protected void prepare(
Map stormConf, final TopologyContext context, final IOutputCollector collector) {
_rand = new Random();
_collector = collector;
_context = context;
heartbeatTimeoutMills = getHeartbeatTimeoutMillis(stormConf);
_process = new NuShellProcess(_command, this, this);
// subprocesses must send their pid first thing
Number subpid = _process.launch(stormConf, context);
LOG.info("Launched subprocess with pid " + subpid);
this.pid = subpid.longValue();
/**
* randomizing the initial delay would prevent all shell bolts from heartbeating at the same
* time frame
*/
int initialDelayMillis = random.nextInt(4000) + 1000;
BoltHeartbeatTimerTask task = new BoltHeartbeatTimerTask(this);
heartBeatExecutorService.scheduleAtFixedRate(
task, initialDelayMillis, getHeartbeatPeriodMillis(stormConf), TimeUnit.MILLISECONDS);
}
