metricReporter.start();
LOG.info("Start metrics reporter, enable performance metrics: "
+ isMetricsEnable);
// create task heartbeat
TaskHeartbeatRunable taskHB = new TaskHeartbeatRunable(workerData);
AsyncLoopThread taskHBThread = new AsyncLoopThread(taskHB);
threads.add(taskHBThread);
// refresh hearbeat to Local dir
RunnableCallback heartbeat_fn = new WorkerHeartbeatRunable(workerData);