YARN-335. Fair scheduler doesn't check whether rack needs containers before assigning to node. Contributed by Sandy Ryza.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1433484 13f79535-47bb-0310-9956-ffa450edef68

hadoop-yarn-project/CHANGES.txt

@@ -190,6 +190,9 @@ Release 2.0.3-alpha - Unreleased
     YARN-330. Fix flakey test: TestNodeManagerShutdown#testKillContainersOnShutdown.
     (Sandy Ryza via hitesh)
     
+    YARN-335. Fair scheduler doesn't check whether rack needs containers
+    before assigning to node. (Sandy Ryza via tomwhite)
+
 Release 2.0.2-alpha - 2012-09-07 
 
   INCOMPATIBLE CHANGES

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

@@ -307,20 +307,27 @@ public class AppSchedulable extends Schedulable {
     // (not scheduled) in order to promote better locality.
     synchronized (app) {
       for (Priority priority : prioritiesToTry) {
+        if (app.getTotalRequiredResources(priority) <= 0) {
+          continue;
+        }
+        
         app.addSchedulingOpportunity(priority);
+
+        ResourceRequest rackLocalRequest = app.getResourceRequest(priority,
+            node.getRackName());
+        ResourceRequest localRequest = app.getResourceRequest(priority,
+            node.getHostName());
+        
         NodeType allowedLocality = app.getAllowedLocalityLevel(priority,
             scheduler.getNumClusterNodes(), scheduler.getNodeLocalityThreshold(),
             scheduler.getRackLocalityThreshold());
         
-        ResourceRequest localRequest = app.getResourceRequest(priority,
+        if (rackLocalRequest != null && rackLocalRequest.getNumContainers() != 0
-            node.getHostName());
+            && localRequest != null && localRequest.getNumContainers() != 0) {
-        if (localRequest != null && localRequest.getNumContainers() != 0) {
           return assignContainer(node, app, priority,
               localRequest, NodeType.NODE_LOCAL, reserved);
         }
 
-        ResourceRequest rackLocalRequest = app.getResourceRequest(priority,
-            node.getRackName());
         if (rackLocalRequest != null && rackLocalRequest.getNumContainers() != 0
             && (allowedLocality.equals(NodeType.RACK_LOCAL) ||
                 allowedLocality.equals(NodeType.OFF_SWITCH))) {

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

@@ -1275,4 +1275,46 @@ public class TestFairScheduler {
     FSSchedulerApp app2 = scheduler.applications.get(attId2);
     assertNull("The application was allowed", app2);
   }
+  
+  @Test
+  public void testMultipleNodesSingleRackRequest() throws Exception {
+    RMNode node1 = MockNodes.newNodeInfo(1, Resources.createResource(1024));
+    RMNode node2 = MockNodes.newNodeInfo(1, Resources.createResource(1024));
+    RMNode node3 = MockNodes.newNodeInfo(2, Resources.createResource(1024));
+    NodeAddedSchedulerEvent nodeEvent1 = new NodeAddedSchedulerEvent(node1);
+    scheduler.handle(nodeEvent1);
+    NodeAddedSchedulerEvent nodeEvent2 = new NodeAddedSchedulerEvent(node2);
+    scheduler.handle(nodeEvent2);
+    
+    ApplicationAttemptId appId = createAppAttemptId(this.APP_ID++, this.ATTEMPT_ID++);
+    scheduler.addApplication(appId, "queue1", "user1");
+    
+    // 1 request with 2 nodes on the same rack. another request with 1 node on
+    // a different rack
+    List<ResourceRequest> asks = new ArrayList<ResourceRequest>();
+    asks.add(createResourceRequest(1024, node1.getHostName(), 1, 1));
+    asks.add(createResourceRequest(1024, node2.getHostName(), 1, 1));
+    asks.add(createResourceRequest(1024, node3.getHostName(), 1, 1));
+    asks.add(createResourceRequest(1024, node1.getRackName(), 1, 1));
+    asks.add(createResourceRequest(1024, node3.getRackName(), 1, 1));
+    asks.add(createResourceRequest(1024, RMNode.ANY, 1, 2));
+
+    scheduler.allocate(appId, asks, new ArrayList<ContainerId>());
+    
+    // node 1 checks in
+    scheduler.update();
+    NodeUpdateSchedulerEvent updateEvent1 = new NodeUpdateSchedulerEvent(node1,
+      new ArrayList<ContainerStatus>(), new ArrayList<ContainerStatus>());
+    scheduler.handle(updateEvent1);
+    // should assign node local
+    assertEquals(1, scheduler.applications.get(appId).getLiveContainers().size());
+
+    // node 2 checks in
+    scheduler.update();
+    NodeUpdateSchedulerEvent updateEvent2 = new NodeUpdateSchedulerEvent(node2,
+      new ArrayList<ContainerStatus>(), new ArrayList<ContainerStatus>());
+    scheduler.handle(updateEvent2);
+    // should assign rack local
+    assertEquals(2, scheduler.applications.get(appId).getLiveContainers().size());
+  }
 }