Add file type-based exclusion setting for searchable snapshots cache

x-pack/plugin/searchable-snapshots/src/main/java/org/elasticsearch/index/store/SearchableSnapshotDirectory.java

@@ -5,6 +5,7 @@
  */
 package org.elasticsearch.index.store;
 
+import org.apache.lucene.index.IndexFileNames;
 import org.apache.lucene.store.BaseDirectory;
 import org.apache.lucene.store.BufferedIndexInput;
 import org.apache.lucene.store.Directory;
@@ -37,17 +38,20 @@
 import java.nio.file.Path;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.LongSupplier;
 
+import static org.elasticsearch.xpack.searchablesnapshots.SearchableSnapshots.SNAPSHOT_CACHE_EXCLUDED_FILE_TYPES_SETTING;
 import static org.elasticsearch.xpack.searchablesnapshots.SearchableSnapshots.SNAPSHOT_CACHE_ENABLED_SETTING;
 import static org.elasticsearch.xpack.searchablesnapshots.SearchableSnapshots.SNAPSHOT_INDEX_ID_SETTING;
 import static org.elasticsearch.xpack.searchablesnapshots.SearchableSnapshots.SNAPSHOT_REPOSITORY_SETTING;
 import static org.elasticsearch.xpack.searchablesnapshots.SearchableSnapshots.SNAPSHOT_SNAPSHOT_ID_SETTING;
 import static org.elasticsearch.xpack.searchablesnapshots.SearchableSnapshots.SNAPSHOT_SNAPSHOT_NAME_SETTING;
+import static org.elasticsearch.xpack.searchablesnapshots.SearchableSnapshots.SNAPSHOT_UNCACHED_CHUNK_SIZE_SETTING;
 
 /**
  * Implementation of {@link Directory} that exposes files from a snapshot as a Lucene directory. Because snapshot are immutable this
@@ -71,6 +75,8 @@ public class SearchableSnapshotDirectory extends BaseDirectory {
     private final Map<String, IndexInputStats> stats;
     private final CacheService cacheService;
     private final boolean useCache;
+    private final Set<String> excludedFileTypes;
+    private final long uncachedChunkSize;
     private final Path cacheDir;
     private final AtomicBoolean closed;
 
@@ -97,6 +103,10 @@ public SearchableSnapshotDirectory(
         this.cacheDir = Objects.requireNonNull(cacheDir);
         this.closed = new AtomicBoolean(false);
         this.useCache = SNAPSHOT_CACHE_ENABLED_SETTING.get(indexSettings);
+        this.excludedFileTypes = new HashSet<>(SNAPSHOT_CACHE_EXCLUDED_FILE_TYPES_SETTING.get(indexSettings));
+        this.uncachedChunkSize = SNAPSHOT_UNCACHED_CHUNK_SIZE_SETTING.get(indexSettings).getBytes() < 0 ?
+            blobContainer.readBlobPreferredLength() :
+            SNAPSHOT_UNCACHED_CHUNK_SIZE_SETTING.get(indexSettings).getBytes();
     }
 
     public BlobContainer blobContainer() {
@@ -223,14 +233,18 @@ public IndexInput openInput(final String name, final IOContext context) throws I
         ensureOpen();
         final BlobStoreIndexShardSnapshot.FileInfo fileInfo = fileInfo(name);
         final IndexInputStats inputStats = stats.computeIfAbsent(name, n -> createIndexInputStats(fileInfo.length()));
-        if (useCache) {
+        if (useCache && isExcludedFromCache(name) == false) {
             return new CacheBufferedIndexInput(this, fileInfo, context, inputStats);
         } else {
-            long preferredLength = blobContainer.readBlobPreferredLength();
-            return new SearchableSnapshotIndexInput(blobContainer, fileInfo, context, preferredLength, BufferedIndexInput.BUFFER_SIZE);
+            return new SearchableSnapshotIndexInput(blobContainer, fileInfo, context, uncachedChunkSize, BufferedIndexInput.BUFFER_SIZE);
         }
     }
 
+    private boolean isExcludedFromCache(String name) {
+        final String ext = IndexFileNames.getExtension(name);
+        return ext != null && excludedFileTypes.contains(ext);
+    }
+
     @Override
     public String toString() {
         return this.getClass().getSimpleName() + "@" + snapshot.snapshot() + " lockFactory=" + lockFactory;

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

@@ -19,6 +19,8 @@
 import org.elasticsearch.common.settings.Setting;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.settings.SettingsFilter;
+import org.elasticsearch.common.unit.ByteSizeUnit;
+import org.elasticsearch.common.unit.ByteSizeValue;
 import org.elasticsearch.common.xcontent.NamedXContentRegistry;
 import org.elasticsearch.env.Environment;
 import org.elasticsearch.env.NodeEnvironment;
@@ -77,6 +79,13 @@ public class SearchableSnapshots extends Plugin implements IndexStorePlugin, Rep
         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);
+    // The file extensions that are excluded from the cache
+    public static final Setting<List<String>> SNAPSHOT_CACHE_EXCLUDED_FILE_TYPES_SETTING =
+        Setting.listSetting("index.store.snapshot.cache.excluded_file_types", Collections.emptyList(), Function.identity(),
+            Setting.Property.IndexScope, Setting.Property.NodeScope);
+    public static final Setting<ByteSizeValue> SNAPSHOT_UNCACHED_CHUNK_SIZE_SETTING =
+        Setting.byteSizeSetting("index.store.snapshot.uncached_chunk_size", new ByteSizeValue(-1, ByteSizeUnit.BYTES),
+            Setting.Property.IndexScope, Setting.Property.NodeScope);
 
     public static final String SNAPSHOT_DIRECTORY_FACTORY_KEY = "snapshot";
 
@@ -97,6 +106,8 @@ public List<Setting<?>> getSettings() {
             SNAPSHOT_SNAPSHOT_ID_SETTING,
             SNAPSHOT_INDEX_ID_SETTING,
             SNAPSHOT_CACHE_ENABLED_SETTING,
+            SNAPSHOT_CACHE_EXCLUDED_FILE_TYPES_SETTING,
+            SNAPSHOT_UNCACHED_CHUNK_SIZE_SETTING,
             CacheService.SNAPSHOT_CACHE_SIZE_SETTING,
             CacheService.SNAPSHOT_CACHE_RANGE_SIZE_SETTING
         );

x-pack/plugin/searchable-snapshots/src/test/java/org/elasticsearch/xpack/searchablesnapshots/SearchableSnapshotsIntegTests.java

@@ -36,6 +36,7 @@
 
 import java.nio.file.Path;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
@@ -122,12 +123,23 @@ public void testCreateAndRestoreSearchableSnapshot() throws Exception {
         final boolean cacheEnabled = randomBoolean();
         logger.info("--> restoring index [{}] with cache [{}]", restoredIndexName, cacheEnabled ? "enabled" : "disabled");
 
+        Settings.Builder indexSettingsBuilder = Settings.builder()
+            .put(SearchableSnapshots.SNAPSHOT_CACHE_ENABLED_SETTING.getKey(), cacheEnabled)
+            .put(IndexSettings.INDEX_CHECK_ON_STARTUP.getKey(), Boolean.FALSE.toString());
+        final List<String> nonCachedExtensions;
+        if (randomBoolean()) {
+            nonCachedExtensions = randomSubsetOf(Arrays.asList("fdt", "fdx", "nvd", "dvd", "tip", "cfs", "dim"));
+            indexSettingsBuilder.putList(SearchableSnapshots.SNAPSHOT_CACHE_EXCLUDED_FILE_TYPES_SETTING.getKey(), nonCachedExtensions);
+        } else {
+            nonCachedExtensions = Collections.emptyList();
+        }
+        if (randomBoolean()) {
+            indexSettingsBuilder.put(SearchableSnapshots.SNAPSHOT_UNCACHED_CHUNK_SIZE_SETTING.getKey(),
+                new ByteSizeValue(randomLongBetween(10, 100_000)));
+        }
         final MountSearchableSnapshotRequest req = new MountSearchableSnapshotRequest(restoredIndexName, fsRepoName,
             snapshotInfo.snapshotId().getName(), indexName,
-            Settings.builder()
-                .put(SearchableSnapshots.SNAPSHOT_CACHE_ENABLED_SETTING.getKey(), cacheEnabled)
-                .put(IndexSettings.INDEX_CHECK_ON_STARTUP.getKey(), Boolean.FALSE.toString())
-                .build(), Strings.EMPTY_ARRAY, true);
+            indexSettingsBuilder.build(), Strings.EMPTY_ARRAY, true);
 
         final RestoreSnapshotResponse restoreSnapshotResponse = client().execute(MountSearchableSnapshotAction.INSTANCE, req).get();
         assertThat(restoreSnapshotResponse.getRestoreInfo().failedShards(), equalTo(0));
@@ -151,6 +163,13 @@ public void testCreateAndRestoreSearchableSnapshot() throws Exception {
             for (SearchableSnapshotShardStats stats : statsResponse.getStats()) {
                 assertThat(stats.getShardRouting().getIndexName(), equalTo(restoredIndexName));
                 assertThat(stats.getStats().size(), greaterThan(0));
+                for (SearchableSnapshotShardStats.CacheIndexInputStats indexInputStats : stats.getStats()) {
+                    for (String ext : nonCachedExtensions) {
+                        if (indexInputStats.getFileName().endsWith(ext)) {
+                            assertEquals(indexInputStats.getFileName(), 0, indexInputStats.getOpenCount());
+                        }
+                    }
+                }
             }
         } else {
             expectThrows(ResourceNotFoundException.class, future::actionGet);

x-pack/plugin/searchable-snapshots/src/test/java/org/elasticsearch/xpack/searchablesnapshots/cache/TestUtils.java

@@ -78,6 +78,11 @@ public InputStream readBlob(String name, long position, long length) throws IOEx
                 return Streams.limitStream(new ByteArrayInputStream(blobContent, Math.toIntExact(position), blobContent.length), length);
             }
 
+            @Override
+            public long readBlobPreferredLength() {
+                return Long.MAX_VALUE;
+            }
+
             @Override
             public Map<String, BlobMetaData> listBlobs() {
                 throw unsupportedException();