[Erp5-dev] "requested resource does not exist" Error

[Bartek Gorny]

We found it :) You'd never guess what it was. I'll describe it here
for future reference.

The reason was not in ERP5 - it was apache proxy, which had a timeout
set to 10 seconds instead of the default 300 (I've no idea why). If a
task took ERP5 more, apache returned an error. The tricky part was
that "502 BadGateway", it said "404" and displayed a Zope's "resource
not found" page. The reson for that was misconfiguration of
mod_rewrite directives - mod_rewrite was rewriting everything, so when
Apache wanted to display its HTTP_BAD_GATEWAY it tried to get it from
Zope, which returned 404...

The conclusion is that while setting up apache proxy, we should add
RewriteCond so that some of the error pages are served locally, not
rewritten. I'll set up a wiki page about it.

Bartek


2009/2/17 Rafael Monnerat <rafael at nexedi.com>:
>
> Hi,
>
> Some months ago one student that I was starting to help had some similar
> problems because he installed by mistake 2 ERP5 sites using the same
> MYSQL database (test test) and this is totally wrong.
>
> One reference related to it:
>
> - http://www.erp5.org/HowToCreateMultipleERP5Sites
>
> Regards,
>
> Jean-Paul Smets wrote:
>> Jacek Medrzycki a écrit :
>>
>>> Hello everybody.
>>>
>>> We often encounter following error:
>>>
>>>
>> Could you describe precisely "we" (ie. situation, application, number of
>> users, etc.)
>>
>>> Resource not found
>>> Sorry, the requested resource does not exist.
>>>
>>>
>> I did not see such an error for ages, even on the largest sites Nexedi
>> has implemented, with 300+ users and 10,000,000+documents.
>>
>> Very long ago (many years), I saw this kind of error in relation with
>>     - Zope sessions
>>     - caching objects into RAM (coding crime)
>>     - misuse of volatile attributes
>>     - creating 2 ERP5 instances on the same Zope (forbidden)
>>
>>> while accessing an object or module. The object or module of course
>>> EXISTS, and sometimes page reloading solves the problem for a while -
>>> however sometimes error repeats very frequently.
>>> It seems that zope restarting or database packing helps for some time
>>> but i'm not sure - it can be just a coincidence.
>>>
>>>
>> It is not a solution to restart or pack.
>>
>>> There is nothing in zope log (except "resource not found" message itself).
>>>
>>> It's common on rather old erp5 site, but also appeared few times on
>>> fresh new ERP5 installation, and this new installation wasn't used very
>>> hard (test only). However, both sites are on the same machine.
>>>
>>> What this error can be related to? Can anybody had similar problems?
>>>
>>>
>>>
>> I do not see such error on any of our client sites. I suppose that this
>> error is related to some customisations you made or to the use of
>> incompatible libraries / versions of python / zope.
>>
>>> The machine has 2Gs of memory. Can this be a problem?
>>>
>>>
>>>
>> No.
>>
>>> Regards and TIA
>>> J.
>>> _______________________________________________
>>> Erp5-dev mailing list
>>> Erp5-dev at erp5.org
>>> http://mail.nexedi.com/mailman/listinfo/erp5-dev
>>>
>>>
>>
>>
>>
>
>
> --
> Rafael Manhães Monnerat, Nexedi Developer - Tel. +55 (22) 8808 8500
> ERP5 Enterprise: Free / Open Source ERP for Critical Applications
> http://www.erp5.com
> ERP5 Express: Hosted Open Source ERP for small companies
> http://www.myerp5.com
> Nexedi: Consulting and Development of Free / Open Source Software
> http://www.nexedi.com
>
> _______________________________________________
> Erp5-dev mailing list
> Erp5-dev at erp5.org
> http://mail.nexedi.com/mailman/listinfo/erp5-dev
>



-- 
"Software is largely a service industry operating under the persistent
but unfounded delusion that it is a manufacturing industry."
Eric S.Raymond, "The Magic Cauldron"