merge -c 1437156 from trunk to branch-2 to fix YARN-277. Use AMRMClient in DistributedShell to exemplify the approach. Contriubed by Bikas Saha

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1437159 13f79535-47bb-0310-9956-ffa450edef68

hadoop-yarn-project/CHANGES.txt

@@ -84,6 +84,9 @@ Release 2.0.3-alpha - Unreleased
 
     YARN-331. Fill in missing fair scheduler documentation. (sandyr via tucu)
 
+    YARN-277. Use AMRMClient in DistributedShell to exemplify the approach.
+    (Bikas Saha via hitesh)
+
   OPTIMIZATIONS
 
   BUG FIXES 

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-distributedshell/src/main/java/org/apache/hadoop/yarn/applications/distributedshell/ApplicationMaster.java

@@ -29,7 +29,6 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Vector;
-import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import org.apache.commons.cli.CommandLine;
@@ -51,9 +50,6 @@ import org.apache.hadoop.yarn.api.ContainerManager;
 import org.apache.hadoop.yarn.api.protocolrecords.AllocateRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.AllocateResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.FinishApplicationMasterRequest;
-//import org.apache.hadoop.yarn.api.protocolrecords.GetContainerStatusRequest;
-//import org.apache.hadoop.yarn.api.protocolrecords.GetContainerStatusResponse;
-import org.apache.hadoop.yarn.api.protocolrecords.RegisterApplicationMasterRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.RegisterApplicationMasterResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.StartContainerRequest;
 
@@ -71,6 +67,9 @@ import org.apache.hadoop.yarn.api.records.LocalResourceVisibility;
 import org.apache.hadoop.yarn.api.records.Priority;
 import org.apache.hadoop.yarn.api.records.Resource;
 import org.apache.hadoop.yarn.api.records.ResourceRequest;
+import org.apache.hadoop.yarn.client.AMRMClient;
+import org.apache.hadoop.yarn.client.AMRMClient.ContainerRequest;
+import org.apache.hadoop.yarn.client.AMRMClientImpl;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.apache.hadoop.yarn.exceptions.YarnRemoteException;
 import org.apache.hadoop.yarn.ipc.YarnRPC;
@@ -78,37 +77,64 @@ import org.apache.hadoop.yarn.util.ConverterUtils;
 import org.apache.hadoop.yarn.util.Records;
 
 /**
- * An ApplicationMaster for executing shell commands on a set of launched containers using the YARN framework. 
+ * An ApplicationMaster for executing shell commands on a set of launched
+ * containers using the YARN framework.
  * 
- * <p>This class is meant to act as an example on how to write yarn-based application masters. </p>
+ * <p>
+ * This class is meant to act as an example on how to write yarn-based
+ * application masters.
+ * </p>
  * 
- * <p> The ApplicationMaster is started on a container by the <code>ResourceManager</code>'s launcher. 
- * The first thing that the <code>ApplicationMaster</code> needs to do is to connect and register itself with 
- * the <code>ResourceManager</code>. The registration sets up information within the <code>ResourceManager</code>
- * regarding what host:port the ApplicationMaster is listening on to provide any form of functionality to a client
- * as well as a tracking url that a client can use to keep track of status/job history if needed. </p>
+ * <p>
+ * The ApplicationMaster is started on a container by the
+ * <code>ResourceManager</code>'s launcher. The first thing that the
+ * <code>ApplicationMaster</code> needs to do is to connect and register itself
+ * with the <code>ResourceManager</code>. The registration sets up information
+ * within the <code>ResourceManager</code> regarding what host:port the
+ * ApplicationMaster is listening on to provide any form of functionality to a
+ * client as well as a tracking url that a client can use to keep track of
+ * status/job history if needed.
+ * </p>
  * 
- * <p> The <code>ApplicationMaster</code> needs to send a heartbeat to the <code>ResourceManager</code> at regular intervals
- * to inform the <code>ResourceManager</code> that it is up and alive. The {@link AMRMProtocol#allocate} to the 
- * <code>ResourceManager</code> from the <code>ApplicationMaster</code> acts as a heartbeat.
+ * <p>
+ * The <code>ApplicationMaster</code> needs to send a heartbeat to the
+ * <code>ResourceManager</code> at regular intervals to inform the
+ * <code>ResourceManager</code> that it is up and alive. The
+ * {@link AMRMProtocol#allocate} to the <code>ResourceManager</code> from the
+ * <code>ApplicationMaster</code> acts as a heartbeat.
  * 
- * <p> For the actual handling of the job, the <code>ApplicationMaster</code> has to request the 
- * <code>ResourceManager</code> via {@link AllocateRequest} for the required no. of containers using {@link ResourceRequest}
- * with the necessary resource specifications such as node location, computational (memory/disk/cpu) resource requirements.
- * The <code>ResourceManager</code> responds with an {@link AllocateResponse} that informs the <code>ApplicationMaster</code> 
- * of the set of newly allocated containers, completed containers as well as current state of available resources. </p>
+ * <p>
+ * For the actual handling of the job, the <code>ApplicationMaster</code> has to
+ * request the <code>ResourceManager</code> via {@link AllocateRequest} for the
+ * required no. of containers using {@link ResourceRequest} with the necessary
+ * resource specifications such as node location, computational
+ * (memory/disk/cpu) resource requirements. The <code>ResourceManager</code>
+ * responds with an {@link AllocateResponse} that informs the
+ * <code>ApplicationMaster</code> of the set of newly allocated containers,
+ * completed containers as well as current state of available resources.
+ * </p>
  * 
- * <p> For each allocated container, the <code>ApplicationMaster</code> can then set up the necessary launch context via 
- * {@link ContainerLaunchContext} to specify the allocated container id, local resources required by the executable, 
- * the environment to be setup for the executable, commands to execute, etc. and submit a {@link StartContainerRequest} 
- * to the {@link ContainerManager} to launch and execute the defined commands on the given allocated container. </p>
- *  
- * <p> The <code>ApplicationMaster</code> can monitor the launched container by either querying the <code>ResourceManager</code> 
- * using {@link AMRMProtocol#allocate} to get updates on completed containers or via the {@link ContainerManager} 
- * by querying for the status of the allocated container's {@link ContainerId}.
+ * <p>
+ * For each allocated container, the <code>ApplicationMaster</code> can then set
+ * up the necessary launch context via {@link ContainerLaunchContext} to specify
+ * the allocated container id, local resources required by the executable, the
+ * environment to be setup for the executable, commands to execute, etc. and
+ * submit a {@link StartContainerRequest} to the {@link ContainerManager} to
+ * launch and execute the defined commands on the given allocated container.
+ * </p>
  * 
- * <p> After the job has been completed, the <code>ApplicationMaster</code> has to send a {@link FinishApplicationMasterRequest} 
- * to the <code>ResourceManager</code> to inform it that the <code>ApplicationMaster</code> has been completed. 
+ * <p>
+ * The <code>ApplicationMaster</code> can monitor the launched container by
+ * either querying the <code>ResourceManager</code> using
+ * {@link AMRMProtocol#allocate} to get updates on completed containers or via
+ * the {@link ContainerManager} by querying for the status of the allocated
+ * container's {@link ContainerId}.
+ *
+ * <p>
+ * After the job has been completed, the <code>ApplicationMaster</code> has to
+ * send a {@link FinishApplicationMasterRequest} to the
+ * <code>ResourceManager</code> to inform it that the
+ * <code>ApplicationMaster</code> has been completed.
  */
 @InterfaceAudience.Public
 @InterfaceStability.Unstable
@@ -116,61 +142,58 @@ public class ApplicationMaster {
 
   private static final Log LOG = LogFactory.getLog(ApplicationMaster.class);
 
-  // Configuration 
+  // Configuration
   private Configuration conf;
   // YARN RPC to communicate with the Resource Manager or Node Manager
   private YarnRPC rpc;
 
   // Handle to communicate with the Resource Manager
-  private AMRMProtocol resourceManager;
+  private AMRMClient resourceManager;
 
   // Application Attempt Id ( combination of attemptId and fail count )
   private ApplicationAttemptId appAttemptID;
 
   // TODO
   // For status update for clients - yet to be implemented
-  // Hostname of the container 
+  // Hostname of the container
   private String appMasterHostname = "";
-  // Port on which the app master listens for status update requests from clients
+  // Port on which the app master listens for status updates from clients
   private int appMasterRpcPort = 0;
-  // Tracking url to which app master publishes info for clients to monitor 
+  // Tracking url to which app master publishes info for clients to monitor
   private String appMasterTrackingUrl = "";
 
   // App Master configuration
   // No. of containers to run shell command on
   private int numTotalContainers = 1;
-  // Memory to request for the container on which the shell command will run 
+  // Memory to request for the container on which the shell command will run
   private int containerMemory = 10;
   // Priority of the request
-  private int requestPriority; 
-
-  // Incremental counter for rpc calls to the RM
-  private AtomicInteger rmRequestID = new AtomicInteger();
+  private int requestPriority;
 
   // Simple flag to denote whether all works is done
-  private boolean appDone = false; 
+  private boolean appDone = false;
   // Counter for completed containers ( complete denotes successful or failed )
   private AtomicInteger numCompletedContainers = new AtomicInteger();
   // Allocated container count so that we know how many containers has the RM
   // allocated to us
   private AtomicInteger numAllocatedContainers = new AtomicInteger();
-  // Count of failed containers 
+  // Count of failed containers
   private AtomicInteger numFailedContainers = new AtomicInteger();
   // Count of containers already requested from the RM
-  // Needed as once requested, we should not request for containers again and again. 
-  // Only request for more if the original requirement changes. 
+  // Needed as once requested, we should not request for containers again.
+  // Only request for more if the original requirement changes.
   private AtomicInteger numRequestedContainers = new AtomicInteger();
 
-  // Shell command to be executed 
-  private String shellCommand = ""; 
+  // Shell command to be executed
+  private String shellCommand = "";
   // Args to be passed to the shell command
   private String shellArgs = "";
-  // Env variables to be setup for the shell command 
+  // Env variables to be setup for the shell command
   private Map<String, String> shellEnv = new HashMap<String, String>();
 
   // Location of shell script ( obtained from info set in env )
   // Shell script path in fs
-  private String shellScriptPath = ""; 
+  private String shellScriptPath = "";
   // Timestamp needed for creating a local resource
   private long shellScriptPathTimestamp = 0;
   // File length needed for local resource
@@ -179,9 +202,6 @@ public class ApplicationMaster {
   // Hardcoded path to shell script in launch container's local env
   private final String ExecShellStringPath = "ExecShellScript.sh";
 
-  // Containers to be released
-  private CopyOnWriteArrayList<ContainerId> releasedContainers = new CopyOnWriteArrayList<ContainerId>();
-
   // Launch threads
   private List<Thread> launchThreads = new ArrayList<Thread>();
 
@@ -205,8 +225,7 @@ public class ApplicationMaster {
     if (result) {
       LOG.info("Application Master completed successfully. exiting");
       System.exit(0);
-    }
-    else {
+    } else {
       LOG.info("Application Master failed. exiting");
       System.exit(2);
     }
@@ -221,7 +240,8 @@ public class ApplicationMaster {
     Map<String, String> envs = System.getenv();
     for (Map.Entry<String, String> env : envs.entrySet()) {
       LOG.info("System env: key=" + env.getKey() + ", val=" + env.getValue());
-      System.out.println("System env: key=" + env.getKey() + ", val=" + env.getValue());
+      System.out.println("System env: key=" + env.getKey() + ", val="
+          + env.getValue());
     }
 
     String cmd = "ls -al";
@@ -231,9 +251,10 @@ public class ApplicationMaster {
       pr = run.exec(cmd);
       pr.waitFor();
 
-      BufferedReader buf = new BufferedReader(new InputStreamReader(pr.getInputStream()));
+      BufferedReader buf = new BufferedReader(new InputStreamReader(
+          pr.getInputStream()));
       String line = "";
-      while ((line=buf.readLine())!=null) {
+      while ((line = buf.readLine()) != null) {
         LOG.info("System CWD content: " + line);
         System.out.println("System CWD content: " + line);
       }
@@ -242,31 +263,39 @@ public class ApplicationMaster {
       e.printStackTrace();
     } catch (InterruptedException e) {
       e.printStackTrace();
-    } 
+    }
   }
 
   public ApplicationMaster() throws Exception {
     // Set up the configuration and RPC
-    conf = new Configuration();
+    conf = new YarnConfiguration();
     rpc = YarnRPC.create(conf);
   }
+
   /**
    * Parse command line options
-   * @param args Command line args 
-   * @return Whether init successful and run should be invoked 
+   *
+   * @param args Command line args
+   * @return Whether init successful and run should be invoked
    * @throws ParseException
-   * @throws IOException 
+   * @throws IOException
    */
   public boolean init(String[] args) throws ParseException, IOException {
 
     Options opts = new Options();
-    opts.addOption("app_attempt_id", true, "App Attempt ID. Not to be used unless for testing purposes");
-    opts.addOption("shell_command", true, "Shell command to be executed by the Application Master");
-    opts.addOption("shell_script", true, "Location of the shell script to be executed");
+    opts.addOption("app_attempt_id", true,
+        "App Attempt ID. Not to be used unless for testing purposes");
+    opts.addOption("shell_command", true,
+        "Shell command to be executed by the Application Master");
+    opts.addOption("shell_script", true,
+        "Location of the shell script to be executed");
     opts.addOption("shell_args", true, "Command line args for the shell script");
-    opts.addOption("shell_env", true, "Environment for shell script. Specified as env_key=env_val pairs");
-    opts.addOption("container_memory", true, "Amount of memory in MB to be requested to run the shell command");
-    opts.addOption("num_containers", true, "No. of containers on which the shell command needs to be executed");
+    opts.addOption("shell_env", true,
+        "Environment for shell script. Specified as env_key=env_val pairs");
+    opts.addOption("container_memory", true,
+        "Amount of memory in MB to be requested to run the shell command");
+    opts.addOption("num_containers", true,
+        "No. of containers on which the shell command needs to be executed");
     opts.addOption("priority", true, "Application Priority. Default 0");
     opts.addOption("debug", false, "Dump out debug information");
 
@@ -275,7 +304,8 @@ public class ApplicationMaster {
 
     if (args.length == 0) {
       printUsage(opts);
-      throw new IllegalArgumentException("No args specified for application master to initialize");
+      throw new IllegalArgumentException(
+          "No args specified for application master to initialize");
     }
 
     if (cliParser.hasOption("help")) {
@@ -289,7 +319,6 @@ public class ApplicationMaster {
 
     Map<String, String> envs = System.getenv();
 
-    appAttemptID = Records.newRecord(ApplicationAttemptId.class);
     if (envs.containsKey(ApplicationConstants.AM_APP_ATTEMPT_ID_ENV)) {
       appAttemptID = ConverterUtils.toApplicationAttemptId(envs
           .get(ApplicationConstants.AM_APP_ATTEMPT_ID_ENV));
@@ -297,29 +326,31 @@ public class ApplicationMaster {
       if (cliParser.hasOption("app_attempt_id")) {
         String appIdStr = cliParser.getOptionValue("app_attempt_id", "");
         appAttemptID = ConverterUtils.toApplicationAttemptId(appIdStr);
-      } 
-      else {
-        throw new IllegalArgumentException("Application Attempt Id not set in the environment");
+      } else {
+        throw new IllegalArgumentException(
+            "Application Attempt Id not set in the environment");
       }
     } else {
-      ContainerId containerId = ConverterUtils.toContainerId(envs.get(ApplicationConstants.AM_CONTAINER_ID_ENV));
+      ContainerId containerId = ConverterUtils.toContainerId(envs
+          .get(ApplicationConstants.AM_CONTAINER_ID_ENV));
       appAttemptID = containerId.getApplicationAttemptId();
     }
 
-    LOG.info("Application master for app"
-        + ", appId=" + appAttemptID.getApplicationId().getId()
-        + ", clustertimestamp=" + appAttemptID.getApplicationId().getClusterTimestamp()
+    LOG.info("Application master for app" + ", appId="
+        + appAttemptID.getApplicationId().getId() + ", clustertimestamp="
+        + appAttemptID.getApplicationId().getClusterTimestamp()
         + ", attemptId=" + appAttemptID.getAttemptId());
 
     if (!cliParser.hasOption("shell_command")) {
-      throw new IllegalArgumentException("No shell command specified to be executed by application master");
+      throw new IllegalArgumentException(
+          "No shell command specified to be executed by application master");
     }
     shellCommand = cliParser.getOptionValue("shell_command");
 
     if (cliParser.hasOption("shell_args")) {
       shellArgs = cliParser.getOptionValue("shell_args");
     }
-    if (cliParser.hasOption("shell_env")) { 
+    if (cliParser.hasOption("shell_env")) {
       String shellEnvs[] = cliParser.getOptionValues("shell_env");
       for (String env : shellEnvs) {
         env = env.trim();
@@ -330,8 +361,8 @@ public class ApplicationMaster {
         }
         String key = env.substring(0, index);
         String val = "";
-        if (index < (env.length()-1)) {
-          val = env.substring(index+1);
+        if (index < (env.length() - 1)) {
+          val = env.substring(index + 1);
         }
         shellEnv.put(key, val);
       }
@@ -341,32 +372,37 @@ public class ApplicationMaster {
       shellScriptPath = envs.get(DSConstants.DISTRIBUTEDSHELLSCRIPTLOCATION);
 
       if (envs.containsKey(DSConstants.DISTRIBUTEDSHELLSCRIPTTIMESTAMP)) {
-        shellScriptPathTimestamp = Long.valueOf(envs.get(DSConstants.DISTRIBUTEDSHELLSCRIPTTIMESTAMP));
+        shellScriptPathTimestamp = Long.valueOf(envs
+            .get(DSConstants.DISTRIBUTEDSHELLSCRIPTTIMESTAMP));
       }
       if (envs.containsKey(DSConstants.DISTRIBUTEDSHELLSCRIPTLEN)) {
-        shellScriptPathLen = Long.valueOf(envs.get(DSConstants.DISTRIBUTEDSHELLSCRIPTLEN));
+        shellScriptPathLen = Long.valueOf(envs
+            .get(DSConstants.DISTRIBUTEDSHELLSCRIPTLEN));
       }
 
       if (!shellScriptPath.isEmpty()
-          && (shellScriptPathTimestamp <= 0 
-          || shellScriptPathLen <= 0)) {
-        LOG.error("Illegal values in env for shell script path"
-            + ", path=" + shellScriptPath
-            + ", len=" + shellScriptPathLen
-            + ", timestamp=" + shellScriptPathTimestamp);
-        throw new IllegalArgumentException("Illegal values in env for shell script path");
+          && (shellScriptPathTimestamp <= 0 || shellScriptPathLen <= 0)) {
+        LOG.error("Illegal values in env for shell script path" + ", path="
+            + shellScriptPath + ", len=" + shellScriptPathLen + ", timestamp="
+            + shellScriptPathTimestamp);
+        throw new IllegalArgumentException(
+            "Illegal values in env for shell script path");
       }
     }
 
-    containerMemory = Integer.parseInt(cliParser.getOptionValue("container_memory", "10"));
-    numTotalContainers = Integer.parseInt(cliParser.getOptionValue("num_containers", "1"));
-    requestPriority = Integer.parseInt(cliParser.getOptionValue("priority", "0"));
+    containerMemory = Integer.parseInt(cliParser.getOptionValue(
+        "container_memory", "10"));
+    numTotalContainers = Integer.parseInt(cliParser.getOptionValue(
+        "num_containers", "1"));
+    requestPriority = Integer.parseInt(cliParser
+        .getOptionValue("priority", "0"));
 
     return true;
   }
 
   /**
-   * Helper function to print usage 
+   * Helper function to print usage
+   *
    * @param opts Parsed command line options
    */
   private void printUsage(Options opts) {
@@ -375,228 +411,240 @@ public class ApplicationMaster {
 
   /**
    * Main run function for the application master
+   *
    * @throws YarnRemoteException
    */
   public boolean run() throws YarnRemoteException {
     LOG.info("Starting ApplicationMaster");
 
     // Connect to ResourceManager
-    resourceManager = connectToRM();
-
-    // Setup local RPC Server to accept status requests directly from clients 
-    // TODO need to setup a protocol for client to be able to communicate to the RPC server 
-    // TODO use the rpc port info to register with the RM for the client to send requests to this app master
-
-    // Register self with ResourceManager 
-    RegisterApplicationMasterResponse response = registerToRM();
-    // Dump out information about cluster capability as seen by the resource manager
-    int minMem = response.getMinimumResourceCapability().getMemory();
-    int maxMem = response.getMaximumResourceCapability().getMemory();
-    LOG.info("Min mem capabililty of resources in this cluster " + minMem);
-    LOG.info("Max mem capabililty of resources in this cluster " + maxMem);
-
-    // A resource ask has to be atleast the minimum of the capability of the cluster, the value has to be 
-    // a multiple of the min value and cannot exceed the max. 
-    // If it is not an exact multiple of min, the RM will allocate to the nearest multiple of min
-    if (containerMemory < minMem) {
-      LOG.info("Container memory specified below min threshold of cluster. Using min value."
-          + ", specified=" + containerMemory
-          + ", min=" + minMem);
-      containerMemory = minMem; 
-    } 
-    else if (containerMemory > maxMem) {
-      LOG.info("Container memory specified above max threshold of cluster. Using max value."
-          + ", specified=" + containerMemory
-          + ", max=" + maxMem);
-      containerMemory = maxMem;
-    }
+    resourceManager = new AMRMClientImpl(appAttemptID);
+    resourceManager.init(conf);
+    resourceManager.start();
 
-    // Setup heartbeat emitter
-    // TODO poll RM every now and then with an empty request to let RM know that we are alive
-    // The heartbeat interval after which an AM is timed out by the RM is defined by a config setting: 
-    // RM_AM_EXPIRY_INTERVAL_MS with default defined by DEFAULT_RM_AM_EXPIRY_INTERVAL_MS
-    // The allocate calls to the RM count as heartbeats so, for now, this additional heartbeat emitter 
-    // is not required.
-
-    // Setup ask for containers from RM
-    // Send request for containers to RM
-    // Until we get our fully allocated quota, we keep on polling RM for containers
-    // Keep looping until all the containers are launched and shell script executed on them 
-    // ( regardless of success/failure). 
-
-    int loopCounter = -1;
-
-    while (numCompletedContainers.get() < numTotalContainers
-        && !appDone) {
-      loopCounter++;
-
-      // log current state
-      LOG.info("Current application state: loop=" + loopCounter 
-          + ", appDone=" + appDone
-          + ", total=" + numTotalContainers
-          + ", requested=" + numRequestedContainers
-          + ", completed=" + numCompletedContainers
-          + ", failed=" + numFailedContainers
-          + ", currentAllocated=" + numAllocatedContainers);
-
-      // Sleep before each loop when asking RM for containers
-      // to avoid flooding RM with spurious requests when it 
-      // need not have any available containers 
-      // Sleeping for 1000 ms.
-      try {
-        Thread.sleep(1000);
-      } catch (InterruptedException e) {
-        LOG.info("Sleep interrupted " + e.getMessage());
+    try {
+      // Setup local RPC Server to accept status requests directly from clients
+      // TODO need to setup a protocol for client to be able to communicate to
+      // the RPC server
+      // TODO use the rpc port info to register with the RM for the client to
+      // send requests to this app master
+
+      // Register self with ResourceManager
+      RegisterApplicationMasterResponse response = resourceManager
+          .registerApplicationMaster(appMasterHostname, appMasterRpcPort,
+              appMasterTrackingUrl);
+      // Dump out information about cluster capability as seen by the
+      // resource manager
+      int minMem = response.getMinimumResourceCapability().getMemory();
+      int maxMem = response.getMaximumResourceCapability().getMemory();
+      LOG.info("Min mem capabililty of resources in this cluster " + minMem);
+      LOG.info("Max mem capabililty of resources in this cluster " + maxMem);
+
+      // A resource ask has to be atleast the minimum of the capability of the
+      // cluster, the value has to be a multiple of the min value and cannot
+      // exceed the max.
+      // If it is not an exact multiple of min, the RM will allocate to the
+      // nearest multiple of min
+      if (containerMemory < minMem) {
+        LOG.info("Container memory specified below min threshold of cluster."
+            + " Using min value." + ", specified=" + containerMemory + ", min="
+            + minMem);
+        containerMemory = minMem;
+      } else if (containerMemory > maxMem) {
+        LOG.info("Container memory specified above max threshold of cluster."
+            + " Using max value." + ", specified=" + containerMemory + ", max="
+            + maxMem);
+        containerMemory = maxMem;
       }
 
-      // No. of containers to request 
-      // For the first loop, askCount will be equal to total containers needed 
-      // From that point on, askCount will always be 0 as current implementation 
-      // does not change its ask on container failures. 
-      int askCount = numTotalContainers - numRequestedContainers.get();
-      numRequestedContainers.addAndGet(askCount);
-
-      // Setup request to be sent to RM to allocate containers
-      List<ResourceRequest> resourceReq = new ArrayList<ResourceRequest>();
-      if (askCount > 0) {
-        ResourceRequest containerAsk = setupContainerAskForRM(askCount);
-        resourceReq.add(containerAsk);
-      }
+      // Setup heartbeat emitter
+      // TODO poll RM every now and then with an empty request to let RM know
+      // that we are alive
+      // The heartbeat interval after which an AM is timed out by the RM is
+      // defined by a config setting:
+      // RM_AM_EXPIRY_INTERVAL_MS with default defined by
+      // DEFAULT_RM_AM_EXPIRY_INTERVAL_MS
+      // The allocate calls to the RM count as heartbeats so, for now,
+      // this additional heartbeat emitter is not required.
+
+      // Setup ask for containers from RM
+      // Send request for containers to RM
+      // Until we get our fully allocated quota, we keep on polling RM for
+      // containers
+      // Keep looping until all the containers are launched and shell script
+      // executed on them ( regardless of success/failure).
+
+      int loopCounter = -1;
+
+      while (numCompletedContainers.get() < numTotalContainers && !appDone) {
+        loopCounter++;
+
+        // log current state
+        LOG.info("Current application state: loop=" + loopCounter
+            + ", appDone=" + appDone + ", total=" + numTotalContainers
+            + ", requested=" + numRequestedContainers + ", completed="
+            + numCompletedContainers + ", failed=" + numFailedContainers
+            + ", currentAllocated=" + numAllocatedContainers);
+
+        // Sleep before each loop when asking RM for containers
+        // to avoid flooding RM with spurious requests when it
+        // need not have any available containers
+        // Sleeping for 1000 ms.
+        try {
+          Thread.sleep(1000);
+        } catch (InterruptedException e) {
+          LOG.info("Sleep interrupted " + e.getMessage());
+        }
 
-      // Send the request to RM 
-      LOG.info("Asking RM for containers"
-          + ", askCount=" + askCount);
-      AMResponse amResp =sendContainerAskToRM(resourceReq);
-
-      // Retrieve list of allocated containers from the response 
-      List<Container> allocatedContainers = amResp.getAllocatedContainers();
-      LOG.info("Got response from RM for container ask, allocatedCnt=" + allocatedContainers.size());
-      numAllocatedContainers.addAndGet(allocatedContainers.size());
-      for (Container allocatedContainer : allocatedContainers) {
-        LOG.info("Launching shell command on a new container."
-            + ", containerId=" + allocatedContainer.getId()
-            + ", containerNode=" + allocatedContainer.getNodeId().getHost() 
-            + ":" + allocatedContainer.getNodeId().getPort()
-            + ", containerNodeURI=" + allocatedContainer.getNodeHttpAddress()
-            + ", containerState" + allocatedContainer.getState()
-            + ", containerResourceMemory" + allocatedContainer.getResource().getMemory());
-        //+ ", containerToken" + allocatedContainer.getContainerToken().getIdentifier().toString());
-
-        LaunchContainerRunnable runnableLaunchContainer = new LaunchContainerRunnable(allocatedContainer);
-        Thread launchThread = new Thread(runnableLaunchContainer);
-
-        // launch and start the container on a separate thread to keep the main thread unblocked
-        // as all containers may not be allocated at one go.
-        launchThreads.add(launchThread);
-        launchThread.start();
-      }
+        // No. of containers to request
+        // For the first loop, askCount will be equal to total containers needed
+        // From that point on, askCount will always be 0 as current
+        // implementation does not change its ask on container failures.
+        int askCount = numTotalContainers - numRequestedContainers.get();
+        numRequestedContainers.addAndGet(askCount);
+
+        if (askCount > 0) {
+          ContainerRequest containerAsk = setupContainerAskForRM(askCount);
+          resourceManager.addContainerRequest(containerAsk);
+        }
+
+        // Send the request to RM
+        LOG.info("Asking RM for containers" + ", askCount=" + askCount);
+        AMResponse amResp = sendContainerAskToRM();
+
+        // Retrieve list of allocated containers from the response
+        List<Container> allocatedContainers = amResp.getAllocatedContainers();
+        LOG.info("Got response from RM for container ask, allocatedCnt="
+            + allocatedContainers.size());
+        numAllocatedContainers.addAndGet(allocatedContainers.size());
+        for (Container allocatedContainer : allocatedContainers) {
+          LOG.info("Launching shell command on a new container."
+              + ", containerId=" + allocatedContainer.getId()
+              + ", containerNode=" + allocatedContainer.getNodeId().getHost()
+              + ":" + allocatedContainer.getNodeId().getPort()
+              + ", containerNodeURI=" + allocatedContainer.getNodeHttpAddress()
+              + ", containerState" + allocatedContainer.getState()
+              + ", containerResourceMemory"
+              + allocatedContainer.getResource().getMemory());
+          // + ", containerToken"
+          // +allocatedContainer.getContainerToken().getIdentifier().toString());
+
+          LaunchContainerRunnable runnableLaunchContainer = new LaunchContainerRunnable(
+              allocatedContainer);
+          Thread launchThread = new Thread(runnableLaunchContainer);
+
+          // launch and start the container on a separate thread to keep
+          // the main thread unblocked
+          // as all containers may not be allocated at one go.
+          launchThreads.add(launchThread);
+          launchThread.start();
+        }
 
-      // Check what the current available resources in the cluster are
-      // TODO should we do anything if the available resources are not enough? 
-      Resource availableResources = amResp.getAvailableResources();
-      LOG.info("Current available resources in the cluster " + availableResources);
-
-      // Check the completed containers
-      List<ContainerStatus> completedContainers = amResp.getCompletedContainersStatuses();
-      LOG.info("Got response from RM for container ask, completedCnt=" + completedContainers.size());
-      for (ContainerStatus containerStatus : completedContainers) {
-        LOG.info("Got container status for containerID= " + containerStatus.getContainerId()
-            + ", state=" + containerStatus.getState()
-            + ", exitStatus=" + containerStatus.getExitStatus() 
-            + ", diagnostics=" + containerStatus.getDiagnostics());
-
-        // non complete containers should not be here 
-        assert(containerStatus.getState() == ContainerState.COMPLETE);
-
-        // increment counters for completed/failed containers
-        int exitStatus = containerStatus.getExitStatus();
-        if (0 != exitStatus) {
-          // container failed 
-          if (-100 != exitStatus) {
-            // shell script failed
-            // counts as completed 
+        // Check what the current available resources in the cluster are
+        // TODO should we do anything if the available resources are not enough?
+        Resource availableResources = amResp.getAvailableResources();
+        LOG.info("Current available resources in the cluster "
+            + availableResources);
+
+        // Check the completed containers
+        List<ContainerStatus> completedContainers = amResp
+            .getCompletedContainersStatuses();
+        LOG.info("Got response from RM for container ask, completedCnt="
+            + completedContainers.size());
+        for (ContainerStatus containerStatus : completedContainers) {
+          LOG.info("Got container status for containerID="
+              + containerStatus.getContainerId() + ", state="
+              + containerStatus.getState() + ", exitStatus="
+              + containerStatus.getExitStatus() + ", diagnostics="
+              + containerStatus.getDiagnostics());
+
+          // non complete containers should not be here
+          assert (containerStatus.getState() == ContainerState.COMPLETE);
+
+          // increment counters for completed/failed containers
+          int exitStatus = containerStatus.getExitStatus();
+          if (0 != exitStatus) {
+            // container failed
+            if (-100 != exitStatus) {
+              // shell script failed
+              // counts as completed
+              numCompletedContainers.incrementAndGet();
+              numFailedContainers.incrementAndGet();
+            } else {
+              // something else bad happened
+              // app job did not complete for some reason
+              // we should re-try as the container was lost for some reason
+              numAllocatedContainers.decrementAndGet();
+              numRequestedContainers.decrementAndGet();
+              // we do not need to release the container as it would be done
+              // by the RM/CM.
+            }
+          } else {
+            // nothing to do
+            // container completed successfully
             numCompletedContainers.incrementAndGet();
-            numFailedContainers.incrementAndGet();
-          }
-          else { 
-            // something else bad happened 
-            // app job did not complete for some reason 
-            // we should re-try as the container was lost for some reason
-            numAllocatedContainers.decrementAndGet();
-            numRequestedContainers.decrementAndGet();
-            // we do not need to release the container as it would be done
-            // by the RM/CM.
+            LOG.info("Container completed successfully." + ", containerId="
+                + containerStatus.getContainerId());
           }
         }
-        else { 
-          // nothing to do 
-          // container completed successfully 
-          numCompletedContainers.incrementAndGet();
-          LOG.info("Container completed successfully."
-              + ", containerId=" + containerStatus.getContainerId());
+        if (numCompletedContainers.get() == numTotalContainers) {
+          appDone = true;
         }
 
-      }
-      if (numCompletedContainers.get() == numTotalContainers) {
-        appDone = true;
-      }
-
-      LOG.info("Current application state: loop=" + loopCounter
-          + ", appDone=" + appDone
-          + ", total=" + numTotalContainers
-          + ", requested=" + numRequestedContainers
-          + ", completed=" + numCompletedContainers
-          + ", failed=" + numFailedContainers
-          + ", currentAllocated=" + numAllocatedContainers);
-
-      // TODO 
-      // Add a timeout handling layer 
-      // for misbehaving shell commands
-    }
+        LOG.info("Current application state: loop=" + loopCounter
+            + ", appDone=" + appDone + ", total=" + numTotalContainers
+            + ", requested=" + numRequestedContainers + ", completed="
+            + numCompletedContainers + ", failed=" + numFailedContainers
+            + ", currentAllocated=" + numAllocatedContainers);
 
-    // Join all launched threads
-    // needed for when we time out 
-    // and we need to release containers
-    for (Thread launchThread : launchThreads) {
-      try {
-        launchThread.join(10000);
-      } catch (InterruptedException e) {
-        LOG.info("Exception thrown in thread join: " + e.getMessage());
-        e.printStackTrace();
+        // TODO
+        // Add a timeout handling layer
+        // for misbehaving shell commands
       }
-    }
 
-    // When the application completes, it should send a finish application signal 
-    // to the RM
-    LOG.info("Application completed. Signalling finish to RM");
+      // Join all launched threads
+      // needed for when we time out
+      // and we need to release containers
+      for (Thread launchThread : launchThreads) {
+        try {
+          launchThread.join(10000);
+        } catch (InterruptedException e) {
+          LOG.info("Exception thrown in thread join: " + e.getMessage());
+          e.printStackTrace();
+        }
+      }
 
-    FinishApplicationMasterRequest finishReq = Records.newRecord(FinishApplicationMasterRequest.class);
-    finishReq.setAppAttemptId(appAttemptID);
-    boolean isSuccess = true;
-    if (numFailedContainers.get() == 0) {
-      finishReq.setFinishApplicationStatus(FinalApplicationStatus.SUCCEEDED);
-    }
-    else {
-      finishReq.setFinishApplicationStatus(FinalApplicationStatus.FAILED);
-      String diagnostics = "Diagnostics."
-          + ", total=" + numTotalContainers
-          + ", completed=" + numCompletedContainers.get()
-          + ", allocated=" + numAllocatedContainers.get()
-          + ", failed=" + numFailedContainers.get();
-      finishReq.setDiagnostics(diagnostics);
-      isSuccess = false;
+      // When the application completes, it should send a finish application
+      // signal to the RM
+      LOG.info("Application completed. Signalling finish to RM");
+
+      FinalApplicationStatus appStatus;
+      String appMessage = null;
+      boolean isSuccess = true;
+      if (numFailedContainers.get() == 0) {
+        appStatus = FinalApplicationStatus.SUCCEEDED;
+      } else {
+        appStatus = FinalApplicationStatus.FAILED;
+        appMessage = "Diagnostics." + ", total=" + numTotalContainers
+            + ", completed=" + numCompletedContainers.get() + ", allocated="
+            + numAllocatedContainers.get() + ", failed="
+            + numFailedContainers.get();
+        isSuccess = false;
+      }
+      resourceManager.unregisterApplicationMaster(appStatus, appMessage, null);
+      return isSuccess;
+    } finally {
+      resourceManager.stop();
     }
-    resourceManager.finishApplicationMaster(finishReq);
-    return isSuccess;
   }
 
   /**
-   * Thread to connect to the {@link ContainerManager} and 
-   * launch the container that will execute the shell command. 
+   * Thread to connect to the {@link ContainerManager} and launch the container
+   * that will execute the shell command.
    */
   private class LaunchContainerRunnable implements Runnable {
 
-    // Allocated container 
+    // Allocated container
     Container container;
     // Handle to communicate with ContainerManager
     ContainerManager cm;
@@ -612,15 +660,16 @@ public class ApplicationMaster {
      * Helper function to connect to CM
      */
     private void connectToCM() {
-      LOG.debug("Connecting to ContainerManager for containerid=" + container.getId());
+      LOG.debug("Connecting to ContainerManager for containerid="
+          + container.getId());
       String cmIpPortStr = container.getNodeId().getHost() + ":"
           + container.getNodeId().getPort();
       InetSocketAddress cmAddress = NetUtils.createSocketAddr(cmIpPortStr);
       LOG.info("Connecting to ContainerManager at " + cmIpPortStr);
-      this.cm = ((ContainerManager) rpc.getProxy(ContainerManager.class, cmAddress, conf));
+      this.cm = ((ContainerManager) rpc.getProxy(ContainerManager.class,
+          cmAddress, conf));
     }
 
-
     @Override
     /**
      * Connects to CM, sets up container launch context 
@@ -628,11 +677,13 @@ public class ApplicationMaster {
      * start request to the CM. 
      */
     public void run() {
-      // Connect to ContainerManager 
+      // Connect to ContainerManager
       connectToCM();
 
-      LOG.info("Setting up container launch container for containerid=" + container.getId());
-      ContainerLaunchContext ctx = Records.newRecord(ContainerLaunchContext.class);
+      LOG.info("Setting up container launch container for containerid="
+          + container.getId());
+      ContainerLaunchContext ctx = Records
+          .newRecord(ContainerLaunchContext.class);
 
       ctx.setContainerId(container.getId());
       ctx.setResource(container.getResource());
@@ -642,28 +693,30 @@ public class ApplicationMaster {
       ctx.setUser(jobUserName);
       LOG.info("Setting user in ContainerLaunchContext to: " + jobUserName);
 
-      // Set the environment 
+      // Set the environment
       ctx.setEnvironment(shellEnv);
 
-      // Set the local resources 
+      // Set the local resources
       Map<String, LocalResource> localResources = new HashMap<String, LocalResource>();
 
-      // The container for the eventual shell commands needs its own local resources too. 
-      // In this scenario, if a shell script is specified, we need to have it copied 
-      // and made available to the container. 
+      // The container for the eventual shell commands needs its own local
+      // resources too.
+      // In this scenario, if a shell script is specified, we need to have it
+      // copied and made available to the container.
       if (!shellScriptPath.isEmpty()) {
         LocalResource shellRsrc = Records.newRecord(LocalResource.class);
         shellRsrc.setType(LocalResourceType.FILE);
         shellRsrc.setVisibility(LocalResourceVisibility.APPLICATION);
         try {
-          shellRsrc.setResource(ConverterUtils.getYarnUrlFromURI(new URI(shellScriptPath)));
+          shellRsrc.setResource(ConverterUtils.getYarnUrlFromURI(new URI(
+              shellScriptPath)));
         } catch (URISyntaxException e) {
-          LOG.error("Error when trying to use shell script path specified in env"
-              + ", path=" + shellScriptPath);
+          LOG.error("Error when trying to use shell script path specified"
+              + " in env, path=" + shellScriptPath);
           e.printStackTrace();
 
-          // A failure scenario on bad input such as invalid shell script path 
-          // We know we cannot continue launching the container 
+          // A failure scenario on bad input such as invalid shell script path
+          // We know we cannot continue launching the container
           // so we should release it.
           // TODO
           numCompletedContainers.incrementAndGet();
@@ -676,12 +729,12 @@ public class ApplicationMaster {
       }
       ctx.setLocalResources(localResources);
 
-      // Set the necessary command to execute on the allocated container 
+      // Set the necessary command to execute on the allocated container
       Vector<CharSequence> vargs = new Vector<CharSequence>(5);
 
-      // Set executable command 
+      // Set executable command
       vargs.add(shellCommand);
-      // Set shell script path 
+      // Set shell script path
       if (!shellScriptPath.isEmpty()) {
         vargs.add(ExecShellStringPath);
       }
@@ -689,11 +742,6 @@ public class ApplicationMaster {
       // Set args for the shell command if any
       vargs.add(shellArgs);
       // Add log redirect params
-      // TODO
-      // We should redirect the output to hdfs instead of local logs 
-      // so as to be able to look at the final output after the containers 
-      // have been released. 
-      // Could use a path suffixed with /AppId/AppAttempId/ContainerId/std[out|err] 
       vargs.add("1>" + ApplicationConstants.LOG_DIR_EXPANSION_VAR + "/stdout");
       vargs.add("2>" + ApplicationConstants.LOG_DIR_EXPANSION_VAR + "/stderr");
 
@@ -707,131 +755,78 @@ public class ApplicationMaster {
       commands.add(command.toString());
       ctx.setCommands(commands);
 
-      StartContainerRequest startReq = Records.newRecord(StartContainerRequest.class);
+      StartContainerRequest startReq = Records
+          .newRecord(StartContainerRequest.class);
       startReq.setContainerLaunchContext(ctx);
       try {
         cm.startContainer(startReq);
       } catch (YarnRemoteException e) {
-        LOG.info("Start container failed for :"
-            + ", containerId=" + container.getId());
+        LOG.info("Start container failed for :" + ", containerId="
+            + container.getId());
         e.printStackTrace();
-        // TODO do we need to release this container? 
+        // TODO do we need to release this container?
       }
 
       // Get container status?
-      // Left commented out as the shell scripts are short lived 
-      // and we are relying on the status for completed containers from RM to detect status
-
-      //    GetContainerStatusRequest statusReq = Records.newRecord(GetContainerStatusRequest.class);
-      //    statusReq.setContainerId(container.getId());
-      //    GetContainerStatusResponse statusResp;
-      //try {
-      //statusResp = cm.getContainerStatus(statusReq);
-      //    LOG.info("Container Status"
-      //    + ", id=" + container.getId()
-      //    + ", status=" +statusResp.getStatus());
-      //} catch (YarnRemoteException e) {
-      //e.printStackTrace();
-      //}
+      // Left commented out as the shell scripts are short lived
+      // and we are relying on the status for completed containers
+      // from RM to detect status
+
+      // GetContainerStatusRequest statusReq =
+      // Records.newRecord(GetContainerStatusRequest.class);
+      // statusReq.setContainerId(container.getId());
+      // GetContainerStatusResponse statusResp;
+      // try {
+      // statusResp = cm.getContainerStatus(statusReq);
+      // LOG.info("Container Status"
+      // + ", id=" + container.getId()
+      // + ", status=" +statusResp.getStatus());
+      // } catch (YarnRemoteException e) {
+      // e.printStackTrace();
+      // }
     }
   }
 
-  /**
-   * Connect to the Resource Manager
-   * @return Handle to communicate with the RM
-   */
-  private AMRMProtocol connectToRM() {
-    YarnConfiguration yarnConf = new YarnConfiguration(conf);
-    InetSocketAddress rmAddress = yarnConf.getSocketAddr(
-        YarnConfiguration.RM_SCHEDULER_ADDRESS,
-        YarnConfiguration.DEFAULT_RM_SCHEDULER_ADDRESS,
-        YarnConfiguration.DEFAULT_RM_SCHEDULER_PORT);
-    LOG.info("Connecting to ResourceManager at " + rmAddress);
-    return ((AMRMProtocol) rpc.getProxy(AMRMProtocol.class, rmAddress, conf));
-  }
-
-  /** 
-   * Register the Application Master to the Resource Manager
-   * @return the registration response from the RM
-   * @throws YarnRemoteException
-   */
-  private RegisterApplicationMasterResponse registerToRM() throws YarnRemoteException {
-    RegisterApplicationMasterRequest appMasterRequest = Records.newRecord(RegisterApplicationMasterRequest.class);
-
-    // set the required info into the registration request: 
-    // application attempt id, 
-    // host on which the app master is running
-    // rpc port on which the app master accepts requests from the client 
-    // tracking url for the app master
-    appMasterRequest.setApplicationAttemptId(appAttemptID);
-    appMasterRequest.setHost(appMasterHostname);
-    appMasterRequest.setRpcPort(appMasterRpcPort);
-    appMasterRequest.setTrackingUrl(appMasterTrackingUrl);
-
-    return resourceManager.registerApplicationMaster(appMasterRequest);
-  }
-
   /**
    * Setup the request that will be sent to the RM for the container ask.
+   *
    * @param numContainers Containers to ask for from RM
    * @return the setup ResourceRequest to be sent to RM
    */
-  private ResourceRequest setupContainerAskForRM(int numContainers) {
-    ResourceRequest request = Records.newRecord(ResourceRequest.class);
-
-    // setup requirements for hosts 
-    // whether a particular rack/host is needed 
-    // Refer to apis under org.apache.hadoop.net for more 
-    // details on how to get figure out rack/host mapping.
+  private ContainerRequest setupContainerAskForRM(int numContainers) {
+    // setup requirements for hosts
     // using * as any host will do for the distributed shell app
-    request.setHostName("*");
-
-    // set no. of containers needed
-    request.setNumContainers(numContainers);
-
     // set the priority for the request
     Priority pri = Records.newRecord(Priority.class);
-    // TODO - what is the range for priority? how to decide? 
+    // TODO - what is the range for priority? how to decide?
     pri.setPriority(requestPriority);
-    request.setPriority(pri);
 
     // Set up resource type requirements
     // For now, only memory is supported so we set memory requirements
     Resource capability = Records.newRecord(Resource.class);
     capability.setMemory(containerMemory);
-    request.setCapability(capability);
 
+    ContainerRequest request = new ContainerRequest(capability, null, null,
+        pri, numContainers);
+    LOG.info("Requested container ask: " + request.toString());
     return request;
   }
 
   /**
    * Ask RM to allocate given no. of containers to this Application Master
+   *
    * @param requestedContainers Containers to ask for from RM
-   * @return Response from RM to AM with allocated containers 
+   * @return Response from RM to AM with allocated containers
    * @throws YarnRemoteException
    */
-  private AMResponse sendContainerAskToRM(List<ResourceRequest> requestedContainers)
-      throws YarnRemoteException {
-    AllocateRequest req = Records.newRecord(AllocateRequest.class);
-    req.setResponseId(rmRequestID.incrementAndGet());
-    req.setApplicationAttemptId(appAttemptID);
-    req.addAllAsks(requestedContainers);
-    req.addAllReleases(releasedContainers);
-    req.setProgress((float)numCompletedContainers.get()/numTotalContainers);
-
-    LOG.info("Sending request to RM for containers"
-        + ", requestedSet=" + requestedContainers.size()
-        + ", releasedSet=" + releasedContainers.size()
-        + ", progress=" + req.getProgress());
-
-    for (ResourceRequest  rsrcReq : requestedContainers) {
-      LOG.info("Requested container ask: " + rsrcReq.toString());
-    }
-    for (ContainerId id : releasedContainers) {
-      LOG.info("Released container, id=" + id.getId());
-    }
+  private AMResponse sendContainerAskToRM() throws YarnRemoteException {
+    float progressIndicator = (float) numCompletedContainers.get()
+        / numTotalContainers;
+
+    LOG.info("Sending request to RM for containers" + ", progress="
+        + progressIndicator);
 
-    AllocateResponse resp = resourceManager.allocate(req);
+    AllocateResponse resp = resourceManager.allocate(progressIndicator);
     return resp.getAMResponse();
   }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-distributedshell/src/main/java/org/apache/hadoop/yarn/applications/distributedshell/Client.java

@@ -18,10 +18,7 @@
 
 package org.apache.hadoop.yarn.applications.distributedshell;
 
-import java.io.BufferedReader;
 import java.io.IOException;
-import java.io.InputStream;
-import java.io.InputStreamReader;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
@@ -212,7 +209,7 @@ public class Client extends YarnClientImpl {
   /**
    */
   public Client() throws Exception  {
-    this(new Configuration());
+    this(new YarnConfiguration());
   }
 
   /**

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-distributedshell/src/test/java/org/apache/hadoop/yarn/applications/distributedshell/TestDistributedShell.java

@@ -120,6 +120,7 @@ public class TestDistributedShell {
     boolean exceptionThrown = false;
     try {
       boolean initSuccess = client.init(args);
+      Assert.assertTrue(initSuccess);
     }
     catch (IllegalArgumentException e) {
       exceptionThrown = true;