Hello,

I have a Flask + Sqlalchemy application(connecting to a Sybase database) 
that I am trying to run in Apache + mod_wsgi setup

Few pointers on my wsgi setup:

   - Using WSGIDaemonProcess <nameOfApp> processes=x threads=y
   - Using WSGIApplicationGroup %{GLOBAL}

No matter what combination of values of *x* and *y* I use, after processing 
some request, my apache/mod_wsgi hangs up for sometime showing logs like :

   - Daemon process deadlock timer expired, stopping process <>
   - Shutdown process <nameOfApp>
   - Aborting process <nameOfApp>
   - Exiting process <nameOfApp>

I believe it hangs for 300 seconds(which is default deadlock-timeout)
If I set deadlock-timeout = 60, apache/mod_wsgi recovers in 60sec

Few other logs that I see are :

   - Truncated or oversized response headers received from daemon process 
   <nameOfApp>
   - server seems busy, (you may need to increase StartServers, or 
   Min/MaxServers, spawning 16 children, there are three idle 
   
What could be the reason of this deadlock and other logs shown above?

Could this be because of a rogue C extension as pointed out by Graham at 
various places?

There are bunch of third party modules that I am using which has C 
extension like -> http://python-sybase.sourceforge.net/download.html

Is there anyway to fix this or make it more stable(not going into deadlock 
too frequently and giving 500 to clients)?

FYI, I am using prefork instead of worker at this moment. I am not loading 
unnecessary modules like mod_php.
The only modules that I am loading in my apache conf are 
"mod_authz_host.so", "mod_log_config.so" and "mod_wsgi.so"
I believe the issue I am trying to highlight is totally independent of 
whether it is a prefork or worker setup

-- 
You received this message because you are subscribed to the Google Groups 
"modwsgi" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to modwsgi+unsubscr...@googlegroups.com.
To post to this group, send email to modwsgi@googlegroups.com.
Visit this group at https://groups.google.com/group/modwsgi.
For more options, visit https://groups.google.com/d/optout.

Reply via email to