HDFS-10551. o.a.h.h.s.diskbalancer.command.Command does not actually verify options as expected. Contributed by Anu Engineer.

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

@@ -82,8 +82,6 @@ public abstract class Command extends Configured {
   public Command(Configuration conf) {
     super(conf);
     // These arguments are valid for all commands.
-    addValidCommandParameters(DiskBalancer.HELP, "Help for this command");
-    addValidCommandParameters("arg", "");
     topNodes = 0;
   }
 
@@ -248,12 +246,13 @@ public abstract class Command extends Configured {
     Iterator<Option> iter = cmd.iterator();
     while (iter.hasNext()) {
       Option opt = iter.next();
-      if (!validArgs.containsKey(opt.getArgName())) {
+
+      if (!validArgs.containsKey(opt.getLongOpt())) {
         String errMessage = String
             .format("%nInvalid argument found for command %s : %s%n",
-                commandName, opt.getArgName());
+                commandName, opt.getLongOpt());
         StringBuilder validArguments = new StringBuilder();
-        validArguments.append("Valid arguments are : %n");
+        validArguments.append(String.format("Valid arguments are : %n"));
         for (Map.Entry<String, String> args : validArgs.entrySet()) {
           String key = args.getKey();
           String desc = args.getValue();

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

@@ -47,7 +47,6 @@ public class ExecuteCommand extends Command {
   public ExecuteCommand(Configuration conf) {
     super(conf);
     addValidCommandParameters(DiskBalancer.EXECUTE, "Executes a given plan.");
-    addValidCommandParameters(DiskBalancer.NODE, "Name of the target node.");
   }
 
   /**

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

@@ -37,6 +37,7 @@ public class HelpCommand extends Command {
    */
   public HelpCommand(Configuration conf) {
     super(conf);
+    addValidCommandParameters(DiskBalancer.HELP, "Help Command");
   }
 
   /**

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

@@ -74,6 +74,7 @@ public class PlanCommand extends Command {
         "between 2 disks");
     addValidCommandParameters(DiskBalancer.VERBOSE, "Run plan command in " +
         "verbose mode.");
+    addValidCommandParameters(DiskBalancer.PLAN, "Plan Command");
   }
 
   /**

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

@@ -399,13 +399,19 @@ public class DiskBalancer extends Configured implements Tool {
     getReportOptions().addOption(report);
     opt.addOption(report);
 
-    Option top = new Option(TOP, true,
+    Option top = OptionBuilder.withLongOpt(TOP)
-        "specify the number of nodes to be listed which has data imbalance.");
+        .hasArg()
+        .withDescription("specify the number of nodes to be listed which has" +
+            " data imbalance.")
+        .create();
     getReportOptions().addOption(top);
     opt.addOption(top);
 
-    Option node = new Option(NODE, true,
+    Option node =  OptionBuilder.withLongOpt(NODE)
-        "Datanode address, it can be DataNodeID, IP or hostname.");
+        .hasArg()
+        .withDescription("Datanode address, " +
+            "it can be DataNodeID, IP or hostname.")
+        .create();
     getReportOptions().addOption(node);
     opt.addOption(node);
   }

hadoop-hdfs-project/hadoop-hdfs/src/main/resources/hdfs-default.xml

@@ -4086,4 +4086,44 @@
     Truststore password for HTTPS SSL configuration
   </description>
 </property>
+
+<!--Disk baalncer properties-->
+  <property>
+    <name>dfs.disk.balancer.max.disk.throughputInMBperSec</name>
+    <value>10</value>
+    <description>Maximum disk bandwidth used by diskbalancer
+      during read from a source disk. The unit is MB/sec.
+    </description>
+  </property>
+
+  <property>
+    <name>dfs.disk.balancer.block.tolerance.percent</name>
+    <value>10</value>
+    <description>
+      When a disk balancer copy operation is proceeding, the datanode is still
+      active. So it might not be possible to move the exactly specified
+      amount of data. So tolerance allows us to define a percentage which
+      defines a good enough move.
+    </description>
+  </property>
+
+  <property>
+    <name>dfs.disk.balancer.max.disk.errors</name>
+    <value>5</value>
+    <description>
+      During a block move from a source to destination disk, we might
+      encounter various errors. This defines how many errors we can tolerate
+      before we declare a move between 2 disks (or a step) has failed.
+    </description>
+  </property>
+
+
+  <property>
+    <name>dfs.disk.balancer.enabled</name>
+    <value>false</value>
+    <description>
+        This enables the diskbalancer feature on a cluster. By default, disk
+      balancer is disabled.
+    </description>
+  </property>
 </configuration>

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/diskbalancer/command/TestDiskBalancerCommand.java

@@ -5,9 +5,9 @@
  * 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/>
+ * <p>
  * http://www.apache.org/licenses/LICENSE-2.0
- * <p/>
+ * <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
@@ -44,16 +44,27 @@ import org.junit.Test;
 
 import com.google.common.collect.Lists;
 
+import static org.apache.hadoop.hdfs.tools.DiskBalancer.CANCEL;
+import static org.apache.hadoop.hdfs.tools.DiskBalancer.HELP;
+import static org.apache.hadoop.hdfs.tools.DiskBalancer.NODE;
+import static org.apache.hadoop.hdfs.tools.DiskBalancer.PLAN;
+import static org.apache.hadoop.hdfs.tools.DiskBalancer.QUERY;
+
+import org.junit.Rule;
+import org.junit.rules.ExpectedException;
+
 /**
  * Tests various CLI commands of DiskBalancer.
  */
 public class TestDiskBalancerCommand {
+  @Rule
+  public ExpectedException thrown = ExpectedException.none();
   private MiniDFSCluster cluster;
   private URI clusterJson;
+  private Configuration conf = new HdfsConfiguration();
 
   @Before
   public void setUp() throws Exception {
-    Configuration conf = new HdfsConfiguration();
     conf.setBoolean(DFSConfigKeys.DFS_DISK_BALANCER_ENABLED, true);
     cluster = new MiniDFSCluster.Builder(conf).numDataNodes(3)
         .storagesPerDatanode(2).build();
@@ -251,9 +262,6 @@ public class TestDiskBalancerCommand {
 
   @Test(timeout = 60000)
   public void testReadClusterFromJson() throws Exception {
-    Configuration conf = new HdfsConfiguration();
-    conf.setBoolean(DFSConfigKeys.DFS_DISK_BALANCER_ENABLED, true);
-
     ClusterConnector jsonConnector = ConnectorFactory.getCluster(clusterJson,
         conf);
     DiskBalancerCluster diskBalancerCluster = new DiskBalancerCluster(
@@ -262,10 +270,72 @@ public class TestDiskBalancerCommand {
     assertEquals(64, diskBalancerCluster.getNodes().size());
   }
 
-  private List<String> runCommand(final String cmdLine) throws Exception {
+  /* test -plan  DataNodeID */
+  @Test(timeout = 60000)
+  public void testPlanNode() throws Exception {
+    final String planArg = String.format("-%s %s", PLAN,
+        cluster.getDataNodes().get(0).getDatanodeUuid());
 
+    final String cmdLine = String
+        .format(
+            "hdfs diskbalancer %s", planArg);
+    runCommand(cmdLine);
+  }
+
+  /* Test that illegal arguments are handled correctly*/
+  @Test(timeout = 60000)
+  public void testIllegalArgument() throws Exception {
+    final String planArg = String.format("-%s %s", PLAN,
+        "a87654a9-54c7-4693-8dd9-c9c7021dc340");
+
+    final String cmdLine = String
+        .format(
+            "hdfs diskbalancer %s -report", planArg);
+    // -plan and -report cannot be used together.
+    // tests the validate command line arguments function.
+    thrown.expect(java.lang.IllegalArgumentException.class);
+    runCommand(cmdLine);
+  }
+
+  @Test(timeout = 60000)
+  public void testCancelCommand() throws Exception {
+    final String cancelArg = String.format("-%s %s", CANCEL, "nosuchplan");
+    final String nodeArg = String.format("-%s %s", NODE,
+        cluster.getDataNodes().get(0).getDatanodeUuid());
+
+    // Port:Host format is expected. So cancel command will throw.
+    thrown.expect(java.lang.IllegalArgumentException.class);
+    final String cmdLine = String
+        .format(
+            "hdfs diskbalancer  %s %s", cancelArg, nodeArg);
+    runCommand(cmdLine);
+  }
+
+  /*
+   Makes an invalid query attempt to non-existent Datanode.
+   */
+  @Test(timeout = 60000)
+  public void testQueryCommand() throws Exception {
+    final String queryArg = String.format("-%s %s", QUERY,
+        cluster.getDataNodes().get(0).getDatanodeUuid());
+    thrown.expect(java.net.UnknownHostException.class);
+    final String cmdLine = String
+        .format(
+            "hdfs diskbalancer %s", queryArg);
+    runCommand(cmdLine);
+  }
+
+  @Test(timeout = 60000)
+  public void testHelpCommand() throws Exception {
+    final String helpArg = String.format("-%s", HELP);
+    final String cmdLine = String
+        .format(
+            "hdfs diskbalancer %s", helpArg);
+    runCommand(cmdLine);
+  }
+
+  private List<String> runCommand(final String cmdLine) throws Exception {
     String[] cmds = StringUtils.split(cmdLine, ' ');
-    Configuration conf = new HdfsConfiguration();
     org.apache.hadoop.hdfs.tools.DiskBalancer db =
         new org.apache.hadoop.hdfs.tools.DiskBalancer(conf);