Shane Hathaway wrote:
On Wed, 19 Mar 2003, Thierry FLORAC wrote:
And another one : does the fact of splitting a Zope site between several ZODBs can have any impact (improvement or not) on the whole performances ??
There is no measurable difference in performance unless you mount a large number of databases. The MountPoint._setDB() and MountPoint.close() methods are the issue here: they have to open/close all mounted connections, even if they won't be used in the course of a transaction.
Hmmm... well, just a data point, but since I moved one of our big setups (Two ClientStorages mounted into another ClientStorage) from ExtMount to DBTab, I've noticed that the first object loaded from a mounted storage takes significantly(and I do mean significant ;-) longer than it used to and longer than any subsequent loads of objects from that storage. I wonder what's taking the time? The mounted storages all have fairly large (100-400Mb) ZEO client caches, but they were that way with ExtMount too. The only other difference I can think of is that one of the mounted storages is basically a folder with about 11,000 items in it. This used to be a BTreeFolder but I've moved it to a BTreeFolder2 (mainly in order to stop the ZMI left pane killing hte machine by trying to load all 11,000 objects into memory :-S ) Any ideas? cheers, Chris