HDFS-17733. [ARR] Optimize isMultiDestDirectory method using AsyncUtil class (#7415). Contributed by hfutatzhanghb.

Reviewed-by: Jian Zhang <keepromise@apache.org>
Signed-off-by: He Xiaoqiao <hexiaoqiao@apache.org>

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/RouterClientProtocol.java

@@ -2448,7 +2448,7 @@ public class RouterClientProtocol implements ClientProtocol {
    * @throws IOException if unable to get the file status.
    */
   @VisibleForTesting
-  protected boolean isMultiDestDirectory(String src) throws IOException {
+  public boolean isMultiDestDirectory(String src) throws IOException {
     try {
       if (rpcServer.isPathAll(src)) {
         List<RemoteLocation> locations;

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/async/RouterAsyncClientProtocol.java

@@ -17,6 +17,7 @@
  */
 package org.apache.hadoop.hdfs.server.federation.router.async;
 
+import org.apache.hadoop.classification.VisibleForTesting;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.crypto.CryptoProtocolVersion;
 import org.apache.hadoop.fs.ContentSummary;
@@ -85,7 +86,6 @@ import static org.apache.hadoop.hdfs.server.federation.router.async.utils.AsyncU
 import static org.apache.hadoop.hdfs.server.federation.router.async.utils.AsyncUtil.asyncForEach;
 import static org.apache.hadoop.hdfs.server.federation.router.async.utils.AsyncUtil.asyncReturn;
 import static org.apache.hadoop.hdfs.server.federation.router.async.utils.AsyncUtil.asyncTry;
-import static org.apache.hadoop.hdfs.server.federation.router.async.utils.AsyncUtil.getCompletableFuture;
 
 /**
  * Module that implements all the async RPC calls in {@link ClientProtocol} in the
@@ -1055,11 +1055,11 @@ public class RouterAsyncClientProtocol extends RouterClientProtocol {
    * @param src the source path
    * @return true if the path is directory and is supposed to be present in all
    *         subclusters else false in all other scenarios.
-   * @throws IOException if unable to get the file status.
    */
+  @VisibleForTesting
   @Override
-  public boolean isMultiDestDirectory(String src) throws IOException {
-    try {
+  public boolean isMultiDestDirectory(String src) {
+    asyncTry(() -> {
       if (rpcServer.isPathAll(src)) {
         List<RemoteLocation> locations;
         locations = rpcServer.getLocationsForPath(src, false, false);
@@ -1067,23 +1067,23 @@ public class RouterAsyncClientProtocol extends RouterClientProtocol {
             new Class<?>[] {String.class}, new RemoteParam());
         rpcClient.invokeSequential(locations,
             method, HdfsFileStatus.class, null);
-        CompletableFuture<Object> completableFuture = getCompletableFuture();
-        completableFuture = completableFuture.thenApply(o -> {
-          HdfsFileStatus fileStatus = (HdfsFileStatus) o;
+        asyncApply((ApplyFunction<HdfsFileStatus, Boolean>) fileStatus -> {
           if (fileStatus != null) {
             return fileStatus.isDirectory();
           } else {
             LOG.debug("The destination {} doesn't exist.", src);
+            return false;
           }
-          return false;
         });
-        asyncCompleteWith(completableFuture);
-        return asyncReturn(Boolean.class);
+      } else {
+        asyncComplete(false);
       }
-    } catch (UnresolvedPathException e) {
+    });
+    asyncCatch((CatchFunction<Object, UnresolvedPathException>) (o, e) -> {
       LOG.debug("The destination {} is a symlink.", src);
-    }
-    asyncCompleteWith(CompletableFuture.completedFuture(false));
-    return asyncReturn(Boolean.class);
+      return false;
+    }, UnresolvedPathException.class);
+
+    return asyncReturn(boolean.class);
   }
 }

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/router/TestRouterRPCMultipleDestinationMountTableResolver.java

@@ -75,17 +75,18 @@ import org.junit.Test;
 /**
  * Tests router rpc with multiple destination mount table resolver.
  */
+@SuppressWarnings("checkstyle:visibilitymodifier")
 public class TestRouterRPCMultipleDestinationMountTableResolver {
-  private static final List<String> NS_IDS = Arrays.asList("ns0", "ns1", "ns2");
+  protected static final List<String> NS_IDS = Arrays.asList("ns0", "ns1", "ns2");
 
-  private static StateStoreDFSCluster cluster;
-  private static RouterContext routerContext;
-  private static MountTableResolver resolver;
-  private static DistributedFileSystem nnFs0;
-  private static DistributedFileSystem nnFs1;
-  private static DistributedFileSystem nnFs2;
-  private static DistributedFileSystem routerFs;
-  private static RouterRpcServer rpcServer;
+  protected static StateStoreDFSCluster cluster;
+  protected static RouterContext routerContext;
+  protected static MountTableResolver resolver;
+  protected static DistributedFileSystem nnFs0;
+  protected static DistributedFileSystem nnFs1;
+  protected static DistributedFileSystem nnFs2;
+  protected static DistributedFileSystem routerFs;
+  protected static RouterRpcServer rpcServer;
 
   @BeforeClass
   public static void setUp() throws Exception {
@@ -408,7 +409,7 @@ public class TestRouterRPCMultipleDestinationMountTableResolver {
    * @return If it was successfully added.
    * @throws IOException + * Problems adding entries.
    */
-  private boolean addMountTable(final MountTable entry) throws IOException {
+  protected boolean addMountTable(final MountTable entry) throws IOException {
     RouterClient client = routerContext.getAdminClient();
     MountTableManager mountTableManager = client.getMountTableManager();
     AddMountTableEntryRequest addRequest =

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/router/async/TestRouterAsyncRPCMultipleDestinationMountTableResolver.java

@@ -0,0 +1,152 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hdfs.server.federation.router.async;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FsServerDefaults;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.hdfs.DistributedFileSystem;
+import org.apache.hadoop.hdfs.MiniDFSCluster;
+import org.apache.hadoop.hdfs.server.federation.RouterConfigBuilder;
+import org.apache.hadoop.hdfs.server.federation.StateStoreDFSCluster;
+import org.apache.hadoop.hdfs.server.federation.resolver.MountTableResolver;
+import org.apache.hadoop.hdfs.server.federation.resolver.MultipleDestinationMountTableResolver;
+import org.apache.hadoop.hdfs.server.federation.resolver.order.DestinationOrder;
+import org.apache.hadoop.hdfs.server.federation.router.RemoteMethod;
+import org.apache.hadoop.hdfs.server.federation.router.RouterClientProtocol;
+import org.apache.hadoop.hdfs.server.federation.router.RouterQuotaUsage;
+import org.apache.hadoop.hdfs.server.federation.router.TestRouterRPCMultipleDestinationMountTableResolver;
+import org.apache.hadoop.hdfs.server.federation.store.records.MountTable;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.apache.hadoop.hdfs.server.federation.router.RBFConfigKeys.DFS_ROUTER_ASYNC_RPC_ENABLE_KEY;
+import static org.apache.hadoop.hdfs.server.federation.router.async.utils.AsyncUtil.syncReturn;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * Tests router async rpc with multiple destination mount table resolver.
+ */
+public class TestRouterAsyncRPCMultipleDestinationMountTableResolver extends
+    TestRouterRPCMultipleDestinationMountTableResolver {
+
+  @BeforeClass
+  public static void setUp() throws Exception {
+
+    // Build and start a federated cluster.
+    cluster = new StateStoreDFSCluster(false, 3,
+        MultipleDestinationMountTableResolver.class);
+    Configuration routerConf =
+        new RouterConfigBuilder().stateStore().admin().quota().rpc().build();
+    routerConf.setBoolean(DFS_ROUTER_ASYNC_RPC_ENABLE_KEY, true);
+
+    Configuration hdfsConf = new Configuration(false);
+    hdfsConf.setBoolean(DFSConfigKeys.DFS_NAMENODE_ACLS_ENABLED_KEY, true);
+
+    cluster.addRouterOverrides(routerConf);
+    cluster.addNamenodeOverrides(hdfsConf);
+    cluster.startCluster();
+    cluster.startRouters();
+    cluster.waitClusterUp();
+
+    routerContext = cluster.getRandomRouter();
+    resolver =
+        (MountTableResolver) routerContext.getRouter().getSubclusterResolver();
+    nnFs0 = (DistributedFileSystem) cluster
+        .getNamenode(cluster.getNameservices().get(0), null).getFileSystem();
+    nnFs1 = (DistributedFileSystem) cluster
+        .getNamenode(cluster.getNameservices().get(1), null).getFileSystem();
+    nnFs2 = (DistributedFileSystem) cluster
+        .getNamenode(cluster.getNameservices().get(2), null).getFileSystem();
+    routerFs = (DistributedFileSystem) routerContext.getFileSystem();
+    rpcServer =routerContext.getRouter().getRpcServer();
+  }
+
+  @Override
+  @Test
+  public void testInvokeAtAvailableNs() throws IOException {
+    // Create a mount point with multiple destinations.
+    Path path = new Path("/testInvokeAtAvailableNs");
+    Map<String, String> destMap = new HashMap<>();
+    destMap.put("ns0", "/testInvokeAtAvailableNs");
+    destMap.put("ns1", "/testInvokeAtAvailableNs");
+    nnFs0.mkdirs(path);
+    nnFs1.mkdirs(path);
+    MountTable addEntry =
+        MountTable.newInstance("/testInvokeAtAvailableNs", destMap);
+    addEntry.setQuota(new RouterQuotaUsage.Builder().build());
+    addEntry.setDestOrder(DestinationOrder.RANDOM);
+    addEntry.setFaultTolerant(true);
+    assertTrue(addMountTable(addEntry));
+
+    // Make one subcluster unavailable.
+    MiniDFSCluster dfsCluster = cluster.getCluster();
+    dfsCluster.shutdownNameNode(0);
+    dfsCluster.shutdownNameNode(1);
+    try {
+      // Verify that #invokeAtAvailableNs works by calling #getServerDefaults.
+      RemoteMethod method = new RemoteMethod("getServerDefaults");
+      FsServerDefaults serverDefaults = null;
+      rpcServer.invokeAtAvailableNsAsync(method, FsServerDefaults.class);
+      try {
+        serverDefaults = syncReturn(FsServerDefaults.class);
+      } catch (Exception e) {
+        throw new RuntimeException(e);
+      }
+      assertNotNull(serverDefaults);
+    } finally {
+      dfsCluster.restartNameNode(0);
+      dfsCluster.restartNameNode(1);
+    }
+  }
+
+  @Override
+  @Test
+  public void testIsMultiDestDir() throws Exception {
+    RouterClientProtocol client =
+        routerContext.getRouter().getRpcServer().getClientProtocolModule();
+    setupOrderMountPath(DestinationOrder.HASH_ALL);
+    // Should be true only for directory and false for all other cases.
+    client.isMultiDestDirectory("/mount/dir");
+    assertTrue(syncReturn(boolean.class));
+    client.isMultiDestDirectory("/mount/nodir");
+    assertFalse(syncReturn(boolean.class));
+    client.isMultiDestDirectory("/mount/dir/file");
+    assertFalse(syncReturn(boolean.class));
+    routerFs.createSymlink(new Path("/mount/dir/file"),
+        new Path("/mount/dir/link"), true);
+    client.isMultiDestDirectory("/mount/dir/link");
+    assertFalse(syncReturn(boolean.class));
+    routerFs.createSymlink(new Path("/mount/dir/dir"),
+        new Path("/mount/dir/linkDir"), true);
+    client.isMultiDestDirectory("/mount/dir/linkDir");
+    assertFalse(syncReturn(boolean.class));
+    resetTestEnvironment();
+    // Test single directory destination. Should be false for the directory.
+    setupOrderMountPath(DestinationOrder.HASH);
+    client.isMultiDestDirectory("/mount/dir");
+    assertFalse(syncReturn(boolean.class));
+  }
+}