YARN-80. Add support for delaying rack-local containers in CapacityScheduler. Contributed by Arun C. Murthy.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1381872 13f79535-47bb-0310-9956-ffa450edef68

hadoop-yarn-project/CHANGES.txt

@@ -44,6 +44,9 @@ Release 2.1.0-alpha - Unreleased
     YARN-10. Fix DistributedShell module to not have a dependency on 
     hadoop-mapreduce-client-core. (Hitesh Shah via vinodkv)
 
+    YARN-80. Add support for delaying rack-local containers in
+    CapacityScheduler. (acmurthy) 
+
   OPTIMAZATIONS
 
   BUG FIXES

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/CapacitySchedulerConfiguration.java

@@ -115,6 +115,13 @@ public class CapacitySchedulerConfiguration extends Configuration {
   @Private
   public static final String ROOT = "root";
 
+  @Private 
+  public static final String NODE_LOCALITY_DELAY = 
+     PREFIX + "node-locality-delay";
+
+  @Private 
+  public static final int DEFAULT_NODE_LOCALITY_DELAY = -1;
+
   public CapacitySchedulerConfiguration() {
     this(new Configuration());
   }
@@ -290,4 +297,9 @@ public class CapacitySchedulerConfiguration extends Configuration {
   public boolean getEnableUserMetrics() {
     return getBoolean(ENABLE_USER_METRICS, DEFAULT_ENABLE_USER_METRICS);
   }
+
+  public int getNodeLocalityDelay() {
+    int delay = getInt(NODE_LOCALITY_DELAY, DEFAULT_NODE_LOCALITY_DELAY);
+    return (delay == DEFAULT_NODE_LOCALITY_DELAY) ? 0 : delay;
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/LeafQueue.java

@@ -124,6 +124,8 @@ public class LeafQueue implements CSQueue {
   
   private final ActiveUsersManager activeUsersManager;
   
+  private final int nodeLocalityDelay;
+  
   public LeafQueue(CapacitySchedulerContext cs, 
       String queueName, CSQueue parent, 
       Comparator<FiCaSchedulerApp> applicationComparator, CSQueue old) {
@@ -188,6 +190,9 @@ public class LeafQueue implements CSQueue {
     Map<QueueACL, AccessControlList> acls = 
       cs.getConfiguration().getAcls(getQueuePath());
 
+    this.nodeLocalityDelay = 
+        cs.getConfiguration().getNodeLocalityDelay();
+    
     setupQueueConfigs(
         cs.getClusterResources(),
         capacity, absoluteCapacity, 
@@ -528,6 +533,11 @@ public class LeafQueue implements CSQueue {
     return Collections.singletonList(userAclInfo);
   }
 
+  @Private
+  public int getNodeLocalityDelay() {
+    return nodeLocalityDelay;
+  }
+  
   public String toString() {
     return queueName + ": " + 
         "capacity=" + capacity + ", " + 
@@ -1095,7 +1105,7 @@ public class LeafQueue implements CSQueue {
           reservedContainer)) {
         return assignContainer(clusterResource, node, application, priority, request, 
             NodeType.RACK_LOCAL, reservedContainer);
-      }
+      } 
     }
     return Resources.none();
   }
@@ -1112,7 +1122,6 @@ public class LeafQueue implements CSQueue {
             NodeType.OFF_SWITCH, reservedContainer);
       }
     }
-    
     return Resources.none();
   }
 
@@ -1147,7 +1156,12 @@ public class LeafQueue implements CSQueue {
       
     // If we are here, we do need containers on this rack for RACK_LOCAL req
     if (type == NodeType.RACK_LOCAL) {
-      return true;
+      // 'Delay' rack-local just a little bit...
+      long missedOpportunities = application.getSchedulingOpportunities(priority);
+      return (
+          Math.min(scheduler.getNumClusterNodes(), getNodeLocalityDelay()) < 
+          missedOpportunities
+          );
     }
 
     // Check if we need containers on this host

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/resources/capacity-scheduler.xml

@@ -92,4 +92,15 @@
     </description>
   </property>
 
+  <property>
+    <name>yarn.scheduler.capacity.node-locality-delay</name>
+    <value>-1</value>
+    <description>
+      Number of missed scheduling opportunities after which the CapacityScheduler 
+      attempts to schedule rack-local containers. 
+      Typically this should be set to number of racks in the cluster, this 
+      feature is disabled by default, set to -1.
+    </description>
+  </property>
+
 </configuration>

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/TestLeafQueue.java

@@ -24,6 +24,7 @@ import static org.junit.Assert.assertTrue;
 import static org.mockito.Matchers.any;
 import static org.mockito.Matchers.eq;
 import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.doNothing;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
@@ -1288,19 +1289,29 @@ public class TestLeafQueue {
         TestUtils.createResourceRequest(rack_1, 1*GB, 1, 
             priority, recordFactory));
     app_0_requests_0.add(
-        TestUtils.createResourceRequest(RMNodeImpl.ANY, 1*GB, 1, // one extra 
+        TestUtils.createResourceRequest(RMNodeImpl.ANY, 1*GB, 2, // one extra 
             priority, recordFactory));
     app_0.updateResourceRequests(app_0_requests_0);
-    assertEquals(1, app_0.getTotalRequiredResources(priority));
+    assertEquals(2, app_0.getTotalRequiredResources(priority));
     
     String host_3 = "host_3"; // on rack_1
     FiCaSchedulerNode node_3 = TestUtils.getMockNode(host_3, rack_1, 0, 8*GB);
     
+    // Rack-delay
+    doReturn(1).when(a).getNodeLocalityDelay();
+    
+    // Shouldn't assign RACK_LOCAL yet
+    assignment = a.assignContainers(clusterResource, node_3);
+    assertEquals(1, app_0.getSchedulingOpportunities(priority));
+    assertEquals(2, app_0.getTotalRequiredResources(priority));
+    assertEquals(NodeType.NODE_LOCAL, assignment.getType()); // None->NODE_LOCAL
+
+    // Should assign RACK_LOCAL now
     assignment = a.assignContainers(clusterResource, node_3);
     verify(app_0).allocate(eq(NodeType.RACK_LOCAL), eq(node_3), 
         any(Priority.class), any(ResourceRequest.class), any(Container.class));
     assertEquals(0, app_0.getSchedulingOpportunities(priority)); // should reset
-    assertEquals(0, app_0.getTotalRequiredResources(priority));
+    assertEquals(1, app_0.getTotalRequiredResources(priority));
     assertEquals(NodeType.RACK_LOCAL, assignment.getType());
   }