/**
* 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.hadoop.mapred;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintStream;
import java.net.InetSocketAddress;
import java.net.URI;
import java.security.PrivilegedExceptionAction;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Vector;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.filecache.DistributedCache;
import org.apache.hadoop.filecache.TaskDistributedCacheManager;
import org.apache.hadoop.filecache.TrackerDistributedCacheManager;
import org.apache.hadoop.mapreduce.security.TokenCache;
import org.apache.hadoop.mapreduce.server.tasktracker.Localizer;
import org.apache.hadoop.fs.FSError;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.FileUtil;
import org.apache.hadoop.fs.LocalDirAllocator;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.util.Shell;
import org.apache.hadoop.util.StringUtils;
import org.apache.hadoop.mapreduce.JobContext;
/** Base class that runs a task in a separate process. Tasks are run in a
* separate process in order to isolate the map/reduce system code from bugs in
* user supplied map and reduce functions.
*/
abstract class TaskRunner extends Thread {
public static final Log LOG =
LogFactory.getLog(TaskRunner.class);
volatile boolean killed = false;
private TaskTracker.TaskInProgress tip;
private Task t;
private Object lock = new Object();
private volatile boolean done = false;
private int exitCode = -1;
private boolean exitCodeSet = false;
private static String SYSTEM_PATH_SEPARATOR = System.getProperty("path.separator");
private TaskTracker tracker;
private TaskDistributedCacheManager taskDistributedCacheManager;
protected JobConf conf;
JvmManager jvmManager;
/**
* for cleaning up old map outputs
*/
protected MapOutputFile mapOutputFile;
public TaskRunner(TaskTracker.TaskInProgress tip, TaskTracker tracker,
JobConf conf) {
this.tip = tip;
this.t = tip.getTask();
this.tracker = tracker;
this.conf = conf;
this.mapOutputFile = new MapOutputFile();
this.mapOutputFile.setConf(conf);
this.jvmManager = tracker.getJvmManagerInstance();
}
public Task getTask() { return t; }
public TaskTracker.TaskInProgress getTaskInProgress() { return tip; }
public TaskTracker getTracker() { return tracker; }
/** Called to assemble this task's input. This method is run in the parent
* process before the child is spawned. It should not execute user code,
* only system code. */
public boolean prepare() throws IOException {
return true;
}
/** Called when this task's output is no longer needed.
* This method is run in the parent process after the child exits. It should
* not execute user code, only system code.
*/
public void close() throws IOException {}
/**
* Get the java command line options for the child map/reduce tasks.
* @param jobConf job configuration
* @param defaultValue default value
* @return the java command line options for child map/reduce tasks
* @deprecated Use command line options specific to map or reduce tasks set
* via {@link JobConf#MAPRED_MAP_TASK_JAVA_OPTS} or
* {@link JobConf#MAPRED_REDUCE_TASK_JAVA_OPTS}
*/
@Deprecated
public String getChildJavaOpts(JobConf jobConf, String defaultValue) {
return jobConf.get(JobConf.MAPRED_TASK_JAVA_OPTS, defaultValue);
}
/**
* Get the maximum virtual memory of the child map/reduce tasks.
* @param jobConf job configuration
* @return the maximum virtual memory of the child task or <code>-1</code> if
* none is specified
* @deprecated Use limits specific to the map or reduce tasks set via
* {@link JobConf#MAPRED_MAP_TASK_ULIMIT} or
* {@link JobConf#MAPRED_REDUCE_TASK_ULIMIT}
*/
@Deprecated
public int getChildUlimit(JobConf jobConf) {
return jobConf.getInt(JobConf.MAPRED_TASK_ULIMIT, -1);
}
/**
* Get the environment variables for the child map/reduce tasks.
* @param jobConf job configuration
* @return the environment variables for the child map/reduce tasks or
* <code>null</code> if unspecified
* @deprecated Use environment variables specific to the map or reduce tasks
* set via {@link JobConf#MAPRED_MAP_TASK_ENV} or
* {@link JobConf#MAPRED_REDUCE_TASK_ENV}
*/
public String getChildEnv(JobConf jobConf) {
return jobConf.get(JobConf.MAPRED_TASK_ENV);
}
@Override
public final void run() {
String errorInfo = "Child Error";
try {
//before preparing the job localize
//all the archives
TaskAttemptID taskid = t.getTaskID();
final LocalDirAllocator lDirAlloc = new LocalDirAllocator("mapred.local.dir");
final File workDir = formWorkDir(lDirAlloc, taskid, t.isTaskCleanupTask(), conf);
// We don't create any symlinks yet, so presence/absence of workDir
// actually on the file system doesn't matter.
tip.getUGI().doAs(new PrivilegedExceptionAction<Void>() {
public Void run() throws IOException {
taskDistributedCacheManager =
tracker.getTrackerDistributedCacheManager()
.newTaskDistributedCacheManager(conf);
taskDistributedCacheManager.setup(lDirAlloc, workDir, TaskTracker
.getPrivateDistributedCacheDir(conf.getUser()),
TaskTracker.getPublicDistributedCacheDir());
return null;
}
});
// Set up the child task's configuration. After this call, no localization
// of files should happen in the TaskTracker's process space. Any changes to
// the conf object after this will NOT be reflected to the child.
setupChildTaskConfiguration(lDirAlloc);
if (!prepare()) {
return;
}
// Accumulates class paths for child.
List<String> classPaths = getClassPaths(conf, workDir,
taskDistributedCacheManager);
long logSize = TaskLog.getTaskLogLength(conf);
// Build exec child JVM args.
Vector<String> vargs = getVMArgs(taskid, workDir, classPaths, logSize);
tracker.addToMemoryManager(t.getTaskID(), t.isMapTask(), conf);
// set memory limit using ulimit if feasible and necessary ...
List<String> setup = getVMSetupCmd();
// Set up the redirection of the task's stdout and stderr streams
File[] logFiles = prepareLogFiles(taskid, t.isTaskCleanupTask());
File stdout = logFiles[0];
File stderr = logFiles[1];
List<TaskTrackerInstrumentation> ttInstrumentations =
tracker.getTaskTrackerInstrumentations();
for (TaskTrackerInstrumentation inst: ttInstrumentations) {
inst.reportTaskLaunch(taskid, stdout, stderr);
}
Map<String, String> env = new HashMap<String, String>();
errorInfo = getVMEnvironment(errorInfo, workDir, conf, env, taskid,
logSize);
launchJvmAndWait(setup, vargs, stdout, stderr, logSize, workDir, env);
for (TaskTrackerInstrumentation inst: ttInstrumentations) {
inst.reportTaskEnd(t.getTaskID());
}
if (exitCodeSet) {
if (!killed && exitCode != 0) {
if (exitCode == 65) {
for (TaskTrackerInstrumentation inst: ttInstrumentations) {
inst.taskFailedPing(t.getTaskID());
}
}
throw new IOException("Task process exit with nonzero status of " +
exitCode + ".");
}
}
} catch (FSError e) {
LOG.fatal("FSError", e);
try {
tracker.internalFsError(t.getTaskID(), e.getMessage());
} catch (IOException ie) {
LOG.fatal(t.getTaskID()+" reporting FSError", ie);
}
} catch (Throwable throwable) {
LOG.warn(t.getTaskID() + " : " + errorInfo, throwable);
Throwable causeThrowable = new Throwable(errorInfo, throwable);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
causeThrowable.printStackTrace(new PrintStream(baos));
try {
tracker.internalReportDiagnosticInfo(t.getTaskID(), baos.toString());
} catch (IOException e) {
LOG.warn(t.getTaskID()+" Reporting Diagnostics", e);
}
} finally {
try{
if (taskDistributedCacheManager != null) {
taskDistributedCacheManager.release();
}
}catch(IOException ie){
LOG.warn("Error releasing caches : Cache files might not have been cleaned up");
}
// It is safe to call TaskTracker.TaskInProgress.reportTaskFinished with
// *false* since the task has either
// a) SUCCEEDED - which means commit has been done
// b) FAILED - which means we do not need to commit
tip.reportTaskFinished(false);
}
}
void launchJvmAndWait(List<String> setup, Vector<String> vargs, File stdout,
File stderr, long logSize, File workDir, Map<String, String> env)
throws InterruptedException {
jvmManager.launchJvm(this, jvmManager.constructJvmEnv(setup, vargs, stdout,
stderr, logSize, workDir, env, conf));
synchronized (lock) {
while (!done) {
lock.wait();
}
}
}
/**
* Prepare the log files for the task
*
* @param taskid
* @param isCleanup
* @return an array of files. The first file is stdout, the second is stderr.
* @throws IOException
*/
File[] prepareLogFiles(TaskAttemptID taskid, boolean isCleanup)
throws IOException {
File[] logFiles = new File[2];
logFiles[0] = TaskLog.getTaskLogFile(taskid, isCleanup,
TaskLog.LogName.STDOUT);
logFiles[1] = TaskLog.getTaskLogFile(taskid, isCleanup,
TaskLog.LogName.STDERR);
File logDir = logFiles[0].getParentFile();
boolean b = logDir.mkdirs();
if (!b) {
LOG.warn("mkdirs failed. Ignoring");
} else {
Localizer.PermissionsHandler.setPermissions(logDir,
Localizer.PermissionsHandler.sevenZeroZero);
}
return logFiles;
}
/**
* Write the child's configuration to the disk and set it in configuration so
* that the child can pick it up from there.
*
* @param lDirAlloc
* @throws IOException
*/
void setupChildTaskConfiguration(LocalDirAllocator lDirAlloc)
throws IOException {
Path localTaskFile =
lDirAlloc.getLocalPathForWrite(TaskTracker.getTaskConfFile(
t.getUser(), t.getJobID().toString(), t.getTaskID().toString(), t
.isTaskCleanupTask()), conf);
// write the child's task configuration file to the local disk
writeLocalTaskFile(localTaskFile.toString(), conf);
// Set the final job file in the task. The child needs to know the correct
// path to job.xml. So set this path accordingly.
t.setJobFile(localTaskFile.toString());
}
/**
* @return
*/
private List<String> getVMSetupCmd() {
String[] ulimitCmd = Shell.getUlimitMemoryCommand(getChildUlimit(conf));
List<String> setup = null;
if (ulimitCmd != null) {
setup = new ArrayList<String>();
for (String arg : ulimitCmd) {
setup.add(arg);
}
}
return setup;
}
/**
* @param taskid
* @param workDir
* @param classPaths
* @param logSize
* @return
* @throws IOException
*/
private Vector<String> getVMArgs(TaskAttemptID taskid, File workDir,
List<String> classPaths, long logSize)
throws IOException {
Vector<String> vargs = new Vector<String>(8);
File jvm = // use same jvm as parent
new File(new File(System.getProperty("java.home"), "bin"), "java");
vargs.add(jvm.toString());
// Add child (task) java-vm options.
//
// The following symbols if present in mapred.{map|reduce}.child.java.opts
// value are replaced:
// + @taskid@ is interpolated with value of TaskID.
// Other occurrences of @ will not be altered.
//
// Example with multiple arguments and substitutions, showing
// jvm GC logging, and start of a passwordless JVM JMX agent so can
// connect with jconsole and the likes to watch child memory, threads
// and get thread dumps.
//
// <property>
// <name>mapred.map.child.java.opts</name>
// <value>-Xmx 512M -verbose:gc -Xloggc:/tmp/@taskid@.gc \
// -Dcom.sun.management.jmxremote.authenticate=false \
// -Dcom.sun.management.jmxremote.ssl=false \
// </value>
// </property>
//
// <property>
// <name>mapred.reduce.child.java.opts</name>
// <value>-Xmx 1024M -verbose:gc -Xloggc:/tmp/@taskid@.gc \
// -Dcom.sun.management.jmxremote.authenticate=false \
// -Dcom.sun.management.jmxremote.ssl=false \
// </value>
// </property>
//
String javaOpts = getChildJavaOpts(conf,
JobConf.DEFAULT_MAPRED_TASK_JAVA_OPTS);
javaOpts = javaOpts.replace("@taskid@", taskid.toString());
String [] javaOptsSplit = javaOpts.split(" ");
// Add java.library.path; necessary for loading native libraries.
//
// 1. To support native-hadoop library i.e. libhadoop.so, we add the
// parent processes' java.library.path to the child.
// 2. We also add the 'cwd' of the task to it's java.library.path to help
// users distribute native libraries via the DistributedCache.
// 3. The user can also specify extra paths to be added to the
// java.library.path via mapred.{map|reduce}.child.java.opts.
//
String libraryPath = System.getProperty("java.library.path");
if (libraryPath == null) {
libraryPath = workDir.getAbsolutePath();
} else {
libraryPath += SYSTEM_PATH_SEPARATOR + workDir;
}
boolean hasUserLDPath = false;
for(int i=0; i<javaOptsSplit.length ;i++) {
if(javaOptsSplit[i].startsWith("-Djava.library.path=")) {
javaOptsSplit[i] += SYSTEM_PATH_SEPARATOR + libraryPath;
hasUserLDPath = true;
break;
}
}
if(!hasUserLDPath) {
vargs.add("-Djava.library.path=" + libraryPath);
}
for (int i = 0; i < javaOptsSplit.length; i++) {
vargs.add(javaOptsSplit[i]);
}
Path childTmpDir = createChildTmpDir(workDir, conf);
vargs.add("-Djava.io.tmpdir=" + childTmpDir);
// Add classpath.
vargs.add("-classpath");
String classPath = StringUtils.join(SYSTEM_PATH_SEPARATOR, classPaths);
vargs.add(classPath);
// Setup the log4j prop
setupLog4jProperties(vargs, taskid, logSize);
if (conf.getProfileEnabled()) {
if (conf.getProfileTaskRange(t.isMapTask()
).isIncluded(t.getPartition())) {
File prof = TaskLog.getTaskLogFile(taskid, t.isTaskCleanupTask(),
TaskLog.LogName.PROFILE);
vargs.add(String.format(conf.getProfileParams(), prof.toString()));
}
}
// Add main class and its arguments
vargs.add(Child.class.getName()); // main of Child
// pass umbilical address
InetSocketAddress address = tracker.getTaskTrackerReportAddress();
vargs.add(address.getAddress().getHostAddress());
vargs.add(Integer.toString(address.getPort()));
vargs.add(taskid.toString()); // pass task identifier
// pass task log location
vargs.add(TaskLog.getAttemptDir(taskid, t.isTaskCleanupTask()).toString());
return vargs;
}
private void setupLog4jProperties(Vector<String> vargs, TaskAttemptID taskid,
long logSize) {
vargs.add("-Dhadoop.log.dir=" +
new File(System.getProperty("hadoop.log.dir")).getAbsolutePath());
vargs.add("-Dhadoop.root.logger=INFO,TLA");
vargs.add("-Dhadoop.tasklog.taskid=" + taskid);
vargs.add("-Dhadoop.tasklog.iscleanup=" + t.isTaskCleanupTask());
vargs.add("-Dhadoop.tasklog.totalLogFileSize=" + logSize);
}
/**
* @param taskid
* @param workDir
* @return
* @throws IOException
*/
static Path createChildTmpDir(File workDir,
JobConf conf)
throws IOException {
// add java.io.tmpdir given by mapred.child.tmp
String tmp = conf.get("mapred.child.tmp", "./tmp");
Path tmpDir = new Path(tmp);
// if temp directory path is not absolute, prepend it with workDir.
if (!tmpDir.isAbsolute()) {
tmpDir = new Path(workDir.toString(), tmp);
FileSystem localFs = FileSystem.getLocal(conf);
if (!localFs.mkdirs(tmpDir) && !localFs.getFileStatus(tmpDir).isDir()) {
throw new IOException("Mkdirs failed to create " + tmpDir.toString());
}
}
return tmpDir;
}
/**
*/
private static List<String> getClassPaths(JobConf conf, File workDir,
TaskDistributedCacheManager taskDistributedCacheManager)
throws IOException {
// Accumulates class paths for child.
List<String> classPaths = new ArrayList<String>();
// start with same classpath as parent process
appendSystemClasspaths(classPaths);
// include the user specified classpath
appendJobJarClasspaths(conf.getJar(), classPaths);
// Distributed cache paths
classPaths.addAll(taskDistributedCacheManager.getClassPaths());
// Include the working dir too
classPaths.add(workDir.toString());
return classPaths;
}
/**
* @param errorInfo
* @param workDir
* @param env
* @return
* @throws Throwable
*/
private String getVMEnvironment(String errorInfo, File workDir, JobConf conf,
Map<String, String> env, TaskAttemptID taskid, long logSize)
throws Throwable {
StringBuffer ldLibraryPath = new StringBuffer();
ldLibraryPath.append(workDir.toString());
String oldLdLibraryPath = null;
oldLdLibraryPath = System.getenv("LD_LIBRARY_PATH");
if (oldLdLibraryPath != null) {
ldLibraryPath.append(SYSTEM_PATH_SEPARATOR);
ldLibraryPath.append(oldLdLibraryPath);
}
env.put("LD_LIBRARY_PATH", ldLibraryPath.toString());
String jobTokenFile = conf.get(TokenCache.JOB_TOKENS_FILENAME);
LOG.debug("putting jobToken file name into environment fn=" + jobTokenFile);
env.put(UserGroupInformation.HADOOP_TOKEN_FILE_LOCATION, jobTokenFile);
// for the child of task jvm, set hadoop.root.logger
env.put("HADOOP_ROOT_LOGGER","INFO,TLA");
String hadoopClientOpts = System.getenv("HADOOP_CLIENT_OPTS");
if (hadoopClientOpts == null) {
hadoopClientOpts = "";
} else {
hadoopClientOpts = hadoopClientOpts + " ";
}
hadoopClientOpts = hadoopClientOpts + "-Dhadoop.tasklog.taskid=" + taskid
+ " -Dhadoop.tasklog.iscleanup=" + t.isTaskCleanupTask()
+ " -Dhadoop.tasklog.totalLogFileSize=" + logSize;
env.put("HADOOP_CLIENT_OPTS", "\"" + hadoopClientOpts + "\"");
// add the env variables passed by the user
String mapredChildEnv = getChildEnv(conf);
if (mapredChildEnv != null && mapredChildEnv.length() > 0) {
String childEnvs[] = mapredChildEnv.split(",");
for (String cEnv : childEnvs) {
try {
String[] parts = cEnv.split("="); // split on '='
String value = env.get(parts[0]);
if (value != null) {
// replace $env with the child's env constructed by tt's
// example LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/tmp
value = parts[1].replace("$" + parts[0], value);
} else {
// this key is not configured by the tt for the child .. get it
// from the tt's env
// example PATH=$PATH:/tmp
value = System.getenv(parts[0]);
if (value != null) {
// the env key is present in the tt's env
value = parts[1].replace("$" + parts[0], value);
} else {
// the env key is note present anywhere .. simply set it
// example X=$X:/tmp or X=/tmp
value = parts[1].replace("$" + parts[0], "");
}
}
env.put(parts[0], value);
} catch (Throwable t) {
// set the error msg
errorInfo = "Invalid User environment settings : " + mapredChildEnv
+ ". Failed to parse user-passed environment param."
+ " Expecting : env1=value1,env2=value2...";
LOG.warn(errorInfo);
throw t;
}
}
}
return errorInfo;
}
/**
* Write the task specific job-configuration file.
*
* @param localFs
* @throws IOException
*/
private static void writeLocalTaskFile(String jobFile, JobConf conf)
throws IOException {
Path localTaskFile = new Path(jobFile);
FileSystem localFs = FileSystem.getLocal(conf);
localFs.delete(localTaskFile, true);
OutputStream out = localFs.create(localTaskFile);
try {
conf.writeXml(out);
} finally {
out.close();
}
}
/**
* Prepare the mapred.local.dir for the child. The child is sand-boxed now.
* Whenever it uses LocalDirAllocator from now on inside the child, it will
* only see files inside the attempt-directory. This is done in the Child's
* process space.
*/
static void setupChildMapredLocalDirs(Task t, JobConf conf) {
String[] localDirs = conf.getStrings(JobConf.MAPRED_LOCAL_DIR_PROPERTY);
String jobId = t.getJobID().toString();
String taskId = t.getTaskID().toString();
boolean isCleanup = t.isTaskCleanupTask();
String user = t.getUser();
StringBuffer childMapredLocalDir =
new StringBuffer(localDirs[0] + Path.SEPARATOR
+ TaskTracker.getLocalTaskDir(user, jobId, taskId, isCleanup));
for (int i = 1; i < localDirs.length; i++) {
childMapredLocalDir.append("," + localDirs[i] + Path.SEPARATOR
+ TaskTracker.getLocalTaskDir(user, jobId, taskId, isCleanup));
}
LOG.debug("mapred.local.dir for child : " + childMapredLocalDir);
conf.set("mapred.local.dir", childMapredLocalDir.toString());
}
/** Creates the working directory pathname for a task attempt. */
static File formWorkDir(LocalDirAllocator lDirAlloc,
TaskAttemptID task, boolean isCleanup, JobConf conf)
throws IOException {
Path workDir =
lDirAlloc.getLocalPathToRead(TaskTracker.getTaskWorkDir(
conf.getUser(), task.getJobID().toString(), task.toString(),
isCleanup), conf);
return new File(workDir.toString());
}
private static void appendSystemClasspaths(List<String> classPaths) {
for (String c : System.getProperty("java.class.path").split(
SYSTEM_PATH_SEPARATOR)) {
classPaths.add(c);
}
}
/**
* Given a "jobJar" (typically retrieved via {@link Configuration.getJar()}),
* appends classpath entries for it, as well as its lib/ and classes/
* subdirectories.
*
* @param jobJar Job jar from configuration
* @param classPaths Accumulator for class paths
*/
static void appendJobJarClasspaths(String jobJar, List<String> classPaths) {
if (jobJar == null) {
return;
}
File jobCacheDir = new File(new Path(jobJar).getParent().toString());
// if jar exists, it into workDir
File[] libs = new File(jobCacheDir, "lib").listFiles();
if (libs != null) {
for (File l : libs) {
classPaths.add(l.toString());
}
}
classPaths.add(new File(jobCacheDir, "classes").toString());
classPaths.add(jobJar);
}
/**
* Creates distributed cache symlinks and tmp directory, as appropriate.
* Note that when we setup the distributed
* cache, we didn't create the symlinks. This is done on a per task basis
* by the currently executing task.
*
* @param conf The job configuration.
* @param workDir Working directory, which is completely deleted.
*/
public static void setupWorkDir(JobConf conf, File workDir) throws IOException {
if (LOG.isDebugEnabled()) {
LOG.debug("Fully deleting contents of " + workDir);
}
/** delete only the contents of workDir leaving the directory empty. We
* can't delete the workDir as it is the current working directory.
*/
FileUtil.fullyDeleteContents(workDir);
if (DistributedCache.getSymlink(conf)) {
URI[] archives = DistributedCache.getCacheArchives(conf);
URI[] files = DistributedCache.getCacheFiles(conf);
Path[] localArchives = DistributedCache.getLocalCacheArchives(conf);
Path[] localFiles = DistributedCache.getLocalCacheFiles(conf);
if (archives != null) {
for (int i = 0; i < archives.length; i++) {
String link = archives[i].getFragment();
String target = localArchives[i].toString();
symlink(workDir, target, link);
}
}
if (files != null) {
for (int i = 0; i < files.length; i++) {
String link = files[i].getFragment();
String target = localFiles[i].toString();
symlink(workDir, target, link);
}
}
}
if (conf.getJar() != null) {
File jobCacheDir = new File(
new Path(conf.getJar()).getParent().toString());
// create symlinks for all the files in job cache dir in current
// workingdir for streaming
try{
TrackerDistributedCacheManager.createAllSymlink(conf, jobCacheDir,
workDir);
} catch(IOException ie){
// Do not exit even if symlinks have not been created.
LOG.warn(StringUtils.stringifyException(ie));
}
}
createChildTmpDir(workDir, conf);
}
/**
* Utility method for creating a symlink and warning on errors.
*
* If link is null, does nothing.
*/
private static void symlink(File workDir, String target, String link)
throws IOException {
if (link != null) {
link = workDir.toString() + Path.SEPARATOR + link;
File flink = new File(link);
if (!flink.exists()) {
LOG.info(String.format("Creating symlink: %s <- %s", target, link));
if (0 != FileUtil.symLink(target, link)) {
LOG.warn(String.format("Failed to create symlink: %s <- %s", target, link));
}
}
}
}
/**
* Kill the child process
*/
public void kill() {
killed = true;
jvmManager.taskKilled(this);
signalDone();
}
public void signalDone() {
synchronized (lock) {
done = true;
lock.notify();
}
}
public void setExitCode(int exitCode) {
this.exitCodeSet = true;
this.exitCode = exitCode;
}
}