YARN-10714. Remove dangling dynamic queues on reinitialization. Contributed by Andras Gyori

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

@@ -27,8 +27,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
-import org.apache.hadoop.yarn.util.resource.ResourceUtils;
-import org.apache.hadoop.yarn.util.resource.Resources;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.apache.hadoop.classification.InterfaceAudience.Private;
@@ -340,11 +338,14 @@ public class CapacitySchedulerQueueManager implements SchedulerQueueManager<
     }
 
     for (CSQueue queue : existingQueues.getQueues()) {
-      if (!((AbstractCSQueue) queue).isDynamicQueue() && newQueues.get(
-          queue.getQueuePath()) == null && !(
-          queue instanceof AutoCreatedLeafQueue && conf
-              .isAutoCreateChildQueueEnabled(
-                  queue.getParent().getQueuePath()))) {
+      boolean isDanglingDynamicQueue = isDanglingDynamicQueue(
+          newQueues, existingQueues, queue);
+      boolean isRemovable = isDanglingDynamicQueue || !isDynamicQueue(queue)
+          && newQueues.get(queue.getQueuePath()) == null
+          && !(queue instanceof AutoCreatedLeafQueue &&
+          conf.isAutoCreateChildQueueEnabled(queue.getParent().getQueuePath()));
+
+      if (isRemovable) {
         existingQueues.remove(queue);
       }
     }
@@ -435,4 +436,32 @@ public class CapacitySchedulerQueueManager implements SchedulerQueueManager<
       getQueueStateManager() {
     return this.queueStateManager;
   }
+
+  private boolean isDynamicQueue(CSQueue queue) {
+    return (queue instanceof AbstractCSQueue) &&
+        ((AbstractCSQueue) queue).isDynamicQueue();
+  }
+
+  private boolean isDanglingDynamicQueue(
+      CSQueueStore newQueues, CSQueueStore existingQueues,
+      CSQueue queue) {
+    if (!isDynamicQueue(queue)) {
+      return false;
+    }
+    if (queue.getParent() == null) {
+      return true;
+    }
+    if (newQueues.get(queue.getParent().getQueuePath()) != null) {
+      return false;
+    }
+    CSQueue parent = existingQueues.get(queue.getParent().getQueuePath());
+    if (parent == null) {
+      return true;
+    }
+    // A dynamic queue is dangling, if its parent is not parsed in newQueues
+    // or if its parent is not a dynamic queue. Dynamic queues are not parsed in
+    // newQueues but they are deleted automatically, so it is safe to assume
+    // that existingQueues contain valid dynamic queues.
+    return !isDynamicQueue(parent);
+  }
 }

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

@@ -22,6 +22,7 @@ import org.apache.hadoop.test.GenericTestUtils;
 import org.apache.hadoop.util.Time;
 import org.apache.hadoop.yarn.api.records.ApplicationAttemptId;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
+import org.apache.hadoop.yarn.api.records.QueueState;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
 import org.apache.hadoop.yarn.exceptions.YarnException;
 import org.apache.hadoop.yarn.server.resourcemanager.MockNM;
@@ -968,6 +969,66 @@ public class TestCapacitySchedulerNewQueueAutoCreation
         bAutoLeafQueue.getQueueInfo().getQueueName());
   }
 
+  @Test
+  public void testRemoveDanglingAutoCreatedQueuesOnReinit() throws Exception {
+    startScheduler();
+
+    // Validate static parent deletion
+    createQueue("root.a.a-auto");
+    AbstractCSQueue aAuto = (AbstractCSQueue) cs.
+        getQueue("root.a.a-auto");
+    Assert.assertTrue(aAuto.isDynamicQueue());
+
+    csConf.setState("root.a", QueueState.STOPPED);
+    cs.reinitialize(csConf, mockRM.getRMContext());
+    aAuto = (AbstractCSQueue) cs.
+        getQueue("root.a.a-auto");
+    Assert.assertEquals("root.a.a-auto is not in STOPPED state", QueueState.STOPPED, aAuto.getState());
+    csConf.setQueues("root", new String[]{"b"});
+    cs.reinitialize(csConf, mockRM.getRMContext());
+    CSQueue aAutoNew = cs.getQueue("root.a.a-auto");
+    Assert.assertNull(aAutoNew);
+
+    submitApp(cs, USER0, "a-auto", "root.a");
+    aAutoNew = cs.getQueue("root.a.a-auto");
+    Assert.assertNotNull(aAutoNew);
+
+    // Validate static grandparent deletion
+    csConf.setQueues("root", new String[]{"a", "b"});
+    csConf.setQueues("root.a", new String[]{"a1"});
+    csConf.setAutoQueueCreationV2Enabled("root.a.a1", true);
+    cs.reinitialize(csConf, mockRM.getRMContext());
+
+    createQueue("root.a.a1.a1-auto");
+    CSQueue a1Auto = cs.getQueue("root.a.a1.a1-auto");
+    Assert.assertNotNull("a1-auto should exist", a1Auto);
+
+    csConf.setQueues("root", new String[]{"b"});
+    cs.reinitialize(csConf, mockRM.getRMContext());
+    a1Auto = cs.getQueue("root.a.a1.a1-auto");
+    Assert.assertNull("a1-auto has no parent and should not exist", a1Auto);
+
+    // Validate dynamic parent deletion
+    csConf.setState("root.b", QueueState.STOPPED);
+    cs.reinitialize(csConf, mockRM.getRMContext());
+    csConf.setAutoQueueCreationV2Enabled("root.b", true);
+    cs.reinitialize(csConf, mockRM.getRMContext());
+
+    createQueue("root.b.b-auto-parent.b-auto-leaf");
+    CSQueue bAutoParent = cs.getQueue("root.b.b-auto-parent");
+    Assert.assertNotNull("b-auto-parent should exist", bAutoParent);
+    ParentQueue b = (ParentQueue) cs.getQueue("root.b");
+    b.removeChildQueue(bAutoParent);
+
+    cs.reinitialize(csConf, mockRM.getRMContext());
+
+    bAutoParent = cs.getQueue("root.b.b-auto-parent");
+    Assert.assertNull("b-auto-parent should not exist ", bAutoParent);
+    CSQueue bAutoLeaf = cs.getQueue("root.b.b-auto-parent.b-auto-leaf");
+    Assert.assertNull("b-auto-leaf should not exist " +
+        "when its dynamic parent is removed", bAutoLeaf);
+  }
+
   protected LeafQueue createQueue(String queuePath) throws YarnException {
     return autoQueueHandler.autoCreateQueue(
         CSQueueUtils.extractQueuePath(queuePath));