YARN-5746. The state of the parentQueue and its childQueues should be synchronized. Contributed by Xuan Gong

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

@@ -291,7 +291,8 @@ public abstract class AbstractCSQueue implements CSQueue {
 
       authorizer = YarnAuthorizationProvider.getInstance(csContext.getConf());
 
-      this.state = csContext.getConfiguration().getState(getQueuePath());
+      initializeQueueState();
+
       this.acls = csContext.getConfiguration().getAcls(getQueuePath());
 
       // Update metrics
@@ -330,6 +331,29 @@ public abstract class AbstractCSQueue implements CSQueue {
     }
   }
 
+  private void initializeQueueState() {
+    // inherit from parent if state not set, only do this when we are not root
+    if (parent != null) {
+      QueueState configuredState = csContext.getConfiguration()
+          .getConfiguredState(getQueuePath());
+      QueueState parentState = parent.getState();
+      if (configuredState == null) {
+        this.state = parentState;
+      } else if (configuredState == QueueState.RUNNING
+          && parentState == QueueState.STOPPED) {
+        throw new IllegalArgumentException(
+            "The parent queue:" + parent.getQueueName() + " state is STOPPED, "
+            + "child queue:" + queueName + " state cannot be RUNNING.");
+      } else {
+        this.state = configuredState;
+      }
+    } else {
+      // if this is the root queue, get the state from the configuration.
+      // if the state is not set, use RUNNING as default state.
+      this.state = csContext.getConfiguration().getState(getQueuePath());
+    }
+  }
+
   protected QueueInfo getQueueInfo() {
     // Deliberately doesn't use lock here, because this method will be invoked
     // from schedulerApplicationAttempt, to avoid deadlock, sacrifice

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

@@ -448,10 +448,24 @@ public class CapacitySchedulerConfiguration extends ReservationSchedulerConfigur
     setFloat(getQueuePrefix(queue) + USER_LIMIT_FACTOR, userLimitFactor); 
   }
   
-  public QueueState getState(String queue) {
+  public QueueState getConfiguredState(String queue) {
     String state = get(getQueuePrefix(queue) + STATE);
-    return (state != null) ? 
+    if (state == null) {
-        QueueState.valueOf(StringUtils.toUpperCase(state)) : QueueState.RUNNING;
+      return null;
+    } else {
+      return QueueState.valueOf(StringUtils.toUpperCase(state));
+    }
+  }
+
+  public QueueState getState(String queue) {
+    QueueState state = getConfiguredState(queue);
+    return (state == null) ? QueueState.RUNNING : state;
+  }
+
+  @Private
+  @VisibleForTesting
+  public void setState(String queue, QueueState state) {
+    set(getQueuePrefix(queue) + STATE, state.name());
   }
 
   public void setAccessibleNodeLabels(String queue, Set<String> labels) {

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

@@ -0,0 +1,96 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity;
+
+import java.io.IOException;
+import org.apache.hadoop.yarn.api.records.QueueState;
+import org.apache.hadoop.yarn.conf.YarnConfiguration;
+import org.apache.hadoop.yarn.server.resourcemanager.RMContext;
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * Test Queue States.
+ */
+public class TestQueueState {
+
+  private static final String Q1 = "q1";
+  private static final String Q2 = "q2";
+
+  private final static String Q1_PATH =
+      CapacitySchedulerConfiguration.ROOT + "." + Q1;
+  private final static String Q2_PATH =
+      Q1_PATH + "." + Q2;
+  private CapacityScheduler cs;
+  private YarnConfiguration conf;
+
+  @Test (timeout = 15000)
+  public void testQueueState() throws IOException {
+    CapacitySchedulerConfiguration csConf =
+        new CapacitySchedulerConfiguration();
+    csConf.setQueues(CapacitySchedulerConfiguration.ROOT, new String[] {Q1});
+    csConf.setQueues(Q1_PATH, new String[] {Q2});
+
+    csConf.setCapacity(Q1_PATH, 100);
+    csConf.setCapacity(Q2_PATH, 100);
+
+    conf = new YarnConfiguration(csConf);
+    cs = new CapacityScheduler();
+
+    RMContext rmContext = TestUtils.getMockRMContext();
+    cs.setConf(conf);
+    cs.setRMContext(rmContext);
+    cs.init(conf);
+
+    //by default, the state of both queues should be RUNNING
+    Assert.assertEquals(QueueState.RUNNING, cs.getQueue(Q1).getState());
+    Assert.assertEquals(QueueState.RUNNING, cs.getQueue(Q2).getState());
+
+    // Change the state of Q1 to STOPPED, and re-initiate the CS
+    csConf.setState(Q1_PATH, QueueState.STOPPED);
+    conf = new YarnConfiguration(csConf);
+    cs.reinitialize(conf, rmContext);
+    // The state of Q1 and its child: Q2 should be STOPPED
+    Assert.assertEquals(QueueState.STOPPED, cs.getQueue(Q1).getState());
+    Assert.assertEquals(QueueState.STOPPED, cs.getQueue(Q2).getState());
+
+    // Change the state of Q1 to RUNNING, and change the state of Q2 to STOPPED
+    csConf.setState(Q1_PATH, QueueState.RUNNING);
+    csConf.setState(Q2_PATH, QueueState.STOPPED);
+    conf = new YarnConfiguration(csConf);
+    // reinitialize the CS, the operation should be successful
+    cs.reinitialize(conf, rmContext);
+    Assert.assertEquals(QueueState.RUNNING, cs.getQueue(Q1).getState());
+    Assert.assertEquals(QueueState.STOPPED, cs.getQueue(Q2).getState());
+
+    // Change the state of Q1 to STOPPED, and change the state of Q2 to RUNNING
+    csConf.setState(Q1_PATH, QueueState.STOPPED);
+    csConf.setState(Q2_PATH, QueueState.RUNNING);
+    conf = new YarnConfiguration(csConf);
+    // reinitialize the CS, the operation should be failed.
+    try {
+      cs.reinitialize(conf, rmContext);
+      Assert.fail("Should throw an Exception.");
+    } catch (Exception ex) {
+      Assert.assertTrue(ex.getCause().getMessage().contains(
+          "The parent queue:q1 state is STOPPED, "
+          + "child queue:q2 state cannot be RUNNING."));
+    }
+  }
+}