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* 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.pig.backend.hadoop.executionengine.shims;
import java.io.IOException;
import java.util.Arrays;
import java.util.Iterator;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.mapred.Counters;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.RunningJob;
import org.apache.hadoop.mapred.jobcontrol.Job;
import org.apache.hadoop.mapred.jobcontrol.JobControl;
import org.apache.hadoop.mapred.TaskReport;
import org.apache.hadoop.mapreduce.JobContext;
import org.apache.hadoop.mapreduce.JobID;
import org.apache.hadoop.mapreduce.OutputCommitter;
import org.apache.hadoop.mapreduce.TaskAttemptContext;
import org.apache.hadoop.mapreduce.TaskAttemptID;
import org.apache.hadoop.mapreduce.TaskType;
import org.apache.pig.PigConfiguration;
import org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MRConfiguration;
import org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigOutputCommitter;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POStore;
import org.apache.pig.backend.hadoop20.PigJobControl;
/**
* We need to make Pig work with both hadoop 20 and hadoop 23 (PIG-2125). However,
* there is API differences between hadoop 20 and 23. Here we use a shims layer to
* hide these API differences. A dynamic shims layer is not possible due to some
* static dependencies. We adopt a static shims approach. For different hadoop version,
* we need to recompile.
*
* This class wrapping all static method. PigMapReduce, PigMapBase, MiniCluster wrapping hadoop
* version dependant implementation of PigGenericMapReduce, PigGenericMapBase and MiniGenericCluster.
**/
public class HadoopShims {
private static Log LOG = LogFactory.getLog(HadoopShims.class);
static public JobContext cloneJobContext(JobContext original) throws IOException, InterruptedException {
JobContext newContext = new JobContext(original.getConfiguration(), original.getJobID());
return newContext;
}
static public TaskAttemptContext createTaskAttemptContext(Configuration conf,
TaskAttemptID taskId) {
TaskAttemptContext newContext = new TaskAttemptContext(conf,
taskId);
return newContext;
}
static public JobContext createJobContext(Configuration conf,
JobID jobId) {
JobContext newJobContext = new JobContext(
conf, jobId);
return newJobContext;
}
static public boolean isMap(TaskAttemptID taskAttemptID) {
return taskAttemptID.isMap();
}
static public TaskAttemptID getNewTaskAttemptID() {
return new TaskAttemptID();
}
static public TaskAttemptID createTaskAttemptID(String jtIdentifier, int jobId, boolean isMap,
int taskId, int id) {
return new TaskAttemptID(jtIdentifier, jobId, isMap, taskId, id);
}
static public void storeSchemaForLocal(Job job, POStore st) throws IOException {
JobContext jc = HadoopShims.createJobContext(job.getJobConf(),
new org.apache.hadoop.mapreduce.JobID());
JobContext updatedJc = PigOutputCommitter.setUpContext(jc, st);
PigOutputCommitter.storeCleanup(st, updatedJc.getConfiguration());
}
static public String getFsCounterGroupName() {
return "FileSystemCounters";
}
static public void commitOrCleanup(OutputCommitter oc, JobContext jc) throws IOException {
oc.cleanupJob(jc);
}
public static JobControl newJobControl(String groupName, int timeToSleep) {
return new PigJobControl(groupName, timeToSleep);
}
public static long getDefaultBlockSize(FileSystem fs, Path path) {
return fs.getDefaultBlockSize();
}
public static Counters getCounters(Job job) throws IOException {
JobClient jobClient = job.getJobClient();
return jobClient.getJob(job.getAssignedJobID()).getCounters();
}
public static boolean isJobFailed(TaskReport report) {
float successfulProgress = 1.0f;
// if the progress reported is not 1.0f then the map or reduce
// job failed
// this comparison is in place for the backward compatibility
// for Hadoop 0.20
return report.getProgress() != successfulProgress;
}
public static void unsetConf(Configuration conf, String key) {
// Not supported in Hadoop 0.20/1.x
}
/**
* Fetch mode needs to explicitly set the task id which is otherwise done by Hadoop
* @param conf
* @param taskAttemptID
*/
public static void setTaskAttemptId(Configuration conf, TaskAttemptID taskAttemptID) {
conf.set(MRConfiguration.TASK_ID, taskAttemptID.toString());
}
/**
* Returns whether the give path has a FileSystem implementation.
*
* @param path path
* @param conf configuration
* @return true if the give path's scheme has a FileSystem implementation,
* false otherwise
*/
public static boolean hasFileSystemImpl(Path path, Configuration conf) {
String scheme = path.toUri().getScheme();
if (scheme != null) {
String fsImpl = conf.get("fs." + scheme + ".impl");
if (fsImpl == null) {
return false;
}
}
return true;
}
/**
* Returns the progress of a Job j which is part of a submitted JobControl
* object. The progress is for this Job. So it has to be scaled down by the
* num of jobs that are present in the JobControl.
*
* @param j The Job for which progress is required
* @return Returns the percentage progress of this Job
* @throws IOException
*/
public static double progressOfRunningJob(Job j)
throws IOException {
RunningJob rj = j.getJobClient().getJob(j.getAssignedJobID());
if (rj == null && j.getState() == Job.SUCCESS)
return 1;
else if (rj == null)
return 0;
else {
return (rj.mapProgress() + rj.reduceProgress()) / 2;
}
}
public static void killJob(Job job) throws IOException {
RunningJob runningJob = job.getJobClient().getJob(job.getAssignedJobID());
if (runningJob != null)
runningJob.killJob();
}
public static Iterator<TaskReport> getTaskReports(Job job, TaskType type) throws IOException {
if (job.getJobConf().getBoolean(PigConfiguration.PIG_NO_TASK_REPORT, false)) {
LOG.info("TaskReports are disabled for job: " + job.getAssignedJobID());
return null;
}
JobClient jobClient = job.getJobClient();
TaskReport[] reports = null;
if (type == TaskType.MAP) {
reports = jobClient.getMapTaskReports(job.getAssignedJobID());
} else {
reports = jobClient.getReduceTaskReports(job.getAssignedJobID());
}
return reports == null ? null : Arrays.asList(reports).iterator();
}
public static boolean isHadoopYARN() {
return false;
}
}