Major Description
Distcp doesn't close the job after the job is completed. This leads to leaked Truststore Reloader Threads.
The fix is to close the job once it is complete. job.close internally calls yarnClient.close(), which then calls timelineConnector.serviceStop() . This destroys the sslFactory cleaning up the ReloadingX509TrustManager.
Without the patch for each distcp job, a new ReloadingX509TrustManager is created which creates a new thread. These threads are never killed and they remain like that till HS2 is restarted. With the close, the thread will be cleaned up once the job is completed.