YARN-4878. Expose scheduling policy and max running apps over JMX for Yarn queues. (Yufei Gu via kasha)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/FSQueue.java

@@ -70,6 +70,10 @@ public abstract class FSQueue implements Queue, Schedulable {
     this.metrics = FSQueueMetrics.forQueue(getName(), parent, true, scheduler.getConf());
     metrics.setMinShare(getMinShare());
     metrics.setMaxShare(getMaxShare());
+
+    AllocationConfiguration allocConf = scheduler.getAllocationConfiguration();
+    metrics.setMaxApps(allocConf.getQueueMaxApps(name));
+    metrics.setSchedulingPolicy(allocConf.getSchedulingPolicy(name).getName());
     this.parent = parent;
   }
   

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/FSQueueMetrics.java

@@ -39,6 +39,9 @@ public class FSQueueMetrics extends QueueMetrics {
   @Metric("Minimum share of CPU in vcores") MutableGaugeInt minShareVCores;
   @Metric("Maximum share of memory in MB") MutableGaugeInt maxShareMB;
   @Metric("Maximum share of CPU in vcores") MutableGaugeInt maxShareVCores;
+  @Metric("Maximum number of applications") MutableGaugeInt maxApps;
+
+  private String schedulingPolicy;
 
   FSQueueMetrics(MetricsSystem ms, String queueName, Queue parent,
       boolean enableUserMetrics, Configuration conf) {
@@ -97,6 +100,22 @@ public class FSQueueMetrics extends QueueMetrics {
     return maxShareVCores.value();
   }
 
+  public int getMaxApps() {
+    return maxApps.value();
+  }
+
+  public void setMaxApps(int max) {
+    maxApps.set(max);
+  }
+
+  public String getSchedulingPolicy() {
+    return schedulingPolicy;
+  }
+
+  public void setSchedulingPolicy(String policy) {
+    schedulingPolicy = policy;
+  }
+
   public synchronized
   static FSQueueMetrics forQueue(String queueName, Queue parent,
       boolean enableUserMetrics, Configuration conf) {

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/QueueManager.java

@@ -430,11 +430,14 @@ public class QueueManager {
       FSQueueMetrics queueMetrics = queue.getMetrics();
       queueMetrics.setMinShare(queue.getMinShare());
       queueMetrics.setMaxShare(queue.getMaxShare());
-      // Set scheduling policies
+      // Set scheduling policies and update queue metrics
       try {
         SchedulingPolicy policy = queueConf.getSchedulingPolicy(queue.getName());
         policy.initialize(scheduler.getClusterResource());
         queue.setPolicy(policy);
+
+        queueMetrics.setMaxApps(queueConf.getQueueMaxApps(queue.getName()));
+        queueMetrics.setSchedulingPolicy(policy.getName());
       } catch (AllocationConfigurationException ex) {
         LOG.warn("Cannot apply configured scheduling policy to queue "
             + queue.getName(), ex);

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestFSLeafQueue.java

@@ -86,7 +86,14 @@ public class TestFSLeafQueue extends FairSchedulerTestBase {
     String queueName = "root.queue1";
     when(scheduler.allocConf.getMaxResources(queueName)).thenReturn(maxResource);
     when(scheduler.allocConf.getMinResources(queueName)).thenReturn(Resources.none());
+    when(scheduler.allocConf.getQueueMaxApps(queueName)).
+        thenReturn(Integer.MAX_VALUE);
+    when(scheduler.allocConf.getSchedulingPolicy(queueName))
+        .thenReturn(SchedulingPolicy.DEFAULT_POLICY);
     FSLeafQueue schedulable = new FSLeafQueue(queueName, scheduler, null);
+    assertEquals(schedulable.getMetrics().getMaxApps(), Integer.MAX_VALUE);
+    assertEquals(schedulable.getMetrics().getSchedulingPolicy(),
+        SchedulingPolicy.DEFAULT_POLICY.getName());
 
     FSAppAttempt app = mock(FSAppAttempt.class);
     Mockito.when(app.getDemand()).thenReturn(maxResource);
@@ -118,6 +125,11 @@ public class TestFSLeafQueue extends FairSchedulerTestBase {
     resourceManager = new MockRM(conf);
     resourceManager.start();
     scheduler = (FairScheduler) resourceManager.getResourceScheduler();
+    for(FSQueue queue: scheduler.getQueueManager().getQueues()) {
+      assertEquals(queue.getMetrics().getMaxApps(), Integer.MAX_VALUE);
+      assertEquals(queue.getMetrics().getSchedulingPolicy(),
+          SchedulingPolicy.DEFAULT_POLICY.getName());
+    }
 
     // Add one big node (only care about aggregate capacity)
     RMNode node1 =