How to debug a hung spark application

[Manas Kar <ma...@gmail.com>]

Hi,
 I have a spark application that hangs on doing just one task (Rest 200-300
task gets completed in reasonable time)
I can see in the Thread dump which function gets stuck how ever I don't
have a clue as to what value is causing that behaviour.
Also, logging the inputs before the function is executed does not help as
the actual message gets buried in logs.

How do one go about debugging such case?
Also, is there a way I can wrap my function inside some sort of timer based
environment and if it took too long I would throw a stack trace or some
sort.

Thanks