> Thanks for the prompt response. I am aware of the problems with using
> SQLObject in a multi-process environment
> so mod_wsgi was configured to run in daemon mode. I'm not entirely
> familiar with apache configuration so I am guessing the daemon
> process is running as Apache user since I did not explicitly set that
> configuration option.

> I did discover an issue in the my code which lead to the error when
> mod_wsgi is enabled. I loaded a dictionary of SQLObject instances at
> module scope in a controller module in order to avoid hitting the
> database with each request.  This dictionary of course persists across
> transactions so perhaps that indicates something. To resolve the
> issue, I simply copied the data into
> wrapper objects in order to disconnect the data from the SQLObject
> machinery. That did the trick, however, I am a curious to know if
> there is a more intelligent solution. It is worth pointing out that I
> did set cacheValues=False in the SQLObject class definition and that
> did not solve the problem.

> The apache configuration is as follows(purged of sensitive details of
> course):

> WSGIDaemonProcess site-1 threads=25
> WSGIProcessGroup site-1

> Alias /static /project_dir/static

> WSGIScriptAlias / /project_dir/project.wsgi

> NameVirtualHost *:80
> <VirtualHost *:80>
>         ServerAdmin webmaster@localhost

>         DocumentRoot /project_dir

>         # Possible values include: debug, info, notice, warn, error,
> crit,
>         # alert, emerg.
>         LogLevel warn

>         CustomLog /var/log/apache2/access.log combined
>         ServerSignature On

>         <Directory /project_dir>
>            Order deny,allow
>            Allow from all
>         </Directory>
> </VirtualHost>

> Thanks for your help!

> On Mar 28, 10:48 pm, Graham Dumpleton <Graham.Dumple...@gmail.com>
> wrote:

> > On Mar 29, 10:17 am, vandevel <vande...@gmail.com> wrote:

> > > I am wondering if anyone has experienced database transaction problems
> > > usingmod_wsgi1.3.
> > > My turbogears project is based on TG 1.0.4.4 using SQLObject and I am
> > > observing this error when executing some controller methods:

> > > AssertionError: This transaction has already gone through ROLLBACK;
> > > begin another transaction.

> > > This only occurs when running the app behindmod_wsgi, however it is
> > > not a problem when running the app straight from cherrypy. Clearly,mod_wsgiis doing something which causes the app to behave in this
> > > manner.

> > More information required.

> > Are you running your application in embedded mode of mod_wsgi or in
> > daemon mode? If in embedded mode, you did read about the problems with
> > SQLObject and multiprocess web servers in:

> >  http://code.google.com/p/modwsgi/wiki/IntegrationWithTurboGears

> > If running in daemon mode, are you running it as Apache user, or did
> > you configure daemon process to run as you? Also, if in daemon mode,
> > how many processes did you set for the daemon process group. Like
> > above, if more than one and using multiprocess server, there can be
> > issues, although it shouldn't be what you are seeing.

> > Anyway, post what the mod_wsgi configuration you are using is from
> > your Apache configuration.

> > Grahamth