[Zope-DB] ZSQL parallelism problem

M.-A. Lemburg mal@lemburg.com
Thu, 31 Jul 2003 10:05:55 +0200

Kent Hoxsey wrote:
> I'm using Zope 2.6.1 to encapsulate a bunch of sql scripts my 
> group uses for ad-hoc queries. It's really sweet, and simplifies
> a lot of my support issues for them.
> But I've noticed a performance issue, and have run out of ideas
> to try to fix it.  Basically, my Zope setup can only run two ZSQL
> queries at a time, and as soon as I start a second one, the 
> whole instance stops serving new requests until one of the ZSQL
> queries finishes.
> These are long-running queries (a couple minutes at least), so
> it's not useful to have the server unavailable. While the sql
> is executing, the Zope server is basically asleep, so there are
> no loading problems. It seems like something is blocking that
> keeps Zope from doing any useful work.
> The setup:
> Win2k
> Zope 2.6.1
> Python 2.1.3
> Oracle 9i client libraries
> Options I've tried:
> More Zope threads - 20 (-t option on startup)
> More ZODB threads - 20 (changed source code)
> DCOracle2 DA
> mxODBC and DA from egenix (even with multiple connections open)
> Clearly, the server, database, and all intervening software are
> capable, I just can't get them configured correctly. Anybody
> have any ideas?

It's possible that your queries are locking the database or
part of it, or that the two queries introduce a dead-lock
situation. That shouldn't stop Zope from serving non-database
related requests, though.

Marc-Andre Lemburg

Professional Python Software directly from the Source  (#1, Jul 31 2003)
 >>> Python/Zope Products & Consulting ...         http://www.egenix.com/
 >>> mxODBC, mxDateTime, mxTextTools ...        http://python.egenix.com/