/**
* 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, true);
}
