Java tutorial
/** * 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.impala.yarn.server.resourcemanager.scheduler.fair; //YARNUTIL: VANILLA import java.io.IOException; import java.util.ArrayList; import java.util.Collections; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Set; import org.apache.hadoop.classification.InterfaceAudience.Private; import org.apache.hadoop.classification.InterfaceStability.Unstable; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.security.Groups; import org.apache.hadoop.util.ReflectionUtils; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList; @Private @Unstable public class QueuePlacementPolicy { private static final Map<String, Class<? extends QueuePlacementRule>> ruleClasses; static { Map<String, Class<? extends QueuePlacementRule>> map = new HashMap<String, Class<? extends QueuePlacementRule>>(); map.put("user", QueuePlacementRule.User.class); map.put("primaryGroup", QueuePlacementRule.PrimaryGroup.class); map.put("secondaryGroupExistingQueue", QueuePlacementRule.SecondaryGroupExistingQueue.class); map.put("specified", QueuePlacementRule.Specified.class); map.put("nestedUserQueue", QueuePlacementRule.NestedUserQueue.class); map.put("default", QueuePlacementRule.Default.class); map.put("reject", QueuePlacementRule.Reject.class); ruleClasses = Collections.unmodifiableMap(map); } private final Configuration conf_; // Testing only. private final List<QueuePlacementRule> rules; private final Map<FSQueueType, Set<String>> configuredQueues; private final Groups groups; public QueuePlacementPolicy(List<QueuePlacementRule> rules, Map<FSQueueType, Set<String>> configuredQueues, Configuration conf) throws AllocationConfigurationException { for (int i = 0; i < rules.size() - 1; i++) { if (rules.get(i).isTerminal()) { throw new AllocationConfigurationException( "Rules after rule " + i + " in queue placement policy can never be reached"); } } if (!rules.get(rules.size() - 1).isTerminal()) { throw new AllocationConfigurationException( "Could get past last queue placement rule without assigning"); } this.rules = rules; this.configuredQueues = configuredQueues; this.conf_ = conf; groups = new Groups(conf); } /** * Builds a QueuePlacementPolicy from an xml element. */ public static QueuePlacementPolicy fromXml(Element el, Map<FSQueueType, Set<String>> configuredQueues, Configuration conf) throws AllocationConfigurationException { List<QueuePlacementRule> rules = new ArrayList<QueuePlacementRule>(); NodeList elements = el.getChildNodes(); for (int i = 0; i < elements.getLength(); i++) { Node node = elements.item(i); if (node instanceof Element) { QueuePlacementRule rule = createAndInitializeRule(node); rules.add(rule); } } return new QueuePlacementPolicy(rules, configuredQueues, conf); } /** * Create and initialize a rule given a xml node * @param node * @return QueuePlacementPolicy * @throws AllocationConfigurationException */ public static QueuePlacementRule createAndInitializeRule(Node node) throws AllocationConfigurationException { Element element = (Element) node; String ruleName = element.getAttribute("name"); if ("".equals(ruleName)) { throw new AllocationConfigurationException("No name provided for a " + "rule element"); } Class<? extends QueuePlacementRule> clazz = ruleClasses.get(ruleName); if (clazz == null) { throw new AllocationConfigurationException("No rule class found for " + ruleName); } QueuePlacementRule rule = ReflectionUtils.newInstance(clazz, null); rule.initializeFromXml(element); return rule; } /** * Build a simple queue placement policy from the allow-undeclared-pools and * user-as-default-queue configuration options. */ public static QueuePlacementPolicy fromConfiguration(Configuration conf, Map<FSQueueType, Set<String>> configuredQueues) { boolean create = conf.getBoolean(FairSchedulerConfiguration.ALLOW_UNDECLARED_POOLS, FairSchedulerConfiguration.DEFAULT_ALLOW_UNDECLARED_POOLS); boolean userAsDefaultQueue = conf.getBoolean(FairSchedulerConfiguration.USER_AS_DEFAULT_QUEUE, FairSchedulerConfiguration.DEFAULT_USER_AS_DEFAULT_QUEUE); List<QueuePlacementRule> rules = new ArrayList<QueuePlacementRule>(); rules.add(new QueuePlacementRule.Specified().initialize(create, null)); if (userAsDefaultQueue) { rules.add(new QueuePlacementRule.User().initialize(create, null)); } if (!userAsDefaultQueue || !create) { rules.add(new QueuePlacementRule.Default().initialize(true, null)); } try { return new QueuePlacementPolicy(rules, configuredQueues, conf); } catch (AllocationConfigurationException ex) { throw new RuntimeException("Should never hit exception when loading" + "placement policy from conf", ex); } } /** * Applies this rule to an app with the given requested queue and user/group * information. * * @param requestedQueue * The queue specified in the ApplicationSubmissionContext * @param user * The user submitting the app * @return * The name of the queue to assign the app to. Or null if the app should * be rejected. * @throws IOException * If an exception is encountered while getting the user's groups */ public String assignAppToQueue(String requestedQueue, String user) throws IOException { for (QueuePlacementRule rule : rules) { String queue = rule.assignAppToQueue(requestedQueue, user, groups, configuredQueues); if (queue == null || !queue.isEmpty()) { return queue; } } throw new IllegalStateException("Should have applied a rule before " + "reaching here"); } public List<QueuePlacementRule> getRules() { return rules; } public Configuration getConf() { return conf_; } }