MAPREDUCE-6265. Make ContainerLauncherImpl.INITIAL_POOL_SIZE configurable to better control to launch/kill containers. Contributed by Zhihai Xu

hadoop-mapreduce-project/CHANGES.txt

@@ -340,6 +340,9 @@ Release 2.7.0 - UNRELEASED
     MAPREDUCE-6263. Configurable timeout between YARNRunner terminate the 
     application and forcefully kill. (Eric Payne via junping_du)
 
+    MAPREDUCE-6265. Make ContainerLauncherImpl.INITIAL_POOL_SIZE configurable 
+    to better control to launch/kill containers. (Zhihai Xu via ozawa)
+
   OPTIMIZATIONS
 
     MAPREDUCE-6169. MergeQueue should release reference to the current item 

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapreduce/v2/app/launcher/ContainerLauncherImpl.java

@@ -70,7 +70,7 @@ public class ContainerLauncherImpl extends AbstractService implements
     new ConcurrentHashMap<ContainerId, Container>(); 
   private final AppContext context;
   protected ThreadPoolExecutor launcherPool;
-  protected static final int INITIAL_POOL_SIZE = 10;
+  protected int initialPoolSize;
   private int limitOnPoolSize;
   private Thread eventHandlingThread;
   protected BlockingQueue<ContainerLauncherEvent> eventQueue =
@@ -246,6 +246,12 @@ protected void serviceInit(Configuration conf) throws Exception {
         MRJobConfig.MR_AM_CONTAINERLAUNCHER_THREAD_COUNT_LIMIT,
         MRJobConfig.DEFAULT_MR_AM_CONTAINERLAUNCHER_THREAD_COUNT_LIMIT);
     LOG.info("Upper limit on the thread pool size is " + this.limitOnPoolSize);
+
+    this.initialPoolSize = conf.getInt(
+        MRJobConfig.MR_AM_CONTAINERLAUNCHER_THREADPOOL_INITIAL_SIZE,
+        MRJobConfig.DEFAULT_MR_AM_CONTAINERLAUNCHER_THREADPOOL_INITIAL_SIZE);
+    LOG.info("The thread pool initial size is " + this.initialPoolSize);
+
     super.serviceInit(conf);
     cmProxy = new ContainerManagementProtocolProxy(conf);
   }
@@ -256,7 +262,7 @@ protected void serviceStart() throws Exception {
         "ContainerLauncher #%d").setDaemon(true).build();
 
     // Start with a default core-pool size of 10 and change it dynamically.
-    launcherPool = new ThreadPoolExecutor(INITIAL_POOL_SIZE,
+    launcherPool = new ThreadPoolExecutor(initialPoolSize,
         Integer.MAX_VALUE, 1, TimeUnit.HOURS,
         new LinkedBlockingQueue<Runnable>(),
         tf);
@@ -289,11 +295,11 @@ public void run() {
             int idealPoolSize = Math.min(limitOnPoolSize, numNodes);
 
             if (poolSize < idealPoolSize) {
-              // Bump up the pool size to idealPoolSize+INITIAL_POOL_SIZE, the
+              // Bump up the pool size to idealPoolSize+initialPoolSize, the
               // later is just a buffer so we are not always increasing the
               // pool-size
               int newPoolSize = Math.min(limitOnPoolSize, idealPoolSize
-                  + INITIAL_POOL_SIZE);
+                  + initialPoolSize);
               LOG.info("Setting ContainerLauncher pool size to " + newPoolSize
                   + " as number-of-nodes to talk to is " + numNodes);
               launcherPool.setCorePoolSize(newPoolSize);

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/launcher/TestContainerLauncher.java

@@ -90,7 +90,7 @@ public class TestContainerLauncher {
 
   static final Log LOG = LogFactory.getLog(TestContainerLauncher.class);
 
-  @Test (timeout = 5000)
+  @Test (timeout = 10000)
   public void testPoolSize() throws InterruptedException {
 
     ApplicationId appId = ApplicationId.newInstance(12345, 67);
@@ -108,12 +108,14 @@ public void testPoolSize() throws InterruptedException {
     ThreadPoolExecutor threadPool = containerLauncher.getThreadPool();
 
     // No events yet
+    Assert.assertEquals(containerLauncher.initialPoolSize,
+        MRJobConfig.DEFAULT_MR_AM_CONTAINERLAUNCHER_THREADPOOL_INITIAL_SIZE);
     Assert.assertEquals(0, threadPool.getPoolSize());
-    Assert.assertEquals(ContainerLauncherImpl.INITIAL_POOL_SIZE,
+    Assert.assertEquals(containerLauncher.initialPoolSize,
       threadPool.getCorePoolSize());
     Assert.assertNull(containerLauncher.foundErrors);
 
-    containerLauncher.expectedCorePoolSize = ContainerLauncherImpl.INITIAL_POOL_SIZE;
+    containerLauncher.expectedCorePoolSize = containerLauncher.initialPoolSize;
     for (int i = 0; i < 10; i++) {
       ContainerId containerId = ContainerId.newContainerId(appAttemptId, i);
       TaskAttemptId taskAttemptId = MRBuilderUtils.newTaskAttemptId(taskId, i);
@@ -152,7 +154,7 @@ public void testPoolSize() throws InterruptedException {
     // Different hosts, there should be an increase in core-thread-pool size to
     // 21(11hosts+10buffer)
     // Core pool size should be 21 but the live pool size should be only 11.
-    containerLauncher.expectedCorePoolSize = 11 + ContainerLauncherImpl.INITIAL_POOL_SIZE;
+    containerLauncher.expectedCorePoolSize = 11 + containerLauncher.initialPoolSize;
     containerLauncher.finishEventHandling = false;
     ContainerId containerId = ContainerId.newContainerId(appAttemptId, 21);
     TaskAttemptId taskAttemptId = MRBuilderUtils.newTaskAttemptId(taskId, 21);
@@ -164,6 +166,15 @@ public void testPoolSize() throws InterruptedException {
     Assert.assertNull(containerLauncher.foundErrors);
 
     containerLauncher.stop();
+
+    // change configuration MR_AM_CONTAINERLAUNCHER_THREADPOOL_INITIAL_SIZE
+    // and verify initialPoolSize value.
+    Configuration conf = new Configuration();
+    conf.setInt(MRJobConfig.MR_AM_CONTAINERLAUNCHER_THREADPOOL_INITIAL_SIZE,
+        20);
+    containerLauncher = new CustomContainerLauncher(context);
+    containerLauncher.init(conf);
+    Assert.assertEquals(containerLauncher.initialPoolSize, 20);
   }
 
   @Test(timeout = 5000)
@@ -187,7 +198,7 @@ public void testPoolLimits() throws InterruptedException {
     ThreadPoolExecutor threadPool = containerLauncher.getThreadPool();
 
     // 10 different hosts
-    containerLauncher.expectedCorePoolSize = ContainerLauncherImpl.INITIAL_POOL_SIZE;
+    containerLauncher.expectedCorePoolSize = containerLauncher.initialPoolSize;
     for (int i = 0; i < 10; i++) {
       containerLauncher.handle(new ContainerLauncherEvent(taskAttemptId,
         containerId, "host" + i + ":1234", null,

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/MRJobConfig.java

@@ -504,6 +504,14 @@ public interface MRJobConfig {
   public static final int DEFAULT_MR_AM_CONTAINERLAUNCHER_THREAD_COUNT_LIMIT = 
       500;
 
+  /**
+   * The initial size of thread pool to launch containers in the app master
+   */
+  public static final String MR_AM_CONTAINERLAUNCHER_THREADPOOL_INITIAL_SIZE =
+      MR_AM_PREFIX+"containerlauncher.threadpool-initial-size";
+  public static final int DEFAULT_MR_AM_CONTAINERLAUNCHER_THREADPOOL_INITIAL_SIZE =
+      10;
+
   /** Number of threads to handle job client RPC requests.*/
   public static final String MR_AM_JOB_CLIENT_THREAD_COUNT =
     MR_AM_PREFIX + "job.client.thread-count";

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/resources/mapred-default.xml

@@ -1694,4 +1694,12 @@
     calculated as (heapSize / mapreduce.heap.memory-mb.ratio).
   </description>
 </property>
+
+<property>
+  <name>yarn.app.mapreduce.am.containerlauncher.threadpool-initial-size</name>
+  <value>10</value>
+  <description>The initial size of thread pool to launch containers in the
+    app master.
+  </description>
+</property>
 </configuration>