Description

If you set up multiple wiki (not using a wiki farm) using Apache and mod_python, Apache does not serve always the right wiki. The correct wiki might show after refresh.

Example

Just enable two or more wiki on the same web server. I cant let my webserver configured like this cause the bug seams to be very important.

• describe the setup that cause this problem.

Details

Workaround

• Do not use mod_py in threaded mode.
• Use a wiki farm instead of multiple wikis?

Discussion

The nasty bug is still alive

Hi I have updated to moin 1.3.0 today. The bugs is still alive. Two wikis are accessible through modpython. They are correctly configured. Each one work perfectly when it is the only one served by modpython.

Try it by yourself on my server (it is a wonderfull p200 so please be patient )

• http://r0ug3.dyndns.org/wikiwd/FrontPage : this wiki should be named "Wiki WD" a fresh moin 1.3 wiki content

• https://r0ug3.dyndns.org/moinmoin/FrontPage : this wiki should be nammed "Roug3.dyndns.org's Wiki" an upgraded 1.2 moin wiki.

because of the fact that the pages are not from the same version of moin, you should be able to detect the differences. Try to play with both the two wikis at the same time. From time to time on an address the wrong wiki is served (use Shift + reload on your browser).

Maybe a modpython bug. Who knows

Bug Confirmation

I have also experienced this problem. I set up five wikis using Apache 2.0.49, modpython 3.1.3 and python 2.3.3 on SuSE 9.1. I experienced the problem (wiki instance displayed does not match wiki instance of URL requested and displayed in browser address line after display) using FireFox 1.0. I can confirm that the problem is on the server side as the first time I pasted a URL into the address line in Internet Explorer, again, the the wiki instance displayed was not the wiki instance of that URL. This was the first and only time I accessed that server and those wikis using Internet Explorer. Several refreshes eventually displays the correct wiki instance, but while continuing to work in that wiki instance other wiki instances may appear incorrectly as time continues without attempting to switch to those wiki instances.

Initially, I had a single .htaccess file with five <files> entries for the five wikis. I rearranged my URL references so that I had five files each with a single <files> entry, without any change in behaviour. -- MarkFriedman

I could see this bug as well (MoinMoin 1.3.1, Apache 2, mod_py 3.1.3, linux machine). -- AlexanderSchremmer 2005-01-21 23:13:07

Please add a steps to reproduce, including configuration files.

Solution

From http://www.modpython.org/live/current/doc-html/pyapi-interps.html:

• Python C API provides the ability to create subinterpreters in which each subinterpreter has its own separate namespace, not accessible from other subinterpreters. At server start-up or mod_python initialisation time, mod_python initialises an interpreter called main interpreter. The main interpreter is named "main_interpreter". The way all other interpreters are named can be controlled by PythonInterp* directives. Default behaviour is to name interpreters using the Apache virtual server name (ServerName directive). This means that all scripts in the same virtual server execute in the same subinterpreter, but scripts in different virtual servers execute in different subinterpreters with completely separate namespaces. PythonInterpPerDirectory and PythonInterpPerDirective directives alter the naming convention to use the absolute path of the directory being accessed, or the directory in which the Python*Handler was encountered, respectively. PythonInterpreter can be used to force the interpreter name to a specific string overriding any naming conventions.

I included a PythonInterpreter directive within each <Files> section with a unique identifier, and now wiki instances to be returned as requested. -- MarkFriedman 2005-01-22 00:32:07

Its not clear how this is related to the bug. Moin get a url and load a wiki config by matching the url - how one or more subinterpreters can brake this? Do we get wrong url?

• No, but wrong modules. Mod_py seems to lose thread-safety. Fixing this bug is easy - just document this setting for users that do not like farmconfig. Nir, remember our "you can login as me trials" months ago? At least such things happen for these users, but more often

Plan

• Priority:
• Assigned to:
• Status: Config error, documented correct config

CategoryMoinMoinBugFixed