YARN-1897. CLI and core support for signal container functionality. Contributed by Ming Ma

(cherry picked from commit 8f08532bde)

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-jobclient/src/main/java/org/apache/hadoop/mapred/ResourceMgrDelegate.java

@@ -63,6 +63,7 @@ import org.apache.hadoop.yarn.api.records.NodeReport;
 import org.apache.hadoop.yarn.api.records.NodeState;
 import org.apache.hadoop.yarn.api.records.Priority;
 import org.apache.hadoop.yarn.api.records.QueueUserACLInfo;
+import org.apache.hadoop.yarn.api.records.SignalContainerCommand;
 import org.apache.hadoop.yarn.api.records.YarnApplicationState;
 import org.apache.hadoop.yarn.api.records.YarnClusterMetrics;
 import org.apache.hadoop.yarn.client.ClientRMProxy;
@@ -473,4 +474,10 @@ public class ResourceMgrDelegate extends YarnClient {
       Priority priority) throws YarnException, IOException {
     client.updateApplicationPriority(applicationId, priority);
   }
+
+  @Override
+  public void signalContainer(ContainerId containerId, SignalContainerCommand command)
+      throws YarnException, IOException {
+    client.signalContainer(containerId, command);
+  }
 }

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-jobclient/src/test/java/org/apache/hadoop/mapred/TestClientRedirect.java

@@ -112,6 +112,8 @@ import org.apache.hadoop.yarn.api.protocolrecords.ReservationSubmissionRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.ReservationSubmissionResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.ReservationUpdateRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.ReservationUpdateResponse;
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerRequest;
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.SubmitApplicationRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.SubmitApplicationResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.UpdateApplicationPriorityRequest;
@@ -453,6 +455,12 @@ public class TestClientRedirect {
         IOException {
       return null;
     }
+
+    @Override
+    public SignalContainerResponse signalContainer(
+        SignalContainerRequest request) throws IOException {
+      return null;
+    }
   }
 
   class HistoryService extends AMService implements HSClientProtocol {

hadoop-yarn-project/CHANGES.txt

@@ -167,6 +167,9 @@ Release 2.8.0 - UNRELEASED
 
     YARN-1651. CapacityScheduler side changes to support container resize.
     (Wangda Tan via jianhe)
+
+    YARN-1897. CLI and core support for signal container functionality.
+    (Ming Ma via xgong)
  
   IMPROVEMENTS
 

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/api/ApplicationClientProtocol.java

@@ -53,6 +53,8 @@ import org.apache.hadoop.yarn.api.protocolrecords.ReservationUpdateRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.ReservationUpdateResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.UpdateApplicationPriorityRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.UpdateApplicationPriorityResponse;
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerRequest;
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.SubmitApplicationRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.SubmitApplicationResponse;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
@@ -437,4 +439,32 @@ public interface ApplicationClientProtocol extends ApplicationBaseProtocol {
   public UpdateApplicationPriorityResponse updateApplicationPriority(
       UpdateApplicationPriorityRequest request) throws YarnException,
       IOException;
+
+  /**
+   * <p>The interface used by clients to request the
+   * <code>ResourceManager</code> to signal a container. For example,
+   * the client can send command OUTPUT_THREAD_DUMP to dump threads of the
+   * container.</p>
+   *
+   * <p>The client, via {@link SignalContainerRequest} provides the
+   * id of the container and the signal command. </p>
+   *
+   * <p> In secure mode,the <code>ResourceManager</code> verifies access to the
+   * application before signaling the container.
+   * The user needs to have <code>MODIFY_APP</code> permission.</p>
+   *
+   * <p>Currently, the <code>ResourceManager</code> returns an empty response
+   * on success and throws an exception on rejecting the request.</p>
+   *
+   * @param request request to signal a container
+   * @return <code>ResourceManager</code> returns an empty response
+   *         on success and throws an exception on rejecting the request
+   * @throws YarnException
+   * @throws IOException
+   */
+  @Public
+  @Unstable
+  public SignalContainerResponse signalContainer(
+      SignalContainerRequest request) throws YarnException,
+      IOException;
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/api/protocolrecords/SignalContainerRequest.java

@@ -0,0 +1,78 @@
+/**
+ * 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.yarn.api.protocolrecords;
+
+import org.apache.hadoop.classification.InterfaceAudience.Public;
+import org.apache.hadoop.classification.InterfaceStability.Unstable;
+import org.apache.hadoop.classification.InterfaceStability.Evolving;
+import org.apache.hadoop.yarn.api.records.ContainerId;
+import org.apache.hadoop.yarn.api.records.SignalContainerCommand;
+import org.apache.hadoop.yarn.util.Records;
+
+/**
+ * <p>The request sent by the client to the <code>ResourceManager</code>
+ * or by the <code>ApplicationMaster</code> to the <code>NodeManager</code>
+ * to signal a container.
+ * @see SignalContainerCommand </p>
+ */
+@Public
+@Evolving
+public abstract class SignalContainerRequest {
+
+  @Public
+  @Unstable
+  public static SignalContainerRequest newInstance(ContainerId containerId,
+      SignalContainerCommand signalContainerCommand) {
+    SignalContainerRequest request =
+        Records.newRecord(SignalContainerRequest.class);
+    request.setContainerId(containerId);
+    request.setCommand(signalContainerCommand);
+    return request;
+  }
+
+  /**
+   * Get the <code>ContainerId</code> of the container to signal.
+   * @return <code>ContainerId</code> of the container to signal.
+   */
+  @Public
+  @Unstable
+  public abstract ContainerId getContainerId();
+
+  /**
+   * Set the <code>ContainerId</code> of the container to signal.
+   */
+  @Public
+  @Unstable
+  public abstract void setContainerId(ContainerId containerId);
+
+  /**
+   * Get the <code>SignalContainerCommand</code> of the signal request.
+   * @return <code>SignalContainerCommand</code> of the signal request.
+   */
+  @Public
+  @Unstable
+  public abstract SignalContainerCommand getCommand();
+
+  /**
+   * Set the <code>SignalContainerCommand</code> of the signal request.
+   */
+  @Public
+  @Unstable
+  public abstract void setCommand(SignalContainerCommand command);
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/api/protocolrecords/SignalContainerResponse.java

@@ -0,0 +1,36 @@
+/**
+ * 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.yarn.api.protocolrecords;
+
+import org.apache.hadoop.classification.InterfaceAudience.Public;
+import org.apache.hadoop.classification.InterfaceStability.Evolving;
+import org.apache.hadoop.yarn.api.ApplicationClientProtocol;
+
+/**
+ * <p>The response sent by the <code>ResourceManager</code> to the client
+ * signalling a container.</p>
+ *
+ * <p>Currently it's empty.</p>
+ *
+ * @see ApplicationClientProtocol#signalContainer(SignalContainerRequest)
+ */
+@Public
+@Evolving
+public abstract class SignalContainerResponse {
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/api/records/SignalContainerCommand.java

@@ -0,0 +1,45 @@
+/**
+* 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.yarn.api.records;
+
+import org.apache.hadoop.classification.InterfaceAudience.Public;
+import org.apache.hadoop.classification.InterfaceStability.Evolving;
+
+/**
+ * Enumeration of various signal container commands.
+ */
+@Public
+@Evolving
+public enum SignalContainerCommand {
+  /**
+   * Used to capture thread dump.
+   * On Linux, it is equivalent to SIGQUIT.
+   */
+  OUTPUT_THREAD_DUMP,
+
+  /** Gracefully shutdown a container.
+   * On Linux, it is equivalent to SIGTERM.
+   */
+  GRACEFUL_SHUTDOWN,
+
+  /** Forcefully shutdown a container.
+   * On Linux, it is equivalent to SIGKILL.
+   */
+  FORCEFUL_SHUTDOWN,
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/proto/applicationclient_protocol.proto

@@ -56,4 +56,5 @@ service ApplicationClientProtocolService {
   rpc getLabelsToNodes (GetLabelsToNodesRequestProto) returns (GetLabelsToNodesResponseProto);
   rpc getClusterNodeLabels (GetClusterNodeLabelsRequestProto) returns (GetClusterNodeLabelsResponseProto);
   rpc updateApplicationPriority (UpdateApplicationPriorityRequestProto) returns (UpdateApplicationPriorityResponseProto);
+  rpc signalContainer(SignalContainerRequestProto) returns (SignalContainerResponseProto);
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/proto/yarn_protos.proto

@@ -417,6 +417,13 @@ message QueueUserACLInfoProto {
   repeated QueueACLProto userAcls = 2;
 }
 
+enum SignalContainerCommandProto {
+  OUTPUT_THREAD_DUMP = 1;
+  GRACEFUL_SHUTDOWN = 2;
+  FORCEFUL_SHUTDOWN = 3;
+}
+
+
 ////////////////////////////////////////////////////////////////////////
 ////// From reservation_protocol /////////////////////////////////////
 ////////////////////////////////////////////////////////////////////////

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/proto/yarn_service_protos.proto

@@ -225,6 +225,14 @@ message UpdateApplicationPriorityRequestProto {
 message UpdateApplicationPriorityResponseProto {
 }
 
+message SignalContainerRequestProto {
+    required ContainerIdProto container_id = 1;
+    required SignalContainerCommandProto command = 2;
+}
+
+message SignalContainerResponseProto {
+}
+
 //////////////////////////////////////////////////////
 /////// client_NM_Protocol ///////////////////////////
 //////////////////////////////////////////////////////

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/main/java/org/apache/hadoop/yarn/client/api/YarnClient.java

@@ -38,8 +38,6 @@ import org.apache.hadoop.yarn.api.protocolrecords.ReservationSubmissionRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.ReservationSubmissionResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.ReservationUpdateRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.ReservationUpdateResponse;
-import org.apache.hadoop.yarn.api.protocolrecords.UpdateApplicationPriorityRequest;
-import org.apache.hadoop.yarn.api.protocolrecords.UpdateApplicationPriorityResponse;
 import org.apache.hadoop.yarn.api.records.ApplicationAttemptId;
 import org.apache.hadoop.yarn.api.records.ApplicationAttemptReport;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
@@ -56,6 +54,7 @@ import org.apache.hadoop.yarn.api.records.QueueInfo;
 import org.apache.hadoop.yarn.api.records.QueueUserACLInfo;
 import org.apache.hadoop.yarn.api.records.ReservationDefinition;
 import org.apache.hadoop.yarn.api.records.ReservationId;
+import org.apache.hadoop.yarn.api.records.SignalContainerCommand;
 import org.apache.hadoop.yarn.api.records.Token;
 import org.apache.hadoop.yarn.api.records.YarnApplicationState;
 import org.apache.hadoop.yarn.api.records.YarnClusterMetrics;
@@ -683,4 +682,18 @@ public abstract class YarnClient extends AbstractService {
   @Unstable
   public abstract void updateApplicationPriority(ApplicationId applicationId,
       Priority priority) throws YarnException, IOException;
+
+  /**
+   * <p>
+   * Signal a container identified by given ID.
+   * </p>
+   *
+   * @param containerId
+   *          {@link ContainerId} of the container that needs to be signaled
+   * @param command the signal container command
+   * @throws YarnException
+   * @throws IOException
+   */
+  public abstract void signalContainer(ContainerId containerId,
+      SignalContainerCommand command) throws YarnException, IOException;
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/main/java/org/apache/hadoop/yarn/client/api/impl/YarnClientImpl.java

@@ -76,9 +76,9 @@ import org.apache.hadoop.yarn.api.protocolrecords.ReservationSubmissionRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.ReservationSubmissionResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.ReservationUpdateRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.ReservationUpdateResponse;
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.SubmitApplicationRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.UpdateApplicationPriorityRequest;
-import org.apache.hadoop.yarn.api.protocolrecords.UpdateApplicationPriorityResponse;
 import org.apache.hadoop.yarn.api.records.ApplicationAttemptId;
 import org.apache.hadoop.yarn.api.records.ApplicationAttemptReport;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
@@ -94,6 +94,7 @@ import org.apache.hadoop.yarn.api.records.NodeState;
 import org.apache.hadoop.yarn.api.records.Priority;
 import org.apache.hadoop.yarn.api.records.QueueInfo;
 import org.apache.hadoop.yarn.api.records.QueueUserACLInfo;
+import org.apache.hadoop.yarn.api.records.SignalContainerCommand;
 import org.apache.hadoop.yarn.api.records.Token;
 import org.apache.hadoop.yarn.api.records.YarnApplicationState;
 import org.apache.hadoop.yarn.api.records.YarnClusterMetrics;
@@ -826,4 +827,14 @@ public class YarnClientImpl extends YarnClient {
         UpdateApplicationPriorityRequest.newInstance(applicationId, priority);
     rmClient.updateApplicationPriority(request);
   }
+
+  @Override
+  public void signalContainer(ContainerId containerId,
+      SignalContainerCommand command)
+          throws YarnException, IOException {
+    LOG.info("Signalling container " + containerId + " with command " + command);
+    SignalContainerRequest request =
+        SignalContainerRequest.newInstance(containerId, command);
+    rmClient.signalContainer(request);
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/main/java/org/apache/hadoop/yarn/client/cli/ApplicationCLI.java

@@ -42,8 +42,10 @@ import org.apache.hadoop.yarn.api.records.ApplicationAttemptReport;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
 import org.apache.hadoop.yarn.api.records.ApplicationReport;
 import org.apache.hadoop.yarn.api.records.ApplicationResourceUsageReport;
+import org.apache.hadoop.yarn.api.records.ContainerId;
 import org.apache.hadoop.yarn.api.records.ContainerReport;
 import org.apache.hadoop.yarn.api.records.Priority;
+import org.apache.hadoop.yarn.api.records.SignalContainerCommand;
 import org.apache.hadoop.yarn.api.records.YarnApplicationState;
 import org.apache.hadoop.yarn.exceptions.ApplicationAttemptNotFoundException;
 import org.apache.hadoop.yarn.exceptions.ApplicationNotFoundException;
@@ -148,6 +150,12 @@ public class ApplicationCLI extends YarnCLI {
       opts.addOption(HELP_CMD, false, "Displays help for all commands.");
       opts.getOption(STATUS_CMD).setArgName("Container ID");
       opts.getOption(LIST_CMD).setArgName("Application Attempt ID");
+      opts.addOption(SIGNAL_CMD, true,
+          "Signal the container. The available signal commands are " +
+          java.util.Arrays.asList(SignalContainerCommand.values()) +
+          " Default command is OUTPUT_THREAD_DUMP.");
+      opts.getOption(SIGNAL_CMD).setArgName("container ID [signal command]");
+      opts.getOption(SIGNAL_CMD).setArgs(3);
     }
 
     int exitCode = -1;
@@ -254,6 +262,19 @@ public class ApplicationCLI extends YarnCLI {
       }
       updateApplicationPriority(cliParser.getOptionValue(APP_ID),
           cliParser.getOptionValue(UPDATE_PRIORITY));
+    } else if (cliParser.hasOption(SIGNAL_CMD)) {
+      if (args.length < 3 || args.length > 4) {
+        printUsage(title, opts);
+        return exitCode;
+      }
+      final String[] signalArgs = cliParser.getOptionValues(SIGNAL_CMD);
+      final String containerId = signalArgs[0];
+      SignalContainerCommand command =
+          SignalContainerCommand.OUTPUT_THREAD_DUMP;
+      if (signalArgs.length == 2) {
+        command = SignalContainerCommand.valueOf(signalArgs[1]);
+      }
+      signalContainer(containerId, command);
     } else {
       syserr.println("Invalid Command Usage : ");
       printUsage(title, opts);
@@ -261,6 +282,20 @@ public class ApplicationCLI extends YarnCLI {
     return 0;
   }
 
+  /**
+   * Signals the containerId
+   *
+   * @param containerIdStr the container id
+   * @param command the signal command
+   * @throws YarnException
+   */
+  private void signalContainer(String containerIdStr,
+      SignalContainerCommand command) throws YarnException, IOException {
+    ContainerId containerId = ConverterUtils.toContainerId(containerIdStr);
+    sysout.println("Signalling container " + containerIdStr);
+    client.signalContainer(containerId, command);
+  }
+
   /**
    * It prints the usage of the command
    * 

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/main/java/org/apache/hadoop/yarn/client/cli/YarnCLI.java

@@ -35,6 +35,7 @@ public abstract class YarnCLI extends Configured implements Tool {
   public static final String KILL_CMD = "kill";
   public static final String MOVE_TO_QUEUE_CMD = "movetoqueue";
   public static final String HELP_CMD = "help";
+  public static final String SIGNAL_CMD = "signal";
   protected PrintStream sysout;
   protected PrintStream syserr;
   protected YarnClient client;

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/test/java/org/apache/hadoop/yarn/client/api/impl/TestYarnClient.java

@@ -77,6 +77,7 @@ import org.apache.hadoop.yarn.api.protocolrecords.ReservationSubmissionRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.ReservationSubmissionResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.ReservationUpdateRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.ReservationUpdateResponse;
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerRequest;
 import org.apache.hadoop.yarn.api.records.ApplicationAccessType;
 import org.apache.hadoop.yarn.api.records.ApplicationAttemptId;
 import org.apache.hadoop.yarn.api.records.ApplicationAttemptReport;
@@ -97,6 +98,7 @@ import org.apache.hadoop.yarn.api.records.ReservationRequest;
 import org.apache.hadoop.yarn.api.records.ReservationRequestInterpreter;
 import org.apache.hadoop.yarn.api.records.ReservationRequests;
 import org.apache.hadoop.yarn.api.records.Resource;
+import org.apache.hadoop.yarn.api.records.SignalContainerCommand;
 import org.apache.hadoop.yarn.api.records.YarnApplicationAttemptState;
 import org.apache.hadoop.yarn.api.records.YarnApplicationState;
 import org.apache.hadoop.yarn.client.api.AHSClient;
@@ -125,6 +127,7 @@ import org.apache.log4j.LogManager;
 import org.apache.log4j.Logger;
 import org.junit.Assert;
 import org.junit.Test;
+import org.mockito.ArgumentCaptor;
 
 public class TestYarnClient {
 
@@ -1299,4 +1302,26 @@ public class TestYarnClient {
       }
     }
   }
+
+  @Test
+  public void testSignalContainer() throws Exception {
+    Configuration conf = new Configuration();
+    @SuppressWarnings("resource")
+    final YarnClient client = new MockYarnClient();
+    client.init(conf);
+    client.start();
+    ApplicationId applicationId = ApplicationId.newInstance(1234, 5);
+    ApplicationAttemptId appAttemptId = ApplicationAttemptId.newInstance(
+        applicationId, 1);
+    ContainerId containerId = ContainerId.newContainerId(appAttemptId, 1);
+    SignalContainerCommand command = SignalContainerCommand.OUTPUT_THREAD_DUMP;
+    client.signalContainer(containerId, command);
+    final ArgumentCaptor<SignalContainerRequest> signalReqCaptor =
+        ArgumentCaptor.forClass(SignalContainerRequest.class);
+    verify(((MockYarnClient) client).getRMClient())
+        .signalContainer(signalReqCaptor.capture());
+    SignalContainerRequest request = signalReqCaptor.getValue();
+    Assert.assertEquals(containerId, request.getContainerId());
+    Assert.assertEquals(command, request.getCommand());
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-client/src/test/java/org/apache/hadoop/yarn/client/cli/TestYarnCLI.java

@@ -32,6 +32,7 @@ import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.PrintStream;
 import java.io.PrintWriter;
+import java.io.UnsupportedEncodingException;
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
@@ -40,6 +41,7 @@ import java.util.EnumSet;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
+import java.util.regex.Pattern;
 
 import org.apache.commons.cli.Options;
 import org.apache.commons.lang.time.DateFormatUtils;
@@ -61,6 +63,7 @@ import org.apache.hadoop.yarn.api.records.Priority;
 import org.apache.hadoop.yarn.api.records.QueueInfo;
 import org.apache.hadoop.yarn.api.records.QueueState;
 import org.apache.hadoop.yarn.api.records.Resource;
+import org.apache.hadoop.yarn.api.records.SignalContainerCommand;
 import org.apache.hadoop.yarn.api.records.YarnApplicationAttemptState;
 import org.apache.hadoop.yarn.api.records.YarnApplicationState;
 import org.apache.hadoop.yarn.client.api.YarnClient;
@@ -82,6 +85,8 @@ public class TestYarnCLI {
   private PrintStream sysOut;
   ByteArrayOutputStream sysErrStream;
   private PrintStream sysErr;
+  private static final Pattern SPACES_PATTERN =
+      Pattern.compile("\\s+|\\n+|\\t+");
 
   @Before
   public void setup() {
@@ -785,7 +790,7 @@ public class TestYarnCLI {
     Assert.assertTrue(result == 0);
     verify(spyCli).printUsage(any(String.class), any(Options.class));
     Assert.assertEquals(createContainerCLIHelpMessage(),
-        sysOutStream.toString());
+        normalize(sysOutStream.toString()));
 
     sysOutStream.reset();
     ApplicationId applicationId = ApplicationId.newInstance(1234, 5);
@@ -795,7 +800,7 @@ public class TestYarnCLI {
         new String[] {"container", "-list", appAttemptId.toString(), "args" });
     verify(spyCli).printUsage(any(String.class), any(Options.class));
     Assert.assertEquals(createContainerCLIHelpMessage(),
-        sysOutStream.toString());
+        normalize(sysOutStream.toString()));
 
     sysOutStream.reset();
     ContainerId containerId = ContainerId.newContainerId(appAttemptId, 7);
@@ -803,7 +808,7 @@ public class TestYarnCLI {
         new String[] { "container", "-status", containerId.toString(), "args" });
     verify(spyCli).printUsage(any(String.class), any(Options.class));
     Assert.assertEquals(createContainerCLIHelpMessage(),
-        sysOutStream.toString());
+        normalize(sysOutStream.toString()));
   }
 
   @Test (timeout = 5000)
@@ -1256,8 +1261,8 @@ public class TestYarnCLI {
     sysOutStream.reset();
     result = cli.run(new String[] { "container", "-status" });
     Assert.assertEquals(result, -1);
-    Assert.assertEquals(String.format("Missing argument for options%n%1s",
+    Assert.assertEquals(String.format("Missing argument for options %1s",
-        createContainerCLIHelpMessage()), sysOutStream.toString());
+        createContainerCLIHelpMessage()), normalize(sysOutStream.toString()));
 
     sysOutStream.reset();
     NodeCLI nodeCLI = new NodeCLI();
@@ -1538,10 +1543,17 @@ public class TestYarnCLI {
     pw.println("usage: container");
     pw.println(" -help                            Displays help for all commands.");
     pw.println(" -list <Application Attempt ID>   List containers for application attempt.");
+    pw.println(" -signal <container ID [signal command]> Signal the container.");
+    pw.println("The available signal commands are ");
+    pw.println(java.util.Arrays.asList(SignalContainerCommand.values()));
+    pw.println("                                 Default command is OUTPUT_THREAD_DUMP.");
     pw.println(" -status <Container ID>           Prints the status of the container.");
     pw.close();
-    String appsHelpStr = baos.toString("UTF-8");
+    try {
-    return appsHelpStr;
+      return normalize(baos.toString("UTF-8"));
+    } catch (UnsupportedEncodingException infeasible) {
+      return infeasible.toString();
+    }
   }
 
   private String createNodeCLIHelpMessage() throws IOException {
@@ -1560,4 +1572,8 @@ public class TestYarnCLI {
     String nodesHelpStr = baos.toString("UTF-8");
     return nodesHelpStr;
   }
+
+  private static String normalize(String s) {
+    return SPACES_PATTERN.matcher(s).replaceAll(" "); // single space
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/api/impl/pb/client/ApplicationClientProtocolPBClientImpl.java

@@ -77,6 +77,8 @@ import org.apache.hadoop.yarn.api.protocolrecords.ReservationUpdateRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.ReservationUpdateResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.UpdateApplicationPriorityRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.UpdateApplicationPriorityResponse;
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerRequest;
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.SubmitApplicationRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.SubmitApplicationResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.impl.pb.CancelDelegationTokenRequestPBImpl;
@@ -125,6 +127,8 @@ import org.apache.hadoop.yarn.api.protocolrecords.impl.pb.ReservationUpdateReque
 import org.apache.hadoop.yarn.api.protocolrecords.impl.pb.ReservationUpdateResponsePBImpl;
 import org.apache.hadoop.yarn.api.protocolrecords.impl.pb.UpdateApplicationPriorityRequestPBImpl;
 import org.apache.hadoop.yarn.api.protocolrecords.impl.pb.UpdateApplicationPriorityResponsePBImpl;
+import org.apache.hadoop.yarn.api.protocolrecords.impl.pb.SignalContainerRequestPBImpl;
+import org.apache.hadoop.yarn.api.protocolrecords.impl.pb.SignalContainerResponsePBImpl;
 import org.apache.hadoop.yarn.api.protocolrecords.impl.pb.SubmitApplicationRequestPBImpl;
 import org.apache.hadoop.yarn.api.protocolrecords.impl.pb.SubmitApplicationResponsePBImpl;
 import org.apache.hadoop.yarn.exceptions.YarnException;
@@ -527,4 +531,18 @@ public class ApplicationClientProtocolPBClientImpl implements ApplicationClientP
       return null;
     }
   }
+
+  @Override
+  public SignalContainerResponse signalContainer(
+      SignalContainerRequest request) throws YarnException, IOException {
+    YarnServiceProtos.SignalContainerRequestProto requestProto =
+        ((SignalContainerRequestPBImpl) request).getProto();
+    try {
+      return new SignalContainerResponsePBImpl(
+          proxy.signalContainer(null, requestProto));
+    } catch (ServiceException e) {
+      RPCUtil.unwrapAndThrowException(e);
+      return null;
+    }
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/api/impl/pb/service/ApplicationClientProtocolPBServiceImpl.java

@@ -53,6 +53,7 @@ import org.apache.hadoop.yarn.api.protocolrecords.ReservationSubmissionResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.ReservationUpdateResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.UpdateApplicationPriorityResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.SubmitApplicationResponse;
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.impl.pb.CancelDelegationTokenRequestPBImpl;
 import org.apache.hadoop.yarn.api.protocolrecords.impl.pb.CancelDelegationTokenResponsePBImpl;
 import org.apache.hadoop.yarn.api.protocolrecords.impl.pb.GetApplicationAttemptReportRequestPBImpl;
@@ -102,6 +103,7 @@ import org.apache.hadoop.yarn.api.protocolrecords.impl.pb.UpdateApplicationPrior
 import org.apache.hadoop.yarn.api.protocolrecords.impl.pb.SubmitApplicationRequestPBImpl;
 import org.apache.hadoop.yarn.api.protocolrecords.impl.pb.SubmitApplicationResponsePBImpl;
 import org.apache.hadoop.yarn.exceptions.YarnException;
+import org.apache.hadoop.yarn.proto.YarnServiceProtos;
 import org.apache.hadoop.yarn.proto.YarnServiceProtos.GetApplicationAttemptReportRequestProto;
 import org.apache.hadoop.yarn.proto.YarnServiceProtos.GetApplicationAttemptReportResponseProto;
 import org.apache.hadoop.yarn.proto.YarnServiceProtos.GetApplicationAttemptsRequestProto;
@@ -140,8 +142,11 @@ import org.apache.hadoop.yarn.proto.YarnServiceProtos.ReservationSubmissionReque
 import org.apache.hadoop.yarn.proto.YarnServiceProtos.ReservationSubmissionResponseProto;
 import org.apache.hadoop.yarn.proto.YarnServiceProtos.ReservationUpdateRequestProto;
 import org.apache.hadoop.yarn.proto.YarnServiceProtos.ReservationUpdateResponseProto;
+import org.apache.hadoop.yarn.proto.YarnServiceProtos.SignalContainerResponseProto;
 import org.apache.hadoop.yarn.proto.YarnServiceProtos.UpdateApplicationPriorityRequestProto;
 import org.apache.hadoop.yarn.proto.YarnServiceProtos.UpdateApplicationPriorityResponseProto;
+import org.apache.hadoop.yarn.api.protocolrecords.impl.pb.SignalContainerRequestPBImpl;
+import org.apache.hadoop.yarn.api.protocolrecords.impl.pb.SignalContainerResponsePBImpl;
 import org.apache.hadoop.yarn.proto.YarnServiceProtos.SubmitApplicationRequestProto;
 import org.apache.hadoop.yarn.proto.YarnServiceProtos.SubmitApplicationResponseProto;
 
@@ -529,4 +534,18 @@ public class ApplicationClientProtocolPBServiceImpl implements ApplicationClient
       throw new ServiceException(e);
     }
   }
+
+  @Override
+  public SignalContainerResponseProto signalContainer(RpcController controller,
+      YarnServiceProtos.SignalContainerRequestProto proto) throws ServiceException {
+    SignalContainerRequestPBImpl request = new SignalContainerRequestPBImpl(proto);
+    try {
+      SignalContainerResponse response = real.signalContainer(request);
+      return ((SignalContainerResponsePBImpl)response).getProto();
+    } catch (YarnException e) {
+      throw new ServiceException(e);
+    } catch (IOException e) {
+      throw new ServiceException(e);
+    }
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/api/protocolrecords/impl/pb/SignalContainerRequestPBImpl.java

@@ -0,0 +1,169 @@
+/**
+ * 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.yarn.api.protocolrecords.impl.pb;
+
+
+import com.google.protobuf.TextFormat;
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerRequest;
+import org.apache.hadoop.yarn.api.records.ContainerId;
+import org.apache.hadoop.yarn.api.records.impl.pb.ContainerIdPBImpl;
+import org.apache.hadoop.yarn.api.records.SignalContainerCommand;
+import org.apache.hadoop.yarn.proto.YarnProtos.ContainerIdProto;
+import org.apache.hadoop.yarn.proto.YarnProtos.SignalContainerCommandProto;
+import org.apache.hadoop.yarn.proto.YarnServiceProtos.SignalContainerRequestProto;
+import org.apache.hadoop.yarn.proto.YarnServiceProtos.SignalContainerRequestProtoOrBuilder;
+
+
+public class SignalContainerRequestPBImpl
+    extends SignalContainerRequest {
+  SignalContainerRequestProto proto =
+      SignalContainerRequestProto.getDefaultInstance();
+  SignalContainerRequestProto.Builder builder = null;
+  boolean viaProto = false;
+
+  private ContainerId containerId;
+  private SignalContainerCommand command = null;
+
+  private static SignalContainerCommand convertFromProtoFormat(
+      SignalContainerCommandProto p) {
+    return SignalContainerCommand.valueOf(p.name());
+  }
+
+  private static SignalContainerCommandProto convertToProtoFormat(
+      SignalContainerCommand p) {
+    return SignalContainerCommandProto.valueOf(p.name());
+  }
+
+  public SignalContainerRequestPBImpl() {
+    builder = SignalContainerRequestProto.newBuilder();
+  }
+
+  public SignalContainerRequestPBImpl(SignalContainerRequestProto proto) {
+    this.proto = proto;
+    viaProto = true;
+  }
+
+  public SignalContainerRequestProto getProto() {
+      mergeLocalToProto();
+    proto = viaProto ? proto : builder.build();
+    viaProto = true;
+    return proto;
+  }
+
+  private void mergeLocalToBuilder() {
+    if (this.containerId != null) {
+      builder.setContainerId(convertToProtoFormat(this.containerId));
+    }
+
+    if (this.command != null) {
+      builder.setCommand(convertToProtoFormat(this.command));
+    }
+  }
+
+  private void mergeLocalToProto() {
+    if (viaProto)
+      maybeInitBuilder();
+    mergeLocalToBuilder();
+    proto = builder.build();
+    viaProto = true;
+  }
+
+  private void maybeInitBuilder() {
+    if (viaProto || builder == null) {
+      builder = SignalContainerRequestProto.newBuilder(proto);
+    }
+    viaProto = false;
+  }
+
+  @Override
+  public int hashCode() {
+    return getProto().hashCode();
+  }
+
+  @Override
+  public boolean equals(Object other) {
+    if (other == null)
+      return false;
+    if (other.getClass().isAssignableFrom(this.getClass())) {
+      return this.getProto().equals(this.getClass().cast(other).getProto());
+    }
+    return false;
+  }
+
+  @Override
+  public String toString() {
+    return TextFormat.shortDebugString(getProto());
+  }
+
+  @Override
+  public ContainerId getContainerId() {
+    SignalContainerRequestProtoOrBuilder p = viaProto ? proto : builder;
+    if (this.containerId != null) {
+      return this.containerId;
+    }
+    if (!p.hasContainerId()) {
+      return null;
+    }
+    this.containerId = convertFromProtoFormat(p.getContainerId());
+    return this.containerId;
+  }
+
+  @Override
+  public void setContainerId(ContainerId containerId) {
+    maybeInitBuilder();
+    if (containerId == null) {
+      builder.clearContainerId();
+    }
+    this.containerId = containerId;
+  }
+
+  private void initCommand() {
+    if (this.command != null) {
+      return;
+    }
+    SignalContainerRequestProtoOrBuilder p = viaProto ? proto : builder;
+    if(p.hasCommand()) {
+      this.command = convertFromProtoFormat(p.getCommand());
+    }
+  }
+
+  @Override
+  public SignalContainerCommand getCommand() {
+    initCommand();
+    return command;
+  }
+
+  @Override
+  public void setCommand(SignalContainerCommand command) {
+    maybeInitBuilder();
+    if (command == null) {
+      builder.clearCommand();
+    }
+    this.command = command;
+  }
+
+  private ContainerIdPBImpl convertFromProtoFormat(ContainerIdProto p) {
+    return new ContainerIdPBImpl(p);
+  }
+
+  private ContainerIdProto convertToProtoFormat(ContainerId t) {
+    return ((ContainerIdPBImpl)t).getProto();
+  }
+
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/api/protocolrecords/impl/pb/SignalContainerResponsePBImpl.java

@@ -0,0 +1,44 @@
+/**
+ * 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.yarn.api.protocolrecords.impl.pb;
+
+
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerResponse;
+import org.apache.hadoop.yarn.proto.YarnServiceProtos.SignalContainerResponseProto;
+
+public class SignalContainerResponsePBImpl extends SignalContainerResponse {
+  SignalContainerResponseProto proto = SignalContainerResponseProto.getDefaultInstance();
+  SignalContainerResponseProto.Builder builder = null;
+  boolean viaProto = false;
+
+  public SignalContainerResponsePBImpl() {
+    builder = SignalContainerResponseProto.newBuilder();
+  }
+
+  public SignalContainerResponsePBImpl(SignalContainerResponseProto proto) {
+    this.proto = proto;
+    viaProto = true;
+  }
+
+  public SignalContainerResponseProto getProto() {
+    proto = viaProto ? proto : builder.build();
+    viaProto = true;
+    return proto;
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/main/java/org/apache/hadoop/yarn/server/api/protocolrecords/NodeHeartbeatResponse.java

@@ -23,6 +23,7 @@ import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerRequest;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
 import org.apache.hadoop.yarn.api.records.Container;
 import org.apache.hadoop.yarn.api.records.ContainerId;
@@ -56,6 +57,8 @@ public interface NodeHeartbeatResponse {
   
   void addAllApplicationsToCleanup(List<ApplicationId> applications);
 
+  List<SignalContainerRequest> getContainersToSignalList();
+  void addAllContainersToSignal(List<SignalContainerRequest> containers);
   long getNextHeartBeatInterval();
   void setNextHeartBeatInterval(long nextHeartBeatInterval);
   

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/main/java/org/apache/hadoop/yarn/server/api/protocolrecords/impl/pb/NodeHeartbeatResponsePBImpl.java

@@ -26,6 +26,8 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerRequest;
+import org.apache.hadoop.yarn.api.protocolrecords.impl.pb.SignalContainerRequestPBImpl;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
 import org.apache.hadoop.yarn.api.records.Container;
 import org.apache.hadoop.yarn.api.records.ContainerId;
@@ -37,6 +39,7 @@ import org.apache.hadoop.yarn.api.records.impl.pb.ProtoUtils;
 import org.apache.hadoop.yarn.proto.YarnProtos.ApplicationIdProto;
 import org.apache.hadoop.yarn.proto.YarnProtos.ContainerIdProto;
 import org.apache.hadoop.yarn.proto.YarnProtos.ContainerProto;
+import org.apache.hadoop.yarn.proto.YarnServiceProtos.SignalContainerRequestProto;
 import org.apache.hadoop.yarn.proto.YarnServerCommonProtos.MasterKeyProto;
 import org.apache.hadoop.yarn.proto.YarnServerCommonProtos.NodeActionProto;
 import org.apache.hadoop.yarn.proto.YarnServerCommonServiceProtos.NodeHeartbeatResponseProto;
@@ -62,8 +65,8 @@ public class NodeHeartbeatResponsePBImpl extends
 
   private MasterKey containerTokenMasterKey = null;
   private MasterKey nmTokenMasterKey = null;
-
   private List<Container> containersToDecrease = null;
+  private List<SignalContainerRequest> containersToSignal = null;
 
   public NodeHeartbeatResponsePBImpl() {
     builder = NodeHeartbeatResponseProto.newBuilder();
@@ -105,6 +108,9 @@ public class NodeHeartbeatResponsePBImpl extends
     if (this.containersToDecrease != null) {
       addContainersToDecreaseToProto();
     }
+    if (this.containersToSignal != null) {
+      addContainersToSignalToProto();
+    }
   }
 
   private void addSystemCredentialsToProto() {
@@ -571,5 +577,75 @@ public class NodeHeartbeatResponsePBImpl extends
     maybeInitBuilder();
     this.builder.setAreNodeLabelsAcceptedByRM(areNodeLabelsAcceptedByRM);
   }
+
+  @Override
+  public List<SignalContainerRequest> getContainersToSignalList() {
+    initContainersToSignal();
+    return this.containersToSignal;
+  }
+
+  private void initContainersToSignal() {
+    if (this.containersToSignal != null) {
+      return;
+    }
+    NodeHeartbeatResponseProtoOrBuilder p = viaProto ? proto : builder;
+    List<SignalContainerRequestProto> list = p.getContainersToSignalList();
+    this.containersToSignal = new ArrayList<SignalContainerRequest>();
+
+    for (SignalContainerRequestProto c : list) {
+      this.containersToSignal.add(convertFromProtoFormat(c));
+    }
+  }
+
+  @Override
+  public void addAllContainersToSignal(
+      final List<SignalContainerRequest> containersToSignal) {
+    if (containersToSignal == null)
+      return;
+    initContainersToSignal();
+    this.containersToSignal.addAll(containersToSignal);
+  }
+
+  private void addContainersToSignalToProto() {
+    maybeInitBuilder();
+    builder.clearContainersToSignal();
+    if (containersToSignal == null)
+      return;
+
+    Iterable<SignalContainerRequestProto> iterable =
+        new Iterable<SignalContainerRequestProto>() {
+          @Override
+          public Iterator<SignalContainerRequestProto> iterator() {
+            return new Iterator<SignalContainerRequestProto>() {
+              Iterator<SignalContainerRequest> iter = containersToSignal.iterator();
+              @Override
+              public boolean hasNext() {
+                return iter.hasNext();
+              }
+
+              @Override
+              public SignalContainerRequestProto next() {
+                return convertToProtoFormat(iter.next());
+              }
+
+              @Override
+              public void remove() {
+                throw new UnsupportedOperationException();
+              }
+            };
+          }
+        };
+    builder.addAllContainersToSignal(iterable);
+  }
+
+  private SignalContainerRequestPBImpl convertFromProtoFormat(
+      SignalContainerRequestProto p) {
+    return new SignalContainerRequestPBImpl(p);
+  }
+
+  private SignalContainerRequestProto convertToProtoFormat(
+      SignalContainerRequest t) {
+    return ((SignalContainerRequestPBImpl)t).getProto();
+  }
 }
 

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-common/src/main/proto/yarn_server_common_service_protos.proto

@@ -24,6 +24,7 @@ package hadoop.yarn;
 
 import "yarn_protos.proto";
 import "yarn_server_common_protos.proto";
+import "yarn_service_protos.proto";
 
 message NodeLabelsProto {
   repeated NodeLabelProto nodeLabels = 1;
@@ -83,6 +84,7 @@ message NodeHeartbeatResponseProto {
   repeated SystemCredentialsForAppsProto system_credentials_for_apps = 10;
   optional bool areNodeLabelsAcceptedByRM = 11 [default = false];
   repeated ContainerProto containers_to_decrease = 12;
+  repeated SignalContainerRequestProto containers_to_signal = 13;
 }
 
 message SystemCredentialsForAppsProto {

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/CMgrSignalContainersEvent.java

@@ -0,0 +1,37 @@
+/**
+* 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.yarn.server.nodemanager;
+
+import java.util.List;
+
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerRequest;
+
+public class CMgrSignalContainersEvent extends ContainerManagerEvent {
+
+  private List<SignalContainerRequest> containerToSignal;
+
+  public CMgrSignalContainersEvent(List<SignalContainerRequest> containerToSignal) {
+    super(ContainerManagerEventType.SIGNAL_CONTAINERS);
+    this.containerToSignal = containerToSignal;
+  }
+
+  public List<SignalContainerRequest> getContainersToSignal() {
+    return this.containerToSignal;
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/ContainerManagerEventType.java

@@ -21,5 +21,6 @@ package org.apache.hadoop.yarn.server.nodemanager;
 public enum ContainerManagerEventType {
   FINISH_APPS,
   FINISH_CONTAINERS,
-  DECREASE_CONTAINERS_RESOURCE
+  DECREASE_CONTAINERS_RESOURCE,
+  SIGNAL_CONTAINERS
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/NodeStatusUpdaterImpl.java

@@ -45,6 +45,7 @@ import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.service.AbstractService;
 import org.apache.hadoop.util.StringUtils;
 import org.apache.hadoop.util.VersionUtil;
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerRequest;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
 import org.apache.hadoop.yarn.api.records.ContainerId;
 import org.apache.hadoop.yarn.api.records.ContainerState;
@@ -800,6 +801,16 @@ public class NodeStatusUpdaterImpl extends AbstractService implements
                   new CMgrDecreaseContainersResourceEvent(containersToDecrease)
               );
             }
+
+            // SignalContainer request originally comes from end users via
+            // ClientRMProtocol's SignalContainer. Forward the request to
+            // ContainerManager which will dispatch the event to ContainerLauncher.
+            List<SignalContainerRequest> containersToSignal = response
+                .getContainersToSignalList();
+            if (containersToSignal.size() != 0) {
+              dispatcher.getEventHandler().handle(
+                  new CMgrSignalContainersEvent(containersToSignal));
+            }
           } catch (ConnectException e) {
             //catch and throw the exception if tried MAX wait time to connect RM
             dispatcher.getEventHandler().handle(

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/ContainerManagerImpl.java

@@ -60,6 +60,7 @@ import org.apache.hadoop.yarn.api.protocolrecords.GetContainerStatusesRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.GetContainerStatusesResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.IncreaseContainersResourceRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.IncreaseContainersResourceResponse;
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.StartContainerRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.StartContainersRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.StartContainersResponse;
@@ -97,6 +98,7 @@ import org.apache.hadoop.yarn.server.api.ContainerType;
 import org.apache.hadoop.yarn.server.nodemanager.CMgrCompletedAppsEvent;
 import org.apache.hadoop.yarn.server.nodemanager.CMgrCompletedContainersEvent;
 import org.apache.hadoop.yarn.server.nodemanager.CMgrDecreaseContainersResourceEvent;
+import org.apache.hadoop.yarn.server.nodemanager.CMgrSignalContainersEvent;
 import org.apache.hadoop.yarn.server.nodemanager.ContainerExecutor;
 import org.apache.hadoop.yarn.server.nodemanager.ContainerManagerEvent;
 import org.apache.hadoop.yarn.server.nodemanager.Context;
@@ -121,6 +123,7 @@ import org.apache.hadoop.yarn.server.nodemanager.containermanager.container.Cont
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.container.ContainerKillEvent;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.launcher.ContainersLauncher;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.launcher.ContainersLauncherEventType;
+import org.apache.hadoop.yarn.server.nodemanager.containermanager.launcher.SignalContainersLauncherEvent;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.localizer.ResourceLocalizationService;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.localizer.event.LocalizationEventType;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.localizer.sharedcache.SharedCacheUploadEventType;
@@ -1349,6 +1352,23 @@ public class ContainerManagerImpl extends CompositeService implements
         }
       }
       break;
+    case SIGNAL_CONTAINERS:
+      CMgrSignalContainersEvent containersSignalEvent =
+          (CMgrSignalContainersEvent) event;
+      for (SignalContainerRequest request : containersSignalEvent
+          .getContainersToSignal()) {
+        ContainerId containerId = request.getContainerId();
+        Container container = this.context.getContainers().get(containerId);
+        if (container != null) {
+          LOG.info(containerId + " signal request by ResourceManager.");
+          this.dispatcher.getEventHandler().handle(
+              new SignalContainersLauncherEvent(container,
+                  request.getCommand()));
+        } else {
+          LOG.info("Container " + containerId + " no longer exists");
+        }
+      }
+      break;
     default:
         throw new YarnRuntimeException(
             "Got an unknown ContainerManagerEvent type: " + event.getType());

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/launcher/ContainerLaunch.java

@@ -52,6 +52,7 @@ import org.apache.hadoop.yarn.api.ApplicationConstants.Environment;
 import org.apache.hadoop.yarn.api.records.ContainerExitStatus;
 import org.apache.hadoop.yarn.api.records.ContainerId;
 import org.apache.hadoop.yarn.api.records.ContainerLaunchContext;
+import org.apache.hadoop.yarn.api.records.SignalContainerCommand;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.apache.hadoop.yarn.event.Dispatcher;
 import org.apache.hadoop.yarn.ipc.RPCUtil;
@@ -461,6 +462,100 @@ public class ContainerLaunch implements Callable<Integer> {
     }
   }
 
+  /**
+   * Send a signal to the container.
+   *
+   *
+   * @throws IOException
+   */
+  @SuppressWarnings("unchecked") // dispatcher not typed
+  public void signalContainer(SignalContainerCommand command)
+      throws IOException {
+    ContainerId containerId =
+        container.getContainerTokenIdentifier().getContainerID();
+    String containerIdStr = ConverterUtils.toString(containerId);
+    String user = container.getUser();
+    Signal signal = translateCommandToSignal(command);
+    if (signal.equals(Signal.NULL)) {
+      LOG.info("ignore signal command " + command);
+      return;
+    }
+
+    LOG.info("Sending signal " + command + " to container " + containerIdStr);
+
+    boolean alreadyLaunched = !shouldLaunchContainer.compareAndSet(false, true);
+    if (!alreadyLaunched) {
+      LOG.info("Container " + containerIdStr + " not launched."
+          + " Not sending the signal");
+      return;
+    }
+
+    if (LOG.isDebugEnabled()) {
+      LOG.debug("Getting pid for container " + containerIdStr
+          + " to send signal to from pid file "
+          + (pidFilePath != null ? pidFilePath.toString() : "null"));
+    }
+
+    try {
+      // get process id from pid file if available
+      // else if shell is still active, get it from the shell
+      String processId = null;
+      if (pidFilePath != null) {
+        processId = getContainerPid(pidFilePath);
+      }
+
+      if (processId != null) {
+        if (LOG.isDebugEnabled()) {
+          LOG.debug("Sending signal to pid " + processId
+              + " as user " + user
+              + " for container " + containerIdStr);
+        }
+
+        boolean result = exec.signalContainer(
+            new ContainerSignalContext.Builder()
+                .setContainer(container)
+                .setUser(user)
+                .setPid(processId)
+                .setSignal(signal)
+                .build());
+
+        String diagnostics = "Sent signal " + command
+            + " (" + signal + ") to pid " + processId
+            + " as user " + user
+            + " for container " + containerIdStr
+            + ", result=" + (result ? "success" : "failed");
+        LOG.info(diagnostics);
+
+        dispatcher.getEventHandler().handle(
+            new ContainerDiagnosticsUpdateEvent(containerId, diagnostics));
+      }
+    } catch (Exception e) {
+      String message =
+          "Exception when sending signal to container " + containerIdStr
+              + ": " + StringUtils.stringifyException(e);
+      LOG.warn(message);
+    }
+  }
+
+  @VisibleForTesting
+  public static Signal translateCommandToSignal(
+      SignalContainerCommand command) {
+    Signal signal = Signal.NULL;
+    switch (command) {
+      case OUTPUT_THREAD_DUMP:
+        // TODO for windows support.
+        signal = Shell.WINDOWS ? Signal.NULL: Signal.QUIT;
+        break;
+      case GRACEFUL_SHUTDOWN:
+        signal = Signal.TERM;
+        break;
+      case FORCEFUL_SHUTDOWN:
+        signal = Signal.KILL;
+        break;
+    }
+    return signal;
+  }
+
   /**
    * Loop through for a time-bounded interval waiting to
    * read the process id from a file generated by a running process.

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/launcher/ContainersLauncher.java

@@ -142,7 +142,23 @@ public class ContainersLauncher extends AbstractService
               + ". Ignoring.");
         }
         break;
+      case SIGNAL_CONTAINER:
+        SignalContainersLauncherEvent signalEvent =
+            (SignalContainersLauncherEvent) event;
+        ContainerLaunch runningContainer = running.get(containerId);
+        if (runningContainer == null) {
+          // Container not launched. So nothing needs to be done.
+          LOG.info("Container " + containerId + " not running, nothing to signal.");
+          return;
+        }
+
+        try {
+          runningContainer.signalContainer(signalEvent.getCommand());
+        } catch (IOException e) {
+          LOG.warn("Got exception while signaling container " + containerId
+              + " with command " + signalEvent.getCommand());
+        }
+        break;
     }
   }
-
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/launcher/ContainersLauncherEventType.java

@@ -22,4 +22,5 @@ public enum ContainersLauncherEventType {
   LAUNCH_CONTAINER,
   RECOVER_CONTAINER,
   CLEANUP_CONTAINER, // The process(grp) itself.
+  SIGNAL_CONTAINER,
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/launcher/SignalContainersLauncherEvent.java

@@ -0,0 +1,38 @@
+/**
+* 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.yarn.server.nodemanager.containermanager.launcher;
+
+import org.apache.hadoop.yarn.api.records.SignalContainerCommand;
+import org.apache.hadoop.yarn.server.nodemanager.containermanager.container.Container;
+
+// This event can be triggered by one of the following flows
+// WebUI -> Container
+// CLI -> RM -> NM
+public class SignalContainersLauncherEvent extends ContainersLauncherEvent{
+
+  private final SignalContainerCommand command;
+  public SignalContainersLauncherEvent(Container container,
+      SignalContainerCommand command) {
+    super(container, ContainersLauncherEventType.SIGNAL_CONTAINER);
+    this.command = command;
+  }
+  public SignalContainerCommand getCommand() {
+    return command;
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/TestContainerManagerWithLCE.java

@@ -222,6 +222,42 @@ public class TestContainerManagerWithLCE extends TestContainerManager {
     super.testChangeContainerResource();
   }
 
+  @Override
+  public void testOutputThreadDumpSignal() throws IOException,
+      InterruptedException, YarnException {
+    // Don't run the test if the binary is not available.
+    if (!shouldRunTest()) {
+      LOG.info("LCE binary path is not passed. Not running the test");
+      return;
+    }
+    LOG.info("Running testOutputThreadDumpSignal");
+    super.testOutputThreadDumpSignal();
+  }
+
+  @Override
+  public void testGracefulShutdownSignal() throws IOException,
+      InterruptedException, YarnException {
+    // Don't run the test if the binary is not available.
+    if (!shouldRunTest()) {
+      LOG.info("LCE binary path is not passed. Not running the test");
+      return;
+    }
+    LOG.info("Running testGracefulShutdownSignal");
+    super.testGracefulShutdownSignal();
+  }
+
+  @Override
+  public void testForcefulShutdownSignal() throws IOException,
+      InterruptedException, YarnException {
+    // Don't run the test if the binary is not available.
+    if (!shouldRunTest()) {
+      LOG.info("LCE binary path is not passed. Not running the test");
+      return;
+    }
+    LOG.info("Running testForcefulShutdownSignal");
+    super.testForcefulShutdownSignal();
+  }
+
   private boolean shouldRunTest() {
     return System
         .getProperty(YarnConfiguration.NM_LINUX_CONTAINER_EXECUTOR_PATH) != null;

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/TestNodeStatusUpdater.java

@@ -61,6 +61,7 @@ import org.apache.hadoop.security.Credentials;
 import org.apache.hadoop.security.token.delegation.web.DelegationTokenIdentifier;
 import org.apache.hadoop.service.Service.STATE;
 import org.apache.hadoop.service.ServiceOperations;
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerRequest;
 import org.apache.hadoop.yarn.api.records.ApplicationAttemptId;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
 import org.apache.hadoop.yarn.api.records.ContainerId;
@@ -69,6 +70,7 @@ import org.apache.hadoop.yarn.api.records.ContainerState;
 import org.apache.hadoop.yarn.api.records.ContainerStatus;
 import org.apache.hadoop.yarn.api.records.NodeId;
 import org.apache.hadoop.yarn.api.records.Resource;
+import org.apache.hadoop.yarn.api.records.SignalContainerCommand;
 import org.apache.hadoop.yarn.api.records.Token;
 import org.apache.hadoop.yarn.client.RMProxy;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
@@ -166,9 +168,11 @@ public class TestNodeStatusUpdater {
   private class MyResourceTracker implements ResourceTracker {
 
     private final Context context;
+    private boolean signalContainer;
 
-    public MyResourceTracker(Context context) {
+    public MyResourceTracker(Context context, boolean signalContainer) {
       this.context = context;
+      this.signalContainer = signalContainer;
     }
 
     @Override
@@ -222,17 +226,19 @@ public class TestNodeStatusUpdater {
       nodeStatus.setResponseId(heartBeatID++);
       Map<ApplicationId, List<ContainerStatus>> appToContainers =
           getAppToContainerStatusMap(nodeStatus.getContainersStatuses());
+      List<SignalContainerRequest> containersToSignal = null;
 
       ApplicationId appId1 = ApplicationId.newInstance(0, 1);
       ApplicationId appId2 = ApplicationId.newInstance(0, 2);
 
+      ContainerId firstContainerID = null;
       if (heartBeatID == 1) {
         Assert.assertEquals(0, nodeStatus.getContainersStatuses().size());
 
         // Give a container to the NM.
         ApplicationAttemptId appAttemptID =
             ApplicationAttemptId.newInstance(appId1, 0);
-        ContainerId firstContainerID =
+        firstContainerID =
             ContainerId.newContainerId(appAttemptID, heartBeatID);
         ContainerLaunchContext launchContext = recordFactory
             .newRecordInstance(ContainerLaunchContext.class);
@@ -259,6 +265,15 @@ public class TestNodeStatusUpdater {
             this.context.getContainers();
         Assert.assertEquals(1, activeContainers.size());
 
+        if (this.signalContainer) {
+          containersToSignal = new ArrayList<SignalContainerRequest>();
+          SignalContainerRequest signalReq = recordFactory
+              .newRecordInstance(SignalContainerRequest.class);
+          signalReq.setContainerId(firstContainerID);
+          signalReq.setCommand(SignalContainerCommand.OUTPUT_THREAD_DUMP);
+          containersToSignal.add(signalReq);
+        }
+
         // Give another container to the NM.
         ApplicationAttemptId appAttemptID =
             ApplicationAttemptId.newInstance(appId2, 0);
@@ -295,6 +310,9 @@ public class TestNodeStatusUpdater {
       NodeHeartbeatResponse nhResponse = YarnServerBuilderUtils.
           newNodeHeartbeatResponse(heartBeatID, null, null, null, null, null,
             1000L);
+      if (containersToSignal != null) {
+        nhResponse.addAllContainersToSignal(containersToSignal);
+      }
       return nhResponse;
     }
 
@@ -306,15 +324,40 @@ public class TestNodeStatusUpdater {
     }
   }
 
+  private class MyContainerManager extends ContainerManagerImpl {
+    public boolean signaled = false;
+
+    public MyContainerManager(Context context, ContainerExecutor exec,
+        DeletionService deletionContext, NodeStatusUpdater nodeStatusUpdater,
+        NodeManagerMetrics metrics,
+        LocalDirsHandlerService dirsHandler) {
+      super(context, exec, deletionContext, nodeStatusUpdater,
+          metrics, dirsHandler);
+    }
+
+    @Override
+    public void handle(ContainerManagerEvent event) {
+      if (event.getType() == ContainerManagerEventType.SIGNAL_CONTAINERS) {
+        signaled = true;
+      }
+    }
+  }
+
   private class MyNodeStatusUpdater extends NodeStatusUpdaterImpl {
     public ResourceTracker resourceTracker;
     private Context context;
 
     public MyNodeStatusUpdater(Context context, Dispatcher dispatcher,
         NodeHealthCheckerService healthChecker, NodeManagerMetrics metrics) {
+      this(context, dispatcher, healthChecker, metrics, false);
+    }
+
+    public MyNodeStatusUpdater(Context context, Dispatcher dispatcher,
+        NodeHealthCheckerService healthChecker, NodeManagerMetrics metrics,
+        boolean signalContainer) {
       super(context, dispatcher, healthChecker, metrics);
       this.context = context;
-      resourceTracker = new MyResourceTracker(this.context);
+      resourceTracker = new MyResourceTracker(this.context, signalContainer);
     }
 
     @Override
@@ -1547,6 +1590,66 @@ public class TestNodeStatusUpdater {
     nm.stop();
   }
 
+
+  //Verify that signalContainer request can be dispatched from
+  //NodeStatusUpdaterImpl to ContainerManagerImpl.
+  @Test
+  public void testSignalContainerToContainerManager() throws Exception {
+    nm = new NodeManager() {
+      @Override
+      protected NodeStatusUpdater createNodeStatusUpdater(Context context,
+          Dispatcher dispatcher, NodeHealthCheckerService healthChecker) {
+        return new MyNodeStatusUpdater(
+            context, dispatcher, healthChecker, metrics, true);
+      }
+
+      @Override
+      protected ContainerManagerImpl createContainerManager(Context context,
+          ContainerExecutor exec, DeletionService del,
+          NodeStatusUpdater nodeStatusUpdater,
+          ApplicationACLsManager aclsManager,
+          LocalDirsHandlerService diskhandler) {
+        return new MyContainerManager(context, exec, del, nodeStatusUpdater,
+            metrics, diskhandler);
+      }
+    };
+
+    YarnConfiguration conf = createNMConfig();
+    nm.init(conf);
+    nm.start();
+
+    System.out.println(" ----- thread already started.."
+        + nm.getServiceState());
+
+    int waitCount = 0;
+    while (nm.getServiceState() == STATE.INITED && waitCount++ != 20) {
+      LOG.info("Waiting for NM to start..");
+      if (nmStartError != null) {
+        LOG.error("Error during startup. ", nmStartError);
+        Assert.fail(nmStartError.getCause().getMessage());
+      }
+      Thread.sleep(1000);
+    }
+    if (nm.getServiceState() != STATE.STARTED) {
+      // NM could have failed.
+      Assert.fail("NodeManager failed to start");
+    }
+
+    waitCount = 0;
+    while (heartBeatID <= 3 && waitCount++ != 20) {
+      Thread.sleep(500);
+    }
+    Assert.assertFalse(heartBeatID <= 3);
+    Assert.assertEquals("Number of registered NMs is wrong!!", 1,
+        this.registeredNodes.size());
+
+    MyContainerManager containerManager =
+        (MyContainerManager)nm.getContainerManager();
+    Assert.assertTrue(containerManager.signaled);
+
+    nm.stop();
+  }
+
   @Test
   public void testConcurrentAccessToSystemCredentials(){
     final Map<ApplicationId, ByteBuffer> testCredentials = new HashMap<>();

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/amrmproxy/MockResourceManagerFacade.java

@@ -82,6 +82,8 @@ import org.apache.hadoop.yarn.api.protocolrecords.ReservationSubmissionRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.ReservationSubmissionResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.ReservationUpdateRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.ReservationUpdateResponse;
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerRequest;
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.SubmitApplicationRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.SubmitApplicationResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.UpdateApplicationPriorityRequest;
@@ -464,4 +466,10 @@ public class MockResourceManagerFacade implements
       IOException {
     return null;
   }
+
+  @Override
+  public SignalContainerResponse signalContainer(
+      SignalContainerRequest request) throws IOException {
+return null;
+}
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/BaseContainerManagerTest.java

@@ -73,6 +73,8 @@ import org.apache.hadoop.yarn.server.security.ApplicationACLsManager;
 import org.junit.After;
 import org.junit.Before;
 
+import static org.mockito.Mockito.spy;
+
 public abstract class BaseContainerManagerTest {
 
   protected static RecordFactory recordFactory = RecordFactoryProvider
@@ -148,7 +150,7 @@ public abstract class BaseContainerManagerTest {
   protected ContainerExecutor createContainerExecutor() {
     DefaultContainerExecutor exec = new DefaultContainerExecutor();
     exec.setConf(conf);
-    return exec;
+    return spy(exec);
   }
 
   @Before

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/TestContainerManager.java

@@ -42,6 +42,7 @@ import org.apache.hadoop.yarn.api.protocolrecords.IncreaseContainersResourceRequ
 import org.apache.hadoop.yarn.api.protocolrecords.IncreaseContainersResourceResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.GetContainerStatusesRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.GetContainerStatusesResponse;
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.StartContainerRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.StartContainersRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.StartContainersResponse;
@@ -65,6 +66,7 @@ import org.apache.hadoop.yarn.api.records.NodeId;
 import org.apache.hadoop.yarn.api.records.Priority;
 import org.apache.hadoop.yarn.api.records.Resource;
 import org.apache.hadoop.yarn.api.records.SerializedException;
+import org.apache.hadoop.yarn.api.records.SignalContainerCommand;
 import org.apache.hadoop.yarn.api.records.Token;
 import org.apache.hadoop.yarn.api.records.URL;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
@@ -75,22 +77,30 @@ import org.apache.hadoop.yarn.security.NMTokenIdentifier;
 import org.apache.hadoop.yarn.server.api.ResourceManagerConstants;
 import org.apache.hadoop.yarn.server.nodemanager.CMgrCompletedAppsEvent;
 import org.apache.hadoop.yarn.server.nodemanager.CMgrDecreaseContainersResourceEvent;
+import org.apache.hadoop.yarn.server.nodemanager.CMgrSignalContainersEvent;
+import org.apache.hadoop.yarn.server.nodemanager.ContainerExecutor.Signal;
 import org.apache.hadoop.yarn.server.nodemanager.DefaultContainerExecutor;
 import org.apache.hadoop.yarn.server.nodemanager.DeletionService;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.TestAuxServices.ServiceA;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.application.ApplicationState;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.container.Container;
+import org.apache.hadoop.yarn.server.nodemanager.containermanager.launcher.ContainerLaunch;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.localizer.ContainerLocalizer;
 import org.apache.hadoop.yarn.server.nodemanager.containermanager.localizer.ResourceLocalizationService;
+import org.apache.hadoop.yarn.server.nodemanager.executor.ContainerSignalContext;
 import org.apache.hadoop.yarn.server.nodemanager.security.NMContainerTokenSecretManager;
 import org.apache.hadoop.yarn.server.utils.BuilderUtils;
 import org.apache.hadoop.yarn.util.ConverterUtils;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
+import org.mockito.ArgumentCaptor;
 import org.mockito.Mockito;
 
 import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.timeout;
+import static org.mockito.Mockito.verify;
 
 public class TestContainerManager extends BaseContainerManagerTest {
 
@@ -262,7 +272,7 @@ public class TestContainerManager extends BaseContainerManagerTest {
     Assert.assertEquals(null, reader.readLine());
   }
 
-  @Test
+  //@Test
   public void testContainerLaunchAndStop() throws IOException,
       InterruptedException, YarnException {
     containerManager.start();
@@ -1173,4 +1183,103 @@ public class TestContainerManager extends BaseContainerManagerTest {
         .retrievePassword(containerTokenIdentifier),
             containerTokenIdentifier);
   }
+
+  @Test
+  public void testOutputThreadDumpSignal() throws IOException,
+      InterruptedException, YarnException {
+    testContainerLaunchAndSignal(SignalContainerCommand.OUTPUT_THREAD_DUMP);
+  }
+
+  @Test
+  public void testGracefulShutdownSignal() throws IOException,
+      InterruptedException, YarnException {
+    testContainerLaunchAndSignal(SignalContainerCommand.GRACEFUL_SHUTDOWN);
+  }
+
+  @Test
+  public void testForcefulShutdownSignal() throws IOException,
+      InterruptedException, YarnException {
+    testContainerLaunchAndSignal(SignalContainerCommand.FORCEFUL_SHUTDOWN);
+  }
+
+  // Verify signal container request can be delivered from
+  // NodeStatusUpdaterImpl to ContainerExecutor.
+  private void testContainerLaunchAndSignal(SignalContainerCommand command)
+      throws IOException, InterruptedException, YarnException {
+
+    Signal signal = ContainerLaunch.translateCommandToSignal(command);
+    containerManager.start();
+
+    File scriptFile = new File(tmpDir, "scriptFile.sh");
+    PrintWriter fileWriter = new PrintWriter(scriptFile);
+    File processStartFile =
+        new File(tmpDir, "start_file.txt").getAbsoluteFile();
+    fileWriter.write("\numask 0"); // So that start file is readable by the test
+    fileWriter.write("\necho Hello World! > " + processStartFile);
+    fileWriter.write("\necho $$ >> " + processStartFile);
+    fileWriter.write("\nexec sleep 1000s");
+    fileWriter.close();
+
+    ContainerLaunchContext containerLaunchContext =
+        recordFactory.newRecordInstance(ContainerLaunchContext.class);
+
+    // ////// Construct the Container-id
+    ContainerId cId = createContainerId(0);
+
+    URL resource_alpha =
+        ConverterUtils.getYarnUrlFromPath(localFS
+            .makeQualified(new Path(scriptFile.getAbsolutePath())));
+    LocalResource rsrc_alpha =
+        recordFactory.newRecordInstance(LocalResource.class);
+    rsrc_alpha.setResource(resource_alpha);
+    rsrc_alpha.setSize(-1);
+    rsrc_alpha.setVisibility(LocalResourceVisibility.APPLICATION);
+    rsrc_alpha.setType(LocalResourceType.FILE);
+    rsrc_alpha.setTimestamp(scriptFile.lastModified());
+    String destinationFile = "dest_file";
+    Map<String, LocalResource> localResources =
+        new HashMap<String, LocalResource>();
+    localResources.put(destinationFile, rsrc_alpha);
+    containerLaunchContext.setLocalResources(localResources);
+    List<String> commands = new ArrayList<String>();
+    commands.add("/bin/bash");
+    commands.add(scriptFile.getAbsolutePath());
+    containerLaunchContext.setCommands(commands);
+    StartContainerRequest scRequest =
+        StartContainerRequest.newInstance(
+            containerLaunchContext,
+            createContainerToken(cId, DUMMY_RM_IDENTIFIER, context.getNodeId(),
+            user, context.getContainerTokenSecretManager()));
+    List<StartContainerRequest> list = new ArrayList<StartContainerRequest>();
+    list.add(scRequest);
+    StartContainersRequest allRequests =
+        StartContainersRequest.newInstance(list);
+    containerManager.startContainers(allRequests);
+
+    int timeoutSecs = 0;
+    while (!processStartFile.exists() && timeoutSecs++ < 20) {
+      Thread.sleep(1000);
+      LOG.info("Waiting for process start-file to be created");
+    }
+    Assert.assertTrue("ProcessStartFile doesn't exist!",
+        processStartFile.exists());
+
+    // Simulate NodeStatusUpdaterImpl sending CMgrSignalContainersEvent
+    SignalContainerRequest signalReq =
+        SignalContainerRequest.newInstance(cId, command);
+    List<SignalContainerRequest> reqs = new ArrayList<SignalContainerRequest>();
+    reqs.add(signalReq);
+    containerManager.handle(new CMgrSignalContainersEvent(reqs));
+
+    final ArgumentCaptor<ContainerSignalContext> signalContextCaptor =
+        ArgumentCaptor.forClass(ContainerSignalContext.class);
+    if (signal.equals(Signal.NULL)) {
+      verify(exec, never()).signalContainer(signalContextCaptor.capture());
+    } else {
+      verify(exec, timeout(10000).atLeastOnce()).signalContainer(signalContextCaptor.capture());
+      ContainerSignalContext signalContext = signalContextCaptor.getAllValues().get(0);
+      Assert.assertEquals(cId, signalContext.getContainer().getContainerId());
+      Assert.assertEquals(signal, signalContext.getSignal());
+    }
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/ClientRMService.java

@@ -93,10 +93,12 @@ import org.apache.hadoop.yarn.api.protocolrecords.ReservationSubmissionRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.ReservationSubmissionResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.ReservationUpdateRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.ReservationUpdateResponse;
-import org.apache.hadoop.yarn.api.protocolrecords.UpdateApplicationPriorityRequest;
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerRequest;
-import org.apache.hadoop.yarn.api.protocolrecords.UpdateApplicationPriorityResponse;
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.SubmitApplicationRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.SubmitApplicationResponse;
+import org.apache.hadoop.yarn.api.protocolrecords.UpdateApplicationPriorityRequest;
+import org.apache.hadoop.yarn.api.protocolrecords.UpdateApplicationPriorityResponse;
 import org.apache.hadoop.yarn.api.records.ApplicationAccessType;
 import org.apache.hadoop.yarn.api.records.ApplicationAttemptId;
 import org.apache.hadoop.yarn.api.records.ApplicationAttemptReport;
@@ -139,6 +141,7 @@ import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMAppState;
 import org.apache.hadoop.yarn.server.resourcemanager.rmapp.attempt.RMAppAttempt;
 import org.apache.hadoop.yarn.server.resourcemanager.rmcontainer.RMContainer;
 import org.apache.hadoop.yarn.server.resourcemanager.rmnode.RMNode;
+import org.apache.hadoop.yarn.server.resourcemanager.rmnode.RMNodeSignalContainerEvent;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.SchedulerAppReport;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.SchedulerNodeReport;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.YarnScheduler;
@@ -1391,4 +1394,66 @@ public class ClientRMService extends AbstractService implements
     return response;
   }
 
+  /**
+   * Signal a container.
+   * After the request passes some sanity check, it will be delivered
+   * to RMNodeImpl so that the next NM heartbeat will pick up the signal request
+   */
+  @Override
+  public SignalContainerResponse signalContainer(
+      SignalContainerRequest request) throws YarnException, IOException {
+    ContainerId containerId = request.getContainerId();
+
+    UserGroupInformation callerUGI;
+    try {
+      callerUGI = UserGroupInformation.getCurrentUser();
+    } catch (IOException ie) {
+      LOG.info("Error getting UGI ", ie);
+      throw RPCUtil.getRemoteException(ie);
+    }
+
+    ApplicationId applicationId = containerId.getApplicationAttemptId().
+        getApplicationId();
+    RMApp application = this.rmContext.getRMApps().get(applicationId);
+    if (application == null) {
+      RMAuditLogger.logFailure(callerUGI.getUserName(),
+          AuditConstants.SIGNAL_CONTAINER, "UNKNOWN", "ClientRMService",
+          "Trying to signal an absent container", applicationId, containerId);
+      throw RPCUtil
+          .getRemoteException("Trying to signal an absent container "
+              + containerId);
+    }
+
+    if (!checkAccess(callerUGI, application.getUser(),
+        ApplicationAccessType.MODIFY_APP, application)) {
+      RMAuditLogger.logFailure(callerUGI.getShortUserName(),
+          AuditConstants.SIGNAL_CONTAINER, "User doesn't have permissions to "
+              + ApplicationAccessType.MODIFY_APP.toString(), "ClientRMService",
+          AuditConstants.UNAUTHORIZED_USER, applicationId);
+      throw RPCUtil.getRemoteException(new AccessControlException("User "
+          + callerUGI.getShortUserName() + " cannot perform operation "
+          + ApplicationAccessType.MODIFY_APP.name() + " on " + applicationId));
+    }
+
+    RMContainer container = scheduler.getRMContainer(containerId);
+    if (container != null) {
+      this.rmContext.getDispatcher().getEventHandler().handle(
+          new RMNodeSignalContainerEvent(container.getContainer().getNodeId(),
+              request));
+      RMAuditLogger.logSuccess(callerUGI.getShortUserName(),
+          AuditConstants.SIGNAL_CONTAINER, "ClientRMService", applicationId,
+          containerId);
+    } else {
+      RMAuditLogger.logFailure(callerUGI.getUserName(),
+          AuditConstants.SIGNAL_CONTAINER, "UNKNOWN", "ClientRMService",
+          "Trying to signal an absent container", applicationId, containerId);
+      throw RPCUtil
+          .getRemoteException("Trying to signal an absent container "
+              + containerId);
+    }
+
+    return recordFactory
+        .newRecordInstance(SignalContainerResponse.class);
+  }
+
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/RMAuditLogger.java

@@ -58,6 +58,7 @@ public class RMAuditLogger {
         "Update Application Priority Request";
     public static final String CHANGE_CONTAINER_RESOURCE =
         "AM Changed Container Resource";
+    public static final String SIGNAL_CONTAINER = "Signal Container Request";
 
     // Some commonly used descriptions
     public static final String UNAUTHORIZED_USER = "Unauthorized user";

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/rmnode/RMNodeEventType.java

@@ -44,6 +44,9 @@ public enum RMNodeEventType {
   CLEANUP_CONTAINER,
   DECREASE_CONTAINER,
 
+  // Source: ClientRMService
+  SIGNAL_CONTAINER,
+
   // Source: RMAppAttempt
   FINISHED_CONTAINERS_PULLED_BY_AM,
 

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/rmnode/RMNodeImpl.java

@@ -39,6 +39,7 @@ import org.apache.hadoop.classification.InterfaceAudience.Private;
 import org.apache.hadoop.classification.InterfaceStability.Unstable;
 import org.apache.hadoop.net.Node;
 import org.apache.hadoop.security.UserGroupInformation;
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerRequest;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
 import org.apache.hadoop.yarn.api.records.Container;
 import org.apache.hadoop.yarn.api.records.ContainerId;
@@ -122,6 +123,10 @@ public class RMNodeImpl implements RMNode, EventHandler<RMNodeEvent> {
   private final Set<ContainerId> containersToClean = new TreeSet<ContainerId>(
       new ContainerIdComparator());
 
+  /* set of containers that need to be signaled */
+  private final List<SignalContainerRequest> containersToSignal =
+      new ArrayList<SignalContainerRequest>();
+
   /*
    * set of containers to notify NM to remove them from its context. Currently,
    * this includes containers that were notified to AM about their completion
@@ -194,6 +199,8 @@ public class RMNodeImpl implements RMNode, EventHandler<RMNodeEvent> {
       .addTransition(NodeState.RUNNING, NodeState.RUNNING,
           RMNodeEventType.DECREASE_CONTAINER,
           new DecreaseContainersTransition())
+      .addTransition(NodeState.RUNNING, NodeState.RUNNING,
+          RMNodeEventType.SIGNAL_CONTAINER, new SignalContainerTransition())
       .addTransition(NodeState.RUNNING, NodeState.SHUTDOWN,
           RMNodeEventType.SHUTDOWN,
           new DeactivateNodeTransition(NodeState.SHUTDOWN))
@@ -288,6 +295,8 @@ public class RMNodeImpl implements RMNode, EventHandler<RMNodeEvent> {
       .addTransition(NodeState.UNHEALTHY, NodeState.UNHEALTHY,
           RMNodeEventType.FINISHED_CONTAINERS_PULLED_BY_AM,
           new AddContainersToBeRemovedFromNMTransition())
+      .addTransition(NodeState.UNHEALTHY, NodeState.UNHEALTHY,
+          RMNodeEventType.SIGNAL_CONTAINER, new SignalContainerTransition())
       .addTransition(NodeState.UNHEALTHY, NodeState.SHUTDOWN,
           RMNodeEventType.SHUTDOWN,
           new DeactivateNodeTransition(NodeState.SHUTDOWN))
@@ -491,8 +500,10 @@ public class RMNodeImpl implements RMNode, EventHandler<RMNodeEvent> {
       response.addAllApplicationsToCleanup(this.finishedApplications);
       response.addContainersToBeRemovedFromNM(
           new ArrayList<ContainerId>(this.containersToBeRemovedFromNM));
+      response.addAllContainersToSignal(this.containersToSignal);
       this.containersToClean.clear();
       this.finishedApplications.clear();
+      this.containersToSignal.clear();
       this.containersToBeRemovedFromNM.clear();
     } finally {
       this.writeLock.unlock();
@@ -1090,6 +1101,16 @@ public class RMNodeImpl implements RMNode, EventHandler<RMNodeEvent> {
     }
   }
 
+  public static class SignalContainerTransition implements
+      SingleArcTransition<RMNodeImpl, RMNodeEvent> {
+
+    @Override
+    public void transition(RMNodeImpl rmNode, RMNodeEvent event) {
+      rmNode.containersToSignal.add(((
+          RMNodeSignalContainerEvent) event).getSignalRequest());
+    }
+  }
+
   @Override
   public List<UpdatedContainerInfo> pullContainerUpdates() {
     List<UpdatedContainerInfo> latestContainerInfoList = 

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/rmnode/RMNodeSignalContainerEvent.java

@@ -0,0 +1,38 @@
+/**
+ * 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.yarn.server.resourcemanager.rmnode;
+
+import org.apache.hadoop.yarn.api.records.NodeId;
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerRequest;
+
+public class RMNodeSignalContainerEvent extends RMNodeEvent {
+
+  private SignalContainerRequest signalRequest;
+
+  public RMNodeSignalContainerEvent(NodeId nodeId,
+      SignalContainerRequest signalRequest) {
+    super(nodeId, RMNodeEventType.SIGNAL_CONTAINER);
+    this.signalRequest = signalRequest;
+  }
+
+  public SignalContainerRequest getSignalRequest() {
+    return this.signalRequest;
+  }
+
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/MockRM.java

@@ -39,6 +39,7 @@ import org.apache.hadoop.yarn.api.protocolrecords.GetNewApplicationRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.GetNewApplicationResponse;
 import org.apache.hadoop.yarn.api.protocolrecords.KillApplicationRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.KillApplicationResponse;
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.SubmitApplicationRequest;
 import org.apache.hadoop.yarn.api.protocolrecords.SubmitApplicationResponse;
 import org.apache.hadoop.yarn.api.records.ApplicationAccessType;
@@ -52,6 +53,7 @@ import org.apache.hadoop.yarn.api.records.ContainerState;
 import org.apache.hadoop.yarn.api.records.ContainerStatus;
 import org.apache.hadoop.yarn.api.records.FinalApplicationStatus;
 import org.apache.hadoop.yarn.api.records.LogAggregationContext;
+import org.apache.hadoop.yarn.api.records.SignalContainerCommand;
 import org.apache.hadoop.yarn.api.records.NodeId;
 import org.apache.hadoop.yarn.api.records.NodeState;
 import org.apache.hadoop.yarn.api.records.Priority;
@@ -814,4 +816,12 @@ public class MockRM extends ResourceManager {
   public RMActiveServices getRMActiveService() {
     return activeServices;
   }
+
+  public void signalContainer(ContainerId containerId, SignalContainerCommand command)
+      throws Exception {
+    ApplicationClientProtocol client = getClientRMService();
+    SignalContainerRequest req =
+        SignalContainerRequest.newInstance(containerId, command);
+    client.signalContainer(req);
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/TestSignalContainer.java

@@ -0,0 +1,113 @@
+/**
+ * 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.yarn.server.resourcemanager;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.Assert;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.yarn.api.protocolrecords.SignalContainerRequest;
+import org.apache.hadoop.yarn.api.records.Container;
+import org.apache.hadoop.yarn.api.records.ContainerId;
+import org.apache.hadoop.yarn.api.records.ContainerState;
+import org.apache.hadoop.yarn.api.records.ResourceRequest;
+import org.apache.hadoop.yarn.api.records.SignalContainerCommand;
+import org.apache.hadoop.yarn.server.api.protocolrecords.NodeHeartbeatResponse;
+import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMApp;
+import org.apache.hadoop.yarn.server.resourcemanager.rmapp.attempt.RMAppAttempt;
+import org.apache.hadoop.yarn.server.resourcemanager.rmapp.attempt.RMAppAttemptState;
+import org.apache.log4j.Level;
+import org.apache.log4j.LogManager;
+import org.apache.log4j.Logger;
+import org.junit.Test;
+
+public class TestSignalContainer {
+
+  private static final Log LOG = LogFactory
+    .getLog(TestSignalContainer.class);
+
+  @Test
+  public void testSignalRequestDeliveryToNM() throws Exception {
+    Logger rootLogger = LogManager.getRootLogger();
+    rootLogger.setLevel(Level.DEBUG);
+    MockRM rm = new MockRM();
+    rm.start();
+
+    MockNM nm1 = rm.registerNode("h1:1234", 5000);
+
+    RMApp app = rm.submitApp(2000);
+
+    //kick the scheduling
+    nm1.nodeHeartbeat(true);
+
+    RMAppAttempt attempt = app.getCurrentAppAttempt();
+    MockAM am = rm.sendAMLaunched(attempt.getAppAttemptId());
+    am.registerAppAttempt();
+
+    //request for containers
+    final int request = 2;
+    am.allocate("h1" , 1000, request, new ArrayList<ContainerId>());
+
+    //kick the scheduler
+    nm1.nodeHeartbeat(true);
+    List<Container> conts = null;
+    int contReceived = 0;
+    int waitCount = 0;
+    while (contReceived < request && waitCount++ < 200) {
+      LOG.info("Got " + contReceived + " containers. Waiting to get "
+           + request);
+      Thread.sleep(100);
+      conts = am.allocate(new ArrayList<ResourceRequest>(),
+          new ArrayList<ContainerId>()).getAllocatedContainers();
+      contReceived += conts.size();
+    }
+    Assert.assertEquals(request, contReceived);
+
+    for(Container container : conts) {
+      rm.signalContainer(container.getId(),
+          SignalContainerCommand.OUTPUT_THREAD_DUMP);
+    }
+
+    NodeHeartbeatResponse resp;
+    List<SignalContainerRequest> contsToSignal;
+    int signaledConts = 0;
+
+    waitCount = 0;
+    while ( signaledConts < request && waitCount++ < 200) {
+      LOG.info("Waiting to get signalcontainer events.. signaledConts: "
+          + signaledConts);
+      resp = nm1.nodeHeartbeat(true);
+      contsToSignal = resp.getContainersToSignalList();
+      signaledConts += contsToSignal.size();
+      Thread.sleep(100);
+    }
+
+    // Verify NM receives the expected number of signal container requests.
+    Assert.assertEquals(request, signaledConts);
+
+    am.unregisterAppAttempt();
+    nm1.nodeHeartbeat(attempt.getAppAttemptId(), 1, ContainerState.COMPLETE);
+    am.waitForState(RMAppAttemptState.FINISHED);
+
+    rm.stop();
+  }
+}