HDFS-16087. Fix stuck issue in rbfbalance tool (#3141). Contributed by Eric Yin.

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/rbfbalance/RouterDistCpProcedure.java

@@ -44,6 +44,7 @@ public class RouterDistCpProcedure extends DistCpProcedure {
     Configuration conf = context.getConf();
     String mount = context.getMount();
     MountTableProcedure.disableWrite(mount, conf);
+    updateStage(Stage.FINAL_DISTCP);
   }
 
   /**

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/rbfbalance/TestRouterDistCpProcedure.java

@@ -0,0 +1,120 @@
+/**
+ * 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
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * 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.rbfbalance;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.permission.FsPermission;
+import org.apache.hadoop.ha.HAServiceProtocol;
+import org.apache.hadoop.hdfs.DFSClient;
+import org.apache.hadoop.hdfs.server.federation.MiniRouterDFSCluster;
+import org.apache.hadoop.hdfs.server.federation.RouterConfigBuilder;
+import org.apache.hadoop.hdfs.server.federation.StateStoreDFSCluster;
+import org.apache.hadoop.hdfs.server.federation.resolver.ActiveNamenodeResolver;
+import org.apache.hadoop.hdfs.server.federation.resolver.MountTableManager;
+import org.apache.hadoop.hdfs.server.federation.router.RBFConfigKeys;
+import org.apache.hadoop.hdfs.server.federation.router.Router;
+import org.apache.hadoop.hdfs.server.federation.store.StateStoreService;
+import org.apache.hadoop.hdfs.server.federation.store.impl.MountTableStoreImpl;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.AddMountTableEntryRequest;
+import org.apache.hadoop.hdfs.server.federation.store.protocol.AddMountTableEntryResponse;
+import org.apache.hadoop.hdfs.server.federation.store.records.MountTable;
+import org.apache.hadoop.ipc.RemoteException;
+import org.apache.hadoop.tools.fedbalance.DistCpProcedure.Stage;
+import org.apache.hadoop.tools.fedbalance.FedBalanceContext;
+import org.apache.hadoop.tools.fedbalance.TestDistCpProcedure;
+import org.apache.hadoop.util.Time;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+
+import java.net.InetSocketAddress;
+import java.net.URI;
+import java.util.Collections;
+
+import static org.apache.hadoop.hdfs.server.federation.FederationTestUtils.createNamenodeReport;
+import static org.apache.hadoop.test.LambdaTestUtils.intercept;
+import static org.junit.Assert.assertTrue;
+
+
+public class TestRouterDistCpProcedure extends TestDistCpProcedure {
+  private static StateStoreDFSCluster cluster;
+  private static MiniRouterDFSCluster.RouterContext routerContext;
+  private static Configuration routerConf;
+  private static StateStoreService stateStore;
+
+  @BeforeClass
+  public static void globalSetUp() throws Exception {
+    cluster = new StateStoreDFSCluster(false, 1);
+    // Build and start a router with State Store + admin + RPC
+    Configuration conf = new RouterConfigBuilder()
+        .stateStore()
+        .admin()
+        .rpc()
+        .build();
+    cluster.addRouterOverrides(conf);
+    cluster.startRouters();
+    routerContext = cluster.getRandomRouter();
+    Router router = routerContext.getRouter();
+    stateStore = router.getStateStore();
+
+    // Add one name services for testing
+    ActiveNamenodeResolver membership = router.getNamenodeResolver();
+    membership.registerNamenode(createNamenodeReport("ns0", "nn1",
+        HAServiceProtocol.HAServiceState.ACTIVE));
+    stateStore.refreshCaches(true);
+
+    routerConf = new Configuration();
+    InetSocketAddress routerSocket = router.getAdminServerAddress();
+    routerConf.setSocketAddr(RBFConfigKeys.DFS_ROUTER_ADMIN_ADDRESS_KEY,
+        routerSocket);
+  }
+
+  @Override
+  public void testDisableWrite() throws Exception {
+    // Firstly add mount entry: /test-write->{ns0,/test-write}.
+    String mount = "/test-write";
+    MountTable newEntry = MountTable
+        .newInstance(mount, Collections.singletonMap("ns0", mount),
+        Time.now(), Time.now());
+    MountTableManager mountTable =
+        routerContext.getAdminClient().getMountTableManager();
+    AddMountTableEntryRequest addRequest =
+        AddMountTableEntryRequest.newInstance(newEntry);
+    AddMountTableEntryResponse addResponse =
+        mountTable.addMountTableEntry(addRequest);
+    assertTrue(addResponse.getStatus());
+    stateStore.loadCache(MountTableStoreImpl.class, true); // load cache.
+
+    // Construct client.
+    URI address = routerContext.getFileSystemURI();
+    DFSClient routerClient = new DFSClient(address, routerConf);
+
+    FedBalanceContext context = new FedBalanceContext
+        .Builder(null, null, mount, routerConf).build();
+    RouterDistCpProcedure dcProcedure = new RouterDistCpProcedure();
+    executeProcedure(dcProcedure, Stage.FINAL_DISTCP,
+        () -> dcProcedure.disableWrite(context));
+    intercept(RemoteException.class, "is in a read only mount point",
+        "Expect readonly exception.", () -> routerClient
+        .mkdirs(mount + "/dir", new FsPermission(020), false));
+  }
+
+  @AfterClass
+  public static void tearDown() {
+    cluster.stopRouter(routerContext);
+  }
+}

hadoop-tools/hadoop-federation-balance/src/main/java/org/apache/hadoop/tools/fedbalance/DistCpProcedure.java

@@ -72,7 +72,7 @@ public class DistCpProcedure extends BalanceProcedure {
       LoggerFactory.getLogger(DistCpProcedure.class);
 
   /* Stages of this procedure. */
-  enum Stage {
+  public enum Stage {
     PRE_CHECK, INIT_DISTCP, DIFF_DISTCP, DISABLE_WRITE, FINAL_DISTCP, FINISH
   }
 
@@ -325,7 +325,7 @@ public class DistCpProcedure extends BalanceProcedure {
   }
 
   @VisibleForTesting
-  void updateStage(Stage value) {
+  protected void updateStage(Stage value) {
     String oldStage = stage == null ? "null" : stage.name();
     String newStage = value == null ? "null" : value.name();
     LOG.info("Stage updated from {} to {}.", oldStage, newStage);

hadoop-tools/hadoop-federation-balance/src/test/java/org/apache/hadoop/tools/fedbalance/TestDistCpProcedure.java

@@ -389,7 +389,7 @@ public class TestDistCpProcedure {
         .setDiffThreshold(diffThreshold).build();
   }
 
-  interface Call {
+  protected interface Call {
     void execute() throws IOException, RetryException;
   }
 
@@ -400,8 +400,8 @@ public class TestDistCpProcedure {
    * @param target the target stage.
    * @param call the function executing the procedure.
    */
-  private static void executeProcedure(DistCpProcedure procedure, Stage target,
-      Call call) throws IOException {
+  protected static void executeProcedure(DistCpProcedure procedure,
+      Stage target, Call call) throws IOException {
     Stage stage = Stage.PRE_CHECK;
     procedure.updateStage(stage);
     while (stage != target) {