[Zope] ZEO and a front end...

[Bill Anderson]

Toby Dickenson wrote:
> 
> On Mon, 17 Jul 2000 05:45:49 -0600, Bill Anderson <bill@libc.org>
> wrote:
> 
> > >> I'm wondering if anyone can suggest something good to run in front of
> > >> 2 zopes talking to a zeo server - for failover and load balancing.  I
> 
> >> One disadvantage is that solution is that each Zope will have poor
> >> locality-of-reference within the object database. I think I can avoid
> >> that using a squid redirector (www.squid-cache.org). Ill post any
> >> news.
> >
> >What do you mean?
> 
> Suppose your zope site www.contrived-example.com is comprised of many
> largely independant sections,
> http://www.contrived-example.com/section1,
> http://www.contrived-example.com/section2 etc.
> 
> Your multiple Zopes can all serve all of these sections, however
> theres not enough storage for each machine to hold all the sections
> simultaneously.

As I understand ZEO, each machine _doesn't_ hold the site. The ZEO
clients (servers) communicate with a central ZSS (Zope Storage Server).
So in this contrived example, the problem is non-extant. ;-)


> You can make better use of ZODB's in-memory cache and the ZEO pickle
> cache if the requests for /section1 usually go to the same server.

AIUI (I'm no ZEO expert, I just use it ;) ), you can have each server
cache a certain amount, thus ameliorating the problem somewhat.

 
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