[Zope] ZEO and a front end...

[Toby Dickenson]

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.

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.

However, you don't want to hardwire this relationship since any other
machine should handle /section1 if its 'home' machine goes down, or is
busy.


This problem can't be solved without parsing http headers, so
low-level solutions such as www.linux-ha.com are not a total solution.



Toby Dickenson
tdickenson@geminidataloggers.com