| /** |
| * 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.mapreduce.lib.jobcontrol; |
| |
| |
| import java.io.IOException; |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.FileSystem; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.mapreduce.Job; |
| import org.apache.hadoop.mapreduce.JobID; |
| import org.apache.hadoop.mapreduce.lib.input.FileInputFormat; |
| import org.apache.hadoop.util.StringUtils; |
| |
| /** |
| * This class encapsulates a MapReduce job and its dependency. It monitors |
| * the states of the depending jobs and updates the state of this job. |
| * A job starts in the WAITING state. If it does not have any depending jobs, |
| * or all of the depending jobs are in SUCCESS state, then the job state |
| * will become READY. If any depending jobs fail, the job will fail too. |
| * When in READY state, the job can be submitted to Hadoop for execution, with |
| * the state changing into RUNNING state. From RUNNING state, the job |
| * can get into SUCCESS or FAILED state, depending |
| * the status of the job execution. |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Evolving |
| public class ControlledJob { |
| |
| // A job will be in one of the following states |
| public static enum State {SUCCESS, WAITING, RUNNING, READY, FAILED, |
| DEPENDENT_FAILED}; |
| public static final String CREATE_DIR = "mapreduce.jobcontrol.createdir.ifnotexist"; |
| private State state; |
| private String controlID; // assigned and used by JobControl class |
| private Job job; // mapreduce job to be executed. |
| // some info for human consumption, e.g. the reason why the job failed |
| private String message; |
| // the jobs the current job depends on |
| private List<ControlledJob> dependingJobs; |
| |
| /** |
| * Construct a job. |
| * @param job a mapreduce job to be executed. |
| * @param dependingJobs an array of jobs the current job depends on |
| */ |
| public ControlledJob(Job job, List<ControlledJob> dependingJobs) |
| throws IOException { |
| this.job = job; |
| this.dependingJobs = dependingJobs; |
| this.state = State.WAITING; |
| this.controlID = "unassigned"; |
| this.message = "just initialized"; |
| } |
| |
| /** |
| * Construct a job. |
| * |
| * @param conf mapred job configuration representing a job to be executed. |
| * @throws IOException |
| */ |
| public ControlledJob(Configuration conf) throws IOException { |
| this(new Job(conf), null); |
| } |
| |
| @Override |
| public String toString() { |
| StringBuffer sb = new StringBuffer(); |
| sb.append("job name:\t").append(this.job.getJobName()).append("\n"); |
| sb.append("job id:\t").append(this.controlID).append("\n"); |
| sb.append("job state:\t").append(this.state).append("\n"); |
| sb.append("job mapred id:\t").append(this.job.getJobID()).append("\n"); |
| sb.append("job message:\t").append(this.message).append("\n"); |
| |
| if (this.dependingJobs == null || this.dependingJobs.size() == 0) { |
| sb.append("job has no depending job:\t").append("\n"); |
| } else { |
| sb.append("job has ").append(this.dependingJobs.size()). |
| append(" dependeng jobs:\n"); |
| for (int i = 0; i < this.dependingJobs.size(); i++) { |
| sb.append("\t depending job ").append(i).append(":\t"); |
| sb.append((this.dependingJobs.get(i)).getJobName()).append("\n"); |
| } |
| } |
| return sb.toString(); |
| } |
| |
| /** |
| * @return the job name of this job |
| */ |
| public String getJobName() { |
| return job.getJobName(); |
| } |
| |
| /** |
| * Set the job name for this job. |
| * @param jobName the job name |
| */ |
| public void setJobName(String jobName) { |
| job.setJobName(jobName); |
| } |
| |
| /** |
| * @return the job ID of this job assigned by JobControl |
| */ |
| public String getJobID() { |
| return this.controlID; |
| } |
| |
| /** |
| * Set the job ID for this job. |
| * @param id the job ID |
| */ |
| public void setJobID(String id) { |
| this.controlID = id; |
| } |
| |
| /** |
| * @return the mapred ID of this job as assigned by the |
| * mapred framework. |
| */ |
| public JobID getMapredJobID() { |
| return this.job.getJobID(); |
| } |
| |
| /** |
| * @return the mapreduce job |
| */ |
| public synchronized Job getJob() { |
| return this.job; |
| } |
| |
| /** |
| * Set the mapreduce job |
| * @param job the mapreduce job for this job. |
| */ |
| public synchronized void setJob(Job job) { |
| this.job = job; |
| } |
| |
| /** |
| * @return the state of this job |
| */ |
| public synchronized State getJobState() { |
| return this.state; |
| } |
| |
| /** |
| * Set the state for this job. |
| * @param state the new state for this job. |
| */ |
| protected synchronized void setJobState(State state) { |
| this.state = state; |
| } |
| |
| /** |
| * @return the message of this job |
| */ |
| public synchronized String getMessage() { |
| return this.message; |
| } |
| |
| /** |
| * Set the message for this job. |
| * @param message the message for this job. |
| */ |
| public synchronized void setMessage(String message) { |
| this.message = message; |
| } |
| |
| /** |
| * @return the depending jobs of this job |
| */ |
| public List<ControlledJob> getDependentJobs() { |
| return this.dependingJobs; |
| } |
| |
| /** |
| * Add a job to this jobs' dependency list. |
| * Dependent jobs can only be added while a Job |
| * is waiting to run, not during or afterwards. |
| * |
| * @param dependingJob Job that this Job depends on. |
| * @return <tt>true</tt> if the Job was added. |
| */ |
| public synchronized boolean addDependingJob(ControlledJob dependingJob) { |
| if (this.state == State.WAITING) { //only allowed to add jobs when waiting |
| if (this.dependingJobs == null) { |
| this.dependingJobs = new ArrayList<ControlledJob>(); |
| } |
| return this.dependingJobs.add(dependingJob); |
| } else { |
| return false; |
| } |
| } |
| |
| /** |
| * @return true if this job is in a complete state |
| */ |
| public synchronized boolean isCompleted() { |
| return this.state == State.FAILED || |
| this.state == State.DEPENDENT_FAILED || |
| this.state == State.SUCCESS; |
| } |
| |
| /** |
| * @return true if this job is in READY state |
| */ |
| public synchronized boolean isReady() { |
| return this.state == State.READY; |
| } |
| |
| public void killJob() throws IOException, InterruptedException { |
| job.killJob(); |
| } |
| |
| /** |
| * Check the state of this running job. The state may |
| * remain the same, become SUCCESS or FAILED. |
| */ |
| private void checkRunningState() throws IOException, InterruptedException { |
| try { |
| if (job.isComplete()) { |
| if (job.isSuccessful()) { |
| this.state = State.SUCCESS; |
| } else { |
| this.state = State.FAILED; |
| this.message = "Job failed!"; |
| } |
| } |
| } catch (IOException ioe) { |
| this.state = State.FAILED; |
| this.message = StringUtils.stringifyException(ioe); |
| try { |
| if (job != null) { |
| job.killJob(); |
| } |
| } catch (IOException e) {} |
| } |
| } |
| |
| /** |
| * Check and update the state of this job. The state changes |
| * depending on its current state and the states of the depending jobs. |
| */ |
| synchronized State checkState() throws IOException, InterruptedException { |
| if (this.state == State.RUNNING) { |
| checkRunningState(); |
| } |
| if (this.state != State.WAITING) { |
| return this.state; |
| } |
| if (this.dependingJobs == null || this.dependingJobs.size() == 0) { |
| this.state = State.READY; |
| return this.state; |
| } |
| ControlledJob pred = null; |
| int n = this.dependingJobs.size(); |
| for (int i = 0; i < n; i++) { |
| pred = this.dependingJobs.get(i); |
| State s = pred.checkState(); |
| if (s == State.WAITING || s == State.READY || s == State.RUNNING) { |
| break; // a pred is still not completed, continue in WAITING |
| // state |
| } |
| if (s == State.FAILED || s == State.DEPENDENT_FAILED) { |
| this.state = State.DEPENDENT_FAILED; |
| this.message = "depending job " + i + " with jobID " |
| + pred.getJobID() + " failed. " + pred.getMessage(); |
| break; |
| } |
| // pred must be in success state |
| if (i == n - 1) { |
| this.state = State.READY; |
| } |
| } |
| |
| return this.state; |
| } |
| |
| /** |
| * Submit this job to mapred. The state becomes RUNNING if submission |
| * is successful, FAILED otherwise. |
| */ |
| protected synchronized void submit() { |
| try { |
| Configuration conf = job.getConfiguration(); |
| if (conf.getBoolean(CREATE_DIR, false)) { |
| FileSystem fs = FileSystem.get(conf); |
| Path inputPaths[] = FileInputFormat.getInputPaths(job); |
| for (int i = 0; i < inputPaths.length; i++) { |
| if (!fs.exists(inputPaths[i])) { |
| try { |
| fs.mkdirs(inputPaths[i]); |
| } catch (IOException e) { |
| |
| } |
| } |
| } |
| } |
| job.submit(); |
| this.state = State.RUNNING; |
| } catch (Exception ioe) { |
| this.state = State.FAILED; |
| this.message = StringUtils.stringifyException(ioe); |
| } |
| } |
| |
| } |