Perl's worker don't process connections, waiting on a futex

Question

We have 10 workers processing user's connections. Workers are implemented in Perl, using FCGI and FCGI::ProcManager.

Sometimes, one worker stop processing of connections. Strace displays:

futex(0x7fa9ebde0e80, FUTEX_WAIT_PRIVATE, 2, NULL

That is it sleep, waiting on a futex.

The worker never returns from waiting.

If we kill this worker with

kill -9

then its parent reap it. Return code equal 9.

Our project is highload. This issue appears very rarely.

Okay, and you want to know from us why?? or How to fix it or what? The question is still not clear .. — , Jul 02 '13 at 08:01

score 0 · Answer 1 · answered Jul 02 '13 at 08:14

0

This system call is typically used to implement the contended case of a lock in shared memory, as described in futex(7)

So my first question: is your Perl script using "Perl Threads" and are you having contention on a shared memory variable?

answered Jul 02 '13 at 08:14

PP.

I don't use any "Perl Threads" explicitly. I don't use any shared memory variables explicitly. May be, one of standart modules use them. – drlexa Jul 02 '13 at 08:29

1 Answers1