/**
* 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.test;
import java.io.*;
import java.util.Properties;
import org.apache.hadoop.hdfs.MiniDFSCluster;
import org.apache.hadoop.mapred.MiniMRCluster;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.fs.FileSystem;
import org.apache.pig.backend.hadoop.datastorage.ConfigurationUtil;
/**
* This class builds a single instance of itself with the Singleton
* design pattern. While building the single instance, it sets up a
* mini cluster that actually consists of a mini DFS cluster and a
* mini MapReduce cluster on the local machine and also sets up the
* environment for Pig to run on top of the mini cluster.
*/
public class MiniCluster {
private MiniDFSCluster m_dfs = null;
private MiniMRCluster m_mr = null;
private FileSystem m_fileSys = null;
private JobConf m_conf = null;
private final static MiniCluster INSTANCE = new MiniCluster();
private static boolean isSetup = true;
private MiniCluster() {
setupMiniDfsAndMrClusters();
}
private void setupMiniDfsAndMrClusters() {
try {
final int dataNodes = 4; // There will be 4 data nodes
final int taskTrackers = 4; // There will be 4 task tracker nodes
Configuration config = new Configuration();
// Builds and starts the mini dfs and mapreduce clusters
m_dfs = new MiniDFSCluster(config, dataNodes, true, null);
m_fileSys = m_dfs.getFileSystem();
m_mr = new MiniMRCluster(taskTrackers, m_fileSys.getUri().toString(), 1);
// Create the configuration hadoop-site.xml file
File conf_dir = new File(System.getProperty("user.home"), "pigtest/conf/");
conf_dir.mkdirs();
File conf_file = new File(conf_dir, "hadoop-site.xml");
// Write the necessary config info to hadoop-site.xml
m_conf = m_mr.createJobConf();
m_conf.setInt("mapred.submit.replication", 2);
m_conf.set("dfs.datanode.address", "0.0.0.0:0");
m_conf.set("dfs.datanode.http.address", "0.0.0.0:0");
m_conf.writeXml(new FileOutputStream(conf_file));
// Set the system properties needed by Pig
System.setProperty("cluster", m_conf.get("mapred.job.tracker"));
System.setProperty("namenode", m_conf.get("fs.default.name"));
System.setProperty("junit.hadoop.conf", conf_dir.getPath());
} catch (IOException e) {
throw new RuntimeException(e);
}
}
/**
* Returns the single instance of class MiniClusterBuilder that
* represents the resouces for a mini dfs cluster and a mini
* mapreduce cluster.
*/
public static MiniCluster buildCluster() {
if(! isSetup){
INSTANCE.setupMiniDfsAndMrClusters();
isSetup = true;
}
return INSTANCE;
}
public void shutDown(){
INSTANCE.shutdownMiniDfsAndMrClusters();
}
protected void finalize() {
shutdownMiniDfsAndMrClusters();
}
private void shutdownMiniDfsAndMrClusters() {
isSetup = false;
try {
if (m_fileSys != null) { m_fileSys.close(); }
} catch (IOException e) {
e.printStackTrace();
}
if (m_dfs != null) { m_dfs.shutdown(); }
if (m_mr != null) { m_mr.shutdown(); }
m_fileSys = null;
m_dfs = null;
m_mr = null;
}
public Properties getProperties() {
errorIfNotSetup();
return ConfigurationUtil.toProperties(m_conf);
}
public Configuration getConfiguration() {
return new Configuration(m_conf);
}
public void setProperty(String name, String value) {
errorIfNotSetup();
m_conf.set(name, value);
}
public FileSystem getFileSystem() {
errorIfNotSetup();
return m_fileSys;
}
/**
* Throw RunTimeException if isSetup is false
*/
private void errorIfNotSetup(){
if(isSetup)
return;
String msg = "function called on MiniCluster that has been shutdown";
throw new RuntimeException(msg);
}
}