[Zope-dev] newInteraction problem

[Mattia Belletti]

Hi all,
  I have quite a technical problem, so I thought this list was the
best choice. Tell me if there's a better place.

  I was working on a site developed over Zope 2.10, using python 2.4
and a Debian Etch (ask me if you need more informations). Sometimes,
at non-predictable times (I think, when concurrent accesses are
performed, because of the nature of the error), I get this backtrace
[ in http://codepad.org/cM76kVjT too ]:






Site Error
An error was encountered while publishing this resource.

AssertionError

Sorry, a site error occurred.

Traceback (innermost last):

Module ZPublisher.Publish, line 202, in publish_module_standard
Module Products.Localizer.patches, line 89, in new_publish
Module ZPublisher.Publish, line 150, in publish
Module Zope2.App.startup, line 221, in zpublisher_exception_hook
Module ZPublisher.Publish, line 79, in publish
Module zope.security.management, line 85, in newInteraction
AssertionError: newInteraction called while another interaction is
active:
File "/usr/lib/zope2.10/lib/python/ZServer/PubCore/
ZServerPublisher.py", line 25, in __init__ response=b)
File "/usr/lib/zope2.10/lib/python/ZPublisher/Publish.py", line 401,
in publish_module environ, debug, request, response)
File "/usr/lib/zope2.10/lib/python/ZPublisher/Publish.py", line 202,
in publish_module_standard response = publish(request, module_name,
after_list, debug=debug)
File "/var/lib/zope2.10/instance/oldrevision/Products/Localizer/
patches.py", line 89, in new_publish
File "/usr/lib/zope2.10/lib/python/ZPublisher/Publish.py", line 79, in
publish newInteraction()
File "/usr/lib/zope2.10/lib/python/zope/security/management.py", line
91, in newInteraction
  interaction._newInteraction_called_from = traceback.extract_stack()
  (Also, the following error occurred while attempting to render the
standard error message, please see the event log for full details:
name 'PARENTS' is not defined)



--------------------------------------------------------------------------------

Troubleshooting Suggestions

The URL may be incorrect.
The parameters passed to this resource may be incorrect.
A resource that this resource relies on may be encountering an error.
For more detailed information about the error, please refer to the
error log.

If the error persists please contact the site maintainer. Thank you
for your patience.






It seems that two concurrent "interactions" were performed. I'm not so
much in the inner workings of Zope, especially not for the exact
semantic of "interaction", so I may be going around in circles, but I
tried looking at the newInteraction / endInteraction implementations,
which simply check for concurrent interactions not to happen
(otherwise, throw the above AssertionError). What I miss is: who
prevents such concurrent interactions to happen? I saw nowhere in the
code such a critical section, so it's obvious that sooner or later two
requests, especially for busy sites, happen concurrently and this
error is generated.

Thank you in advance for any hint.

-- 
Mattia "RedGlow" Belletti
http://thick.foschia.info - http://anacrusi.splinder.com