org.apache.twill.example.yarn.HelloWorld.java Source code

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Here is the source code for org.apache.twill.example.yarn.HelloWorld.java

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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.twill.example.yarn;

import com.google.common.base.Joiner;
import com.google.common.base.Splitter;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import com.google.common.util.concurrent.Futures;
import org.apache.hadoop.yarn.conf.YarnConfiguration;
import org.apache.twill.api.AbstractTwillRunnable;
import org.apache.twill.api.ClassAcceptor;
import org.apache.twill.api.TwillController;
import org.apache.twill.api.TwillRunnerService;
import org.apache.twill.api.logging.PrinterLogHandler;
import org.apache.twill.yarn.YarnTwillRunnerService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.PrintWriter;
import java.net.URL;
import java.util.List;
import java.util.concurrent.ExecutionException;

/**
 * Hello World example using twill-yarn to run a TwillApplication over YARN.
 */
public class HelloWorld {
    public static final Logger LOG = LoggerFactory.getLogger(HelloWorld.class);

    /**
     * Hello World runnable that is provided to TwillRunnerService to be run.
     */
    private static class HelloWorldRunnable extends AbstractTwillRunnable {
        @Override
        public void run() {
            LOG.info("Hello World. My first distributed application.");
        }

        @Override
        public void stop() {
        }
    }

    public static void main(String[] args) {
        if (args.length < 1) {
            System.err.println("Arguments format: <host:port of zookeeper server>");
            System.exit(1);
        }

        String zkStr = args[0];
        YarnConfiguration yarnConfiguration = new YarnConfiguration();
        final TwillRunnerService twillRunner = new YarnTwillRunnerService(yarnConfiguration, zkStr);
        twillRunner.start();

        String yarnClasspath = yarnConfiguration.get(YarnConfiguration.YARN_APPLICATION_CLASSPATH,
                Joiner.on(",").join(YarnConfiguration.DEFAULT_YARN_APPLICATION_CLASSPATH));
        List<String> applicationClassPaths = Lists.newArrayList();
        Iterables.addAll(applicationClassPaths, Splitter.on(",").split(yarnClasspath));
        final TwillController controller = twillRunner.prepare(new HelloWorldRunnable())
                .addLogHandler(new PrinterLogHandler(new PrintWriter(System.out, true)))
                .withApplicationClassPaths(applicationClassPaths)
                .withBundlerClassAcceptor(new HadoopClassExcluder()).start();

        Runtime.getRuntime().addShutdownHook(new Thread() {
            @Override
            public void run() {
                try {
                    Futures.getUnchecked(controller.terminate());
                } finally {
                    twillRunner.stop();
                }
            }
        });

        try {
            controller.awaitTerminated();
        } catch (ExecutionException e) {
            e.printStackTrace();
        }
    }

    static class HadoopClassExcluder extends ClassAcceptor {
        @Override
        public boolean accept(String className, URL classUrl, URL classPathUrl) {
            // exclude hadoop but not hbase package
            return !(className.startsWith("org.apache.hadoop") && !className.startsWith("org.apache.hadoop.hbase"));
        }
    }
}