam("query", Boolean.toString(clearIndicesCacheRequest.queryCache()));
         parameters.putParam("fielddata", Boolean.toString(clearIndicesCacheRequest.fieldDataCache()));
+        parameters.putParam("file", Boolean.toString(clearIndicesCacheRequest.fileCache()));
         parameters.putParam("request", Boolean.toString(clearIndicesCacheRequest.requestCache()));
         parameters.putParam("fields", String.join(",", clearIndicesCacheRequest.fields()));
         request.addParameters(parameters.asMap());

client/rest-high-level/src/test/java/org/opensearch/client/IndicesRequestConvertersTests.java

@@ -596,6 +596,10 @@ public void testClearCache() {
             clearIndicesCacheRequest.fields(RequestConvertersTests.randomIndicesNames(1, 5));
             expectedParams.put("fields", String.join(",", clearIndicesCacheRequest.fields()));
         }
+        if (OpenSearchTestCase.randomBoolean()) {
+            clearIndicesCacheRequest.fileCache(OpenSearchTestCase.randomBoolean());
+        }
+        expectedParams.put("file", Boolean.toString(clearIndicesCacheRequest.fileCache()));
 
         Request request = IndicesRequestConverters.clearCache(clearIndicesCacheRequest);
         StringJoiner endpoint = new StringJoiner("/", "/", "");

rest-api-spec/src/main/resources/rest-api-spec/api/indices.clear_cache.json

@@ -67,6 +67,10 @@
       "request":{
         "type":"boolean",
         "description":"Clear request cache"
+      },
+      "file":{
+        "type":"boolean",
+        "description":"Clear filecache"
       }
     }
   }

server/src/internalClusterTest/java/org/opensearch/action/admin/indices/cache/clear/ClearIndicesCacheBlocksIT.java

@@ -36,6 +36,7 @@
 import org.opensearch.test.OpenSearchIntegTestCase.ClusterScope;
 
 import java.util.Arrays;
+import java.util.Collections;
 
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_BLOCKS_METADATA;
 import static org.opensearch.cluster.metadata.IndexMetadata.SETTING_BLOCKS_READ;
@@ -89,4 +90,42 @@ public void testClearIndicesCacheWithBlocks() {
             }
         }
     }
+
+    public void testClearIndicesFileCacheWithBlocks() {
+        createIndex("test");
+        ensureGreen("test");
+
+        NumShards numShards = getNumShards("test");
+
+        // Request is not blocked
+        for (String blockSetting : Arrays.asList(
+            SETTING_BLOCKS_READ,
+            SETTING_BLOCKS_WRITE,
+            SETTING_READ_ONLY,
+            SETTING_READ_ONLY_ALLOW_DELETE
+        )) {
+            try {
+                enableIndexBlock("test", blockSetting);
+                ClearIndicesCacheResponse clearIndicesCacheResponse = client().admin()
+                    .indices()
+                    .prepareClearCache("test")
+                    .setFileCache(true)
+                    .execute()
+                    .actionGet();
+                assertNoFailures(clearIndicesCacheResponse);
+                assertThat(clearIndicesCacheResponse.getSuccessfulShards(), equalTo(numShards.totalNumShards));
+            } finally {
+                disableIndexBlock("test", blockSetting);
+            }
+        }
+
+        for (String blockSetting : Collections.singletonList(SETTING_BLOCKS_METADATA)) {
+            try {
+                enableIndexBlock("test", blockSetting);
+                assertBlocked(client().admin().indices().prepareClearCache("test").setQueryCache(true).setFileCache(true));
+            } finally {
+                disableIndexBlock("test", blockSetting);
+            }
+        }
+    }
 }

server/src/main/java/org/opensearch/action/admin/indices/cache/clear/ClearIndicesCacheRequest.java

@@ -32,6 +32,7 @@
 
 package org.opensearch.action.admin.indices.cache.clear;
 
+import org.opensearch.Version;
 import org.opensearch.action.support.broadcast.BroadcastRequest;
 import org.opensearch.common.Strings;
 import org.opensearch.common.io.stream.StreamInput;
@@ -49,6 +50,7 @@ public class ClearIndicesCacheRequest extends BroadcastRequest<ClearIndicesCache
     private boolean queryCache = false;
     private boolean fieldDataCache = false;
     private boolean requestCache = false;
+    private boolean fileCache = false;
     private String[] fields = Strings.EMPTY_ARRAY;
 
     public ClearIndicesCacheRequest(StreamInput in) throws IOException {
@@ -57,6 +59,9 @@ public ClearIndicesCacheRequest(StreamInput in) throws IOException {
         fieldDataCache = in.readBoolean();
         fields = in.readStringArray();
         requestCache = in.readBoolean();
+        if (in.getVersion().onOrAfter(Version.V_3_0_0)) {
+            fileCache = in.readBoolean();
+        }
     }
 
     public ClearIndicesCacheRequest(String... indices) {
@@ -90,6 +95,15 @@ public ClearIndicesCacheRequest fieldDataCache(boolean fieldDataCache) {
         return this;
     }
 
+    public boolean fileCache() {
+        return this.fileCache;
+    }
+
+    public ClearIndicesCacheRequest fileCache(boolean fileCache) {
+        this.fileCache = fileCache;
+        return this;
+    }
+
     public ClearIndicesCacheRequest fields(String... fields) {
         this.fields = fields == null ? Strings.EMPTY_ARRAY : fields;
         return this;
@@ -106,5 +120,8 @@ public void writeTo(StreamOutput out) throws IOException {
         out.writeBoolean(fieldDataCache);
         out.writeStringArrayNullable(fields);
         out.writeBoolean(requestCache);
+        if (out.getVersion().onOrAfter(Version.V_3_0_0)) {
+            out.writeBoolean(fileCache);
+        }
     }
 }

server/src/main/java/org/opensearch/action/admin/indices/cache/clear/ClearIndicesCacheRequestBuilder.java

@@ -59,6 +59,11 @@ public ClearIndicesCacheRequestBuilder setRequestCache(boolean requestCache) {
         return this;
     }
 
+    public ClearIndicesCacheRequestBuilder setFileCache(boolean fileCache) {
+        request.fileCache(fileCache);
+        return this;
+    }
+
     public ClearIndicesCacheRequestBuilder setFieldDataCache(boolean fieldDataCache) {
         request.fieldDataCache(fieldDataCache);
         return this;

server/src/main/java/org/opensearch/action/admin/indices/cache/clear/TransportClearIndicesCacheAction.java

@@ -44,12 +44,16 @@
 import org.opensearch.cluster.service.ClusterService;
 import org.opensearch.common.inject.Inject;
 import org.opensearch.common.io.stream.StreamInput;
+import org.opensearch.index.shard.ShardPath;
 import org.opensearch.indices.IndicesService;
+import org.opensearch.node.Node;
 import org.opensearch.threadpool.ThreadPool;
 import org.opensearch.transport.TransportService;
 
 import java.io.IOException;
+import java.nio.file.Path;
 import java.util.List;
+import java.util.function.Predicate;
 
 /**
  * Indices clear cache action.
@@ -63,11 +67,14 @@ public class TransportClearIndicesCacheAction extends TransportBroadcastByNodeAc
 
     private final IndicesService indicesService;
 
+    private final Node node;
+
     @Inject
     public TransportClearIndicesCacheAction(
         ClusterService clusterService,
         TransportService transportService,
         IndicesService indicesService,
+        Node node,
         ActionFilters actionFilters,
         IndexNameExpressionResolver indexNameExpressionResolver
     ) {
@@ -82,6 +89,7 @@ public TransportClearIndicesCacheAction(
             false
         );
         this.indicesService = indicesService;
+        this.node = node;
     }
 
     @Override
@@ -109,6 +117,14 @@ protected ClearIndicesCacheRequest readRequestFrom(StreamInput in) throws IOExce
 
     @Override
     protected EmptyResult shardOperation(ClearIndicesCacheRequest request, ShardRouting shardRouting) {
+        if (request.fileCache()) {
+            if (node.fileCache() != null) {
+                ShardPath shardPath = ShardPath.loadFileCachePath(node.getNodeEnvironment(), shardRouting.shardId());
+                Predicate<Path> pathStartsWithShardPathPredicate = path -> path.startsWith(shardPath.getDataPath());
+                node.fileCache().prune(pathStartsWithShardPathPredicate);
+            }
+        }
+
         indicesService.clearIndexShardCache(
             shardRouting.shardId(),
             request.queryCache(),

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

@@ -22,6 +22,7 @@
 import java.nio.file.Path;
 import java.util.List;
 import java.util.function.BiFunction;
+import java.util.function.Predicate;
 
 import static org.opensearch.index.store.remote.directory.RemoteSnapshotDirectoryFactory.LOCAL_STORE_LOCATION;
 
@@ -121,6 +122,11 @@ public long prune() {
         return theCache.prune();
     }
 
+    @Override
+    public long prune(Predicate<Path> keyPredicate) {
+        return theCache.prune(keyPredicate);
+    }
+
     @Override
     public CacheUsage usage() {
         return theCache.usage();

server/src/main/java/org/opensearch/index/store/remote/utils/cache/LRUCache.java

@@ -22,6 +22,7 @@
 import java.util.Objects;
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.function.BiFunction;
+import java.util.function.Predicate;
 
 /**
  * LRU implementation of {@link RefCountedCache}. As long as {@link Node#refCount} greater than 0 then node is not eligible for eviction.
@@ -256,13 +257,16 @@ public void decRef(K key) {
     }
 
     @Override
-    public long prune() {
+    public long prune(Predicate<K> keyPredicate) {
         long sum = 0L;
         lock.lock();
         try {
             final Iterator<Node<K, V>> iterator = lru.values().iterator();
             while (iterator.hasNext()) {
                 final Node<K, V> node = iterator.next();
+                if (keyPredicate != null && !keyPredicate.test(node.key)) {
+                    continue;
+                }
                 iterator.remove();
                 data.remove(node.key, node);
                 sum += node.weight;

server/src/main/java/org/opensearch/index/store/remote/utils/cache/RefCountedCache.java

@@ -11,6 +11,7 @@
 import org.opensearch.index.store.remote.utils.cache.stats.CacheStats;
 
 import java.util.function.BiFunction;
+import java.util.function.Predicate;
 
 /**
  * Custom Cache which support typical cache operations (put, get, ...) and it support reference counting per individual key which might
@@ -80,7 +81,17 @@ public interface RefCountedCache<K, V> {
      *
      * @return The total weight of all removed entries.
      */
-    long prune();
+    default long prune() {
+        return prune(key -> true);
+    }
+
+    /**
+     * Removes the cache entries which match the predicate criteria for the key
+     * and have a reference count of zero, regardless of current capacity.
+     *
+     * @return The total weight of all removed entries.
+     */
+    long prune(Predicate<K> keyPredicate);
 
     /**
      * Returns the weighted usage of this cache.

server/src/main/java/org/opensearch/index/store/remote/utils/cache/SegmentedCache.java

@@ -15,6 +15,7 @@
 
 import java.util.Objects;
 import java.util.function.BiFunction;
+import java.util.function.Predicate;
 
 /**
  * Segmented {@link LRUCache} to offer concurrent access with less contention.
@@ -138,6 +139,15 @@ public long prune() {
         return sum;
     }
 
+    @Override
+    public long prune(Predicate<K> keyPredicate) {
+        long sum = 0L;
+        for (RefCountedCache<K, V> cache : table) {
+            sum += cache.prune(keyPredicate);
+        }
+        return sum;
+    }
+
     @Override
     public CacheUsage usage() {
         long usage = 0L;

server/src/main/java/org/opensearch/rest/action/admin/indices/RestClearIndicesCacheAction.java

@@ -83,6 +83,7 @@ public static ClearIndicesCacheRequest fromRequest(final RestRequest request, Cl
         clearIndicesCacheRequest.queryCache(request.paramAsBoolean("query", clearIndicesCacheRequest.queryCache()));
         clearIndicesCacheRequest.requestCache(request.paramAsBoolean("request", clearIndicesCacheRequest.requestCache()));
         clearIndicesCacheRequest.fieldDataCache(request.paramAsBoolean("fielddata", clearIndicesCacheRequest.fieldDataCache()));
+        clearIndicesCacheRequest.fileCache(request.paramAsBoolean("file", clearIndicesCacheRequest.fileCache()));
         clearIndicesCacheRequest.fields(request.paramAsStringArray("fields", clearIndicesCacheRequest.fields()));
         return clearIndicesCacheRequest;
     }

server/src/test/java/org/opensearch/action/admin/indices/cache/clear/TransportClearIndicesCacheActionTests.java

@@ -9,26 +9,45 @@
 package org.opensearch.action.admin.indices.cache.clear;
 
 import org.opensearch.action.support.ActionFilters;
+import org.opensearch.action.support.broadcast.node.TransportBroadcastByNodeAction;
 import org.opensearch.cluster.ClusterState;
 import org.opensearch.cluster.block.ClusterBlock;
 import org.opensearch.cluster.block.ClusterBlockLevel;
 import org.opensearch.cluster.block.ClusterBlocks;
 import org.opensearch.cluster.metadata.IndexNameExpressionResolver;
+import org.opensearch.cluster.routing.ShardRouting;
 import org.opensearch.cluster.service.ClusterService;
+import org.opensearch.common.breaker.NoopCircuitBreaker;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.env.Environment;
+import org.opensearch.env.NodeEnvironment;
+import org.opensearch.env.TestEnvironment;
+import org.opensearch.index.shard.ShardId;
+import org.opensearch.index.shard.ShardPath;
+import org.opensearch.index.store.remote.filecache.FileCache;
+import org.opensearch.index.store.remote.filecache.FileCacheFactory;
+import org.opensearch.index.store.remote.filecache.FileCacheTests;
 import org.opensearch.indices.IndicesService;
+import org.opensearch.node.Node;
 import org.opensearch.rest.RestStatus;
 import org.opensearch.test.OpenSearchTestCase;
 import org.opensearch.transport.TransportService;
 
+import java.io.IOException;
+import java.nio.file.Path;
 import java.util.EnumSet;
 
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
 
 public class TransportClearIndicesCacheActionTests extends OpenSearchTestCase {
+
+    private final Node testNode = mock(Node.class);
     private final TransportClearIndicesCacheAction action = new TransportClearIndicesCacheAction(
         mock(ClusterService.class),
         mock(TransportService.class),
         mock(IndicesService.class),
+        testNode,
         mock(ActionFilters.class),
         mock(IndexNameExpressionResolver.class)
     );
@@ -55,6 +74,40 @@ public class TransportClearIndicesCacheActionTests extends OpenSearchTestCase {
         EnumSet.of(ClusterBlockLevel.METADATA_READ)
     );
 
+    public void testOnShardOperation() throws IOException {
+        final String indexName = "test";
+        final Settings settings = buildEnvSettings(Settings.EMPTY);
+        final Environment environment = TestEnvironment.newEnvironment(settings);
+        try (final NodeEnvironment nodeEnvironment = new NodeEnvironment(settings, environment)) {
+            // Initialize necessary stubs for the filecache clear shard operation
+            final ShardId shardId = new ShardId(indexName, indexName, 1);
+            final ShardRouting shardRouting = mock(ShardRouting.class);
+            when(shardRouting.shardId()).thenReturn(shardId);
+            final ShardPath shardPath = ShardPath.loadFileCachePath(nodeEnvironment, shardId);
+            final Path cacheEntryPath = shardPath.getDataPath();
+            final FileCache fileCache = FileCacheFactory.createConcurrentLRUFileCache(1024 * 1024 * 1024, 16, new NoopCircuitBreaker(""));
+
+            when(testNode.fileCache()).thenReturn(fileCache);
+            when(testNode.getNodeEnvironment()).thenReturn(nodeEnvironment);
+
+            // Add an entry into the filecache and reduce the ref count
+            fileCache.put(cacheEntryPath, new FileCacheTests.StubCachedIndexInput(1));
+            fileCache.decRef(cacheEntryPath);
+
+            // Check if the entry exists and reduce the ref count to make it evictable
+            assertNotNull(fileCache.get(cacheEntryPath));
+            fileCache.decRef(cacheEntryPath);
+
+            ClearIndicesCacheRequest clearIndicesCacheRequest = new ClearIndicesCacheRequest();
+            clearIndicesCacheRequest.fileCache(true);
+            assertEquals(
+                TransportBroadcastByNodeAction.EmptyResult.INSTANCE,
+                action.shardOperation(clearIndicesCacheRequest, shardRouting)
+            );
+            assertNull(fileCache.get(cacheEntryPath));
+        }
+    }
+
     public void testGlobalBlockCheck() {
         ClusterBlocks.Builder builder = ClusterBlocks.builder();
         builder.addGlobalBlock(writeClusterBlock);