[Koha-bugs] [Bug 35111] Background jobs worker crashes on SIGPIPE when database connection lost in Ubuntu 22.04

[bugzilla-daemon at bugs.koha-community.org]

https://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=35111

--- Comment #13 from David Cook <dcook at prosentient.com.au> ---
(In reply to Marcel de Rooy from comment #10)
> You have caught some lines from the logfiles for worker and database. But
> wasnt there any further lines in koha-worker-output about the crash? This
> would give us more info about the line in the worker script. Now we are
> guessing? Or do I miss something?

There's nothing in the worker-output.log in this case. That's part of what made
it challenging to troubleshoot initially.

> When worker lost the connection, I would expect DBIx to just raise an
> exception?
> The background worker does not catch it, so perl exits probably with 255 ?
> And daemon respawns (but without 13?)

That's the issue. DBIx has reconnect logic, and on Debian with the mariadb
client libraries it handles this without any exceptions or issues. On Ubuntu
with the mysql client libraries a SIGPIPE signal gets generated. In
Starman/Plack, SIGPIPE is ignored, so the DBIx can just reconnect. In the
background jobs worker, the SIGPIPE is not ignored and it causes the process to
crash.

> When I hear about SIGPIPE, I would first look for problems between parent
> and child processes since we are forking here via Parallel::ForkManager.

I looked at all the different sockets and pipes. It's the database one that's
the problem.

> Also note that this depends on a koha-conf setting.
> background_jobs_worker/max_processes
> What value do you use there?
> If there is a database connection problem in the child process, and we did
> not configure P::F correctly (?), could that trigger a SIGPIPE ?

It's not the child process. It's the parent process. The stacktrace shows that.

-- 
You are receiving this mail because:
You are watching all bug changes.