HDFS-10403. DiskBalancer: Add cancel command. Contributed by Anu Engineer.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/diskbalancer/command/CancelCommand.java

@@ -0,0 +1,137 @@
+/*
+ * 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.diskbalancer.command;
+
+import com.google.common.base.Preconditions;
+import org.apache.commons.cli.CommandLine;
+import org.apache.commons.codec.digest.DigestUtils;
+import org.apache.commons.io.IOUtils;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.hdfs.protocol.ClientDatanodeProtocol;
+import org.apache.hadoop.hdfs.server.diskbalancer.DiskBalancerException;
+import org.apache.hadoop.hdfs.server.diskbalancer.planner.NodePlan;
+import org.apache.hadoop.hdfs.tools.DiskBalancer;
+
+import java.io.IOException;
+
+/**
+ * Cancels a running plan.
+ */
+public class CancelCommand extends Command {
+  /**
+   * Contructs a cancel Command.
+   *
+   * @param conf - Conf
+   */
+  public CancelCommand(Configuration conf) {
+    super(conf);
+    addValidCommandParameters(DiskBalancer.CANCEL, "Cancels a running plan.");
+    addValidCommandParameters(DiskBalancer.NODE, "Node to run the command " +
+        "against in node:port format.");
+  }
+
+  /**
+   * Executes the Client Calls.
+   *
+   * @param cmd - CommandLine
+   */
+  @Override
+  public void execute(CommandLine cmd) throws Exception {
+    LOG.info("Executing \"Cancel plan\" command.");
+    Preconditions.checkState(cmd.hasOption(DiskBalancer.CANCEL));
+    verifyCommandOptions(DiskBalancer.CANCEL, cmd);
+
+    // We can cancel a plan using datanode address and plan ID
+    // that you can read from a datanode using queryStatus
+    if(cmd.hasOption(DiskBalancer.NODE)) {
+      String nodeAddress = cmd.getOptionValue(DiskBalancer.NODE);
+      String planHash = cmd.getOptionValue(DiskBalancer.CANCEL);
+      cancelPlanUsingHash(nodeAddress, planHash);
+    } else {
+      // Or you can cancel a plan using the plan file. If the user
+      // points us to the plan file, we can compute the hash as well as read
+      // the address of the datanode from the plan file.
+      String planFile = cmd.getOptionValue(DiskBalancer.CANCEL);
+      Preconditions.checkArgument(planFile == null || planFile.isEmpty(),
+          "Invalid plan file specified.");
+      String planData = null;
+      try (FSDataInputStream plan = open(planFile)) {
+        planData = IOUtils.toString(plan);
+      }
+      cancelPlan(planData);
+    }
+  }
+
+  /**
+   * Cancels a running plan.
+   *
+   * @param planData - Plan data.
+   * @throws IOException
+   */
+  private void cancelPlan(String planData) throws IOException {
+    Preconditions.checkNotNull(planData);
+    NodePlan plan = readPlan(planData);
+    String dataNodeAddress = plan.getNodeName() + ":" + plan.getPort();
+    Preconditions.checkNotNull(dataNodeAddress);
+    ClientDatanodeProtocol dataNode = getDataNodeProxy(dataNodeAddress);
+    String planHash = DigestUtils.sha512Hex(planData);
+    try {
+      dataNode.cancelDiskBalancePlan(planHash);
+    } catch (DiskBalancerException ex) {
+      LOG.error("Cancelling plan on  {} failed. Result: {}, Message: {}",
+          plan.getNodeName(), ex.getResult().toString(), ex.getMessage());
+      throw ex;
+    }
+  }
+
+  /**
+   * Cancels a running plan.
+   * @param nodeAddress - Address of the data node.
+   * @param hash - Sha512 hash of the plan, which can be read from datanode
+   *             using query status command.
+   * @throws IOException
+   */
+  private void cancelPlanUsingHash(String nodeAddress, String hash) throws
+      IOException {
+    Preconditions.checkNotNull(nodeAddress);
+    Preconditions.checkNotNull(hash);
+    ClientDatanodeProtocol dataNode = getDataNodeProxy(nodeAddress);
+    try {
+      dataNode.cancelDiskBalancePlan(hash);
+    } catch (DiskBalancerException ex) {
+      LOG.error("Cancelling plan on  {} failed. Result: {}, Message: {}",
+          nodeAddress, ex.getResult().toString(), ex.getMessage());
+      throw ex;
+    }
+  }
+
+
+  /**
+   * Gets extended help for this command.
+   *
+   * @return Help Message
+   */
+  @Override
+  protected String getHelp() {
+    return "Cancels a running command. e.g -cancel <PlanFile> or -cancel " +
+        "<planID> -node <datanode>";
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/diskbalancer/command/Command.java

@@ -31,6 +31,7 @@ import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.DFSUtilClient;
 import org.apache.hadoop.hdfs.protocol.ClientDatanodeProtocol;
+import org.apache.hadoop.hdfs.server.diskbalancer.planner.NodePlan;
 import org.apache.hadoop.hdfs.tools.DiskBalancer;
 import org.apache.hadoop.hdfs.server.diskbalancer.connectors.ClusterConnector;
 import org.apache.hadoop.hdfs.server.diskbalancer.connectors.ConnectorFactory;
@@ -39,6 +40,7 @@ import org.apache.hadoop.hdfs.server.diskbalancer.datamodel.DiskBalancerDataNode
 
 import org.apache.hadoop.net.NetUtils;
 import org.apache.hadoop.security.UserGroupInformation;
+import org.apache.htrace.fasterxml.jackson.databind.ObjectMapper;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -392,4 +394,16 @@ public abstract class Command extends Configured {
   protected DiskBalancerCluster getCluster() {
     return cluster;
   }
+
+  /**
+   * Returns a plan from the Json Data.
+   *
+   * @param planData - Json String
+   * @return NodePlan
+   * @throws IOException
+   */
+  protected NodePlan readPlan(String planData) throws IOException {
+    ObjectMapper mapper = new ObjectMapper();
+    return mapper.readValue(planData, NodePlan.class);
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/diskbalancer/command/ExecuteCommand.java

@@ -27,9 +27,9 @@ import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FSDataInputStream;
 import org.apache.hadoop.hdfs.protocol.ClientDatanodeProtocol;
 import org.apache.hadoop.hdfs.server.diskbalancer.DiskBalancerException;
-import org.apache.hadoop.hdfs.tools.DiskBalancer;
 import org.apache.hadoop.hdfs.server.diskbalancer.planner.NodePlan;
-import org.apache.htrace.fasterxml.jackson.databind.ObjectMapper;
+import org.apache.hadoop.hdfs.tools.DiskBalancer;
+
 import java.io.IOException;
 
 
@@ -94,17 +94,7 @@ public class ExecuteCommand extends Command {
     }
   }
 
-  /**
+
-   * Returns a plan from the Json Data.
-   *
-   * @param planData - Json String
-   * @return NodePlan
-   * @throws IOException
-   */
-  private NodePlan readPlan(String planData) throws IOException {
-    ObjectMapper mapper = new ObjectMapper();
-    return mapper.readValue(planData, NodePlan.class);
-  }
 
   /**
    * Gets extended help for this command.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DiskBalancer.java

@@ -24,6 +24,7 @@ import org.apache.commons.cli.Options;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.conf.Configured;
 import org.apache.hadoop.hdfs.HdfsConfiguration;
+import org.apache.hadoop.hdfs.server.diskbalancer.command.CancelCommand;
 import org.apache.hadoop.hdfs.server.diskbalancer.command.Command;
 import org.apache.hadoop.hdfs.server.diskbalancer.command.ExecuteCommand;
 import org.apache.hadoop.hdfs.server.diskbalancer.command.PlanCommand;
@@ -105,7 +106,10 @@ public class DiskBalancer extends Configured implements Tool {
    * Reports the status of disk balancer operation.
    */
   public static final String QUERY = "query";
-
+  /**
+   * Cancels a running plan.
+   */
+  public static final String CANCEL = "cancel";
   /**
    * Template for the Before File. It is node.before.json.
    */
@@ -168,6 +172,7 @@ public class DiskBalancer extends Configured implements Tool {
     addPlanCommands(opts);
     addExecuteCommands(opts);
     addQueryCommands(opts);
+    addCancelCommands(opts);
     return opts;
   }
 
@@ -233,6 +238,19 @@ public class DiskBalancer extends Configured implements Tool {
     opt.addOption(query);
   }
 
+  /**
+   * Adds cancel command options.
+   * @param opt Options
+   */
+  private void addCancelCommands(Options opt) {
+    Option cancel = new Option(CANCEL, true, "Cancels a running plan. -cancel" +
+        " <planFile> or -cancel <planID> -node <datanode:port>");
+    opt.addOption(cancel);
+    Option node = new Option(NODE, true, "Name of the datanode in name:port " +
+        "format");
+    opt.addOption(node);
+  }
+
   /**
    * This function parses all command line arguments and returns the appropriate
    * values.
@@ -271,6 +289,10 @@ public class DiskBalancer extends Configured implements Tool {
         currentCommand = new QueryCommand(getConf());
       }
 
+      if(cmd.hasOption(DiskBalancer.CANCEL)) {
+        currentCommand = new CancelCommand(getConf());
+      }
+
       if(currentCommand == null) {
         HelpFormatter helpFormatter = new HelpFormatter();
         helpFormatter.printHelp(80, "hdfs diskbalancer -uri [args]",