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

Discussion:

Jacek Medrzycki

2009-02-17 11:04:21 UTC

Hello everybody.

We often encounter following error:

Resource not found
Sorry, the requested resource does not exist.

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.

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?

The machine has 2Gs of memory. Can this be a problem?

Regards and TIA
J.

Jean-Paul Smets

2009-02-17 11:19:00 UTC

Permalink

Post by Jacek Medrzycki
Hello everybody.

Could you describe precisely "we" (ie. situation, application, number of
users, etc.)

Post by Jacek Medrzycki
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)

Post by Jacek Medrzycki
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.

Post by Jacek Medrzycki
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.

Post by Jacek Medrzycki
The machine has 2Gs of memory. Can this be a problem?

No.

Post by Jacek Medrzycki
Regards and TIA
J.
_______________________________________________
Erp5-dev mailing list
Erp5-dev at erp5.org
http://mail.nexedi.com/mailman/listinfo/erp5-dev

--
Jean-Paul Smets-Solanes, Nexedi CEO - Tel. +33(0)6 62 05 76 14
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

Rafael Monnerat

2009-02-17 11:57:37 UTC

Permalink

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,

Post by Jean-Paul Smets

Post by Jacek Medrzycki
Hello everybody.

Could you describe precisely "we" (ie. situation, application, number of
users, etc.)

Post by Jacek Medrzycki
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)

It is not a solution to restart or pack.

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.

Post by Jacek Medrzycki
The machine has 2Gs of memory. Can this be a problem?

No.

Post by Jacek Medrzycki
Regards and TIA
J.
_______________________________________________
Erp5-dev mailing list
Erp5-dev at erp5.org
http://mail.nexedi.com/mailman/listinfo/erp5-dev

Bartek Gorny

2009-02-21 11:30:23 UTC

Permalink

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

Post by Rafael Monnerat
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.
- http://www.erp5.org/HowToCreateMultipleERP5Sites
Regards,

Post by Jean-Paul Smets

Post by Jacek Medrzycki
Hello everybody.

Could you describe precisely "we" (ie. situation, application, number of
users, etc.)

Post by Jacek Medrzycki
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)

It is not a solution to restart or pack.

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.

Post by Jacek Medrzycki
The machine has 2Gs of memory. Can this be a problem?

No.

Post by Jacek Medrzycki
Regards and TIA
J.
_______________________________________________
Erp5-dev mailing list
Erp5-dev at erp5.org
http://mail.nexedi.com/mailman/listinfo/erp5-dev

--
Rafael Manh?es 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"

Jean-Paul Smets

2009-02-21 11:33:51 UTC

Permalink

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

Great news.

Post by Bartek Gorny
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.

Thanks. It is a good idea to add a wiki page on how to configure Apache
proxy. It will also be the occasion for us to publish some doc on this
(as soon as we / I review it).

Post by Bartek Gorny
Bartek

Post by Jean-Paul Smets

Post by Jacek Medrzycki
Hello everybody.

Could you describe precisely "we" (ie. situation, application, number of
users, etc.)

Post by Jacek Medrzycki
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)

It is not a solution to restart or pack.

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.

Post by Jacek Medrzycki
The machine has 2Gs of memory. Can this be a problem?

No.

Post by Jacek Medrzycki
Regards and TIA
J.
_______________________________________________
Erp5-dev mailing list
Erp5-dev at erp5.org
http://mail.nexedi.com/mailman/listinfo/erp5-dev