/*
* 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.flink.api.java.hadoop.mapred;
import org.apache.flink.annotation.Internal;
import org.apache.flink.api.common.io.FinalizeOnMaster;
import org.apache.flink.api.java.hadoop.common.HadoopOutputFormatCommonBase;
import org.apache.flink.api.java.hadoop.mapred.utils.HadoopUtils;
import org.apache.flink.api.java.hadoop.mapred.wrapper.HadoopDummyProgressable;
import org.apache.flink.api.java.hadoop.mapred.wrapper.HadoopDummyReporter;
import org.apache.flink.configuration.Configuration;
import org.apache.hadoop.conf.Configurable;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.JobConfigurable;
import org.apache.hadoop.mapred.JobContext;
import org.apache.hadoop.mapred.JobID;
import org.apache.hadoop.mapred.OutputCommitter;
import org.apache.hadoop.mapred.RecordWriter;
import org.apache.hadoop.mapred.TaskAttemptContext;
import org.apache.hadoop.mapred.TaskAttemptID;
import org.apache.hadoop.security.Credentials;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.util.ReflectionUtils;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import static org.apache.flink.api.java.hadoop.common.HadoopInputFormatCommonBase.getCredentialsFromUGI;
/**
* Common base for the mapred HadoopOutputFormat wrappers. There are implementations for Java and Scala.
*
* @param <K> Type of Key
* @param <V> Type of Value
* @param <T> Record type.
*/
@Internal
public abstract class HadoopOutputFormatBase<K, V, T> extends HadoopOutputFormatCommonBase<T> implements FinalizeOnMaster {
private static final long serialVersionUID = 1L;
// Mutexes to avoid concurrent operations on Hadoop OutputFormats.
// Hadoop parallelizes tasks across JVMs which is why they might rely on this JVM isolation.
// In contrast, Flink parallelizes using Threads, so multiple Hadoop OutputFormat instances
// might be used in the same JVM.
protected static final Object OPEN_MUTEX = new Object();
protected static final Object CONFIGURE_MUTEX = new Object();
protected static final Object CLOSE_MUTEX = new Object();
protected JobConf jobConf;
protected org.apache.hadoop.mapred.OutputFormat<K,V> mapredOutputFormat;
protected transient RecordWriter<K,V> recordWriter;
protected transient OutputCommitter outputCommitter;
protected transient TaskAttemptContext context;
public HadoopOutputFormatBase(org.apache.hadoop.mapred.OutputFormat<K, V> mapredOutputFormat, JobConf job) {
super(job.getCredentials());
this.mapredOutputFormat = mapredOutputFormat;
HadoopUtils.mergeHadoopConf(job);
this.jobConf = job;
}
public JobConf getJobConf() {
return jobConf;
}
// --------------------------------------------------------------------------------------------
// OutputFormat
// --------------------------------------------------------------------------------------------
@Override
public void configure(Configuration parameters) {
// enforce sequential configure() calls
synchronized (CONFIGURE_MUTEX) {
// configure MR OutputFormat if necessary
if (this.mapredOutputFormat instanceof Configurable) {
((Configurable) this.mapredOutputFormat).setConf(this.jobConf);
} else if (this.mapredOutputFormat instanceof JobConfigurable) {
((JobConfigurable) this.mapredOutputFormat).configure(this.jobConf);
}
}
}
/**
* create the temporary output file for hadoop RecordWriter.
* @param taskNumber The number of the parallel instance.
* @param numTasks The number of parallel tasks.
* @throws java.io.IOException
*/
@Override
public void open(int taskNumber, int numTasks) throws IOException {
// enforce sequential open() calls
synchronized (OPEN_MUTEX) {
if (Integer.toString(taskNumber + 1).length() > 6) {
throw new IOException("Task id too large.");
}
TaskAttemptID taskAttemptID = TaskAttemptID.forName("attempt__0000_r_"
+ String.format("%" + (6 - Integer.toString(taskNumber + 1).length()) + "s", " ").replace(" ", "0")
+ Integer.toString(taskNumber + 1)
+ "_0");
this.jobConf.set("mapred.task.id", taskAttemptID.toString());
this.jobConf.setInt("mapred.task.partition", taskNumber + 1);
// for hadoop 2.2
this.jobConf.set("mapreduce.task.attempt.id", taskAttemptID.toString());
this.jobConf.setInt("mapreduce.task.partition", taskNumber + 1);
try {
this.context = HadoopUtils.instantiateTaskAttemptContext(this.jobConf, taskAttemptID);
} catch (Exception e) {
throw new RuntimeException(e);
}
this.outputCommitter = this.jobConf.getOutputCommitter();
JobContext jobContext;
try {
jobContext = HadoopUtils.instantiateJobContext(this.jobConf, new JobID());
} catch (Exception e) {
throw new RuntimeException(e);
}
this.outputCommitter.setupJob(jobContext);
this.recordWriter = this.mapredOutputFormat.getRecordWriter(null, this.jobConf, Integer.toString(taskNumber + 1), new HadoopDummyProgressable());
}
}
/**
* commit the task by moving the output file out from the temporary directory.
* @throws java.io.IOException
*/
@Override
public void close() throws IOException {
// enforce sequential close() calls
synchronized (CLOSE_MUTEX) {
this.recordWriter.close(new HadoopDummyReporter());
if (this.outputCommitter.needsTaskCommit(this.context)) {
this.outputCommitter.commitTask(this.context);
}
}
}
@Override
public void finalizeGlobal(int parallelism) throws IOException {
try {
JobContext jobContext = HadoopUtils.instantiateJobContext(this.jobConf, new JobID());
OutputCommitter outputCommitter = this.jobConf.getOutputCommitter();
// finalize HDFS output format
outputCommitter.commitJob(jobContext);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
// --------------------------------------------------------------------------------------------
// Custom serialization methods
// --------------------------------------------------------------------------------------------
private void writeObject(ObjectOutputStream out) throws IOException {
super.write(out);
out.writeUTF(mapredOutputFormat.getClass().getName());
jobConf.write(out);
}
@SuppressWarnings("unchecked")
private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
super.read(in);
String hadoopOutputFormatName = in.readUTF();
if(jobConf == null) {
jobConf = new JobConf();
}
jobConf.readFields(in);
try {
this.mapredOutputFormat = (org.apache.hadoop.mapred.OutputFormat<K,V>) Class.forName(hadoopOutputFormatName, true, Thread.currentThread().getContextClassLoader()).newInstance();
} catch (Exception e) {
throw new RuntimeException("Unable to instantiate the hadoop output format", e);
}
ReflectionUtils.setConf(mapredOutputFormat, jobConf);
jobConf.getCredentials().addAll(this.credentials);
Credentials currentUserCreds = getCredentialsFromUGI(UserGroupInformation.getCurrentUser());
if(currentUserCreds != null) {
jobConf.getCredentials().addAll(currentUserCreds);
}
}
}