[Zope] zope freezes

[Oliver Bleutgen]

Sebastian Lühnsdorf wrote:
> hi!
> 
> we are still having problems with freezing zope servers. we are relaying 
> requests to an http server in the intranet, that means we are retrieving the 
> page via httplib. under some circumstances, i.e. with slow pages and several 
> concurrent requests, Zope freezes completely (all threads) until the requested 
> page is fully processed. If somebody has experienced likewise and/or has any 
> info or help.
> 

The cause of the freeze should be that all of zope's worker threads are, 
well, working. I guess you know that since you increased that value in 
the config.

There may be other tricks you can play, but here's what I can tell you:

- Use timeoutsocket.py (-> google) to pose a timeout on hanging 
requests. This is only usefull if your external server is really 
slow/hangs and you can afford not to display you external pages if that 
happens.

- Modify you product/external method to cache the pages, see for 
instance the zope product KebasData how to do that.

-  retrieve the external pages through a proxycache like squid.

- Let an external (to zope) job retrieve the pages regularly and publish 
them through something like LocalFS (there's a newer product, just 
forgot it's name).

HTH,
oliver