// Checks if the cache has already been localized and is fresh
private static boolean ifExistsAndFresh(
Configuration conf,
FileSystem fs,
URI cache,
long confFileStamp,
CacheStatus lcacheStatus,
FileStatus fileStatus)
throws IOException {
// check for existence of the cache
long dfsFileStamp;
if (fileStatus != null) {
dfsFileStamp = fileStatus.getModificationTime();
} else {
dfsFileStamp = getTimestamp(conf, cache);
}
// ensure that the file on hdfs hasn't been modified since the job started
if (dfsFileStamp != confFileStamp) {
LOG.fatal("File: " + cache + " has changed on HDFS since job started");
throw new IOException("File: " + cache + " has changed on HDFS since job started");
}
if (dfsFileStamp != lcacheStatus.mtime) {
// needs refreshing
return false;
}
return true;
}
/** Added for back compatibility. */
public static Path getLocalCache(
URI cache,
Configuration conf,
Path subdir,
FileStatus fileStatus,
boolean isArchive,
long confFileStamp,
Path currentWorkDir,
boolean honorSymLinkConf,
MRAsyncDiskService asyncDiskService,
LocalDirAllocator lDirAllocator)
throws IOException {
return getLocalCache(
cache,
conf,
subdir,
fileStatus,
isArchive,
confFileStamp,
fileStatus.getLen(),
currentWorkDir,
honorSymLinkConf,
asyncDiskService,
lDirAllocator);
}
/**
* Get the locally cached file or archive; it could either be previously cached (and valid) or
* copy it from the {@link FileSystem} now.
*
* @param cache the cache to be localized, this should be specified as new
* URI(hdfs://hostname:port/absolute_path_to_file#LINKNAME). If no schema or hostname:port is
* provided the file is assumed to be in the filesystem being used in the Configuration
* @param conf The Confguration file which contains the filesystem
* @param baseDir The base cache Dir where you wnat to localize the files/archives
* @param fileStatus The file status on the dfs.
* @param isArchive if the cache is an archive or a file. In case it is an archive with a .zip or
* .jar or .tar or .tgz or .tar.gz extension it will be unzipped/unjarred/untarred
* automatically and the directory where the archive is unzipped/unjarred/untarred is returned
* as the Path. In case of a file, the path to the file is returned
* @param confFileStamp this is the hdfs file modification timestamp to verify that the file to be
* cached hasn't changed since the job started
* @param currentWorkDir this is the directory where you would want to create symlinks for the
* locally cached files/archives
* @return the path to directory where the archives are unjarred in case of archives, the path to
* the file where the file is copied locally
* @throws IOException
*/
public static Path getLocalCache(
URI cache,
Configuration conf,
Path baseDir,
FileStatus fileStatus,
boolean isArchive,
long confFileStamp,
Path currentWorkDir,
MRAsyncDiskService asyncDiskService)
throws IOException {
return getLocalCache(
cache,
conf,
baseDir,
fileStatus,
isArchive,
confFileStamp,
fileStatus.getLen(),
currentWorkDir,
true,
asyncDiskService,
new LocalDirAllocator("mapred.local.dir"));
}
@Override
public final void run() {
try {
// before preparing the job localize
// all the archives
TaskAttemptID taskid = t.getTaskID();
LocalDirAllocator lDirAlloc = new LocalDirAllocator("mapred.local.dir");
File jobCacheDir = null;
if (conf.getJar() != null) {
jobCacheDir = new File(new Path(conf.getJar()).getParent().toString());
}
File workDir =
new File(
lDirAlloc
.getLocalPathToRead(
TaskTracker.getJobCacheSubdir()
+ Path.SEPARATOR
+ t.getJobID()
+ Path.SEPARATOR
+ t.getTaskID()
+ Path.SEPARATOR
+ MRConstants.WORKDIR,
conf)
.toString());
URI[] archives = DistributedCache.getCacheArchives(conf);
URI[] files = DistributedCache.getCacheFiles(conf);
FileStatus fileStatus;
FileSystem fileSystem;
Path localPath;
String baseDir;
if ((archives != null) || (files != null)) {
if (archives != null) {
String[] archivesTimestamps = DistributedCache.getArchiveTimestamps(conf);
Path[] p = new Path[archives.length];
for (int i = 0; i < archives.length; i++) {
fileSystem = FileSystem.get(archives[i], conf);
fileStatus = fileSystem.getFileStatus(new Path(archives[i].getPath()));
String cacheId = DistributedCache.makeRelative(archives[i], conf);
String cachePath = TaskTracker.getCacheSubdir() + Path.SEPARATOR + cacheId;
if (lDirAlloc.ifExists(cachePath, conf)) {
localPath = lDirAlloc.getLocalPathToRead(cachePath, conf);
} else {
localPath = lDirAlloc.getLocalPathForWrite(cachePath, fileStatus.getLen(), conf);
}
baseDir = localPath.toString().replace(cacheId, "");
p[i] =
DistributedCache.getLocalCache(
archives[i],
conf,
new Path(baseDir),
fileStatus,
true,
Long.parseLong(archivesTimestamps[i]),
new Path(workDir.getAbsolutePath()),
false);
}
DistributedCache.setLocalArchives(conf, stringifyPathArray(p));
}
if ((files != null)) {
String[] fileTimestamps = DistributedCache.getFileTimestamps(conf);
Path[] p = new Path[files.length];
for (int i = 0; i < files.length; i++) {
fileSystem = FileSystem.get(files[i], conf);
fileStatus = fileSystem.getFileStatus(new Path(files[i].getPath()));
String cacheId = DistributedCache.makeRelative(files[i], conf);
String cachePath = TaskTracker.getCacheSubdir() + Path.SEPARATOR + cacheId;
if (lDirAlloc.ifExists(cachePath, conf)) {
localPath = lDirAlloc.getLocalPathToRead(cachePath, conf);
} else {
localPath = lDirAlloc.getLocalPathForWrite(cachePath, fileStatus.getLen(), conf);
}
baseDir = localPath.toString().replace(cacheId, "");
p[i] =
DistributedCache.getLocalCache(
files[i],
conf,
new Path(baseDir),
fileStatus,
false,
Long.parseLong(fileTimestamps[i]),
new Path(workDir.getAbsolutePath()),
false);
}
DistributedCache.setLocalFiles(conf, stringifyPathArray(p));
}
Path localTaskFile = new Path(t.getJobFile());
FileSystem localFs = FileSystem.getLocal(conf);
localFs.delete(localTaskFile, true);
OutputStream out = localFs.create(localTaskFile);
try {
conf.writeXml(out);
} finally {
out.close();
}
}
if (!prepare()) {
return;
}
String sep = System.getProperty("path.separator");
StringBuffer classPath = new StringBuffer();
// start with same classpath as parent process
classPath.append(System.getProperty("java.class.path"));
classPath.append(sep);
if (!workDir.mkdirs()) {
if (!workDir.isDirectory()) {
LOG.fatal("Mkdirs failed to create " + workDir.toString());
}
}
String jar = conf.getJar();
if (jar != null) {
// if jar exists, it into workDir
File[] libs = new File(jobCacheDir, "lib").listFiles();
if (libs != null) {
for (int i = 0; i < libs.length; i++) {
classPath.append(sep); // add libs from jar to classpath
classPath.append(libs[i]);
}
}
classPath.append(sep);
classPath.append(new File(jobCacheDir, "classes"));
classPath.append(sep);
classPath.append(jobCacheDir);
}
// include the user specified classpath
// archive paths
Path[] archiveClasspaths = DistributedCache.getArchiveClassPaths(conf);
if (archiveClasspaths != null && archives != null) {
Path[] localArchives = DistributedCache.getLocalCacheArchives(conf);
if (localArchives != null) {
for (int i = 0; i < archives.length; i++) {
for (int j = 0; j < archiveClasspaths.length; j++) {
if (archives[i].getPath().equals(archiveClasspaths[j].toString())) {
classPath.append(sep);
classPath.append(localArchives[i].toString());
}
}
}
}
}
// file paths
Path[] fileClasspaths = DistributedCache.getFileClassPaths(conf);
if (fileClasspaths != null && files != null) {
Path[] localFiles = DistributedCache.getLocalCacheFiles(conf);
if (localFiles != null) {
for (int i = 0; i < files.length; i++) {
for (int j = 0; j < fileClasspaths.length; j++) {
if (files[i].getPath().equals(fileClasspaths[j].toString())) {
classPath.append(sep);
classPath.append(localFiles[i].toString());
}
}
}
}
}
classPath.append(sep);
classPath.append(workDir);
// Build exec child jmv args.
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.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.child.java.opts</name>
// <value>-verbose:gc -Xloggc:/tmp/@[email protected] \
// -Dcom.sun.management.jmxremote.authenticate=false \
// -Dcom.sun.management.jmxremote.ssl=false \
// </value>
// </property>
//
String javaOpts = conf.get("mapred.child.java.opts", "-Xmx200m");
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.child.java.opts.
//
String libraryPath = System.getProperty("java.library.path");
if (libraryPath == null) {
libraryPath = workDir.getAbsolutePath();
} else {
libraryPath += sep + workDir;
}
boolean hasUserLDPath = false;
for (int i = 0; i < javaOptsSplit.length; i++) {
if (javaOptsSplit[i].startsWith("-Djava.library.path=")) {
javaOptsSplit[i] += sep + libraryPath;
hasUserLDPath = true;
break;
}
}
if (!hasUserLDPath) {
vargs.add("-Djava.library.path=" + libraryPath);
}
for (int i = 0; i < javaOptsSplit.length; i++) {
vargs.add(javaOptsSplit[i]);
}
// 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());
}
vargs.add("-Djava.io.tmpdir=" + tmpDir.toString());
// Add classpath.
vargs.add("-classpath");
vargs.add(classPath.toString());
// Setup the log4j prop
long logSize = TaskLog.getTaskLogLength(conf);
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.totalLogFileSize=" + logSize);
if (conf.getProfileEnabled()) {
if (conf.getProfileTaskRange(t.isMapTask()).isIncluded(t.getPartition())) {
File prof = TaskLog.getTaskLogFile(taskid, 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
String pidFile = null;
if (tracker.isTaskMemoryManagerEnabled()) {
pidFile =
lDirAlloc
.getLocalPathForWrite(
(TaskTracker.getPidFilesSubdir() + Path.SEPARATOR + taskid), this.conf)
.toString();
}
// set memory limit using ulimit if feasible and necessary ...
String[] ulimitCmd = Shell.getUlimitMemoryCommand(conf);
List<String> setup = null;
if (ulimitCmd != null) {
setup = new ArrayList<String>();
for (String arg : ulimitCmd) {
setup.add(arg);
}
}
// Set up the redirection of the task's stdout and stderr streams
File stdout = TaskLog.getTaskLogFile(taskid, TaskLog.LogName.STDOUT);
File stderr = TaskLog.getTaskLogFile(taskid, TaskLog.LogName.STDERR);
stdout.getParentFile().mkdirs();
tracker.getTaskTrackerInstrumentation().reportTaskLaunch(taskid, stdout, stderr);
Map<String, String> env = new HashMap<String, String>();
StringBuffer ldLibraryPath = new StringBuffer();
ldLibraryPath.append(workDir.toString());
String oldLdLibraryPath = null;
oldLdLibraryPath = System.getenv("LD_LIBRARY_PATH");
if (oldLdLibraryPath != null) {
ldLibraryPath.append(sep);
ldLibraryPath.append(oldLdLibraryPath);
}
env.put("LD_LIBRARY_PATH", ldLibraryPath.toString());
jvmManager.launchJvm(
this,
jvmManager.constructJvmEnv(
setup, vargs, stdout, stderr, logSize, workDir, env, pidFile, conf));
synchronized (lock) {
while (!done) {
lock.wait();
}
}
tracker.getTaskTrackerInstrumentation().reportTaskEnd(t.getTaskID());
if (exitCodeSet) {
if (!killed && exitCode != 0) {
if (exitCode == 65) {
tracker.getTaskTrackerInstrumentation().taskFailedPing(t.getTaskID());
}
throw new IOException("Task process exit with nonzero status of " + exitCode + ".");
}
}
} catch (FSError e) {
LOG.fatal("FSError", e);
try {
tracker.fsError(t.getTaskID(), e.getMessage());
} catch (IOException ie) {
LOG.fatal(t.getTaskID() + " reporting FSError", ie);
}
} catch (Throwable throwable) {
LOG.warn(t.getTaskID() + " Child Error", throwable);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
throwable.printStackTrace(new PrintStream(baos));
try {
tracker.reportDiagnosticInfo(t.getTaskID(), baos.toString());
} catch (IOException e) {
LOG.warn(t.getTaskID() + " Reporting Diagnostics", e);
}
} finally {
try {
URI[] archives = DistributedCache.getCacheArchives(conf);
URI[] files = DistributedCache.getCacheFiles(conf);
if (archives != null) {
for (int i = 0; i < archives.length; i++) {
DistributedCache.releaseCache(archives[i], conf);
}
}
if (files != null) {
for (int i = 0; i < files.length; i++) {
DistributedCache.releaseCache(files[i], conf);
}
}
} catch (IOException ie) {
LOG.warn("Error releasing caches : Cache files might not have been cleaned up");
}
tracker.reportTaskFinished(t.getTaskID(), false);
if (t.isMapTask()) {
tracker.addFreeMapSlot();
} else {
tracker.addFreeReduceSlot();
}
}
}