| /** |
| * 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.mapred.jobcontrol; |
| |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.Hashtable; |
| import java.util.Map; |
| |
| /** This class encapsulates a set of MapReduce jobs and its dependency. It tracks |
| * the states of the jobs by placing them into different tables according to their |
| * states. |
| * |
| * This class provides APIs for the client app to add a job to the group and to get |
| * the jobs in the group in different states. When a |
| * job is added, an ID unique to the group is assigned to the job. |
| * |
| * This class has a thread that submits jobs when they become ready, monitors the |
| * states of the running jobs, and updates the states of jobs based on the state changes |
| * of their depending jobs states. The class provides APIs for suspending/resuming |
| * the thread,and for stopping the thread. |
| * |
| */ |
| public class JobControl implements Runnable{ |
| |
| // The thread can be in one of the following state |
| private static final int RUNNING = 0; |
| private static final int SUSPENDED = 1; |
| private static final int STOPPED = 2; |
| private static final int STOPPING = 3; |
| private static final int READY = 4; |
| |
| private int runnerState; // the thread state |
| |
| private Map<String, Job> waitingJobs; |
| private Map<String, Job> readyJobs; |
| private Map<String, Job> runningJobs; |
| private Map<String, Job> successfulJobs; |
| private Map<String, Job> failedJobs; |
| |
| private long nextJobID; |
| private String groupName; |
| |
| /** |
| * Construct a job control for a group of jobs. |
| * @param groupName a name identifying this group |
| */ |
| public JobControl(String groupName) { |
| this.waitingJobs = new Hashtable<String, Job>(); |
| this.readyJobs = new Hashtable<String, Job>(); |
| this.runningJobs = new Hashtable<String, Job>(); |
| this.successfulJobs = new Hashtable<String, Job>(); |
| this.failedJobs = new Hashtable<String, Job>(); |
| this.nextJobID = -1; |
| this.groupName = groupName; |
| this.runnerState = JobControl.READY; |
| } |
| |
| private static ArrayList<Job> toArrayList(Map<String, Job> jobs) { |
| ArrayList<Job> retv = new ArrayList<Job>(); |
| synchronized (jobs) { |
| for (Job job : jobs.values()) { |
| retv.add(job); |
| } |
| } |
| return retv; |
| } |
| |
| /** |
| * @return the jobs in the waiting state |
| */ |
| public ArrayList<Job> getWaitingJobs() { |
| return JobControl.toArrayList(this.waitingJobs); |
| } |
| |
| /** |
| * @return the jobs in the running state |
| */ |
| public ArrayList<Job> getRunningJobs() { |
| return JobControl.toArrayList(this.runningJobs); |
| } |
| |
| /** |
| * @return the jobs in the ready state |
| */ |
| public ArrayList<Job> getReadyJobs() { |
| return JobControl.toArrayList(this.readyJobs); |
| } |
| |
| /** |
| * @return the jobs in the success state |
| */ |
| public ArrayList<Job> getSuccessfulJobs() { |
| return JobControl.toArrayList(this.successfulJobs); |
| } |
| |
| public ArrayList<Job> getFailedJobs() { |
| return JobControl.toArrayList(this.failedJobs); |
| } |
| |
| private String getNextJobID() { |
| nextJobID += 1; |
| return this.groupName + this.nextJobID; |
| } |
| |
| private static void addToQueue(Job aJob, Map<String, Job> queue) { |
| synchronized(queue) { |
| queue.put(aJob.getJobID(), aJob); |
| } |
| } |
| |
| private void addToQueue(Job aJob) { |
| Map<String, Job> queue = getQueue(aJob.getState()); |
| addToQueue(aJob, queue); |
| } |
| |
| private Map<String, Job> getQueue(int state) { |
| Map<String, Job> retv = null; |
| if (state == Job.WAITING) { |
| retv = this.waitingJobs; |
| } else if (state == Job.READY) { |
| retv = this.readyJobs; |
| } else if (state == Job.RUNNING) { |
| retv = this.runningJobs; |
| } else if (state == Job.SUCCESS) { |
| retv = this.successfulJobs; |
| } else if (state == Job.FAILED || state == Job.DEPENDENT_FAILED) { |
| retv = this.failedJobs; |
| } |
| return retv; |
| } |
| |
| /** |
| * Add a new job. |
| * @param aJob the new job |
| */ |
| synchronized public String addJob(Job aJob) { |
| String id = this.getNextJobID(); |
| aJob.setJobID(id); |
| aJob.setState(Job.WAITING); |
| this.addToQueue(aJob); |
| return id; |
| } |
| |
| /** |
| * Add a collection of jobs |
| * |
| * @param jobs |
| */ |
| public void addJobs(Collection<Job> jobs) { |
| for (Job job : jobs) { |
| addJob(job); |
| } |
| } |
| |
| /** |
| * @return the thread state |
| */ |
| public int getState() { |
| return this.runnerState; |
| } |
| |
| /** |
| * set the thread state to STOPPING so that the |
| * thread will stop when it wakes up. |
| */ |
| public void stop() { |
| this.runnerState = JobControl.STOPPING; |
| } |
| |
| /** |
| * suspend the running thread |
| */ |
| public void suspend () { |
| if (this.runnerState == JobControl.RUNNING) { |
| this.runnerState = JobControl.SUSPENDED; |
| } |
| } |
| |
| /** |
| * resume the suspended thread |
| */ |
| public void resume () { |
| if (this.runnerState == JobControl.SUSPENDED) { |
| this.runnerState = JobControl.RUNNING; |
| } |
| } |
| |
| synchronized private void checkRunningJobs() { |
| |
| Map<String, Job> oldJobs = null; |
| oldJobs = this.runningJobs; |
| this.runningJobs = new Hashtable<String, Job>(); |
| |
| for (Job nextJob : oldJobs.values()) { |
| int state = nextJob.checkState(); |
| /* |
| if (state != Job.RUNNING) { |
| System.out.println("The state of the running job " + |
| nextJob.getJobName() + " has changed to: " + nextJob.getState()); |
| } |
| */ |
| this.addToQueue(nextJob); |
| } |
| } |
| |
| synchronized private void checkWaitingJobs() { |
| Map<String, Job> oldJobs = null; |
| oldJobs = this.waitingJobs; |
| this.waitingJobs = new Hashtable<String, Job>(); |
| |
| for (Job nextJob : oldJobs.values()) { |
| int state = nextJob.checkState(); |
| /* |
| if (state != Job.WAITING) { |
| System.out.println("The state of the waiting job " + |
| nextJob.getJobName() + " has changed to: " + nextJob.getState()); |
| } |
| */ |
| this.addToQueue(nextJob); |
| } |
| } |
| |
| synchronized private void startReadyJobs() { |
| Map<String, Job> oldJobs = null; |
| oldJobs = this.readyJobs; |
| this.readyJobs = new Hashtable<String, Job>(); |
| |
| for (Job nextJob : oldJobs.values()) { |
| //System.out.println("Job to submit to Hadoop: " + nextJob.getJobName()); |
| nextJob.submit(); |
| //System.out.println("Hadoop ID: " + nextJob.getMapredJobID()); |
| this.addToQueue(nextJob); |
| } |
| } |
| |
| synchronized public boolean allFinished() { |
| return this.waitingJobs.size() == 0 && |
| this.readyJobs.size() == 0 && |
| this.runningJobs.size() == 0; |
| } |
| |
| /** |
| * The main loop for the thread. |
| * The loop does the following: |
| * Check the states of the running jobs |
| * Update the states of waiting jobs |
| * Submit the jobs in ready state |
| */ |
| public void run() { |
| this.runnerState = JobControl.RUNNING; |
| while (true) { |
| while (this.runnerState == JobControl.SUSPENDED) { |
| try { |
| Thread.sleep(5000); |
| } |
| catch (Exception e) { |
| |
| } |
| } |
| checkRunningJobs(); |
| checkWaitingJobs(); |
| startReadyJobs(); |
| if (this.runnerState != JobControl.RUNNING && |
| this.runnerState != JobControl.SUSPENDED) { |
| break; |
| } |
| try { |
| Thread.sleep(5000); |
| } |
| catch (Exception e) { |
| |
| } |
| if (this.runnerState != JobControl.RUNNING && |
| this.runnerState != JobControl.SUSPENDED) { |
| break; |
| } |
| } |
| this.runnerState = JobControl.STOPPED; |
| } |
| |
| } |