YARN-9298. Implement FS placement rules using PlacementRule interface. Contributed by Wilfred Spiegelenburg.

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/placement/DefaultPlacementRule.java

@@ -0,0 +1,113 @@
+/**
+ * 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.placement;
+
+import com.google.common.annotations.VisibleForTesting;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.yarn.api.records.ApplicationSubmissionContext;
+import org.apache.hadoop.yarn.conf.YarnConfiguration;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ResourceScheduler;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FairScheduler;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.w3c.dom.Element;
+
+import java.io.IOException;
+
+import static org.apache.hadoop.yarn.server.resourcemanager.placement.FairQueuePlacementUtils.assureRoot;
+import static org.apache.hadoop.yarn.server.resourcemanager.placement.FairQueuePlacementUtils.isValidQueueName;
+
+/**
+ * Places apps in the specified default queue. If no default queue is
+ * specified the app is placed in root.default queue.
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
+public class DefaultPlacementRule extends FSPlacementRule {
+  private static final Logger LOG =
+      LoggerFactory.getLogger(DefaultPlacementRule.class);
+
+  @VisibleForTesting
+  public String defaultQueueName;
+
+  /**
+   * Set the rule config from the xml config.
+   * @param conf An xml element from the {@link FairScheduler#conf}
+   */
+  @Override
+  public void setConfig(Element conf) {
+    // Get the flag from the config (defaults to true if not set)
+    createQueue = getCreateFlag(conf);
+    // No config can be set when no policy is defined and we use defaults
+    if (conf != null) {
+      defaultQueueName = conf.getAttribute("queue");
+      // A queue read from the config could be illegal check it: fall back to
+      // the config default if it is the case
+      // However we cannot clean the name as a nested name is allowed.
+      if (!isValidQueueName(defaultQueueName)) {
+        LOG.error("Default rule configured with an illegal queue name: '{}'",
+            defaultQueueName);
+        defaultQueueName = null;
+      }
+    }
+    // The queue name does not have to be set and we really use "default"
+    if (defaultQueueName == null || defaultQueueName.isEmpty()) {
+      defaultQueueName = assureRoot(YarnConfiguration.DEFAULT_QUEUE_NAME);
+    } else {
+      defaultQueueName = assureRoot(defaultQueueName);
+    }
+    LOG.debug("Default rule instantiated with queue name: {}, " +
+        "and create flag: {}", defaultQueueName, createQueue);
+  }
+
+  /**
+   * Set the rule config just setting the create flag.
+   * @param create flag to allow queue creation for this rule
+   */
+  @Override
+  public void setConfig(Boolean create) {
+    createQueue = create;
+    // No config so fall back to the real default.
+    defaultQueueName = assureRoot(YarnConfiguration.DEFAULT_QUEUE_NAME);
+    LOG.debug("Default rule instantiated with default queue name: {}, " +
+        "and create flag: {}", defaultQueueName, createQueue);
+  }
+
+  @Override
+  public boolean initialize(ResourceScheduler scheduler) throws IOException {
+    super.initialize(scheduler);
+    if (getParentRule() != null) {
+      throw new IOException(
+          "Parent rule must not be configured for Default rule.");
+    }
+    return true;
+  }
+
+  @Override
+  public ApplicationPlacementContext getPlacementForApp(
+      ApplicationSubmissionContext asc, String user) {
+
+    // If we can create the queue in the rule or the queue exists return it
+    if (createQueue || configuredQueue(defaultQueueName)) {
+      return new ApplicationPlacementContext(defaultQueueName);
+    }
+    return null;
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/placement/FSPlacementRule.java

@@ -0,0 +1,166 @@
+/**
+ * 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.placement;
+
+import com.google.common.annotations.VisibleForTesting;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ResourceScheduler;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FSQueue;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FairScheduler;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.QueueManager;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.w3c.dom.Element;
+
+import java.io.IOException;
+
+/**
+ * Abstract base for all {@link FairScheduler} Placement Rules.
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
+public abstract class FSPlacementRule extends PlacementRule {
+  private static final Logger LOG =
+      LoggerFactory.getLogger(FSPlacementRule.class);
+
+  // Flag to show if the rule can create a queue
+  @VisibleForTesting
+  protected boolean createQueue = true;
+  private QueueManager queueManager;
+  private PlacementRule parentRule;
+
+  /**
+   * Get the {@link QueueManager} loaded from the scheduler when the rule is
+   * initialised. All rules are initialised before the can be called to place
+   * an application.
+   * @return The queue manager from the scheduler, this can never be
+   * <code>null</code> for an initialised rule.
+   */
+  QueueManager getQueueManager() {
+    return queueManager;
+  }
+
+  /**
+   * Set a rule to generate the parent queue dynamically.
+   * @param parent A PlacementRule
+   */
+  void setParentRule(PlacementRule parent) {
+    this.parentRule = parent;
+  }
+
+  /**
+   * Get the rule that is set to generate the parent queue dynamically.
+   * @return The rule set or <code>null</code> if not set.
+   */
+  PlacementRule getParentRule() {
+    return parentRule;
+  }
+
+  /**
+   * Set the config based on the type of object passed in.
+   * @param initArg the config to be set
+   */
+  @Override
+  public void setConfig(Object initArg) {
+    if (null == initArg) {
+      LOG.debug("Null object passed in: no config set");
+      return;
+    }
+    if (initArg instanceof Element) {
+      LOG.debug("Setting config from XML");
+      setConfig((Element) initArg);
+    } else if (initArg instanceof Boolean) {
+      LOG.debug("Setting config from Boolean");
+      setConfig((Boolean) initArg);
+    } else {
+      LOG.info("Unknown object type passed in as config for rule {}: {}",
+          getName(), initArg.getClass());
+    }
+  }
+
+  /**
+   * Set the rule config from the xml config.
+   * @param conf An xml element from the {@link FairScheduler#conf}
+   */
+  protected void setConfig(Element conf) {
+    // Get the flag from the config (defaults to true if not set)
+    createQueue = getCreateFlag(conf);
+  }
+
+  /**
+   * Set the rule config just setting the create flag.
+   * @param create flag to allow queue creation for this rule
+   */
+  protected void setConfig(Boolean create) {
+    createQueue = create;
+  }
+
+  /**
+   * Standard initialisation for {@link FairScheduler} rules, shared by all
+   * rules. Each rule that extends this abstract and overrides this method must
+   * call <code>super.initialize()</code> to run this basic initialisation.
+   * @param scheduler the scheduler using the rule
+   * @return <code>true</code> in all cases
+   * @throws IOException for any errors
+   */
+  @Override
+  public boolean initialize(ResourceScheduler scheduler) throws IOException {
+    if (!(scheduler instanceof FairScheduler)) {
+      throw new IOException(getName() +
+          " rule can only be configured for the FairScheduler");
+    }
+    if (getParentRule() != null &&
+        getParentRule().getName().equals(getName())) {
+      throw new IOException("Parent rule may not be the same type as the " +
+          "child rule: " + getName());
+    }
+
+    FairScheduler fs = (FairScheduler) scheduler;
+    queueManager = fs.getQueueManager();
+
+    return true;
+  }
+
+  /**
+   * Check if the queue exists and is part of the configuration i.e. not
+   * a {@link FSQueue#isDynamic()} queue.
+   * @param queueName name of the queue to check
+   * @return <code>true</code> if the queue exists and is a "configured" queue
+   */
+  boolean configuredQueue(String queueName) {
+    FSQueue queue = queueManager.getQueue(queueName);
+    return (queue != null && !queue.isDynamic());
+  }
+
+  /**
+   * Get the create flag from the xml configuration element.
+   * @param conf The FS configuration element for the queue
+   * @return <code>false</code> only if the flag is set in the configuration to
+   * a text that is not case ignored "true", <code>true</code> in all other
+   * cases
+   */
+  boolean getCreateFlag(Element conf) {
+    if (conf != null) {
+      String create = conf.getAttribute("create");
+      return Boolean.parseBoolean(create);
+    }
+    return true;
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/placement/FairQueuePlacementUtils.java

@@ -0,0 +1,100 @@
+/**
+ * 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.placement;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FairSchedulerUtilities;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Utility methods used by Fair scheduler placement rules.
+ * {@link
+ * org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FairScheduler}
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
+public final class FairQueuePlacementUtils {
+  private static final Logger LOG =
+      LoggerFactory.getLogger(FairQueuePlacementUtils.class);
+
+  // Constants for name clean up and hierarchy checks
+  protected static final String DOT = ".";
+  protected static final String DOT_REPLACEMENT = "_dot_";
+  protected static final String ROOT_QUEUE = "root";
+
+  private FairQueuePlacementUtils() {
+  }
+
+  /**
+   * Replace the periods in the username or group name with "_dot_" and
+   * remove trailing and leading whitespace.
+   *
+   * @param name The name to clean
+   * @return The name with {@link #DOT} replaced with {@link #DOT_REPLACEMENT}
+   */
+  protected static String cleanName(String name) {
+    name = FairSchedulerUtilities.trimQueueName(name);
+    if (name.contains(DOT)) {
+      String converted = name.replaceAll("\\.", DOT_REPLACEMENT);
+      LOG.warn("Name {} is converted to {} when it is used as a queue name.",
+          name, converted);
+      return converted;
+    } else {
+      return name;
+    }
+  }
+
+  /**
+   * Assure root prefix for a queue name.
+   *
+   * @param queueName The queue name to check for the root prefix
+   * @return The root prefixed queue name
+   */
+  protected static String assureRoot(String queueName) {
+    if (queueName != null && !queueName.isEmpty()) {
+      if (!queueName.startsWith(ROOT_QUEUE + DOT) &&
+          !queueName.equals(ROOT_QUEUE)) {
+        queueName = ROOT_QUEUE + DOT + queueName;
+      }
+    } else {
+      LOG.warn("AssureRoot: queueName is empty or null.");
+    }
+    return queueName;
+  }
+
+  /**
+   * Validate the queue name: it may not start or end with a {@link #DOT}.
+   *
+   * @param queueName The queue name to validate
+   * @return <code>false</code> if the queue name starts or ends with a
+   * {@link #DOT}, <code>true</code>
+   */
+  protected static boolean isValidQueueName(String queueName) {
+    if (queueName != null) {
+      if (queueName.equals(FairSchedulerUtilities.trimQueueName(queueName)) &&
+          !queueName.startsWith(DOT) &&
+          !queueName.endsWith(DOT)) {
+        return true;
+      }
+    }
+    return false;
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/placement/PlacementFactory.java

@@ -20,12 +20,16 @@
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.util.ReflectionUtils;
 
 /**
  * Factory class for creating instances of {@link PlacementRule}.
  */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
 public final class PlacementFactory {
 
   private static final Logger LOG =
@@ -35,6 +39,14 @@ private PlacementFactory() {
     // Unused.
   }
 
+  /**
+   * Create a new {@link PlacementRule} based on the rule class from the
+   * configuration. This is used to instantiate rules by the scheduler which
+   * does not resolve the class before this call.
+   * @param ruleStr The name of the class to instantiate
+   * @param conf The configuration object to set for the rule
+   * @return Created class instance
+   */
   public static PlacementRule getPlacementRule(String ruleStr,
       Configuration conf)
       throws ClassNotFoundException {
@@ -43,4 +55,20 @@ public static PlacementRule getPlacementRule(String ruleStr,
     LOG.info("Using PlacementRule implementation - " + ruleClass);
     return ReflectionUtils.newInstance(ruleClass, conf);
   }
+
+  /**
+   * Create a new {@link PlacementRule} based on the rule class from the
+   * configuration. This is used to instantiate rules by the scheduler which
+   * resolve the class before this call.
+   * @param ruleClass The specific class reference to instantiate
+   * @param initArg The config to set
+   * @return Created class instance
+   */
+  public static PlacementRule getPlacementRule(
+      Class<? extends PlacementRule> ruleClass, Object initArg) {
+    LOG.info("Creating PlacementRule implementation: " + ruleClass);
+    PlacementRule rule = ReflectionUtils.newInstance(ruleClass, null);
+    rule.setConfig(initArg);
+    return rule;
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/placement/PlacementRule.java

@@ -20,35 +20,62 @@
 
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.yarn.api.records.ApplicationSubmissionContext;
 import org.apache.hadoop.yarn.exceptions.YarnException;
 import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ResourceScheduler;
 
+/**
+ * Abstract base for all Placement Rules.
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
 public abstract class PlacementRule {
 
+  /**
+   * Set the config based on the passed in argument. This construct is used to
+   * not pollute this abstract class with implementation specific references.
+   */
+  public void setConfig(Object initArg) {
+    // Default is a noop
+  }
+
+  /**
+   * Return the name of the rule.
+   * @return The name of the rule, the fully qualified class name.
+   */
   public String getName() {
     return this.getClass().getName();
   }
 
-  public abstract boolean initialize(
-      ResourceScheduler scheduler) throws IOException;
+  /**
+   * Initialize the rule with the scheduler.
+   * @param scheduler the scheduler using the rule
+   * @return <code>true</code> or <code>false</code> The outcome of the
+   * initialisation, rule dependent response which might not be persisted in
+   * the rule.
+   * @throws IOException for any errors
+   */
+  public abstract boolean initialize(ResourceScheduler scheduler)
+      throws IOException;
 
   /**
-   * Get queue for a given application
+   * Return the scheduler queue name the application should be placed in
+   * wrapped in an {@link ApplicationPlacementContext} object.
    *
-   * @param asc application submission context
-   * @param user userName
+   * A non <code>null</code> return value places the application in a queue,
+   * a <code>null</code> value means the queue is not yet determined. The
+   * next {@link PlacementRule} in the list maintained in the
+   * {@link PlacementManager} will be executed.
    *
-   * @throws YarnException
-   *           if any error happens
+   * @param asc The context of the application created on submission
+   * @param user The name of the user submitting the application
    * 
-   * @return <p>
-   *         non-null value means it is determined
-   *         </p>
-   *         <p>
-   *         null value means it is undetermined, so next {@link PlacementRule}
-   *         in the {@link PlacementManager} will take care
-   *         </p>
+   * @throws YarnException for any error while executing the rule
+   * 
+   * @return The queue name wrapped in {@link ApplicationPlacementContext} or
+   * <code>null</code> if no queue was resolved
    */
   public abstract ApplicationPlacementContext getPlacementForApp(
       ApplicationSubmissionContext asc, String user) throws YarnException;

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/placement/PrimaryGroupPlacementRule.java

@@ -0,0 +1,103 @@
+/**
+ * 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.placement;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.security.Groups;
+import org.apache.hadoop.yarn.api.records.ApplicationSubmissionContext;
+import org.apache.hadoop.yarn.exceptions.YarnException;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ResourceScheduler;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FSLeafQueue;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FairScheduler;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.util.List;
+
+import static org.apache.hadoop.yarn.server.resourcemanager.placement.FairQueuePlacementUtils.DOT;
+import static org.apache.hadoop.yarn.server.resourcemanager.placement.FairQueuePlacementUtils.assureRoot;
+import static org.apache.hadoop.yarn.server.resourcemanager.placement.FairQueuePlacementUtils.cleanName;
+
+/**
+ * Places apps in queues by the primary group of the submitter.
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
+public class PrimaryGroupPlacementRule extends FSPlacementRule {
+  private static final Logger LOG =
+      LoggerFactory.getLogger(PrimaryGroupPlacementRule.class);
+
+  private Groups groupProvider;
+
+  @Override
+  public boolean initialize(ResourceScheduler scheduler) throws IOException {
+    super.initialize(scheduler);
+    groupProvider = new Groups(((FairScheduler)scheduler).getConfig());
+
+    return true;
+  }
+
+  @Override
+  public ApplicationPlacementContext getPlacementForApp(
+      ApplicationSubmissionContext asc, String user) throws YarnException {
+
+    // All users should have at least one group the primary group. If no groups
+    // are returned then there is a real issue.
+    final List<String> groupList;
+    try {
+      groupList = groupProvider.getGroups(user);
+    } catch (IOException ioe) {
+      throw new YarnException("Group resolution failed", ioe);
+    }
+    if (groupList.isEmpty()) {
+      LOG.error("Group placement rule failed: No groups returned for user {}",
+          user);
+      throw new YarnException("No groups returned for user " + user);
+    }
+
+    String cleanGroup = cleanName(groupList.get(0));
+    String queueName;
+    PlacementRule parentRule = getParentRule();
+
+    if (getParentRule() != null) {
+      LOG.debug("PrimaryGroup rule: parent rule found: {}",
+          parentRule.getName());
+      ApplicationPlacementContext parent =
+          parentRule.getPlacementForApp(asc, user);
+      if (parent == null || getQueueManager().
+          getQueue(parent.getQueue()) instanceof FSLeafQueue) {
+        LOG.debug("PrimaryGroup rule: parent rule failed");
+        return null;
+      }
+      LOG.debug("PrimaryGroup rule: parent rule result: {}",
+          parent.getQueue());
+      queueName = parent.getQueue() + DOT + cleanGroup;
+    } else {
+      queueName = assureRoot(cleanGroup);
+    }
+
+    // If we can create the queue in the rule or the queue exists return it
+    if (createQueue || configuredQueue(queueName)) {
+      return new ApplicationPlacementContext(queueName);
+    }
+    return null;
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/placement/RejectPlacementRule.java

@@ -0,0 +1,65 @@
+/**
+ * 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.placement;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.yarn.api.records.ApplicationSubmissionContext;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ResourceScheduler;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+
+/**
+ * Rejects all placements.
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
+public class RejectPlacementRule extends FSPlacementRule {
+  private static final Logger LOG =
+      LoggerFactory.getLogger(RejectPlacementRule.class);
+
+  /**
+   * The Reject rule does not use any configuration. Override and ignore all
+   * configuration.
+   * @param initArg the config to be set
+   */
+  @Override
+  public void setConfig(Object initArg) {
+    // This rule ignores all config, just log and return
+    LOG.debug("RejectPlacementRule instantiated");
+  }
+
+  @Override
+  public boolean initialize(ResourceScheduler scheduler) throws IOException {
+    super.initialize(scheduler);
+    if (getParentRule() != null) {
+      throw new IOException(
+          "Parent rule should not be configured for Reject rule.");
+    }
+    return true;
+  }
+
+  @Override
+  public ApplicationPlacementContext getPlacementForApp(
+      ApplicationSubmissionContext asc, String user) {
+    return null;
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/placement/SecondaryGroupExistingPlacementRule.java

@@ -0,0 +1,102 @@
+/**
+ * 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.placement;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.security.Groups;
+import org.apache.hadoop.yarn.api.records.ApplicationSubmissionContext;
+import org.apache.hadoop.yarn.exceptions.YarnException;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ResourceScheduler;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FSLeafQueue;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FairScheduler;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.util.List;
+
+import static org.apache.hadoop.yarn.server.resourcemanager.placement.FairQueuePlacementUtils.DOT;
+import static org.apache.hadoop.yarn.server.resourcemanager.placement.FairQueuePlacementUtils.assureRoot;
+import static org.apache.hadoop.yarn.server.resourcemanager.placement.FairQueuePlacementUtils.cleanName;
+
+/**
+ * Places apps in queues by the secondary group of the submitter, if the
+ * submitter is a member of more than one group.
+ * The first "matching" queue based on the group list is returned. The match
+ * takes into account the parent rule and create flag,
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
+public class SecondaryGroupExistingPlacementRule extends FSPlacementRule {
+  private static final Logger LOG =
+      LoggerFactory.getLogger(SecondaryGroupExistingPlacementRule.class);
+
+  private Groups groupProvider;
+
+  @Override
+  public boolean initialize(ResourceScheduler scheduler) throws IOException {
+    super.initialize(scheduler);
+    groupProvider = new Groups(((FairScheduler)scheduler).getConfig());
+
+    return true;
+  }
+
+  @Override
+  public ApplicationPlacementContext getPlacementForApp(
+      ApplicationSubmissionContext asc, String user) throws YarnException {
+
+    // All users should have at least one group the primary group. If no groups
+    // are returned then there is a real issue.
+    final List<String> groupList;
+    try {
+      groupList = groupProvider.getGroups(user);
+    } catch (IOException ioe) {
+      throw new YarnException("Group resolution failed", ioe);
+    }
+
+    String parentQueue = null;
+    PlacementRule parentRule = getParentRule();
+
+    if (parentRule != null) {
+      LOG.debug("SecondaryGroupExisting rule: parent rule found: {}",
+          parentRule.getName());
+      ApplicationPlacementContext parent =
+          parentRule.getPlacementForApp(asc, user);
+      if (parent == null || getQueueManager().
+          getQueue(parent.getQueue()) instanceof FSLeafQueue) {
+        LOG.debug("SecondaryGroupExisting rule: parent rule failed");
+        return null;
+      }
+      parentQueue = parent.getQueue();
+      LOG.debug("SecondaryGroupExisting rule: parent rule result: {}",
+          parentQueue);
+    }
+    // now check the groups inside the parent
+    for (int i = 1; i < groupList.size(); i++) {
+      String group = cleanName(groupList.get(i));
+      String queueName =
+          parentQueue == null ? assureRoot(group) : parentQueue + DOT + group;
+      if (configuredQueue(queueName)) {
+        return new ApplicationPlacementContext(queueName);
+      }
+    }
+    return null;
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/placement/SpecifiedPlacementRule.java

@@ -0,0 +1,77 @@
+/**
+ * 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.placement;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.yarn.api.records.ApplicationSubmissionContext;
+import org.apache.hadoop.yarn.conf.YarnConfiguration;
+import org.apache.hadoop.yarn.exceptions.YarnException;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ResourceScheduler;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+
+import static org.apache.hadoop.yarn.server.resourcemanager.placement.FairQueuePlacementUtils.assureRoot;
+import static org.apache.hadoop.yarn.server.resourcemanager.placement.FairQueuePlacementUtils.isValidQueueName;
+
+/**
+ * Places apps in queues by requested queue of the submitter.
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
+public class SpecifiedPlacementRule extends FSPlacementRule {
+  private static final Logger LOG =
+      LoggerFactory.getLogger(SpecifiedPlacementRule.class);
+
+  @Override
+  public boolean initialize(ResourceScheduler scheduler) throws IOException {
+    super.initialize(scheduler);
+    if (getParentRule() != null) {
+      throw new IOException(
+          "Parent rule should not be configured for Specified rule.");
+    }
+    return true;
+  }
+
+  @Override
+  public ApplicationPlacementContext getPlacementForApp(
+      ApplicationSubmissionContext asc, String user) throws YarnException {
+
+    // Sanity check the provided queue
+    String queueName = asc.getQueue();
+    if (!isValidQueueName(queueName)) {
+      LOG.error("Specified queue name not valid: '{}'", queueName);
+      throw new YarnException("Application submitted by user " + user +
+          "with illegal queue name '" + queueName + "'.");
+    }
+    // On submission the requested queue will be set to "default" if no queue
+    // is specified: just check the next rule in that case
+    if (queueName.equals(YarnConfiguration.DEFAULT_QUEUE_NAME)) {
+      return null;
+    }
+    queueName = assureRoot(queueName);
+    // If we can create the queue in the rule or the queue exists return it
+    if (createQueue || configuredQueue(queueName)) {
+      return new ApplicationPlacementContext(queueName);
+    }
+    return null;
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/placement/UserPlacementRule.java

@@ -0,0 +1,70 @@
+/**
+ * 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.placement;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.yarn.api.records.ApplicationSubmissionContext;
+import org.apache.hadoop.yarn.exceptions.YarnException;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FSLeafQueue;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import static org.apache.hadoop.yarn.server.resourcemanager.placement.FairQueuePlacementUtils.DOT;
+import static org.apache.hadoop.yarn.server.resourcemanager.placement.FairQueuePlacementUtils.assureRoot;
+import static org.apache.hadoop.yarn.server.resourcemanager.placement.FairQueuePlacementUtils.cleanName;
+
+/**
+ * Places apps in queues by username of the submitter.
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
+public class UserPlacementRule extends FSPlacementRule {
+  private static final Logger LOG =
+      LoggerFactory.getLogger(UserPlacementRule.class);
+
+  @Override
+  public ApplicationPlacementContext getPlacementForApp(
+      ApplicationSubmissionContext asc, String user) throws YarnException {
+    String queueName;
+
+    String cleanUser = cleanName(user);
+    PlacementRule parentRule = getParentRule();
+    if (parentRule != null) {
+      LOG.debug("User rule: parent rule found: {}", parentRule.getName());
+      ApplicationPlacementContext parent =
+          parentRule.getPlacementForApp(asc, user);
+      if (parent == null || getQueueManager().
+          getQueue(parent.getQueue()) instanceof FSLeafQueue) {
+        LOG.debug("User rule: parent rule failed");
+        return null;
+      }
+      LOG.debug("User rule: parent rule result: {}", parent.getQueue());
+      queueName = parent.getQueue() + DOT + cleanUser;
+    } else {
+      queueName = assureRoot(cleanUser);
+    }
+
+    // If we can create the queue in the rule or the queue exists return it
+    if (createQueue || configuredQueue(queueName)) {
+      return new ApplicationPlacementContext(queueName);
+    }
+    return null;
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/placement/TestFairQueuePlacementUtils.java

@@ -0,0 +1,137 @@
+/**
+ * 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.placement;
+
+import org.junit.Test;
+
+import static org.apache.hadoop.yarn.server.resourcemanager.placement.FairQueuePlacementUtils.DOT;
+import static org.apache.hadoop.yarn.server.resourcemanager.placement.FairQueuePlacementUtils.DOT_REPLACEMENT;
+import static org.apache.hadoop.yarn.server.resourcemanager.placement.FairQueuePlacementUtils.ROOT_QUEUE;
+import static org.apache.hadoop.yarn.server.resourcemanager.placement.FairQueuePlacementUtils.assureRoot;
+import static org.apache.hadoop.yarn.server.resourcemanager.placement.FairQueuePlacementUtils.cleanName;
+import static org.apache.hadoop.yarn.server.resourcemanager.placement.FairQueuePlacementUtils.isValidQueueName;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * Tests of the utility methods from {@link FairQueuePlacementUtils}.
+ */
+public class TestFairQueuePlacementUtils {
+
+  /**
+   * Test name trimming and dot replacement in names.
+   */
+  @Test
+  public void testCleanName() {
+    // permutations of dot placements
+    final String clean = "clean";
+    final String dotted = "not.clean";
+    final String multiDot = "more.un.clean";
+    final String seqDot = "not..clean";
+    final String unTrimmed = " .invalid. "; // not really a valid queue
+
+    String cleaned = cleanName(clean);
+    assertEquals("Name was changed and it should not", clean, cleaned);
+    cleaned = cleanName(dotted);
+    assertFalse("Cleaned name contains dots and it should not",
+        cleaned.contains(DOT));
+    cleaned = cleanName(multiDot);
+    assertFalse("Cleaned name contains dots and it should not",
+        cleaned.contains(DOT));
+    assertNotEquals("Multi dot failed: wrong replacements found",
+        cleaned.indexOf(DOT_REPLACEMENT),
+        cleaned.lastIndexOf(DOT_REPLACEMENT));
+    cleaned = cleanName(seqDot);
+    assertFalse("Cleaned name contains dots and it should not",
+        cleaned.contains(DOT));
+    assertNotEquals("Sequential dot failed: wrong replacements found",
+        cleaned.indexOf(DOT_REPLACEMENT),
+        cleaned.lastIndexOf(DOT_REPLACEMENT));
+    cleaned = cleanName(unTrimmed);
+    assertTrue("Trimming start failed: space not removed or dot not replaced",
+        cleaned.startsWith(DOT_REPLACEMENT));
+    assertTrue("Trimming end failed: space not removed or dot not replaced",
+        cleaned.endsWith(DOT_REPLACEMENT));
+  }
+
+  @Test
+  public void testAssureRoot() {
+    // permutations of rooted queue names
+    final String queueName = "base";
+    final String rootOnly = "root";
+    final String rootNoDot = "rootbase";
+    final String alreadyRoot = "root.base";
+
+    String rooted = assureRoot(queueName);
+    assertTrue("Queue should have root prefix (base)",
+        rooted.startsWith(ROOT_QUEUE + DOT));
+    rooted = assureRoot(rootOnly);
+    assertEquals("'root' queue should not have root prefix (root)",
+        rootOnly, rooted);
+    rooted = assureRoot(rootNoDot);
+    assertTrue("Queue should have root prefix (rootbase)",
+        rooted.startsWith(ROOT_QUEUE + DOT));
+    assertEquals("'root' queue base was replaced and not prefixed", 5,
+        rooted.lastIndexOf(ROOT_QUEUE));
+    rooted = assureRoot(alreadyRoot);
+    assertEquals("Root prefixed queue changed and it should not (root.base)",
+        rooted, alreadyRoot);
+    assertNull("Null queue did not return null queue",
+        assureRoot(null));
+    assertEquals("Empty queue did not return empty name", "",
+        assureRoot(""));
+  }
+
+  @Test
+  public void testIsValidQueueName() {
+    // permutations of valid/invalid names
+    final String valid = "valid";
+    final String validRooted = "root.valid";
+    final String rootOnly = "root";
+    final String startDot = ".invalid";
+    final String endDot = "invalid.";
+    final String startSpace = " invalid";
+    final String endSpace = "invalid ";
+    final String unicodeSpace = "\u00A0invalid";
+
+    assertFalse("'null' queue was not marked as invalid",
+        isValidQueueName(null));
+    assertTrue("empty queue was not tagged valid", isValidQueueName(""));
+    assertTrue("Simple queue name was not tagged valid (valid)",
+        isValidQueueName(valid));
+    assertTrue("Root only queue was not tagged valid (root)",
+        isValidQueueName(rootOnly));
+    assertTrue("Root prefixed queue was not tagged valid (root.valid)",
+        isValidQueueName(validRooted));
+    assertFalse("Queue starting with dot was not tagged invalid (.invalid)",
+        isValidQueueName(startDot));
+    assertFalse("Queue ending with dot was not tagged invalid (invalid.)",
+        isValidQueueName(endDot));
+    assertFalse("Queue starting with space was not tagged invalid ( invalid)",
+        isValidQueueName(startSpace));
+    assertFalse("Queue ending with space was not tagged invalid (invalid )",
+        isValidQueueName(endSpace));
+    // just one for sanity check extensive tests are in the scheduler utils
+    assertFalse("Queue with unicode space was not tagged as invalid (unicode)",
+        isValidQueueName(unicodeSpace));
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/placement/TestPlacementFactory.java

@@ -0,0 +1,75 @@
+/**
+ * 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.placement;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.fail;
+
+/**
+ * Test for the {@link PlacementFactory}.
+ */
+public class TestPlacementFactory {
+
+  /**
+   * Check that non existing class throws exception.
+   *
+   * @throws ClassNotFoundException
+   */
+  @Test(expected = ClassNotFoundException.class)
+  public void testGetNonExistRuleText() throws ClassNotFoundException {
+    final String nonExist = "my.placement.Rule";
+    PlacementFactory.getPlacementRule(nonExist, null);
+  }
+
+  /**
+   * Check existing class using the class name.
+   * Relies on the {@link DefaultPlacementRule} of the FS.
+   */
+  @Test
+  public void testGetExistRuleText() {
+    final String exists = DefaultPlacementRule.class.getCanonicalName();
+    PlacementRule rule = null;
+    try {
+      rule = PlacementFactory.getPlacementRule(exists, null);
+    } catch (ClassNotFoundException cnfe) {
+      fail("Class should have been found");
+    }
+    assertNotNull("Rule object is null", rule);
+    assertEquals("Names not equal", rule.getName(), exists);
+  }
+
+  /**
+   * Existing class using the class reference.
+   * Relies on the {@link DefaultPlacementRule} of the FS.
+   */
+  @Test
+  public void testGetRuleClass() {
+    PlacementRule rule = PlacementFactory.getPlacementRule(
+        DefaultPlacementRule.class, null);
+    assertNotNull("Rule object is null", rule);
+    // Should take anything as the second object: ignores unknown types in the
+    // default implementation.
+    rule = PlacementFactory.getPlacementRule(
+        DefaultPlacementRule.class, "");
+    assertNotNull("Rule object is null", rule);
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/placement/TestPlacementRuleFS.java

@@ -0,0 +1,212 @@
+/**
+ * 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.placement;
+
+import org.apache.commons.io.IOUtils;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FairScheduler;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FairSchedulerConfiguration;
+import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.QueueManager;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.DocumentBuilderFactory;
+import java.io.IOException;
+import java.nio.charset.Charset;
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.apache.hadoop.yarn.server.resourcemanager.placement.PlacementFactory.getPlacementRule;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+/**
+ * Simple tests for FS specific parts of the PlacementRule.
+ */
+public class TestPlacementRuleFS {
+
+  // List of rules that are configurable (reject rule is not!)
+  private static final List<Class <? extends PlacementRule>> CONFIG_RULES =
+      new ArrayList<Class <? extends PlacementRule>>() {
+    {
+      add(DefaultPlacementRule.class);
+      add(PrimaryGroupPlacementRule.class);
+      add(SecondaryGroupExistingPlacementRule.class);
+      add(SpecifiedPlacementRule.class);
+      add(UserPlacementRule.class);
+    }
+  };
+
+  // List of rules that are not configurable
+  private static final List<Class <? extends PlacementRule>> NO_CONFIG_RULES =
+      new ArrayList<Class <? extends PlacementRule>>() {
+    {
+      add(RejectPlacementRule.class);
+    }
+  };
+
+  private final static FairSchedulerConfiguration CONF =
+      new FairSchedulerConfiguration();
+  private FairScheduler scheduler;
+  private QueueManager queueManager;
+
+
+  @Before
+  public void initTest() {
+    scheduler = mock(FairScheduler.class);
+    // needed for all rules that rely on group info
+    when(scheduler.getConfig()).thenReturn(CONF);
+    // needed by all rules
+    queueManager = new QueueManager(scheduler);
+    when(scheduler.getQueueManager()).thenReturn(queueManager);
+  }
+
+  @After
+  public void cleanTest() {
+    queueManager = null;
+    scheduler = null;
+  }
+
+  /**
+   * Check the create and setting the config on the rule.
+   * This walks over all known rules and check the behaviour:
+   * - no config (null object)
+   * - unknown object type
+   * - boolean object
+   * - xml config ({@link Element})
+   * - calling initialize on the rule
+   */
+  @Test
+  public void testRuleSetups() {
+    // test for config(s) and init
+    for (Class <? extends PlacementRule> ruleClass: CONFIG_RULES) {
+      ruleCreateNoConfig(ruleClass);
+      ruleCreateWrongObject(ruleClass);
+      ruleCreateBoolean(ruleClass);
+      ruleCreateElement(ruleClass);
+      ruleInit(ruleClass);
+    }
+  }
+
+  /**
+   * Check the init of rules that do not use a config.
+   */
+  @Test
+  public void testRuleInitOnly() {
+    // test for init
+    for (Class <? extends PlacementRule> ruleClass: NO_CONFIG_RULES) {
+      ruleInit(ruleClass);
+    }
+  }
+
+  private void ruleCreateNoConfig(Class <? extends PlacementRule> ruleClass) {
+    PlacementRule rule = getPlacementRule(ruleClass, null);
+    String name = ruleClass.getName();
+    assertNotNull("Rule object should not be null for " + name, rule);
+  }
+
+  private void ruleCreateWrongObject(
+      Class <? extends PlacementRule> ruleClass) {
+    PlacementRule rule = getPlacementRule(ruleClass, "a string object");
+    String name = ruleClass.getName();
+    assertNotNull("Rule object should not be null for " + name, rule);
+  }
+
+  private void ruleCreateBoolean(Class <? extends PlacementRule> ruleClass) {
+    PlacementRule rule = getPlacementRule(ruleClass, true);
+    String name = ruleClass.getName();
+    assertNotNull("Rule object should not be null for " + name, rule);
+    assertTrue("Create flag was not set to true on " + name,
+        getCreateFlag(rule));
+    rule = getPlacementRule(ruleClass, false);
+    assertNotNull("Rule object should not be null for " + name, rule);
+    assertFalse("Create flag was not set to false on " + name,
+        getCreateFlag(rule));
+  }
+
+  private void ruleCreateElement(Class <? extends PlacementRule> ruleClass) {
+    String str = "<rule name='not used' create=\"true\" />";
+    Element conf = createConf(str);
+    PlacementRule rule = getPlacementRule(ruleClass, conf);
+    String name = ruleClass.getName();
+    assertNotNull("Rule object should not be null for " + name, rule);
+    assertTrue("Create flag was not set to true on " + name,
+        getCreateFlag(rule));
+    str = "<rule name='not used' create=\"false\" />";
+    conf = createConf(str);
+    rule = getPlacementRule(ruleClass, conf);
+    assertNotNull("Rule object should not be null for " + name, rule);
+    assertFalse("Create flag was not set to false on " + name,
+        getCreateFlag(rule));
+  }
+
+  private void ruleInit(Class <? extends PlacementRule> ruleClass) {
+    PlacementRule rule = getPlacementRule(ruleClass, null);
+    String name = ruleClass.getName();
+    assertNotNull("Rule object should not be null for " + name, rule);
+    try {
+      rule.initialize(scheduler);
+    } catch (IOException ioe) {
+      fail("Unexpected exception on initialize of rule " + name);
+    }
+    // now set the parent rule: use the same rule as a child.
+    // always throws: either because parentRule is not allowed or because it
+    // is the same class as the child rule.
+    ((FSPlacementRule)rule).setParentRule(rule);
+    boolean exceptionThrown = false;
+    try {
+      rule.initialize(scheduler);
+    } catch (IOException ioe) {
+      exceptionThrown = true;
+    }
+    assertTrue("Initialize with parent rule should have thrown exception " +
+            name, exceptionThrown);
+  }
+
+  private Element createConf(String str) {
+    // Create a simple rule element to use in the rule create
+    DocumentBuilderFactory docBuilderFactory =
+        DocumentBuilderFactory.newInstance();
+    docBuilderFactory.setIgnoringComments(true);
+    Document doc = null;
+    try {
+      DocumentBuilder builder = docBuilderFactory.newDocumentBuilder();
+      doc = builder.parse(IOUtils.toInputStream(str,
+          Charset.defaultCharset()));
+    } catch (Exception ex) {
+      fail("Element creation failed, failing test");
+    }
+    return doc.getDocumentElement();
+  }
+
+  private boolean getCreateFlag(PlacementRule rule) {
+    if (rule instanceof FSPlacementRule) {
+      return ((FSPlacementRule)rule).createQueue;
+    }
+    fail("Rule is not a FSPlacementRule");
+    return false;
+  }
+}