On Thu, 2004-02-12 at 07:19, Bjorn Stabell wrote:
Toby wrote:
One of the optimization we're thinking of is storing results of ZCatalog searches (e.g., number of replies to postings) in volatile variables so we don't have to run the catalog search at all. We'd like to use memory space shared between threads for this. Using ZEO would require us to store this in the ZODB.
Storing that in ZODB would be a bad idea. Theres no reason to think that this cache would be faster than ZCatalog.
I dont see why you would be *required* to store in ZODB... just dont share your cache between publisher threads on different Zope instances.
(my apologies if this is obvious)
Okay, for example, since it's a BBS we need to have quick access to:
the latest poster the latest posting the latest registered member
Create a zope product that doesn't keep a history (otherwise the ZODB will grow like nuts) and store these values in it whenever there is a new port/registration. Then just read them when you need to. Anyone see anything wrong with that approach?
All of these are complex queries (in the case of the latest registered member it's not even a query but a brute-force search). What I think most ASP/PHP boards do is that they store these values in the database instead of querying for them all the time.
Since many of these can be found through queries, they don't really need persistent storage, but updates need to be seen by all threads; thus the requirement for ZODB if we use ZEO, but the possibility to use (even faster) shared memory if we don't use ZEO.
In effect we want to do something like this:
def getLatestPoster(self): if not hasattr(self, '_v_latestPoster'): self._v_latestPoster = whatever_query() return self._v_latestPoster return self._v_latestPoster
def setLatestPoster(self, poster): self._v_latestPoster = poster
But instead of having thread-local variables we wanted to use Dieter Maurer's SharedResource in order to share the cache between threads:
http://www.dieter.handshake.de/pyprojects/zope/SharedResource.html
Regards,
-- Edward Muller - http://www.interlix.com - "Open Source Specialists" Dedicated Zope Hosting - Web Hosting - Open Source Consulting Network & PC Service & Support - Custom Programming Phone: 417-862-0573 - Cell: 417-844-2435 - Fax: 417-862-0572 Jabber: edwardam@jabber.interlix.com - AIM: edwardam453 - ICQ: 287033