>> On Wed, Oct 24, 2012 at 12:33 AM, Tim Godfrey <t...@obsidian.com.au>
>> wrote:
>> > Hi Jim
>> >
>> > Do you have any idea as to why people recommend against many storages
>> under
>> > a single Zeo?
>> Seriously?
>> Go back and read the thread.
>> Seriously mate. The "why" is very vague. 
> There is nothing vague about the first reply to your question:
>     "ZEO does not handle each storage in a separate thread, so you're
> underusing multiple CPUs if you have them. Multiple ZEO servers would
> also spread the open sockets among them. There could still be a leak,
> but it'd take longer to exhaust file descriptors."

Yes but this is not really strictly accurate. Because it is primarily IO
bound, it is certainly possible to do more than 1 CPU worth of work (which
Jim notes in a followup email).

A useful thread that talks through some of the issues (as they were in
2006, anyway):

>From my point of view, the biggest reason that I have seen *in practice*
for splitting off storages into their own separate ZEO was the issue noted
Where Dieter talks about the "vote" phase on large transactions preventing
other requests from running. I have seen this happen in practice (with 2GB
transactions) and other requests were, without doubt, prevented from being
serviced during this phase.

I hope this helps,

Darryl Dixon
Winterhouse Consulting Ltd
For more information about ZODB, see http://zodb.org/

ZODB-Dev mailing list  -  ZODB-Dev@zope.org

Reply via email to