Can I see the error? Is there a traceback? Is the db server on the
machine?
Massimo
On Jan 9, 11:30 am, VP <vtp2...@gmail.com> wrote:
> It is indeed the case that there was a segmentation fault, reported in
> apache error log.
>
> Perhaps, it's not clear, but this problem occurs under posgres under
> debian lenny, not sqlite. I am not running web2py as a CGI script. I
> am using the web2py deployment script (for setting up apache and
> web2py):
>
> <VirtualHost *:80>
> WSGIDaemonProcess web2py user=myusername group=myusername \
> display-name=%{GROUP}
> WSGIProcessGroup web2py
> WSGIScriptAlias / /home/myusername/web2py/wsgihandler.py
>
> ....
>
> On Jan 8, 9:59 pm, Graham Dumpleton <graham.dumple...@gmail.com>
> wrote:
>
>
>
>
>
>
>
> > You were possibly using a an old version of sqlite which isn't safe to use
> > in a multithreaded configuration.
>
> > The MPM settings are not going to help in this case as that error could only
> > come about because you are using mod_wsgi daemon mode and so application is
> > running in distinct process and not those affected by the MPM or its
> > settings.
>
> > The only other way you could get that error is that you are actually running
> > web2py as a CGI script.
>
> > Overall, that specific error message means your daemon mode process that is
> > running web2py crashed. You would likely find that there is a segmentation
> > fault messages in main Apache error log as well at that time.
>
> > Crashing could be because of sqlite thread problems, but could also be
> > because you are forcing web2py to run in main interpreter of daemon
> > processes and at the same time are using a third party C extension module
> > for Python that is not safe for use in sub interpreters.
>
> > So, ensure sqlite is up to date. And ensure that you have:
>
> > WSGIApplicationGroup %{GLOBAL}
>
> > in configuration to force use of main interpreter.
>
> > Graham
>
> > On Sunday, January 9, 2011 6:44:14 AM UTC+11, VP wrote:
>
> > > We occasionally got an Apache error so the page didn't get displayed.
> > > So I decided to stress test using Apache Bench (ab). It seems the
> > > site suffered failure up to 50-100 concurrent connection.
>
> > > Apache error log showed this error:
>
> > > >>>>>>Premature end of script headers: wsgihandler.py
>
> > > After digging around, I found similar discussions and change
> > > apache2.conf like this:
>
> > > # prefork MPM
> > > StartServers 5
> > > MinSpareServers 5
> > > MaxSpareServers 10
> > > MaxClients 256
> > > MaxRequestsPerChild 500
> > > ServerLimit 256
>
> > > Didn't seem to help.
>
> > > ====
>
> > > A few notes:
>
> > > + It appears when I switched to sqlite instead of posgres, I didn't
> > > have the problem. (Sqlite had other problems, such as occasional
> > > database locking, which is more serious)
>
> > > + I am on a VPS with 768MB with 1GB burstable. While I'm doing the
> > > stress test with Apache Bench (ab), using free on the server revealed
> > > memory usage was about 450MB. (Which is a lot, but is still under
> > > limit).
>
> > > =====
>
> > > In summary, memory was available. But we got this wsgi error in
> > > Apache with multiple requests.
>
> > > Any idea please?
>
> > > Thanks.
