Add searchable snapshots cache directory

x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/SearchableSnapshotRepository.java

@@ -27,8 +27,11 @@
 import org.elasticsearch.repositories.Repository;
 import org.elasticsearch.repositories.blobstore.BlobStoreRepository;
 import org.elasticsearch.snapshots.SnapshotId;
+import org.elasticsearch.xpack.searchablesnapshots.cache.CacheDirectory;
+import org.elasticsearch.xpack.searchablesnapshots.cache.CacheService;
 
 import java.io.IOException;
+import java.nio.file.Path;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.function.Function;
@@ -53,6 +56,8 @@ public class SearchableSnapshotRepository extends FilterRepository {
         Setting.simpleString("index.store.snapshot.snapshot_uuid", Setting.Property.IndexScope, Setting.Property.PrivateIndex);
     public static final Setting<String> SNAPSHOT_INDEX_ID_SETTING =
         Setting.simpleString("index.store.snapshot.index_uuid", Setting.Property.IndexScope, Setting.Property.PrivateIndex);
+    public static final Setting<Boolean> SNAPSHOT_CACHE_ENABLED_SETTING =
+        Setting.boolSetting("index.store.snapshot.cache.enabled", true, Setting.Property.IndexScope);
 
     public static final String SNAPSHOT_DIRECTORY_FACTORY_KEY = "snapshot";
 
@@ -64,12 +69,12 @@ public class SearchableSnapshotRepository extends FilterRepository {
     public SearchableSnapshotRepository(Repository in) {
         super(in);
         if (in instanceof BlobStoreRepository == false) {
-            throw new IllegalArgumentException("Repository [" + in + "] does not support searchable snapshots" );
+            throw new IllegalArgumentException("Repository [" + in + "] does not support searchable snapshots");
         }
         blobStoreRepository = (BlobStoreRepository) in;
     }
 
-    private Directory makeDirectory(IndexSettings indexSettings, ShardPath shardPath) throws IOException {
+    private Directory makeDirectory(IndexSettings indexSettings, ShardPath shardPath, CacheService cacheService) throws IOException {
 
         IndexId indexId = new IndexId(indexSettings.getIndex().getName(), SNAPSHOT_INDEX_ID_SETTING.get(indexSettings.getSettings()));
         BlobContainer blobContainer = blobStoreRepository.shardContainer(indexId, shardPath.getShardId().id());
@@ -78,10 +83,14 @@ private Directory makeDirectory(IndexSettings indexSettings, ShardPath shardPath
             SNAPSHOT_SNAPSHOT_ID_SETTING.get(indexSettings.getSettings()));
         BlobStoreIndexShardSnapshot snapshot = blobStoreRepository.loadShardSnapshot(blobContainer, snapshotId);
 
-        final SearchableSnapshotDirectory searchableSnapshotDirectory = new SearchableSnapshotDirectory(snapshot, blobContainer);
-        final InMemoryNoOpCommitDirectory inMemoryNoOpCommitDirectory = new InMemoryNoOpCommitDirectory(searchableSnapshotDirectory);
+        Directory directory = new SearchableSnapshotDirectory(snapshot, blobContainer);
+        if (SNAPSHOT_CACHE_ENABLED_SETTING.get(indexSettings.getSettings())) {
+            final Path cacheDir = shardPath.getDataPath().resolve("snapshots").resolve(snapshotId.getUUID());
+            directory = new CacheDirectory(directory, cacheService, cacheDir);
+        }
+        directory = new InMemoryNoOpCommitDirectory(directory);
 
-        try (IndexWriter indexWriter = new IndexWriter(inMemoryNoOpCommitDirectory, new IndexWriterConfig())) {
+        try (IndexWriter indexWriter = new IndexWriter(directory, new IndexWriterConfig())) {
             final Map<String, String> userData = new HashMap<>();
             indexWriter.getLiveCommitData().forEach(e -> userData.put(e.getKey(), e.getValue()));
 
@@ -94,7 +103,7 @@ private Directory makeDirectory(IndexSettings indexSettings, ShardPath shardPath
             indexWriter.commit();
         }
 
-        return inMemoryNoOpCommitDirectory;
+        return directory;
     }
 
     @Override
@@ -136,17 +145,21 @@ public Repository create(RepositoryMetaData metaData, Function<String, Factory>
         };
     }
 
-    public static IndexStorePlugin.DirectoryFactory newDirectoryFactory(final Supplier<RepositoriesService> repositoriesService) {
+    public static IndexStorePlugin.DirectoryFactory newDirectoryFactory(final Supplier<RepositoriesService> repositoriesService,
+                                                                        final Supplier<CacheService> cacheService) {
         return (indexSettings, shardPath) -> {
             final RepositoriesService repositories = repositoriesService.get();
             assert repositories != null;
 
             final Repository repository = repositories.repository(SNAPSHOT_REPOSITORY_SETTING.get(indexSettings.getSettings()));
             if (repository instanceof SearchableSnapshotRepository == false) {
-                throw new IllegalArgumentException("Repository [" + repository + "] is not searchable" );
+                throw new IllegalArgumentException("Repository [" + repository + "] is not searchable");
             }
 
-            return ((SearchableSnapshotRepository)repository).makeDirectory(indexSettings, shardPath);
+            final CacheService cache = cacheService.get();
+            assert cache != null;
+
+            return ((SearchableSnapshotRepository) repository).makeDirectory(indexSettings, shardPath, cache);
         };
     }
 }

x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/xpack/searchablesnapshots/SearchableSnapshots.java

@@ -6,10 +6,14 @@
 package org.elasticsearch.xpack.searchablesnapshots;
 
 import org.apache.lucene.util.SetOnce;
+import org.elasticsearch.client.Client;
 import org.elasticsearch.cluster.service.ClusterService;
+import org.elasticsearch.common.io.stream.NamedWriteableRegistry;
 import org.elasticsearch.common.settings.Setting;
+import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.env.Environment;
+import org.elasticsearch.env.NodeEnvironment;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.engine.EngineFactory;
 import org.elasticsearch.index.engine.ReadOnlyEngine;
@@ -21,7 +25,12 @@
 import org.elasticsearch.repositories.RepositoriesModule;
 import org.elasticsearch.repositories.RepositoriesService;
 import org.elasticsearch.repositories.Repository;
+import org.elasticsearch.script.ScriptService;
+import org.elasticsearch.threadpool.ThreadPool;
+import org.elasticsearch.watcher.ResourceWatcherService;
+import org.elasticsearch.xpack.searchablesnapshots.cache.CacheService;
 
+import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
@@ -36,17 +45,41 @@
 public class SearchableSnapshots extends Plugin implements IndexStorePlugin, RepositoryPlugin, EnginePlugin {
 
     private final SetOnce<RepositoriesService> repositoriesService;
+    private final SetOnce<CacheService> cacheService;
+    private final Settings settings;
 
-    public SearchableSnapshots() {
+    public SearchableSnapshots(final Settings settings) {
         this.repositoriesService = new SetOnce<>();
+        this.cacheService = new SetOnce<>();
+        this.settings = settings;
     }
 
     @Override
     public List<Setting<?>> getSettings() {
         return List.of(SearchableSnapshotRepository.SNAPSHOT_REPOSITORY_SETTING,
             SearchableSnapshotRepository.SNAPSHOT_SNAPSHOT_NAME_SETTING,
             SearchableSnapshotRepository.SNAPSHOT_SNAPSHOT_ID_SETTING,
-            SearchableSnapshotRepository.SNAPSHOT_INDEX_ID_SETTING);
+            SearchableSnapshotRepository.SNAPSHOT_INDEX_ID_SETTING,
+            SearchableSnapshotRepository.SNAPSHOT_CACHE_ENABLED_SETTING,
+            CacheService.SNAPSHOT_CACHE_SIZE_SETTING
+        );
+    }
+
+    @Override
+    public Collection<Object> createComponents(
+            final Client client,
+            final ClusterService clusterService,
+            final ThreadPool threadPool,
+            final ResourceWatcherService resourceWatcherService,
+            final ScriptService scriptService,
+            final NamedXContentRegistry xContentRegistry,
+            final Environment environment,
+            final NodeEnvironment nodeEnvironment,
+            final NamedWriteableRegistry namedWriteableRegistry) {
+
+        final CacheService cacheService = new CacheService(settings);
+        this.cacheService.set(cacheService);
+        return List.of(cacheService);
     }
 
     @Override
@@ -57,7 +90,7 @@ public void onRepositoriesModule(RepositoriesModule repositoriesModule) {
     @Override
     public Map<String, DirectoryFactory> getDirectoryFactories() {
         return Map.of(SearchableSnapshotRepository.SNAPSHOT_DIRECTORY_FACTORY_KEY,
-            SearchableSnapshotRepository.newDirectoryFactory(repositoriesService::get));
+            SearchableSnapshotRepository.newDirectoryFactory(repositoriesService::get, cacheService::get));
     }
 
     @Override