YARN-6439. Fix ReservationSystem creation of default ReservationQueue. (Carlo Curino via wangda)

(cherry picked from commit 4d4ad0ebb7)

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

@@ -40,10 +40,13 @@ import org.apache.hadoop.yarn.exceptions.YarnException;
 import org.apache.hadoop.yarn.security.Permission;
 import org.apache.hadoop.yarn.security.YarnAuthorizationProvider;
 import org.apache.hadoop.yarn.server.resourcemanager.nodelabels.RMNodeLabelsManager;
+import org.apache.hadoop.yarn.server.resourcemanager.reservation.ReservationConstants;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.Queue;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.QueueStateManager;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ResourceLimits;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.SchedulerDynamicEditException;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.SchedulerQueueManager;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.common.QueueEntitlement;
 import org.apache.hadoop.yarn.server.resourcemanager.security.AppPriorityACLsManager;
 
 import com.google.common.annotations.VisibleForTesting;
@@ -219,6 +222,23 @@ public class CapacitySchedulerQueueManager implements SchedulerQueueManager<
         queue =
             new PlanQueue(csContext, queueName, parent,
                 oldQueues.get(queueName));
+
+        //initializing the "internal" default queue, for SLS compatibility
+        String defReservationId =
+            queueName + ReservationConstants.DEFAULT_QUEUE_SUFFIX;
+
+        List<CSQueue> childQueues = new ArrayList<>();
+        ReservationQueue resQueue = new ReservationQueue(csContext,
+            defReservationId, (PlanQueue) queue);
+        try {
+          resQueue.setEntitlement(new QueueEntitlement(1.0f, 1.0f));
+        } catch (SchedulerDynamicEditException e) {
+          throw new IllegalStateException(e);
+        }
+        childQueues.add(resQueue);
+        ((PlanQueue) queue).setChildQueues(childQueues);
+        queues.put(defReservationId, resQueue);
+
       } else {
         queue =
             new LeafQueue(csContext, queueName, parent,

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

@@ -93,10 +93,10 @@ public class PlanQueue extends ParentQueue {
 
       PlanQueue newlyParsedParentQueue = (PlanQueue) newlyParsedQueue;
 
-      if (newlyParsedParentQueue.getChildQueues().size() > 0) {
+      if (newlyParsedParentQueue.getChildQueues().size() != 1) {
         throw new IOException(
             "Reservable Queue should not have sub-queues in the"
-                + "configuration");
+                + "configuration expect the default reservation queue");
       }
 
       // Set new configs

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

@@ -153,6 +153,13 @@ public class TestCapacitySchedulerPlanFollower extends
     assertTrue(csQueue.getCapacity() > 0.9);
   }
 
+  @Override
+  protected void checkDefaultQueueBeforePlanFollowerRun(){
+    Queue defQ = getDefaultQueue();
+    Assert.assertEquals(0, getNumberOfApplications(defQ));
+    Assert.assertNotNull(defQ);
+  }
+
   @Override
   protected Queue getDefaultQueue() {
     return cs.getQueue("dedicated" + ReservationConstants.DEFAULT_QUEUE_SUFFIX);

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

@@ -131,6 +131,10 @@ public class TestFairSchedulerPlanFollower extends
     testPlanFollower(false);
   }
 
+  @Override
+  protected void checkDefaultQueueBeforePlanFollowerRun() {
+    Assert.assertNull(getDefaultQueue());
+  }
   @Override
   protected void verifyCapacity(Queue defQ) {
     assertTrue(((FSQueue) defQ).getWeights().getWeight(ResourceType.MEMORY) > 0.9);

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

@@ -89,6 +89,11 @@ public abstract class TestSchedulerPlanFollowerBase {
             "dedicated", 10, 10 + f2.length, ReservationSystemTestUtil
                 .generateAllocation(10L, 1L, f2), res, minAlloc), false));
 
+
+    // default reseration queue should exist before run of PlanFollower AND have
+    // no apps
+    checkDefaultQueueBeforePlanFollowerRun();
+
     AbstractSchedulerPlanFollower planFollower = createPlanFollower();
 
     when(mClock.getTime()).thenReturn(0L);
@@ -108,8 +113,8 @@ public abstract class TestSchedulerPlanFollowerBase {
         new AppAttemptAddedSchedulerEvent(appAttemptId_0, false);
     scheduler.handle(appAttemptAddedEvent);
 
-    // initial default reservation queue should have no apps
 
+    // initial default reservation queue should have no apps after first run
     Queue defQ = getDefaultQueue();
     Assert.assertEquals(0, getNumberOfApplications(defQ));
 
@@ -179,6 +184,8 @@ public abstract class TestSchedulerPlanFollowerBase {
     verifyCapacity(defQ);
   }
 
+  protected abstract void checkDefaultQueueBeforePlanFollowerRun();
+
   protected abstract Queue getReservationQueue(String reservationId);
 
   protected abstract void verifyCapacity(Queue defQ);

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

@@ -76,6 +76,12 @@ public class TestCapacitySchedulerDynamicBehavior {
   public void testRefreshQueuesWithReservations() throws Exception {
     CapacityScheduler cs = (CapacityScheduler) rm.getResourceScheduler();
 
+    //set default queue capacity to zero
+    ((ReservationQueue) cs
+            .getQueue("a" + ReservationConstants.DEFAULT_QUEUE_SUFFIX))
+            .setEntitlement(
+                    new QueueEntitlement(0f, 1f));
+
     // Test add one reservation dynamically and manually modify capacity
     ReservationQueue a1 =
         new ReservationQueue(cs, "a1", (PlanQueue) cs.getQueue("a"));
@@ -120,6 +126,11 @@ public class TestCapacitySchedulerDynamicBehavior {
     ReservationQueue a1 =
         new ReservationQueue(cs, "a1", (PlanQueue) cs.getQueue("a"));
     cs.addQueue(a1);
+    //set default queue capacity to zero
+    ((ReservationQueue) cs
+        .getQueue("a" + ReservationConstants.DEFAULT_QUEUE_SUFFIX))
+            .setEntitlement(
+                new QueueEntitlement(0f, 1f));
     a1.setEntitlement(new QueueEntitlement(A1_CAPACITY / 100, 1f));
 
     // Test add another reservation queue and use setEntitlement to modify