[120] | 1 | /** |
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| 2 | * Licensed to the Apache Software Foundation (ASF) under one |
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| 3 | * or more contributor license agreements. See the NOTICE file |
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| 4 | * distributed with this work for additional information |
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| 5 | * regarding copyright ownership. The ASF licenses this file |
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| 6 | * to you under the Apache License, Version 2.0 (the |
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| 7 | * "License"); you may not use this file except in compliance |
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| 8 | * with the License. You may obtain a copy of the License at |
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| 9 | * |
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| 10 | * http://www.apache.org/licenses/LICENSE-2.0 |
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| 11 | * |
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| 12 | * Unless required by applicable law or agreed to in writing, software |
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| 13 | * distributed under the License is distributed on an "AS IS" BASIS, |
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| 14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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| 15 | * See the License for the specific language governing permissions and |
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| 16 | * limitations under the License. |
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| 17 | */ |
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| 18 | |
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| 19 | package org.apache.hadoop.mapred.jobcontrol; |
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| 20 | |
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| 21 | import java.util.ArrayList; |
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| 22 | import java.util.Collection; |
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| 23 | import java.util.Hashtable; |
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| 24 | import java.util.Map; |
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| 25 | |
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| 26 | /** This class encapsulates a set of MapReduce jobs and its dependency. It tracks |
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| 27 | * the states of the jobs by placing them into different tables according to their |
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| 28 | * states. |
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| 29 | * |
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| 30 | * This class provides APIs for the client app to add a job to the group and to get |
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| 31 | * the jobs in the group in different states. When a |
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| 32 | * job is added, an ID unique to the group is assigned to the job. |
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| 33 | * |
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| 34 | * This class has a thread that submits jobs when they become ready, monitors the |
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| 35 | * states of the running jobs, and updates the states of jobs based on the state changes |
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| 36 | * of their depending jobs states. The class provides APIs for suspending/resuming |
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| 37 | * the thread,and for stopping the thread. |
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| 38 | * |
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| 39 | */ |
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| 40 | public class JobControl implements Runnable{ |
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| 41 | |
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| 42 | // The thread can be in one of the following state |
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| 43 | private static final int RUNNING = 0; |
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| 44 | private static final int SUSPENDED = 1; |
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| 45 | private static final int STOPPED = 2; |
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| 46 | private static final int STOPPING = 3; |
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| 47 | private static final int READY = 4; |
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| 48 | |
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| 49 | private int runnerState; // the thread state |
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| 50 | |
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| 51 | private Map<String, Job> waitingJobs; |
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| 52 | private Map<String, Job> readyJobs; |
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| 53 | private Map<String, Job> runningJobs; |
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| 54 | private Map<String, Job> successfulJobs; |
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| 55 | private Map<String, Job> failedJobs; |
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| 56 | |
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| 57 | private long nextJobID; |
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| 58 | private String groupName; |
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| 59 | |
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| 60 | /** |
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| 61 | * Construct a job control for a group of jobs. |
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| 62 | * @param groupName a name identifying this group |
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| 63 | */ |
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| 64 | public JobControl(String groupName) { |
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| 65 | this.waitingJobs = new Hashtable<String, Job>(); |
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| 66 | this.readyJobs = new Hashtable<String, Job>(); |
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| 67 | this.runningJobs = new Hashtable<String, Job>(); |
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| 68 | this.successfulJobs = new Hashtable<String, Job>(); |
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| 69 | this.failedJobs = new Hashtable<String, Job>(); |
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| 70 | this.nextJobID = -1; |
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| 71 | this.groupName = groupName; |
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| 72 | this.runnerState = JobControl.READY; |
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| 73 | } |
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| 74 | |
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| 75 | private static ArrayList<Job> toArrayList(Map<String, Job> jobs) { |
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| 76 | ArrayList<Job> retv = new ArrayList<Job>(); |
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| 77 | synchronized (jobs) { |
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| 78 | for (Job job : jobs.values()) { |
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| 79 | retv.add(job); |
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| 80 | } |
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| 81 | } |
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| 82 | return retv; |
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| 83 | } |
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| 84 | |
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| 85 | /** |
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| 86 | * @return the jobs in the waiting state |
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| 87 | */ |
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| 88 | public ArrayList<Job> getWaitingJobs() { |
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| 89 | return JobControl.toArrayList(this.waitingJobs); |
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| 90 | } |
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| 91 | |
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| 92 | /** |
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| 93 | * @return the jobs in the running state |
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| 94 | */ |
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| 95 | public ArrayList<Job> getRunningJobs() { |
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| 96 | return JobControl.toArrayList(this.runningJobs); |
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| 97 | } |
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| 98 | |
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| 99 | /** |
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| 100 | * @return the jobs in the ready state |
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| 101 | */ |
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| 102 | public ArrayList<Job> getReadyJobs() { |
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| 103 | return JobControl.toArrayList(this.readyJobs); |
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| 104 | } |
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| 105 | |
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| 106 | /** |
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| 107 | * @return the jobs in the success state |
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| 108 | */ |
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| 109 | public ArrayList<Job> getSuccessfulJobs() { |
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| 110 | return JobControl.toArrayList(this.successfulJobs); |
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| 111 | } |
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| 112 | |
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| 113 | public ArrayList<Job> getFailedJobs() { |
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| 114 | return JobControl.toArrayList(this.failedJobs); |
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| 115 | } |
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| 116 | |
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| 117 | private String getNextJobID() { |
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| 118 | nextJobID += 1; |
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| 119 | return this.groupName + this.nextJobID; |
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| 120 | } |
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| 121 | |
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| 122 | private static void addToQueue(Job aJob, Map<String, Job> queue) { |
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| 123 | synchronized(queue) { |
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| 124 | queue.put(aJob.getJobID(), aJob); |
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| 125 | } |
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| 126 | } |
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| 127 | |
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| 128 | private void addToQueue(Job aJob) { |
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| 129 | Map<String, Job> queue = getQueue(aJob.getState()); |
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| 130 | addToQueue(aJob, queue); |
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| 131 | } |
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| 132 | |
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| 133 | private Map<String, Job> getQueue(int state) { |
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| 134 | Map<String, Job> retv = null; |
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| 135 | if (state == Job.WAITING) { |
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| 136 | retv = this.waitingJobs; |
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| 137 | } else if (state == Job.READY) { |
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| 138 | retv = this.readyJobs; |
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| 139 | } else if (state == Job.RUNNING) { |
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| 140 | retv = this.runningJobs; |
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| 141 | } else if (state == Job.SUCCESS) { |
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| 142 | retv = this.successfulJobs; |
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| 143 | } else if (state == Job.FAILED || state == Job.DEPENDENT_FAILED) { |
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| 144 | retv = this.failedJobs; |
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| 145 | } |
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| 146 | return retv; |
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| 147 | } |
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| 148 | |
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| 149 | /** |
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| 150 | * Add a new job. |
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| 151 | * @param aJob the new job |
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| 152 | */ |
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| 153 | synchronized public String addJob(Job aJob) { |
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| 154 | String id = this.getNextJobID(); |
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| 155 | aJob.setJobID(id); |
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| 156 | aJob.setState(Job.WAITING); |
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| 157 | this.addToQueue(aJob); |
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| 158 | return id; |
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| 159 | } |
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| 160 | |
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| 161 | /** |
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| 162 | * Add a collection of jobs |
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| 163 | * |
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| 164 | * @param jobs |
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| 165 | */ |
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| 166 | public void addJobs(Collection<Job> jobs) { |
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| 167 | for (Job job : jobs) { |
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| 168 | addJob(job); |
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| 169 | } |
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| 170 | } |
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| 171 | |
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| 172 | /** |
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| 173 | * @return the thread state |
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| 174 | */ |
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| 175 | public int getState() { |
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| 176 | return this.runnerState; |
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| 177 | } |
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| 178 | |
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| 179 | /** |
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| 180 | * set the thread state to STOPPING so that the |
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| 181 | * thread will stop when it wakes up. |
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| 182 | */ |
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| 183 | public void stop() { |
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| 184 | this.runnerState = JobControl.STOPPING; |
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| 185 | } |
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| 186 | |
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| 187 | /** |
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| 188 | * suspend the running thread |
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| 189 | */ |
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| 190 | public void suspend () { |
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| 191 | if (this.runnerState == JobControl.RUNNING) { |
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| 192 | this.runnerState = JobControl.SUSPENDED; |
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| 193 | } |
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| 194 | } |
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| 195 | |
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| 196 | /** |
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| 197 | * resume the suspended thread |
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| 198 | */ |
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| 199 | public void resume () { |
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| 200 | if (this.runnerState == JobControl.SUSPENDED) { |
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| 201 | this.runnerState = JobControl.RUNNING; |
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| 202 | } |
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| 203 | } |
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| 204 | |
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| 205 | synchronized private void checkRunningJobs() { |
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| 206 | |
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| 207 | Map<String, Job> oldJobs = null; |
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| 208 | oldJobs = this.runningJobs; |
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| 209 | this.runningJobs = new Hashtable<String, Job>(); |
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| 210 | |
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| 211 | for (Job nextJob : oldJobs.values()) { |
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| 212 | int state = nextJob.checkState(); |
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| 213 | /* |
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| 214 | if (state != Job.RUNNING) { |
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| 215 | System.out.println("The state of the running job " + |
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| 216 | nextJob.getJobName() + " has changed to: " + nextJob.getState()); |
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| 217 | } |
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| 218 | */ |
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| 219 | this.addToQueue(nextJob); |
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| 220 | } |
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| 221 | } |
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| 222 | |
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| 223 | synchronized private void checkWaitingJobs() { |
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| 224 | Map<String, Job> oldJobs = null; |
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| 225 | oldJobs = this.waitingJobs; |
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| 226 | this.waitingJobs = new Hashtable<String, Job>(); |
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| 227 | |
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| 228 | for (Job nextJob : oldJobs.values()) { |
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| 229 | int state = nextJob.checkState(); |
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| 230 | /* |
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| 231 | if (state != Job.WAITING) { |
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| 232 | System.out.println("The state of the waiting job " + |
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| 233 | nextJob.getJobName() + " has changed to: " + nextJob.getState()); |
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| 234 | } |
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| 235 | */ |
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| 236 | this.addToQueue(nextJob); |
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| 237 | } |
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| 238 | } |
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| 239 | |
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| 240 | synchronized private void startReadyJobs() { |
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| 241 | Map<String, Job> oldJobs = null; |
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| 242 | oldJobs = this.readyJobs; |
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| 243 | this.readyJobs = new Hashtable<String, Job>(); |
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| 244 | |
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| 245 | for (Job nextJob : oldJobs.values()) { |
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| 246 | //System.out.println("Job to submit to Hadoop: " + nextJob.getJobName()); |
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| 247 | nextJob.submit(); |
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| 248 | //System.out.println("Hadoop ID: " + nextJob.getMapredJobID()); |
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| 249 | this.addToQueue(nextJob); |
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| 250 | } |
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| 251 | } |
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| 252 | |
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| 253 | synchronized public boolean allFinished() { |
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| 254 | return this.waitingJobs.size() == 0 && |
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| 255 | this.readyJobs.size() == 0 && |
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| 256 | this.runningJobs.size() == 0; |
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| 257 | } |
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| 258 | |
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| 259 | /** |
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| 260 | * The main loop for the thread. |
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| 261 | * The loop does the following: |
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| 262 | * Check the states of the running jobs |
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| 263 | * Update the states of waiting jobs |
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| 264 | * Submit the jobs in ready state |
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| 265 | */ |
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| 266 | public void run() { |
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| 267 | this.runnerState = JobControl.RUNNING; |
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| 268 | while (true) { |
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| 269 | while (this.runnerState == JobControl.SUSPENDED) { |
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| 270 | try { |
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| 271 | Thread.sleep(5000); |
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| 272 | } |
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| 273 | catch (Exception e) { |
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| 274 | |
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| 275 | } |
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| 276 | } |
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| 277 | checkRunningJobs(); |
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| 278 | checkWaitingJobs(); |
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| 279 | startReadyJobs(); |
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| 280 | if (this.runnerState != JobControl.RUNNING && |
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| 281 | this.runnerState != JobControl.SUSPENDED) { |
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| 282 | break; |
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| 283 | } |
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| 284 | try { |
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| 285 | Thread.sleep(5000); |
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| 286 | } |
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| 287 | catch (Exception e) { |
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| 288 | |
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| 289 | } |
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| 290 | if (this.runnerState != JobControl.RUNNING && |
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| 291 | this.runnerState != JobControl.SUSPENDED) { |
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| 292 | break; |
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| 293 | } |
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| 294 | } |
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| 295 | this.runnerState = JobControl.STOPPED; |
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| 296 | } |
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| 297 | |
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| 298 | } |
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