David Pratt wrote at 2005-9-21 13:38 -0300:
... If I wanted to configure with multiple zodb for a single ZEO server you say there may be a possible downside in requiring a single ZEO server per database instance further down the road. Is this something that is currently planned so I don't implement something that will not be supported later?
This was discussed on a zope mailing list (I think "zodb-dev@zope.org"). Please search the archives (via your favorite search engine).
It could be also be a bit of a problem since each ZEO server requires its own RAM. RAM is a valuable commodity.
ZEO is not very RAM hungry. Only for packing, a higher amount of RAM is necessary.
My goal is to ensure that customers I work with are working exclusively in their own zodb. It seems preferable for these zodb's to be associated with a single ZEO server (instead of each zodb mounted in a single zope instance) to make maintenance tasks smooth and handled asynchronously.
Does this not speak for one ZEO server per customer? Imagine, you must restore a storage for one customer (because he destroyed its content). With a single ZEO server, you must bring it down to activate the backup. All your customers are affected. With a separate ZEO for each customer -- you bring down the ZEO for this customer. All others are unaffected.
I realize that if resources were unlimited, it would be best for a single ZEO server to use a single zodb and have one or more ZEO clients.
Huch? I do not understand that argument. With unlimited resources, each customer had its own computer with its own ZEO and ZEO clients...
... I guess I see the possibility of single ZEO for a number of virtual hosted sites as a plus (since it means also that I could add additional ZEO clients to provide more threads for serving the group of virtual sites).
But for this, it does not matter whether you have one or many ZEO servers... -- Dieter