commands.add("rm -rf output/");
commands.add(pathHadoopBin + "hadoop fs -copyToLocal /output .");
// execute
String pathOutputFile = pathExecDir + FILENAME_OUTPUT;
SystemCallRunnable runnable = new SystemCallRunnable(pathOutputFile, commands, execDir);
new Thread(runnable, "xquerymr").start();
return new Success("&" + XQueryMRPage.EXECDIR + "=" + pathExecDir);
}