How can I figure out why my Perl script crashes?

Question

I have written a Perl script that sends data to clients. It works some time (from one minute to 2 hours) and then goes down. No errors in console, no errors in log.

I added an END section to it - it isn't executed.

What can I do to figure out what the problem is?

Answer 1

No errors in the log, but can you put more logging in to see where exactly it's failing? That is, log lines like:

00:00:00 In section 1
00:00:05 In section 2
...
00:09:28 In section 34

Then you can see what section last executed.

If it's really bugging you, you could also try stepping through in the Perl debugger and seeing if you can reproduce it. You could also try simplifying your script, removing various sections, etc. to see if you can really pinpoint the problem.

Hope that helps.

Answer 2

Since the script is writing data to clients, I would guess that its untimely death is due to an unhandled SIGPIPE. If that is the case, installing a signal handler for SIGPIPE is an easy way to verify it. Check out perlipc for details and examples on signal handlers in Perl.