[ZODB-Dev] ZEO Limits

[Jim Fulton]

Toby Dickenson wrote:
> 

Good response. Some minor additions below.


> 4. When connecting, each ZEO client has to revalidate its cached
> objects. That is a big load on the ZEO server time is comes up.

You could mitigate this by using non-persistent caches.
 
> >Do you know anybody with a network instalation with this number of machines?
> 
> no. Do you really need that many zope servers? 

Right. In fact, I'd say "waay no". ;) That is a lot.

(snip)
> If you persue this approach it may be interesting to consider a
> hierarchy of ZEO servers. Each end point does not connect to the
> central ZEO server, but rather to a regional hub ZEO server shared by
> perhaps 100 other endpoints. That hub's storage is itself a ZEO client
> (with a big cache) connecting to the master ZEO server (shared by 22
> hubs). Ive not *used* this configuration personally, but I have
> thought about it, and it looks like it should be more scalable.

Could be. Note that due to an oversight in the ZEO implementation, 
this doesn't work right now, but would be easy to fix, I think. The
problem is that a ClientStorage has certain expectations of a 
database that aren't satisfied by a storage server. :/

Jim

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