[Zope] Multiple ZODB for virtual hosts with ZEO

[David Pratt]

Hi Dieter

> This was discussed on a zope mailing list (I think 
> "zodb-dev at zope.org").
> Please search the archives (via your favorite search engine).

Thanks.  I'll look for this.

> ZEO is not very RAM hungry.
>
> Only for packing, a higher amount of RAM is necessary.

This is good to know.

> Does this not speak for one ZEO server per customer?

Sure does. With a number of sites in a single zeo instance it looks to 
be essentially the same issue as number of sites in a singe zope 
instance, you'd have to stop and start as you have pointed out.

At the same time it does not seem reasonable to run a separate zope 
instance and a separate zeo instance for each site where each zodb 
would not normally exceed 50 MB in my case.  So to me it is clear the 
importance of running separate zodbs per site (but perhaps not as 
important to have a separate framework whether it be a zope instance or 
a zeo instance per site). The zodb size has mostly to do with the heavy 
use of blobs and also relational database storage. But there are still 
thousands of objects in this situation (and it does not mean any less 
site maintenance).

I am interested in what you might recommend when you are dealing with a 
number of virtual sites of the smaller zodb scale since this is really 
the issue I am attempting to solve.  I definitely like the features ZEO 
has to offer as far as asynchronous maintenance, etc.

Regards,
David