OK, that makes sense now. Thanks for the quick response! -Greg On Tuesday, April 14, 2015 at 3:42:19 PM UTC-7, Graham Dumpleton wrote: > > Unfortunately the shutdown timeout how you are using it doesn’t work with > Apache graceful restart. The way that Apache manages these other processes, > ie., mod_wsgi daemon processes, is that it will kill them after 3 seconds > on a graceful restart if they haven’t shutdown already. So the long > requests will be holding the process running and so they get killed after 3 > seconds regardless. This is why you see the 'Truncated or oversized > response headers’ message. Is because the daemon process went away while > Apache child worker process was still waiting for a response due to worker > process happily staying around due to graceful restart. > > No good solution for the problem that I know of at this point to do a > whole of Apache graceful restart such that the daemon processes aren’t > impacted. > > Graham > > On 14 Apr 2015, at 6:37 pm, Greg Janée <[email protected] <javascript:>> > wrote: > > No segfault... the log looks like this: > > [Tue Apr 14 13:18:27 2015] [notice] SIGUSR1 received. Doing graceful > restart > [Tue Apr 14 13:18:30 2015] [error] [client ...] Truncated or oversized > response headers... > > The longish shutdown timeout is because this system performs transactions > that can take significant real time to perform; this is not a system that > is rapidly returning page views. When deploying new code by reloading > modwsgi, the long shutdown timeout has been invaluable because it allows > the current transactions to complete cleanly. > > I should add, the reason why I've been poking around with Apache's > graceful restart is I was looking for a way to safely restart Apache in the > same way that I can currently safely reload modwsgi ("safely" meaning that > current operations are allowed to finish and incoming requests are queued > until the server is ready again). > > -Greg > > > On Tuesday, April 14, 2015 at 3:21:22 PM UTC-7, Graham Dumpleton wrote: >> >> That message can occur for another reason when doing a graceful restart. >> >> Do you see an actual Segmentation fault message in the main Apache error >> log? >> >> If there is no segmentation fault, it is likely to be this other reason. >> At least, it wouldn’t mean it is crashing. >> >> However, why specifically are you running with shutdown-timeout of 60. >> Normally that would be 5 and you wouldn’t generally want to play with it. >> >> Graham >> >> On 14 Apr 2015, at 6:15 pm, Greg Janée <[email protected]> wrote: >> >> I'm running modwsgi in daemon mode and getting a "Truncated or oversized >> response headers received..." error from Apache, which I believe means the >> daemon died. This happens when I do an Apache graceful restart and there >> is an open HTTP connection being handled by modwsgi at the time of the >> restart. The daemon dies almost immediately. If there is no open HTTP >> connection, then a graceful restart works fine. An ordinary (non-graceful) >> restart also works. >> >> This is a mature modwsgi/Django application that runs just fine in every >> other way. I don't think I've ever tried doing a graceful restart before, >> so it's entirely possible this behavior has always been there and I just >> didn't notice it. >> >> My version of modwsgi is pretty recent I believe. If the issue is with >> Apache, I could upgrade to 2.4.x, but it's not obvious that that is >> relevant here. >> >> Apache 2.2.17, MPM worker mode >> modwsgi 4.4.9 >> Python 2.7.6 >> >> MPM config: >> ServerLimit 6 >> StartServers 2 >> MaxClients 150 >> ThreadsPerChild 25 >> MinSpareThreads 25 >> MaxSpareThreads 75 >> >> modwsgi config: >> WSGIDaemonProcess site-1 threads=50 shutdown-timeout=60 >> WSGIApplicationGroup %{GLOBAL} >> WSGIProcessGroup site-1 >> WSGIPassAuthorization on >> >> >> -- >> 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 [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at http://groups.google.com/group/modwsgi. >> For more options, visit https://groups.google.com/d/optout. >> >> >> > -- > 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 [email protected] <javascript:>. > To post to this group, send email to [email protected] <javascript:> > . > Visit this group at http://groups.google.com/group/modwsgi. > For more options, visit https://groups.google.com/d/optout. > > >
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