Java tutorial
/** * 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 com.datatorrent.stram; import java.io.StringWriter; import java.util.Map; import org.apache.commons.cli.CommandLine; import org.apache.commons.cli.GnuParser; import org.apache.commons.cli.HelpFormatter; import org.apache.commons.cli.Options; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.yarn.api.ApplicationConstants.Environment; import org.apache.hadoop.yarn.api.records.ApplicationAttemptId; import org.apache.hadoop.yarn.api.records.ContainerId; import org.apache.hadoop.yarn.conf.YarnConfiguration; import org.apache.hadoop.yarn.util.ConverterUtils; import org.apache.hadoop.yarn.util.Records; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.datatorrent.stram.debug.StdOutErrLog; import com.datatorrent.stram.util.VersionInfo; /** * Entry point for Streaming Application Master * <p> * * @since 0.3.2 */ public class StreamingAppMaster extends StramUtils.YarnContainerMain { private static final Logger LOG = LoggerFactory.getLogger(StreamingAppMaster.class); /** * @param args * Command line args * @throws Throwable */ public static void main(final String[] args) throws Throwable { StdOutErrLog.tieSystemOutAndErrToLog(); LOG.info("Master starting with classpath: {}", System.getProperty("java.class.path")); LOG.info("version: {}", VersionInfo.APEX_VERSION.getBuildVersion()); StringWriter sw = new StringWriter(); for (Map.Entry<String, String> e : System.getenv().entrySet()) { sw.append("\n").append(e.getKey()).append("=").append(e.getValue()); } LOG.info("appmaster env:" + sw.toString()); Options opts = new Options(); opts.addOption("app_attempt_id", true, "App Attempt ID. Not to be used unless for testing purposes"); opts.addOption("help", false, "Print usage"); CommandLine cliParser = new GnuParser().parse(opts, args); // option "help" overrides and cancels any run if (cliParser.hasOption("help")) { new HelpFormatter().printHelp("ApplicationMaster", opts); return; } Map<String, String> envs = System.getenv(); ApplicationAttemptId appAttemptID = Records.newRecord(ApplicationAttemptId.class); if (!envs.containsKey(Environment.CONTAINER_ID.name())) { if (cliParser.hasOption("app_attempt_id")) { String appIdStr = cliParser.getOptionValue("app_attempt_id", ""); appAttemptID = ConverterUtils.toApplicationAttemptId(appIdStr); } else { throw new IllegalArgumentException("Application Attempt Id not set in the environment"); } } else { ContainerId containerId = ConverterUtils.toContainerId(envs.get(Environment.CONTAINER_ID.name())); appAttemptID = containerId.getApplicationAttemptId(); } boolean result = false; StreamingAppMasterService appMaster = null; try { appMaster = new StreamingAppMasterService(appAttemptID); LOG.info("Initializing Application Master."); Configuration conf = new YarnConfiguration(); appMaster.init(conf); appMaster.start(); result = appMaster.run(); } catch (Throwable t) { LOG.error("Exiting Application Master", t); System.exit(1); } finally { if (appMaster != null) { appMaster.stop(); } } if (result) { LOG.info("Application Master completed."); System.exit(0); } else { LOG.info("Application Master failed."); System.exit(2); } } public StreamingAppMaster() { } }