infoServer.setAttribute("job.tracker", this);
// initialize history parameters.
FileSystem historyFS = null;
jobHistory = new JobHistory();
final JobTracker jtFinal = this;
try {
historyFS = getMROwner().doAs(new PrivilegedExceptionAction<FileSystem>() {
public FileSystem run() throws IOException {
jobHistory.init(jtFinal, conf, jtFinal.localMachine, jtFinal.startTime);