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.srini.hadoopYarn; import java.io.File; import java.io.IOException; import java.nio.ByteBuffer; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Vector; 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.commons.cli.ParseException; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.hadoop.classification.InterfaceAudience; import org.apache.hadoop.classification.InterfaceStability; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.FileStatus; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.Path; import org.apache.hadoop.io.DataOutputBuffer; import org.apache.hadoop.security.Credentials; import org.apache.hadoop.security.UserGroupInformation; import org.apache.hadoop.security.token.Token; import org.apache.hadoop.yarn.api.ApplicationClientProtocol; import org.apache.hadoop.yarn.api.ApplicationConstants; import org.apache.hadoop.yarn.api.ApplicationConstants.Environment; import org.apache.hadoop.yarn.api.protocolrecords.GetNewApplicationResponse; import org.apache.hadoop.yarn.api.protocolrecords.KillApplicationRequest; import org.apache.hadoop.yarn.api.records.ApplicationId; import org.apache.hadoop.yarn.api.records.ApplicationReport; import org.apache.hadoop.yarn.api.records.ApplicationSubmissionContext; import org.apache.hadoop.yarn.api.records.ContainerLaunchContext; import org.apache.hadoop.yarn.api.records.FinalApplicationStatus; import org.apache.hadoop.yarn.api.records.LocalResource; import org.apache.hadoop.yarn.api.records.LocalResourceType; import org.apache.hadoop.yarn.api.records.LocalResourceVisibility; import org.apache.hadoop.yarn.api.records.NodeReport; import org.apache.hadoop.yarn.api.records.NodeState; import org.apache.hadoop.yarn.api.records.Priority; import org.apache.hadoop.yarn.api.records.QueueACL; import org.apache.hadoop.yarn.api.records.QueueInfo; import org.apache.hadoop.yarn.api.records.QueueUserACLInfo; import org.apache.hadoop.yarn.api.records.Resource; import org.apache.hadoop.yarn.api.records.YarnApplicationState; import org.apache.hadoop.yarn.api.records.YarnClusterMetrics; import org.apache.hadoop.yarn.client.api.YarnClient; import org.apache.hadoop.yarn.client.api.YarnClientApplication; import org.apache.hadoop.yarn.conf.YarnConfiguration; import org.apache.hadoop.yarn.exceptions.YarnException; import org.apache.hadoop.yarn.util.ConverterUtils; import org.apache.hadoop.yarn.util.Records; /** * Client for Distributed Shell application submission to YARN. * * <p> The distributed shell client allows an application master to be launched that in turn would run * the provided shell command on a set of containers. </p> * * <p>This client is meant to act as an example on how to write yarn-based applications. </p> * * <p> To submit an application, a client first needs to connect to the <code>ResourceManager</code> * aka ApplicationsManager or ASM via the {@link ApplicationClientProtocol}. The {@link ApplicationClientProtocol} * provides a way for the client to get access to cluster information and to request for a * new {@link ApplicationId}. <p> * * <p> For the actual job submission, the client first has to create an {@link ApplicationSubmissionContext}. * The {@link ApplicationSubmissionContext} defines the application details such as {@link ApplicationId} * and application name, the priority assigned to the application and the queue * to which this application needs to be assigned. In addition to this, the {@link ApplicationSubmissionContext} * also defines the {@link ContainerLaunchContext} which describes the <code>Container</code> with which * the {@link ApplicationMaster} is launched. </p> * * <p> The {@link ContainerLaunchContext} in this scenario defines the resources to be allocated for the * {@link ApplicationMaster}'s container, the local resources (jars, configuration files) to be made available * and the environment to be set for the {@link ApplicationMaster} and the commands to be executed to run the * {@link ApplicationMaster}. <p> * * <p> Using the {@link ApplicationSubmissionContext}, the client submits the application to the * <code>ResourceManager</code> and then monitors the application by requesting the <code>ResourceManager</code> * for an {@link ApplicationReport} at regular time intervals. In case of the application taking too long, the client * kills the application by submitting a {@link KillApplicationRequest} to the <code>ResourceManager</code>. </p> * */ @InterfaceAudience.Public @InterfaceStability.Unstable public class Client { private static final Log LOG = LogFactory.getLog(Client.class); // Configuration private Configuration conf; private YarnClient yarnClient; // Application master specific info to register a new Application with RM/ASM private String appName = ""; // App master priority private int amPriority = 0; // Queue for App master private String amQueue = ""; // Amt. of memory resource to request for to run the App Master private int amMemory = 10; // Application master jar file private String appMasterJar = ""; // Main class to invoke application master private final String appMasterMainClass; // Shell command to be executed private String shellCommand = ""; // Location of shell script private String shellScriptPath = ""; // Args to be passed to the shell command private String shellArgs = ""; // Env variables to be setup for the shell command private Map<String, String> shellEnv = new HashMap<String, String>(); // Shell Command Container priority private int shellCmdPriority = 0; // Amt of memory to request for container in which shell script will be executed private int containerMemory = 10; // No. of containers in which the shell script needs to be executed private int numContainers = 1; // log4j.properties file // if available, add to local resources and set into classpath private String log4jPropFile = ""; // Start time for client private final long clientStartTime = System.currentTimeMillis(); // Timeout threshold for client. Kill app after time interval expires. private long clientTimeout = 600000; // Debug flag boolean debugFlag = false; // Command line options private Options opts; /** * @param args Command line arguments */ public static void main(String[] args) { boolean result = false; try { Client client = new Client(); LOG.info("Initializing Client"); try { boolean doRun = client.init(args); if (!doRun) { System.exit(0); } } catch (IllegalArgumentException e) { System.err.println(e.getLocalizedMessage()); client.printUsage(); System.exit(-1); } result = client.run(); } catch (Throwable t) { LOG.fatal("Error running CLient", t); System.exit(1); } if (result) { LOG.info("Application completed successfully"); System.exit(0); } LOG.error("Application failed to complete successfully"); System.exit(2); } /** */ public Client(Configuration conf) throws Exception { this("com.srini.hadoopYarn.ApplicationMaster", conf); } Client(String appMasterMainClass, Configuration conf) { this.conf = conf; this.appMasterMainClass = appMasterMainClass; yarnClient = YarnClient.createYarnClient(); yarnClient.init(conf); opts = new Options(); opts.addOption("appname", true, "Application Name. Default value - DistributedShell"); opts.addOption("priority", true, "Application Priority. Default 0"); opts.addOption("queue", true, "RM Queue in which this application is to be submitted"); opts.addOption("timeout", true, "Application timeout in milliseconds"); opts.addOption("master_memory", true, "Amount of memory in MB to be requested to run the application master"); opts.addOption("jar", true, "Jar file containing the application master"); opts.addOption("shell_command", true, "Shell command to be executed by the Application Master"); opts.addOption("shell_script", true, "Location of the shell script to be executed"); opts.addOption("shell_args", true, "Command line args for the shell script"); opts.addOption("shell_env", true, "Environment for shell script. Specified as env_key=env_val pairs"); opts.addOption("shell_cmd_priority", true, "Priority for the shell command containers"); opts.addOption("container_memory", true, "Amount of memory in MB to be requested to run the shell command"); opts.addOption("num_containers", true, "No. of containers on which the shell command needs to be executed"); opts.addOption("log_properties", true, "log4j.properties file"); opts.addOption("debug", false, "Dump out debug information"); opts.addOption("help", false, "Print usage"); } /** */ public Client() throws Exception { this(new YarnConfiguration()); } /** * Helper function to print out usage */ private void printUsage() { new HelpFormatter().printHelp("Client", opts); } /** * Parse command line options * @param args Parsed command line options * @return Whether the init was successful to run the client * @throws ParseException */ public boolean init(String[] args) throws ParseException { CommandLine cliParser = new GnuParser().parse(opts, args); if (args.length == 0) { throw new IllegalArgumentException("No args specified for client to initialize"); } if (cliParser.hasOption("help")) { printUsage(); return false; } if (cliParser.hasOption("debug")) { debugFlag = true; } appName = cliParser.getOptionValue("appname", "DistributedShell"); amPriority = Integer.parseInt(cliParser.getOptionValue("priority", "0")); amQueue = cliParser.getOptionValue("queue", "default"); amMemory = Integer.parseInt(cliParser.getOptionValue("master_memory", "10")); if (amMemory < 0) { throw new IllegalArgumentException( "Invalid memory specified for application master, exiting." + " Specified memory=" + amMemory); } if (!cliParser.hasOption("jar")) { throw new IllegalArgumentException("No jar file specified for application master"); } appMasterJar = cliParser.getOptionValue("jar"); if (!cliParser.hasOption("shell_command")) { throw new IllegalArgumentException("No shell command specified to be executed by application master"); } shellCommand = cliParser.getOptionValue("shell_command"); if (cliParser.hasOption("shell_script")) { shellScriptPath = cliParser.getOptionValue("shell_script"); } if (cliParser.hasOption("shell_args")) { shellArgs = cliParser.getOptionValue("shell_args"); } if (cliParser.hasOption("shell_env")) { String envs[] = cliParser.getOptionValues("shell_env"); for (String env : envs) { env = env.trim(); int index = env.indexOf('='); if (index == -1) { shellEnv.put(env, ""); continue; } String key = env.substring(0, index); String val = ""; if (index < (env.length() - 1)) { val = env.substring(index + 1); } shellEnv.put(key, val); } } shellCmdPriority = Integer.parseInt(cliParser.getOptionValue("shell_cmd_priority", "0")); containerMemory = Integer.parseInt(cliParser.getOptionValue("container_memory", "10")); numContainers = Integer.parseInt(cliParser.getOptionValue("num_containers", "1")); if (containerMemory < 0 || numContainers < 1) { throw new IllegalArgumentException("Invalid no. of containers or container memory specified, exiting." + " Specified containerMemory=" + containerMemory + ", numContainer=" + numContainers); } clientTimeout = Integer.parseInt(cliParser.getOptionValue("timeout", "600000")); log4jPropFile = cliParser.getOptionValue("log_properties", ""); return true; } /** * Main run function for the client * @return true if application completed successfully * @throws IOException * @throws YarnException */ public boolean run() throws IOException, YarnException { LOG.info("Running Client"); yarnClient.start(); YarnClusterMetrics clusterMetrics = yarnClient.getYarnClusterMetrics(); LOG.info("Got Cluster metric info from ASM" + ", numNodeManagers=" + clusterMetrics.getNumNodeManagers()); List<NodeReport> clusterNodeReports = yarnClient.getNodeReports(NodeState.RUNNING); LOG.info("Got Cluster node info from ASM"); for (NodeReport node : clusterNodeReports) { LOG.info("Got node report from ASM for" + ", nodeId=" + node.getNodeId() + ", nodeAddress" + node.getHttpAddress() + ", nodeRackName" + node.getRackName() + ", nodeNumContainers" + node.getNumContainers()); } QueueInfo queueInfo = yarnClient.getQueueInfo(this.amQueue); LOG.info("Queue info" + ", queueName=" + queueInfo.getQueueName() + ", queueCurrentCapacity=" + queueInfo.getCurrentCapacity() + ", queueMaxCapacity=" + queueInfo.getMaximumCapacity() + ", queueApplicationCount=" + queueInfo.getApplications().size() + ", queueChildQueueCount=" + queueInfo.getChildQueues().size()); List<QueueUserACLInfo> listAclInfo = yarnClient.getQueueAclsInfo(); for (QueueUserACLInfo aclInfo : listAclInfo) { for (QueueACL userAcl : aclInfo.getUserAcls()) { LOG.info("User ACL Info for Queue" + ", queueName=" + aclInfo.getQueueName() + ", userAcl=" + userAcl.name()); } } // Get a new application id YarnClientApplication app = yarnClient.createApplication(); GetNewApplicationResponse appResponse = app.getNewApplicationResponse(); // TODO get min/max resource capabilities from RM and change memory ask if needed // If we do not have min/max, we may not be able to correctly request // the required resources from the RM for the app master // Memory ask has to be a multiple of min and less than max. // Dump out information about cluster capability as seen by the resource manager int maxMem = appResponse.getMaximumResourceCapability().getMemory(); LOG.info("Max mem capabililty of resources in this cluster " + maxMem); // A resource ask cannot exceed the max. if (amMemory > maxMem) { LOG.info("AM memory specified above max threshold of cluster. Using max value." + ", specified=" + amMemory + ", max=" + maxMem); amMemory = maxMem; } // set the application name ApplicationSubmissionContext appContext = app.getApplicationSubmissionContext(); ApplicationId appId = appContext.getApplicationId(); appContext.setApplicationName(appName); // Set up the container launch context for the application master ContainerLaunchContext amContainer = Records.newRecord(ContainerLaunchContext.class); // set local resources for the application master // local files or archives as needed // In this scenario, the jar file for the application master is part of the local resources Map<String, LocalResource> localResources = new HashMap<String, LocalResource>(); LOG.info("Copy App Master jar from local filesystem and add to local environment"); // Copy the application master jar to the filesystem // Create a local resource to point to the destination jar path FileSystem fs = FileSystem.get(conf); Path src = new Path(appMasterJar); String pathSuffix = appName + "/" + appId.getId() + "/AppMaster.jar"; Path dst = new Path(fs.getHomeDirectory(), pathSuffix); fs.copyFromLocalFile(false, true, src, dst); FileStatus destStatus = fs.getFileStatus(dst); LocalResource amJarRsrc = Records.newRecord(LocalResource.class); // Set the type of resource - file or archive // archives are untarred at destination // we don't need the jar file to be untarred for now amJarRsrc.setType(LocalResourceType.FILE); // Set visibility of the resource // Setting to most private option amJarRsrc.setVisibility(LocalResourceVisibility.APPLICATION); // Set the resource to be copied over amJarRsrc.setResource(ConverterUtils.getYarnUrlFromPath(dst)); // Set timestamp and length of file so that the framework // can do basic sanity checks for the local resource // after it has been copied over to ensure it is the same // resource the client intended to use with the application amJarRsrc.setTimestamp(destStatus.getModificationTime()); amJarRsrc.setSize(destStatus.getLen()); localResources.put("AppMaster.jar", amJarRsrc); // Set the log4j properties if needed if (!log4jPropFile.isEmpty()) { Path log4jSrc = new Path(log4jPropFile); Path log4jDst = new Path(fs.getHomeDirectory(), "log4j.props"); fs.copyFromLocalFile(false, true, log4jSrc, log4jDst); FileStatus log4jFileStatus = fs.getFileStatus(log4jDst); LocalResource log4jRsrc = Records.newRecord(LocalResource.class); log4jRsrc.setType(LocalResourceType.FILE); log4jRsrc.setVisibility(LocalResourceVisibility.APPLICATION); log4jRsrc.setResource(ConverterUtils.getYarnUrlFromURI(log4jDst.toUri())); log4jRsrc.setTimestamp(log4jFileStatus.getModificationTime()); log4jRsrc.setSize(log4jFileStatus.getLen()); localResources.put("log4j.properties", log4jRsrc); } // The shell script has to be made available on the final container(s) // where it will be executed. // To do this, we need to first copy into the filesystem that is visible // to the yarn framework. // We do not need to set this as a local resource for the application // master as the application master does not need it. String hdfsShellScriptLocation = ""; long hdfsShellScriptLen = 0; long hdfsShellScriptTimestamp = 0; if (!shellScriptPath.isEmpty()) { Path shellSrc = new Path(shellScriptPath); String shellPathSuffix = appName + "/" + appId.getId() + "/ExecShellScript.sh"; Path shellDst = new Path(fs.getHomeDirectory(), shellPathSuffix); fs.copyFromLocalFile(false, true, shellSrc, shellDst); hdfsShellScriptLocation = shellDst.toUri().toString(); FileStatus shellFileStatus = fs.getFileStatus(shellDst); hdfsShellScriptLen = shellFileStatus.getLen(); hdfsShellScriptTimestamp = shellFileStatus.getModificationTime(); } // Set local resource info into app master container launch context amContainer.setLocalResources(localResources); // Set the necessary security tokens as needed //amContainer.setContainerTokens(containerToken); // Set the env variables to be setup in the env where the application master will be run LOG.info("Set the environment for the application master"); Map<String, String> env = new HashMap<String, String>(); // put location of shell script into env // using the env info, the application master will create the correct local resource for the // eventual containers that will be launched to execute the shell scripts env.put(DSConstants.DISTRIBUTEDSHELLSCRIPTLOCATION, hdfsShellScriptLocation); env.put(DSConstants.DISTRIBUTEDSHELLSCRIPTTIMESTAMP, Long.toString(hdfsShellScriptTimestamp)); env.put(DSConstants.DISTRIBUTEDSHELLSCRIPTLEN, Long.toString(hdfsShellScriptLen)); // Add AppMaster.jar location to classpath // At some point we should not be required to add // the hadoop specific classpaths to the env. // It should be provided out of the box. // For now setting all required classpaths including // the classpath to "." for the application jar StringBuilder classPathEnv = new StringBuilder(Environment.CLASSPATH.$()).append(File.pathSeparatorChar) .append("./*"); for (String c : conf.getStrings(YarnConfiguration.YARN_APPLICATION_CLASSPATH, YarnConfiguration.DEFAULT_YARN_APPLICATION_CLASSPATH)) { classPathEnv.append(File.pathSeparatorChar); classPathEnv.append(c.trim()); } classPathEnv.append(File.pathSeparatorChar).append("./log4j.properties"); // add the runtime classpath needed for tests to work if (conf.getBoolean(YarnConfiguration.IS_MINI_YARN_CLUSTER, false)) { classPathEnv.append(':'); classPathEnv.append(System.getProperty("java.class.path")); } env.put("CLASSPATH", classPathEnv.toString()); amContainer.setEnvironment(env); // Set the necessary command to execute the application master Vector<CharSequence> vargs = new Vector<CharSequence>(30); // Set java executable command LOG.info("Setting up app master command"); vargs.add(Environment.JAVA_HOME.$() + "/bin/java"); // Set Xmx based on am memory size vargs.add("-Xmx" + amMemory + "m"); // Set class name vargs.add(appMasterMainClass); // Set params for Application Master vargs.add("--container_memory " + String.valueOf(containerMemory)); vargs.add("--num_containers " + String.valueOf(numContainers)); vargs.add("--priority " + String.valueOf(shellCmdPriority)); if (!shellCommand.isEmpty()) { vargs.add("--shell_command " + shellCommand + ""); } if (!shellArgs.isEmpty()) { vargs.add("--shell_args " + shellArgs + ""); } for (Map.Entry<String, String> entry : shellEnv.entrySet()) { vargs.add("--shell_env " + entry.getKey() + "=" + entry.getValue()); } if (debugFlag) { vargs.add("--debug"); } vargs.add("1>" + ApplicationConstants.LOG_DIR_EXPANSION_VAR + "/AppMaster.stdout"); vargs.add("2>" + ApplicationConstants.LOG_DIR_EXPANSION_VAR + "/AppMaster.stderr"); // Get final commmand StringBuilder command = new StringBuilder(); for (CharSequence str : vargs) { command.append(str).append(" "); } LOG.info("Completed setting up app master command " + command.toString()); List<String> commands = new ArrayList<String>(); commands.add(command.toString()); amContainer.setCommands(commands); // Set up resource type requirements // For now, only memory is supported so we set memory requirements Resource capability = Records.newRecord(Resource.class); capability.setMemory(amMemory); appContext.setResource(capability); // Service data is a binary blob that can be passed to the application // Not needed in this scenario // amContainer.setServiceData(serviceData); // Setup security tokens if (UserGroupInformation.isSecurityEnabled()) { Credentials credentials = new Credentials(); String tokenRenewer = conf.get(YarnConfiguration.RM_PRINCIPAL); if (tokenRenewer == null || tokenRenewer.length() == 0) { throw new IOException("Can't get Master Kerberos principal for the RM to use as renewer"); } // For now, only getting tokens for the default file-system. final Token<?> tokens[] = fs.addDelegationTokens(tokenRenewer, credentials); if (tokens != null) { for (Token<?> token : tokens) { LOG.info("Got dt for " + fs.getUri() + "; " + token); } } DataOutputBuffer dob = new DataOutputBuffer(); credentials.writeTokenStorageToStream(dob); ByteBuffer fsTokens = ByteBuffer.wrap(dob.getData(), 0, dob.getLength()); amContainer.setTokens(fsTokens); } appContext.setAMContainerSpec(amContainer); // Set the priority for the application master Priority pri = Records.newRecord(Priority.class); // TODO - what is the range for priority? how to decide? pri.setPriority(amPriority); appContext.setPriority(pri); // Set the queue to which this application is to be submitted in the RM appContext.setQueue(amQueue); // Submit the application to the applications manager // SubmitApplicationResponse submitResp = applicationsManager.submitApplication(appRequest); // Ignore the response as either a valid response object is returned on success // or an exception thrown to denote some form of a failure LOG.info("Submitting application to ASM"); yarnClient.submitApplication(appContext); // TODO // Try submitting the same request again // app submission failure? // Monitor the application return monitorApplication(appId); } /** * Monitor the submitted application for completion. * Kill application if time expires. * @param appId Application Id of application to be monitored * @return true if application completed successfully * @throws YarnException * @throws IOException */ private boolean monitorApplication(ApplicationId appId) throws YarnException, IOException { while (true) { // Check app status every 1 second. try { Thread.sleep(1000); } catch (InterruptedException e) { LOG.debug("Thread sleep in monitoring loop interrupted"); } // Get application report for the appId we are interested in ApplicationReport report = yarnClient.getApplicationReport(appId); LOG.info("Got application report from ASM for" + ", appId=" + appId.getId() + ", clientToAMToken=" + report.getClientToAMToken() + ", appDiagnostics=" + report.getDiagnostics() + ", appMasterHost=" + report.getHost() + ", appQueue=" + report.getQueue() + ", appMasterRpcPort=" + report.getRpcPort() + ", appStartTime=" + report.getStartTime() + ", yarnAppState=" + report.getYarnApplicationState().toString() + ", distributedFinalState=" + report.getFinalApplicationStatus().toString() + ", appTrackingUrl=" + report.getTrackingUrl() + ", appUser=" + report.getUser()); YarnApplicationState state = report.getYarnApplicationState(); FinalApplicationStatus dsStatus = report.getFinalApplicationStatus(); if (YarnApplicationState.FINISHED == state) { if (FinalApplicationStatus.SUCCEEDED == dsStatus) { LOG.info("Application has completed successfully. Breaking monitoring loop"); return true; } else { LOG.info("Application did finished unsuccessfully." + " YarnState=" + state.toString() + ", DSFinalStatus=" + dsStatus.toString() + ". Breaking monitoring loop"); return false; } } else if (YarnApplicationState.KILLED == state || YarnApplicationState.FAILED == state) { LOG.info("Application did not finish." + " YarnState=" + state.toString() + ", DSFinalStatus=" + dsStatus.toString() + ". Breaking monitoring loop"); return false; } if (System.currentTimeMillis() > (clientStartTime + clientTimeout)) { LOG.info("Reached client specified timeout for application. Killing application"); forceKillApplication(appId); return false; } } } /** * Kill a submitted application by sending a call to the ASM * @param appId Application Id to be killed. * @throws YarnException * @throws IOException */ private void forceKillApplication(ApplicationId appId) throws YarnException, IOException { // TODO clarify whether multiple jobs with the same app id can be submitted and be running at // the same time. // If yes, can we kill a particular attempt only? // Response can be ignored as it is non-null on success or // throws an exception in case of failures yarnClient.killApplication(appId); } }