yarn.demo.JavaBasedYarnApplicationClusterDemo.java Source code

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Here is the source code for yarn.demo.JavaBasedYarnApplicationClusterDemo.java

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/*
 * Copyright 2014 the original author or authors.
 *
 * Licensed 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 yarn.demo;

import java.io.File;
import java.nio.ByteBuffer;
import java.util.Random;

import org.apache.hadoop.yarn.conf.YarnConfiguration;

import demo.utils.MiniClusterUtils;

import oz.hadoop.yarn.api.ApplicationContainerProcessor;
import oz.hadoop.yarn.api.YarnApplication;
import oz.hadoop.yarn.api.YarnAssembly;
import oz.hadoop.yarn.api.utils.ConfigUtils;

/**
 * Demo of Application Container(s) implemented as Java process and runs in 
 * YARN Cluster
 * 
 * There is an identical demo that runs in YARN Cluster. Please see 
 * JavaBasedYarnApplicationEmulatorDemo.java in this package.
 * 
 * @author Oleg Zhurakousky
 *
 */
public class JavaBasedYarnApplicationClusterDemo {

    /**
     * Before running ensure that properly configured yarn-site.xml are copied
     * into src/main/resources. You can use the yarn-site.xml from local-config
     * directory of this project. The newly checkout out project is already
     * setup for this.
     * Examples for remote configurations are located in remote-config directory,
     * but you might as well use the ones from your installed cluster.
     *
     * If running in Mini-Cluster (see yarn-test-cluster project), make sure you start it
     * by executing StartMiniCluster.java first.
     */
    public static void main(String[] args) throws Exception {
        MiniClusterUtils.startMiniCluster();

        ConfigUtils.addToClasspath(new File("mini-cluster-config"));

        YarnApplication<Void> yarnApplication = YarnAssembly
                .forApplicationContainer(ReverseMessageContainer.class, ByteBuffer.wrap("Hello Yarn!".getBytes()))
                .containerCount(4).withApplicationMaster(new YarnConfiguration()).maxAttempts(2)
                .build("JavaBasedYarnApplicationDemo");

        yarnApplication.launch();
        yarnApplication.awaitFinish();

        MiniClusterUtils.stoptMiniCluster();
    }

    /**
     * As name suggests this ApplicationContainerProcessor will reverse the input message printing it to 
     * the logs.
     */
    public static class ReverseMessageContainer implements ApplicationContainerProcessor {
        @Override
        public ByteBuffer process(ByteBuffer inputMessage) {

            try {
                Thread.sleep(new Random().nextInt(5000));
            } catch (Exception e) {
                // TODO: handle exception
            }
            inputMessage.rewind();
            byte[] inputBytes = new byte[inputMessage.limit()];
            inputMessage.get(inputBytes);
            String strMessage = new String(inputBytes);
            strMessage = new StringBuilder(strMessage).reverse().toString();
            System.out.println("Processed input into: " + strMessage);
            return null;
            // You can also return ByteBuffer, but since its a finite container
            // the contents of the returned ByteBuffer will be logged (see JavaBasedYarnApplicationEmulatorDemo)

            //return ByteBuffer.wrap(strMessage.getBytes());
        }
    }

}