delete state files directly

Author: ywangd

server/src/main/java/org/elasticsearch/gateway/MetaStateService.java

@@ -11,7 +11,6 @@
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-import org.apache.lucene.store.NIOFSDirectory;
 import org.elasticsearch.Version;
 import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.cluster.metadata.Manifest;
@@ -22,6 +21,8 @@
 import org.elasticsearch.xcontent.NamedXContentRegistry;
 
 import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.function.Predicate;
@@ -84,7 +85,23 @@ List<IndexMetadata> loadIndicesStates(Predicate<String> excludeIndexPathIdsPredi
      */
     public void unreferenceAll() throws IOException {
         Manifest.FORMAT.writeAndCleanup(Manifest.empty(), nodeEnv.nodeDataPaths()); // write empty file so that indices become unreferenced
-        MetadataStateFormat.cleanupOldFiles(GLOBAL_STATE_FILE_PREFIX, Long.MAX_VALUE, nodeEnv.nodeDataPaths(), NIOFSDirectory::new);
+        cleanUpGlobalStateFiles();
+    }
+
+    private void cleanUpGlobalStateFiles() throws IOException {
+        for (Path location : nodeEnv.nodeDataPaths()) {
+            logger.trace("cleanupOldFiles: cleaning up {} for global state files", location);
+            final Path stateLocation = location.resolve(MetadataStateFormat.STATE_DIR_NAME);
+            try (var paths = Files.list(stateLocation)) {
+                paths.filter(file -> file.getFileName().toString().startsWith(GLOBAL_STATE_FILE_PREFIX)).forEach(file -> {
+                    try {
+                        Files.deleteIfExists(file);
+                    } catch (IOException e) {
+                        logger.trace("failed to delete global state file: {}", file);
+                    }
+                });
+            }
+        }
     }
 
     /**

server/src/main/java/org/elasticsearch/gateway/MetadataStateFormat.java

@@ -23,7 +23,6 @@
 import org.elasticsearch.common.lucene.store.IndexOutputOutputStream;
 import org.elasticsearch.common.lucene.store.InputStreamIndexInput;
 import org.elasticsearch.common.xcontent.LoggingDeprecationHandler;
-import org.elasticsearch.core.CheckedFunction;
 import org.elasticsearch.core.IOUtils;
 import org.elasticsearch.core.Nullable;
 import org.elasticsearch.core.Tuple;
@@ -351,28 +350,11 @@ protected Directory newDirectory(Path dir) throws IOException {
      * @param locations         state paths.
      */
     public void cleanupOldFiles(final long currentGeneration, final Path[] locations) {
-        cleanupOldFiles(prefix, currentGeneration, locations, this::newDirectory);
-    }
-
-    /**
-     * Clean ups all state files not matching passed generation.
-     *
-     * @param prefix filename prefix for filtering state files.
-     * @param currentGeneration state generation to keep.
-     * @param locations         state paths.
-     * @param directoryFunc function to create a {@link Directory} for the given path.
-     */
-    public static void cleanupOldFiles(
-        final String prefix,
-        final long currentGeneration,
-        final Path[] locations,
-        final CheckedFunction<Path, Directory, IOException> directoryFunc
-    ) {
-        final String fileNameToKeep = getStateFileName(prefix, currentGeneration);
+        final String fileNameToKeep = getStateFileName(currentGeneration);
         for (Path location : locations) {
             logger.trace("cleanupOldFiles: cleaning up {}", location);
             Path stateLocation = location.resolve(STATE_DIR_NAME);
-            try (Directory stateDir = directoryFunc.apply(stateLocation)) {
+            try (Directory stateDir = newDirectory(stateLocation)) {
                 for (String file : stateDir.listAll()) {
                     if (file.startsWith(prefix) && file.equals(fileNameToKeep) == false) {
                         deleteFileIgnoreExceptions(stateLocation, stateDir, file);
@@ -384,14 +366,6 @@ public static void cleanupOldFiles(
         }
     }
 
-    /**
-     * Finds state file with maximum id.
-     *
-     * @param prefix    - filename prefix
-     * @param locations - paths to directories with state folder
-     * @return maximum id of state file or -1 if no such files are found
-     * @throws IOException if IOException occurs
-     */
     long findMaxGenerationId(final String prefix, Path... locations) throws IOException {
         long maxId = -1;
         for (Path dataLocation : locations) {
@@ -430,10 +404,6 @@ List<Path> findStateFilesByGeneration(final long generation, Path... locations)
     }
 
     public String getStateFileName(long generation) {
-        return getStateFileName(prefix, generation);
-    }
-
-    public static String getStateFileName(String prefix, long generation) {
         return prefix + generation + STATE_FILE_EXTENSION;
     }