From: Eric Wong <e@80x24.org>
To: Antony Gelberg <antony.gelberg@gmail.com>
Cc: unicorn-public@bogomips.org
Subject: Re: Timeouts longer than expected.
Date: Thu, 29 Jan 2015 20:00:14 +0000 [thread overview]
Message-ID: <20150129200014.GA29223@dcvr.yhbt.net> (raw)
In-Reply-To: <CADbCqvFZAJGLNHMKAQcMLTcpSuRWtv=CYweASZBJmR_BkwmBXw@mail.gmail.com>
Antony Gelberg <antony.gelberg@gmail.com> wrote:
> Hi all. We use unicorn in production across four servers, behind
> nginx and HAProxy (to load balance). We set a 300s timeout in the
> config file. On an average day, we see something like:
>
> E, [2015-01-22T17:01:24.335600 #4311] ERROR -- : worker=2 PID:21101
> timeout (301s > 300s), killing
>
> in our logs, ~60 times. However, one day we noticed that production
> had gone down with all the unicorns showing entries like the
> following:
>
> E, [2015-01-22T12:35:15.643020 #4311] ERROR -- : worker=1 PID:4605
> timeout (451s > 300s), killing
>
> (note the 451s before it was killed).
What other log entries appear in the 8 minutes leading up to the 451s
line?
Which version of unicorn is this?
There were some bugs fixed in ancient unicorn versions; and current
versions are still affected by big NTP adjustments due to the lack of
monotonic clock API in older Rubies.
I have a patch queued up for 5.x to use the monotonic clock, but
requires Ruby 2.1+ to be useful:
http://bogomips.org/unicorn-public/m/20150118033916.GA4478%40dcvr.yhbt.net.html
Maybe there's another sleep calculation bug, though. Not many people
rely on giant timeouts and probably never notice it.
I'll take a closer look at the master sleep calculations (in
murder_lazy_workers) in a week or so and see if there's another problem
lurking in the current versions.
> Any clues how we can better-understand the root cause, even if it's
> something we'll put in place for the future? We lack visibility here.
I'd use an in-process timeout to get backtraces. The
Application_Timeouts doc in the source and online has more
tips on dealing with timeouts in general.
http://unicorn.bogomips.org/Application_Timeouts.html
Also curious: you have users willing to wait 5 minutes for an
HTTP response? Yikes!
prev parent reply other threads:[~2015-01-29 20:00 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-29 13:06 Timeouts longer than expected Antony Gelberg
2015-01-29 20:00 ` Eric Wong [this message]
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