Mongrel users - Oct 2006 - Possible log rollover mutex problem

It appears that part of the problem could be that when logger rolls over the
mongrel log file. There is a mutex synchronization issue where the various
mongrel instances all try to write to the new log file and block each other.
This keeps them in a continual Application 500 Error state. Has anyone run
into this problem? With log rotation turned off the problem does not appear.

- Jared Brown
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On Mon, 30 Oct 2006 13:48:43 -0500
"Jared Brown" <mongrelmail at gmail.com> wrote:
> It appears that part of the problem could be that when logger rolls over
the
> mongrel log file. There is a mutex synchronization issue where the various
> mongrel instances all try to write to the new log file and block each
other.
> This keeps them in a continual Application 500 Error state. Has anyone run
> into this problem? With log rotation turned off the problem does not
appear.
> 
Aha! I''ve suspected this for a long time, but I could never reproduce
it.  Research this a bit more for me and I''ll tackle it in a few days.

-- 
Zed A. Shaw, MUDCRAP-CE Master Black Belt Sifu
http://www.zedshaw.com/
http://safari.oreilly.com/0321483502 -- The Mongrel Book
http://mongrel.rubyforge.org/
http://www.lingr.com/room/3yXhqKbfPy8 -- Come get help.

In environments.rb I created a new Logger() and set the rollover to
"daily".
All of the mongrels tried to roll the file over at the same time and
continually blocked. Accesses to the site only resulted in application 500
errors. Deleting the logs fixed it. Touching the log file to an old date
reproduces it.


On 10/30/06, Zed A. Shaw <zedshaw at zedshaw.com>
wrote:
>
> On Mon, 30 Oct 2006 13:48:43 -0500
> "Jared Brown" <mongrelmail at gmail.com> wrote:
>
> > It appears that part of the problem could be that when logger rolls
over
> the
> > mongrel log file. There is a mutex synchronization issue where the
> various
> > mongrel instances all try to write to the new log file and block each
> other.
> > This keeps them in a continual Application 500 Error state. Has anyone
> run
> > into this problem? With log rotation turned off the problem does not
> appear.
> >
>
> Aha! I''ve suspected this for a long time, but I could never
reproduce
> it.  Research this a bit more for me and I''ll tackle it in a few
days.
>
> --
> Zed A. Shaw, MUDCRAP-CE Master Black Belt Sifu
> http://www.zedshaw.com/
> http://safari.oreilly.com/0321483502 -- The Mongrel Book
> http://mongrel.rubyforge.org/
> http://www.lingr.com/room/3yXhqKbfPy8 -- Come get help.
> _______________________________________________
> Mongrel-users mailing list
> Mongrel-users at rubyforge.org
> http://rubyforge.org/mailman/listinfo/mongrel-users
>
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