YARN-5952. Create REST API for changing YARN scheduler configurations. (Jonathan Hung via wangda)

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

@@ -0,0 +1,40 @@
+/**
+ * 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;
+
+import org.apache.hadoop.security.UserGroupInformation;
+
+import java.io.IOException;
+import java.util.Map;
+
+/**
+ * Interface for a scheduler that supports changing configuration at runtime.
+ *
+ */
+public interface MutableConfScheduler extends ResourceScheduler {
+
+  /**
+   * Update the scheduler's configuration.
+   * @param user Caller of this update
+   * @param confUpdate key-value map of the configuration update
+   * @throws IOException if update is invalid
+   */
+  void updateConfiguration(UserGroupInformation user,
+      Map<String, String> confUpdate) throws IOException;
+
+}

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

@@ -18,6 +18,7 @@
 
 package org.apache.hadoop.yarn.server.resourcemanager.scheduler;
 
+import java.io.IOException;
 import java.util.Map;
 
 /**
@@ -29,7 +30,9 @@ public interface MutableConfigurationProvider {
    * Update the scheduler configuration with the provided key value pairs.
    * @param user User issuing the request
    * @param confUpdate Key-value pairs for configurations to be updated.
+   * @throws IOException if scheduler could not be reinitialized
    */
-  void mutateConfiguration(String user, Map<String, String> confUpdate);
+  void mutateConfiguration(String user, Map<String, String> confUpdate)
+      throws IOException;
 
 }

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

@@ -86,6 +86,8 @@ import org.apache.hadoop.yarn.server.resourcemanager.scheduler.AbstractYarnSched
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.Allocation;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.AppSchedulingInfo;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ContainerUpdates;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.MutableConfScheduler;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.MutableConfigurationProvider;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.NodeType;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.PreemptableResourceScheduler;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.Queue;
@@ -150,7 +152,7 @@ import com.google.common.util.concurrent.SettableFuture;
 public class CapacityScheduler extends
     AbstractYarnScheduler<FiCaSchedulerApp, FiCaSchedulerNode> implements
     PreemptableResourceScheduler, CapacitySchedulerContext, Configurable,
-    ResourceAllocationCommitter {
+    ResourceAllocationCommitter, MutableConfScheduler {
 
   private static final Log LOG = LogFactory.getLog(CapacityScheduler.class);
 
@@ -2610,4 +2612,16 @@ public class CapacityScheduler extends
     // In seconds
     return ((LeafQueue) queue).getMaximumApplicationLifetime();
   }
+
+  @Override
+  public void updateConfiguration(UserGroupInformation user,
+      Map<String, String> confUpdate) throws IOException {
+    if (csConfProvider instanceof MutableConfigurationProvider) {
+      ((MutableConfigurationProvider) csConfProvider).mutateConfiguration(
+          user.getShortUserName(), confUpdate);
+    } else {
+      throw new UnsupportedOperationException("Configured CS configuration " +
+          "provider does not support updating configuration.");
+    }
+  }
 }

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

@@ -58,7 +58,11 @@ public class InMemoryConfigurationStore implements YarnConfigurationStore {
         if (isValid) {
           Map<String, String> mutations = mutation.getUpdates();
           for (Map.Entry<String, String> kv : mutations.entrySet()) {
-            schedConf.set(kv.getKey(), kv.getValue());
+            if (kv.getValue() == null) {
+              schedConf.unset(kv.getKey());
+            } else {
+              schedConf.set(kv.getKey(), kv.getValue());
+            }
           }
         }
         return true;

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

@@ -60,34 +60,44 @@ public class MutableCSConfigurationProvider implements CSConfigurationProvider,
     }
     Configuration initialSchedConf = new Configuration(false);
     initialSchedConf.addResource(YarnConfiguration.CS_CONFIGURATION_FILE);
-    this.schedConf = initialSchedConf;
+    this.schedConf = new Configuration(false);
-    confStore.initialize(config, initialSchedConf);
+    // We need to explicitly set the key-values in schedConf, otherwise
+    // these configuration keys cannot be deleted when
+    // configuration is reloaded.
+    for (Map.Entry<String, String> kv : initialSchedConf) {
+      schedConf.set(kv.getKey(), kv.getValue());
+    }
+    confStore.initialize(config, schedConf);
     this.conf = config;
   }
 
   @Override
   public CapacitySchedulerConfiguration loadConfiguration(Configuration
       configuration) throws IOException {
-    Configuration loadedConf = new Configuration(configuration);
+    Configuration loadedConf = new Configuration(schedConf);
-    loadedConf.addResource(schedConf);
+    loadedConf.addResource(configuration);
     return new CapacitySchedulerConfiguration(loadedConf, false);
   }
 
   @Override
   public void mutateConfiguration(String user,
-      Map<String, String> confUpdate) {
+      Map<String, String> confUpdate) throws IOException {
     Configuration oldConf = new Configuration(schedConf);
     LogMutation log = new LogMutation(confUpdate, user);
     long id = confStore.logMutation(log);
     for (Map.Entry<String, String> kv : confUpdate.entrySet()) {
-      schedConf.set(kv.getKey(), kv.getValue());
+      if (kv.getValue() == null) {
+        schedConf.unset(kv.getKey());
+      } else {
+        schedConf.set(kv.getKey(), kv.getValue());
+      }
     }
     try {
       rmContext.getScheduler().reinitialize(conf, rmContext);
     } catch (IOException e) {
       schedConf = oldConf;
       confStore.confirmMutation(id, false);
-      return;
+      throw e;
     }
     confStore.confirmMutation(id, true);
   }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/RMWebServices.java

@@ -55,7 +55,8 @@ import javax.ws.rs.core.HttpHeaders;
 import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.Response;
 import javax.ws.rs.core.Response.Status;
-
+import com.google.common.base.Joiner;
+import org.apache.commons.codec.binary.Base64;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
@@ -134,11 +135,14 @@ import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMApp;
 import org.apache.hadoop.yarn.server.resourcemanager.rmapp.attempt.RMAppAttempt;
 import org.apache.hadoop.yarn.server.resourcemanager.rmnode.RMNode;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.AbstractYarnScheduler;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.MutableConfScheduler;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.activities.ActivitiesManager;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ResourceScheduler;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.YarnScheduler;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.activities.ActivitiesManager;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CSQueue;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacitySchedulerConfiguration;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.common.fica.FiCaSchedulerNode;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FairScheduler;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fifo.FifoScheduler;
@@ -2454,4 +2458,170 @@ public class RMWebServices extends WebServices implements RMWebServiceProtocol {
       GetContainersRequest request) throws YarnException, IOException {
     return rm.getClientRMService().getContainers(request).getContainerList();
   }
+
+  @PUT
+  @Path("/queues")
+  @Produces({ MediaType.APPLICATION_JSON + "; " + JettyUtils.UTF_8,
+      MediaType.APPLICATION_XML + "; " + JettyUtils.UTF_8 })
+  @Consumes({ MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML })
+  public Response updateSchedulerConfiguration(QueueConfigsUpdateInfo
+      mutationInfo, @Context HttpServletRequest hsr)
+      throws AuthorizationException, InterruptedException {
+    init();
+
+    UserGroupInformation callerUGI = getCallerUserGroupInformation(hsr, true);
+    ApplicationACLsManager aclsManager = rm.getApplicationACLsManager();
+    if (aclsManager.areACLsEnabled()) {
+      if (callerUGI == null || !aclsManager.isAdmin(callerUGI)) {
+        String msg = "Only admins can carry out this operation.";
+        throw new ForbiddenException(msg);
+      }
+    }
+
+    ResourceScheduler scheduler = rm.getResourceScheduler();
+    if (scheduler instanceof MutableConfScheduler) {
+      try {
+        callerUGI.doAs(new PrivilegedExceptionAction<Void>() {
+          @Override
+          public Void run() throws IOException, YarnException {
+            Map<String, String> confUpdate =
+                constructKeyValueConfUpdate(mutationInfo);
+            ((CapacityScheduler) scheduler).updateConfiguration(callerUGI,
+                confUpdate);
+            return null;
+          }
+        });
+      } catch (IOException e) {
+        return Response.status(Status.BAD_REQUEST).entity(e.getMessage())
+            .build();
+      }
+      return Response.status(Status.OK).entity("Configuration change " +
+          "successfully applied.").build();
+    } else {
+      return Response.status(Status.BAD_REQUEST)
+          .entity("Configuration change only supported by CapacityScheduler.")
+          .build();
+    }
+  }
+
+  private Map<String, String> constructKeyValueConfUpdate(
+      QueueConfigsUpdateInfo mutationInfo) throws IOException {
+    CapacitySchedulerConfiguration currentConf =
+        ((CapacityScheduler) rm.getResourceScheduler()).getConfiguration();
+    CapacitySchedulerConfiguration proposedConf =
+        new CapacitySchedulerConfiguration(currentConf, false);
+    Map<String, String> confUpdate = new HashMap<>();
+    for (String queueToRemove : mutationInfo.getRemoveQueueInfo()) {
+      removeQueue(queueToRemove, proposedConf, confUpdate);
+    }
+    for (QueueConfigInfo addQueueInfo : mutationInfo.getAddQueueInfo()) {
+      addQueue(addQueueInfo, proposedConf, confUpdate);
+    }
+    for (QueueConfigInfo updateQueueInfo : mutationInfo.getUpdateQueueInfo()) {
+      updateQueue(updateQueueInfo, proposedConf, confUpdate);
+    }
+    return confUpdate;
+  }
+
+  private void removeQueue(
+      String queueToRemove, CapacitySchedulerConfiguration proposedConf,
+      Map<String, String> confUpdate) throws IOException {
+    if (queueToRemove == null) {
+      return;
+    } else {
+      CapacityScheduler cs = (CapacityScheduler) rm.getResourceScheduler();
+      String queueName = queueToRemove.substring(
+          queueToRemove.lastIndexOf('.') + 1);
+      CSQueue queue = cs.getQueue(queueName);
+      if (queue == null ||
+          !queue.getQueuePath().equals(queueToRemove)) {
+        throw new IOException("Queue " + queueToRemove + " not found");
+      } else if (queueToRemove.lastIndexOf('.') == -1) {
+        throw new IOException("Can't remove queue " + queueToRemove);
+      }
+      String parentQueuePath = queueToRemove.substring(0, queueToRemove
+          .lastIndexOf('.'));
+      String[] siblingQueues = proposedConf.getQueues(parentQueuePath);
+      List<String> newSiblingQueues = new ArrayList<>();
+      for (String siblingQueue : siblingQueues) {
+        if (!siblingQueue.equals(queueName)) {
+          newSiblingQueues.add(siblingQueue);
+        }
+      }
+      proposedConf.setQueues(parentQueuePath, newSiblingQueues
+          .toArray(new String[0]));
+      String queuesConfig = CapacitySchedulerConfiguration.PREFIX +
+          parentQueuePath + CapacitySchedulerConfiguration.DOT +
+          CapacitySchedulerConfiguration.QUEUES;
+      if (newSiblingQueues.size() == 0) {
+        confUpdate.put(queuesConfig, null);
+      } else {
+        confUpdate.put(queuesConfig, Joiner.on(',').join(newSiblingQueues));
+      }
+      for (Map.Entry<String, String> confRemove : proposedConf.getValByRegex(
+          ".*" + queueToRemove.replaceAll("\\.", "\\.") + "\\..*")
+          .entrySet()) {
+        proposedConf.unset(confRemove.getKey());
+        confUpdate.put(confRemove.getKey(), null);
+      }
+    }
+  }
+
+  private void addQueue(
+      QueueConfigInfo addInfo, CapacitySchedulerConfiguration proposedConf,
+      Map<String, String> confUpdate) throws IOException {
+    if (addInfo == null) {
+      return;
+    } else {
+      CapacityScheduler cs = (CapacityScheduler) rm.getResourceScheduler();
+      String queuePath = addInfo.getQueue();
+      String queueName = queuePath.substring(queuePath.lastIndexOf('.') + 1);
+      if (cs.getQueue(queueName) != null) {
+        throw new IOException("Can't add existing queue " + queuePath);
+      } else if (queuePath.lastIndexOf('.') == -1) {
+        throw new IOException("Can't add invalid queue " + queuePath);
+      }
+      String parentQueue = queuePath.substring(0, queuePath.lastIndexOf('.'));
+      String[] siblings = proposedConf.getQueues(parentQueue);
+      List<String> siblingQueues = siblings == null ? new ArrayList<>() :
+          new ArrayList<>(Arrays.<String>asList(siblings));
+      siblingQueues.add(queuePath.substring(queuePath.lastIndexOf('.') + 1));
+      proposedConf.setQueues(parentQueue,
+          siblingQueues.toArray(new String[0]));
+      confUpdate.put(CapacitySchedulerConfiguration.PREFIX +
+          parentQueue + CapacitySchedulerConfiguration.DOT +
+          CapacitySchedulerConfiguration.QUEUES,
+          Joiner.on(',').join(siblingQueues));
+      String keyPrefix = CapacitySchedulerConfiguration.PREFIX +
+          queuePath + CapacitySchedulerConfiguration.DOT;
+      for (Map.Entry<String, String> kv : addInfo.getParams().entrySet()) {
+        if (kv.getValue() == null) {
+          proposedConf.unset(keyPrefix + kv.getKey());
+        } else {
+          proposedConf.set(keyPrefix + kv.getKey(), kv.getValue());
+        }
+        confUpdate.put(keyPrefix + kv.getKey(), kv.getValue());
+      }
+    }
+  }
+
+  private void updateQueue(QueueConfigInfo updateInfo,
+      CapacitySchedulerConfiguration proposedConf,
+      Map<String, String> confUpdate) {
+    if (updateInfo == null) {
+      return;
+    } else {
+      String queuePath = updateInfo.getQueue();
+      String keyPrefix = CapacitySchedulerConfiguration.PREFIX +
+          queuePath + CapacitySchedulerConfiguration.DOT;
+      for (Map.Entry<String, String> kv : updateInfo.getParams().entrySet()) {
+        if (kv.getValue() == null) {
+          proposedConf.unset(keyPrefix + kv.getKey());
+        } else {
+          proposedConf.set(keyPrefix + kv.getKey(), kv.getValue());
+        }
+        confUpdate.put(keyPrefix + kv.getKey(), kv.getValue());
+      }
+    }
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/dao/QueueConfigInfo.java

@@ -0,0 +1,57 @@
+/**
+ * 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.webapp.dao;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+import javax.xml.bind.annotation.XmlElement;
+import javax.xml.bind.annotation.XmlRootElement;
+
+/**
+ * Information for adding or updating a queue to scheduler configuration
+ * for this queue.
+ */
+@XmlRootElement
+@XmlAccessorType(XmlAccessType.FIELD)
+public class QueueConfigInfo {
+
+  @XmlElement(name = "queueName")
+  private String queue;
+
+  private HashMap<String, String> params = new HashMap<>();
+
+  public QueueConfigInfo() { }
+
+  public QueueConfigInfo(String queue, Map<String, String> params) {
+    this.queue = queue;
+    this.params = new HashMap<>(params);
+  }
+
+  public String getQueue() {
+    return this.queue;
+  }
+
+  public HashMap<String, String> getParams() {
+    return this.params;
+  }
+
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/dao/QueueConfigsUpdateInfo.java

@@ -0,0 +1,60 @@
+/**
+ * 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.webapp.dao;
+
+import java.util.ArrayList;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+import javax.xml.bind.annotation.XmlElement;
+import javax.xml.bind.annotation.XmlRootElement;
+
+/**
+ * Information for making scheduler configuration changes (supports adding,
+ * removing, or updating a queue).
+ */
+@XmlRootElement(name = "schedConf")
+@XmlAccessorType(XmlAccessType.FIELD)
+public class QueueConfigsUpdateInfo {
+
+  @XmlElement(name = "add")
+  private ArrayList<QueueConfigInfo> addQueueInfo = new ArrayList<>();
+
+  @XmlElement(name = "remove")
+  private ArrayList<String> removeQueueInfo = new ArrayList<>();
+
+  @XmlElement(name = "update")
+  private ArrayList<QueueConfigInfo> updateQueueInfo = new ArrayList<>();
+
+  public QueueConfigsUpdateInfo() {
+    // JAXB needs this
+  }
+
+  public ArrayList<QueueConfigInfo> getAddQueueInfo() {
+    return addQueueInfo;
+  }
+
+  public ArrayList<String> getRemoveQueueInfo() {
+    return removeQueueInfo;
+  }
+
+  public ArrayList<QueueConfigInfo> getUpdateQueueInfo() {
+    return updateQueueInfo;
+  }
+}

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

@@ -77,7 +77,11 @@ public class TestMutableCSConfigurationProvider {
     assertNull(confProvider.loadConfiguration(conf).get("badKey"));
     doThrow(new IOException()).when(cs).reinitialize(any(Configuration.class),
         any(RMContext.class));
-    confProvider.mutateConfiguration(TEST_USER, badUpdate);
+    try {
+      confProvider.mutateConfiguration(TEST_USER, badUpdate);
+    } catch (IOException e) {
+      // Expected exception.
+    }
     assertNull(confProvider.loadConfiguration(conf).get("badKey"));
   }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/TestRMWebServicesConfigurationMutation.java

@@ -0,0 +1,477 @@
+/**
+ * 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.webapp;
+
+import com.google.inject.Guice;
+import com.google.inject.servlet.ServletModule;
+import com.sun.jersey.api.client.ClientResponse;
+import com.sun.jersey.api.client.WebResource;
+import com.sun.jersey.api.json.JSONJAXBContext;
+import com.sun.jersey.api.json.JSONMarshaller;
+import com.sun.jersey.guice.spi.container.servlet.GuiceContainer;
+import com.sun.jersey.test.framework.WebAppDescriptor;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.security.UserGroupInformation;
+import org.apache.hadoop.yarn.api.records.QueueState;
+import org.apache.hadoop.yarn.conf.YarnConfiguration;
+import org.apache.hadoop.yarn.server.resourcemanager.MockRM;
+import org.apache.hadoop.yarn.server.resourcemanager.ResourceManager;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ResourceScheduler;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacitySchedulerConfiguration;
+import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.QueueConfigInfo;
+import org.apache.hadoop.yarn.server.resourcemanager.webapp.dao.QueueConfigsUpdateInfo;
+import org.apache.hadoop.yarn.webapp.GenericExceptionHandler;
+import org.apache.hadoop.yarn.webapp.GuiceServletConfig;
+import org.apache.hadoop.yarn.webapp.JerseyTestBase;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response.Status;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.StringWriter;
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+/**
+ * Test scheduler configuration mutation via REST API.
+ */
+public class TestRMWebServicesConfigurationMutation extends JerseyTestBase {
+
+  private static final File CONF_FILE = new File(new File("target",
+      "test-classes"), YarnConfiguration.CS_CONFIGURATION_FILE);
+  private static final File OLD_CONF_FILE = new File(new File("target",
+      "test-classes"), YarnConfiguration.CS_CONFIGURATION_FILE + ".tmp");
+
+  private static MockRM rm;
+  private static String userName;
+  private static CapacitySchedulerConfiguration csConf;
+  private static YarnConfiguration conf;
+
+  private static class WebServletModule extends ServletModule {
+    @Override
+    protected void configureServlets() {
+      bind(JAXBContextResolver.class);
+      bind(RMWebServices.class);
+      bind(GenericExceptionHandler.class);
+      try {
+        userName = UserGroupInformation.getCurrentUser().getShortUserName();
+      } catch (IOException ioe) {
+        throw new RuntimeException("Unable to get current user name "
+            + ioe.getMessage(), ioe);
+      }
+      csConf = new CapacitySchedulerConfiguration(new Configuration(false),
+          false);
+      setupQueueConfiguration(csConf);
+      conf = new YarnConfiguration();
+      conf.setClass(YarnConfiguration.RM_SCHEDULER, CapacityScheduler.class,
+          ResourceScheduler.class);
+      conf.set(CapacitySchedulerConfiguration.CS_CONF_PROVIDER,
+          CapacitySchedulerConfiguration.STORE_CS_CONF_PROVIDER);
+      conf.set(YarnConfiguration.YARN_ADMIN_ACL, userName);
+      try {
+        if (CONF_FILE.exists()) {
+          if (!CONF_FILE.renameTo(OLD_CONF_FILE)) {
+            throw new RuntimeException("Failed to rename conf file");
+          }
+        }
+        FileOutputStream out = new FileOutputStream(CONF_FILE);
+        csConf.writeXml(out);
+        out.close();
+      } catch (IOException e) {
+        throw new RuntimeException("Failed to write XML file", e);
+      }
+      rm = new MockRM(conf);
+      bind(ResourceManager.class).toInstance(rm);
+      serve("/*").with(GuiceContainer.class);
+      filter("/*").through(TestRMWebServicesAppsModification
+          .TestRMCustomAuthFilter.class);
+    }
+  }
+
+  @Override
+  @Before
+  public void setUp() throws Exception {
+    super.setUp();
+    GuiceServletConfig.setInjector(
+        Guice.createInjector(new WebServletModule()));
+  }
+
+  private static void setupQueueConfiguration(
+      CapacitySchedulerConfiguration config) {
+    config.setQueues(CapacitySchedulerConfiguration.ROOT,
+        new String[]{"a", "b", "c"});
+
+    final String a = CapacitySchedulerConfiguration.ROOT + ".a";
+    config.setCapacity(a, 25f);
+    config.setMaximumCapacity(a, 50f);
+
+    final String a1 = a + ".a1";
+    final String a2 = a + ".a2";
+    config.setQueues(a, new String[]{"a1", "a2"});
+    config.setCapacity(a1, 100f);
+    config.setCapacity(a2, 0f);
+
+    final String b = CapacitySchedulerConfiguration.ROOT + ".b";
+    config.setCapacity(b, 75f);
+
+    final String c = CapacitySchedulerConfiguration.ROOT + ".c";
+    config.setCapacity(c, 0f);
+
+    final String c1 = c + ".c1";
+    config.setQueues(c, new String[] {"c1"});
+    config.setCapacity(c1, 0f);
+  }
+
+  public TestRMWebServicesConfigurationMutation() {
+    super(new WebAppDescriptor.Builder(
+        "org.apache.hadoop.yarn.server.resourcemanager.webapp")
+        .contextListenerClass(GuiceServletConfig.class)
+        .filterClass(com.google.inject.servlet.GuiceFilter.class)
+        .contextPath("jersey-guice-filter").servletPath("/").build());
+  }
+
+  @Test
+  public void testAddNestedQueue() throws Exception {
+    WebResource r = resource();
+
+    ClientResponse response;
+
+    // Add parent queue root.d with two children d1 and d2.
+    QueueConfigsUpdateInfo updateInfo = new QueueConfigsUpdateInfo();
+    Map<String, String> d1Capacity = new HashMap<>();
+    d1Capacity.put(CapacitySchedulerConfiguration.CAPACITY, "25");
+    d1Capacity.put(CapacitySchedulerConfiguration.MAXIMUM_CAPACITY, "25");
+    Map<String, String> nearEmptyCapacity = new HashMap<>();
+    nearEmptyCapacity.put(CapacitySchedulerConfiguration.CAPACITY, "1E-4");
+    nearEmptyCapacity.put(CapacitySchedulerConfiguration.MAXIMUM_CAPACITY,
+        "1E-4");
+    Map<String, String> d2Capacity = new HashMap<>();
+    d2Capacity.put(CapacitySchedulerConfiguration.CAPACITY, "75");
+    d2Capacity.put(CapacitySchedulerConfiguration.MAXIMUM_CAPACITY, "75");
+    QueueConfigInfo d1 = new QueueConfigInfo("root.d.d1", d1Capacity);
+    QueueConfigInfo d2 = new QueueConfigInfo("root.d.d2", d2Capacity);
+    QueueConfigInfo d = new QueueConfigInfo("root.d", nearEmptyCapacity);
+    updateInfo.getAddQueueInfo().add(d1);
+    updateInfo.getAddQueueInfo().add(d2);
+    updateInfo.getAddQueueInfo().add(d);
+    response =
+        r.path("ws").path("v1").path("cluster")
+            .path("queues").queryParam("user.name", userName)
+            .accept(MediaType.APPLICATION_JSON)
+            .entity(toJson(updateInfo, QueueConfigsUpdateInfo.class),
+                MediaType.APPLICATION_JSON)
+            .put(ClientResponse.class);
+
+    assertEquals(Status.OK.getStatusCode(), response.getStatus());
+    CapacitySchedulerConfiguration newCSConf =
+        ((CapacityScheduler) rm.getResourceScheduler()).getConfiguration();
+    assertEquals(4, newCSConf.getQueues("root").length);
+    assertEquals(2, newCSConf.getQueues("root.d").length);
+    assertEquals(25.0f, newCSConf.getNonLabeledQueueCapacity("root.d.d1"),
+        0.01f);
+    assertEquals(75.0f, newCSConf.getNonLabeledQueueCapacity("root.d.d2"),
+        0.01f);
+  }
+
+  @Test
+  public void testAddWithUpdate() throws Exception {
+    WebResource r = resource();
+
+    ClientResponse response;
+
+    // Add root.d with capacity 25, reducing root.b capacity from 75 to 50.
+    QueueConfigsUpdateInfo updateInfo = new QueueConfigsUpdateInfo();
+    Map<String, String> dCapacity = new HashMap<>();
+    dCapacity.put(CapacitySchedulerConfiguration.CAPACITY, "25");
+    Map<String, String> bCapacity = new HashMap<>();
+    bCapacity.put(CapacitySchedulerConfiguration.CAPACITY, "50");
+    QueueConfigInfo d = new QueueConfigInfo("root.d", dCapacity);
+    QueueConfigInfo b = new QueueConfigInfo("root.b", bCapacity);
+    updateInfo.getAddQueueInfo().add(d);
+    updateInfo.getUpdateQueueInfo().add(b);
+    response =
+        r.path("ws").path("v1").path("cluster")
+            .path("queues").queryParam("user.name", userName)
+            .accept(MediaType.APPLICATION_JSON)
+            .entity(toJson(updateInfo, QueueConfigsUpdateInfo.class),
+                MediaType.APPLICATION_JSON)
+            .put(ClientResponse.class);
+
+    assertEquals(Status.OK.getStatusCode(), response.getStatus());
+    CapacitySchedulerConfiguration newCSConf =
+        ((CapacityScheduler) rm.getResourceScheduler()).getConfiguration();
+    assertEquals(4, newCSConf.getQueues("root").length);
+    assertEquals(25.0f, newCSConf.getNonLabeledQueueCapacity("root.d"), 0.01f);
+    assertEquals(50.0f, newCSConf.getNonLabeledQueueCapacity("root.b"), 0.01f);
+  }
+
+  @Test
+  public void testRemoveQueue() throws Exception {
+    WebResource r = resource();
+
+    ClientResponse response;
+
+    stopQueue("root.a.a2");
+    // Remove root.a.a2
+    QueueConfigsUpdateInfo updateInfo = new QueueConfigsUpdateInfo();
+    updateInfo.getRemoveQueueInfo().add("root.a.a2");
+    response =
+        r.path("ws").path("v1").path("cluster")
+            .path("queues").queryParam("user.name", userName)
+            .accept(MediaType.APPLICATION_JSON)
+            .entity(toJson(updateInfo, QueueConfigsUpdateInfo.class),
+                MediaType.APPLICATION_JSON)
+            .put(ClientResponse.class);
+
+    assertEquals(Status.OK.getStatusCode(), response.getStatus());
+    CapacitySchedulerConfiguration newCSConf =
+        ((CapacityScheduler) rm.getResourceScheduler()).getConfiguration();
+    assertEquals(1, newCSConf.getQueues("root.a").length);
+    assertEquals("a1", newCSConf.getQueues("root.a")[0]);
+  }
+
+  @Test
+  public void testRemoveParentQueue() throws Exception {
+    WebResource r = resource();
+
+    ClientResponse response;
+
+    stopQueue("root.c", "root.c.c1");
+    // Remove root.c (parent queue)
+    QueueConfigsUpdateInfo updateInfo = new QueueConfigsUpdateInfo();
+    updateInfo.getRemoveQueueInfo().add("root.c");
+    response =
+        r.path("ws").path("v1").path("cluster")
+            .path("queues").queryParam("user.name", userName)
+            .accept(MediaType.APPLICATION_JSON)
+            .entity(toJson(updateInfo, QueueConfigsUpdateInfo.class),
+                MediaType.APPLICATION_JSON)
+            .put(ClientResponse.class);
+
+    assertEquals(Status.OK.getStatusCode(), response.getStatus());
+    CapacitySchedulerConfiguration newCSConf =
+        ((CapacityScheduler) rm.getResourceScheduler()).getConfiguration();
+    assertEquals(2, newCSConf.getQueues("root").length);
+    assertNull(newCSConf.getQueues("root.c"));
+  }
+
+  @Test
+  public void testRemoveParentQueueWithCapacity() throws Exception {
+    WebResource r = resource();
+
+    ClientResponse response;
+
+    stopQueue("root.a", "root.a.a1", "root.a.a2");
+    // Remove root.a (parent queue) with capacity 25
+    QueueConfigsUpdateInfo updateInfo = new QueueConfigsUpdateInfo();
+    updateInfo.getRemoveQueueInfo().add("root.a");
+
+    // Set root.b capacity to 100
+    Map<String, String> bCapacity = new HashMap<>();
+    bCapacity.put(CapacitySchedulerConfiguration.CAPACITY, "100");
+    QueueConfigInfo b = new QueueConfigInfo("root.b", bCapacity);
+    updateInfo.getUpdateQueueInfo().add(b);
+    response =
+        r.path("ws").path("v1").path("cluster")
+            .path("queues").queryParam("user.name", userName)
+            .accept(MediaType.APPLICATION_JSON)
+            .entity(toJson(updateInfo, QueueConfigsUpdateInfo.class),
+                MediaType.APPLICATION_JSON)
+            .put(ClientResponse.class);
+
+    assertEquals(Status.OK.getStatusCode(), response.getStatus());
+    CapacitySchedulerConfiguration newCSConf =
+        ((CapacityScheduler) rm.getResourceScheduler()).getConfiguration();
+    assertEquals(2, newCSConf.getQueues("root").length);
+    assertEquals(100.0f, newCSConf.getNonLabeledQueueCapacity("root.b"),
+        0.01f);
+  }
+
+  @Test
+  public void testRemoveMultipleQueues() throws Exception {
+    WebResource r = resource();
+
+    ClientResponse response;
+
+    stopQueue("root.b", "root.c", "root.c.c1");
+    // Remove root.b and root.c
+    QueueConfigsUpdateInfo updateInfo = new QueueConfigsUpdateInfo();
+    updateInfo.getRemoveQueueInfo().add("root.b");
+    updateInfo.getRemoveQueueInfo().add("root.c");
+    Map<String, String> aCapacity = new HashMap<>();
+    aCapacity.put(CapacitySchedulerConfiguration.CAPACITY, "100");
+    aCapacity.put(CapacitySchedulerConfiguration.MAXIMUM_CAPACITY, "100");
+    QueueConfigInfo configInfo = new QueueConfigInfo("root.a", aCapacity);
+    updateInfo.getUpdateQueueInfo().add(configInfo);
+    response =
+        r.path("ws").path("v1").path("cluster")
+            .path("queues").queryParam("user.name", userName)
+            .accept(MediaType.APPLICATION_JSON)
+            .entity(toJson(updateInfo, QueueConfigsUpdateInfo.class),
+                MediaType.APPLICATION_JSON)
+            .put(ClientResponse.class);
+
+    assertEquals(Status.OK.getStatusCode(), response.getStatus());
+    CapacitySchedulerConfiguration newCSConf =
+        ((CapacityScheduler) rm.getResourceScheduler()).getConfiguration();
+    assertEquals(1, newCSConf.getQueues("root").length);
+  }
+
+  private void stopQueue(String... queuePaths) throws Exception {
+    WebResource r = resource();
+
+    ClientResponse response;
+
+    // Set state of queues to STOPPED.
+    QueueConfigsUpdateInfo updateInfo = new QueueConfigsUpdateInfo();
+    Map<String, String> stoppedParam = new HashMap<>();
+    stoppedParam.put(CapacitySchedulerConfiguration.STATE,
+        QueueState.STOPPED.toString());
+    for (String queue : queuePaths) {
+      QueueConfigInfo stoppedInfo = new QueueConfigInfo(queue, stoppedParam);
+      updateInfo.getUpdateQueueInfo().add(stoppedInfo);
+    }
+    response =
+        r.path("ws").path("v1").path("cluster")
+            .path("queues").queryParam("user.name", userName)
+            .accept(MediaType.APPLICATION_JSON)
+            .entity(toJson(updateInfo, QueueConfigsUpdateInfo.class),
+                MediaType.APPLICATION_JSON)
+            .put(ClientResponse.class);
+    assertEquals(Status.OK.getStatusCode(), response.getStatus());
+    CapacitySchedulerConfiguration newCSConf =
+        ((CapacityScheduler) rm.getResourceScheduler()).getConfiguration();
+    for (String queue : queuePaths) {
+      assertEquals(QueueState.STOPPED, newCSConf.getState(queue));
+    }
+  }
+
+  @Test
+  public void testUpdateQueue() throws Exception {
+    WebResource r = resource();
+
+    ClientResponse response;
+
+    // Update config value.
+    QueueConfigsUpdateInfo updateInfo = new QueueConfigsUpdateInfo();
+    Map<String, String> updateParam = new HashMap<>();
+    updateParam.put(CapacitySchedulerConfiguration.MAXIMUM_AM_RESOURCE_SUFFIX,
+        "0.2");
+    QueueConfigInfo aUpdateInfo = new QueueConfigInfo("root.a", updateParam);
+    updateInfo.getUpdateQueueInfo().add(aUpdateInfo);
+    CapacityScheduler cs = (CapacityScheduler) rm.getResourceScheduler();
+
+    assertEquals(CapacitySchedulerConfiguration
+            .DEFAULT_MAXIMUM_APPLICATIONMASTERS_RESOURCE_PERCENT,
+        cs.getConfiguration()
+            .getMaximumApplicationMasterResourcePerQueuePercent("root.a"),
+        0.001f);
+    response =
+        r.path("ws").path("v1").path("cluster")
+            .path("queues").queryParam("user.name", userName)
+            .accept(MediaType.APPLICATION_JSON)
+            .entity(toJson(updateInfo, QueueConfigsUpdateInfo.class),
+                MediaType.APPLICATION_JSON)
+            .put(ClientResponse.class);
+    assertEquals(Status.OK.getStatusCode(), response.getStatus());
+    CapacitySchedulerConfiguration newCSConf = cs.getConfiguration();
+    assertEquals(0.2f, newCSConf
+        .getMaximumApplicationMasterResourcePerQueuePercent("root.a"), 0.001f);
+
+    // Remove config. Config value should be reverted to default.
+    updateParam.put(CapacitySchedulerConfiguration.MAXIMUM_AM_RESOURCE_SUFFIX,
+        null);
+    aUpdateInfo = new QueueConfigInfo("root.a", updateParam);
+    updateInfo.getUpdateQueueInfo().clear();
+    updateInfo.getUpdateQueueInfo().add(aUpdateInfo);
+    response =
+        r.path("ws").path("v1").path("cluster")
+            .path("queues").queryParam("user.name", userName)
+            .accept(MediaType.APPLICATION_JSON)
+            .entity(toJson(updateInfo, QueueConfigsUpdateInfo.class),
+                MediaType.APPLICATION_JSON)
+            .put(ClientResponse.class);
+    assertEquals(Status.OK.getStatusCode(), response.getStatus());
+    newCSConf = cs.getConfiguration();
+    assertEquals(CapacitySchedulerConfiguration
+        .DEFAULT_MAXIMUM_APPLICATIONMASTERS_RESOURCE_PERCENT, newCSConf
+            .getMaximumApplicationMasterResourcePerQueuePercent("root.a"),
+        0.001f);
+  }
+
+  @Test
+  public void testUpdateQueueCapacity() throws Exception {
+    WebResource r = resource();
+
+    ClientResponse response;
+
+    // Update root.a and root.b capacity to 50.
+    QueueConfigsUpdateInfo updateInfo = new QueueConfigsUpdateInfo();
+    Map<String, String> updateParam = new HashMap<>();
+    updateParam.put(CapacitySchedulerConfiguration.CAPACITY, "50");
+    QueueConfigInfo aUpdateInfo = new QueueConfigInfo("root.a", updateParam);
+    QueueConfigInfo bUpdateInfo = new QueueConfigInfo("root.b", updateParam);
+    updateInfo.getUpdateQueueInfo().add(aUpdateInfo);
+    updateInfo.getUpdateQueueInfo().add(bUpdateInfo);
+
+    response =
+        r.path("ws").path("v1").path("cluster")
+            .path("queues").queryParam("user.name", userName)
+            .accept(MediaType.APPLICATION_JSON)
+            .entity(toJson(updateInfo, QueueConfigsUpdateInfo.class),
+                MediaType.APPLICATION_JSON)
+            .put(ClientResponse.class);
+    assertEquals(Status.OK.getStatusCode(), response.getStatus());
+    CapacitySchedulerConfiguration newCSConf =
+        ((CapacityScheduler) rm.getResourceScheduler()).getConfiguration();
+    assertEquals(50.0f, newCSConf.getNonLabeledQueueCapacity("root.a"), 0.01f);
+    assertEquals(50.0f, newCSConf.getNonLabeledQueueCapacity("root.b"), 0.01f);
+  }
+
+  @Override
+  @After
+  public void tearDown() throws Exception {
+    if (rm != null) {
+      rm.stop();
+    }
+    CONF_FILE.delete();
+    if (!OLD_CONF_FILE.renameTo(CONF_FILE)) {
+      throw new RuntimeException("Failed to re-copy old configuration file");
+    }
+    super.tearDown();
+  }
+
+  @SuppressWarnings("rawtypes")
+  private String toJson(Object nsli, Class klass) throws Exception {
+    StringWriter sw = new StringWriter();
+    JSONJAXBContext ctx = new JSONJAXBContext(klass);
+    JSONMarshaller jm = ctx.createJSONMarshaller();
+    jm.marshallToJSON(nsli, sw);
+    return sw.toString();
+  }
+}