[Zope-dev] Threaded Database Access

Casey Duncan casey@zope.com
Thu, 2 May 2002 10:08:48 -0400


ZPsycopgDA (for postgres) is definitely multi-threaded. I think zPopyDA i=
s=20
too.

Another solution might be to setup your site using ZEO and several single=
=20
threaded ZEO Clients. Then put a load balancer in front of it. Then the=20
single-threadedness is much less of an issue, since you have multiple=20
instances handling the requests. You might need more hardware (or at leas=
t=20
more RAM) to make this pay off though.

-Casey

On Thursday 02 May 2002 12:43 am, Jeff Nielsen / UgoFast allegedly wrote:
> I'm using Zope/Zserver 2.2.4, ZODBCDA v3.1.0b2 and SQL Server 2000. I'v=
e
> noticed that pages generated from database querries are definitely
> single threaded, and these pages are the bulk of my site. My poking
> around seems to indicate that ZODBCDA is the single-threaded culprit,
> and some emails from the list over the last couple months seem to
> confirm that.
>=20
> The volume of my site and the size of the database (hence query respons=
e
> times) are getting to the point that this is a concern. So I'm
> investigating my options, including:
> 1) Cluster the web site with multiple single processor machines.
> 2) Move to a database that Zope supports multi-threaded access to.
> 3) ?
>=20
> I've been considering a move to Oracle or PostgreSQL/MySQL for other
> reasons, but I'm not going to do it just for yucks. Extending and
> populating my site gives better return than porting the database. I'd
> like to make sure I'll get return on my time investment.
>=20
> I saw an document on the Zope web site from 1999 that talked about
> labeling Zope DAs Level 1,2 or 3 based on their sophistication, but I
> don't see any of the current DAs labeled as such. There was text in the
> Oracle and MySQL DA descriptions that seem to imply multi-threaded
> behaivor though.
>=20
> I'm looking for the info from the community on:
> 1. Is the ZODBCDA single-threaded and might that change anytime soon?
> 2. Can someone confirm that the Oracle, PostgreSQL or MySQL DAs are
> multi-threaded.
> 3. Does the multi-threading require using the Zope Session facility or
> some other feature? (My site uses FSSession.)
>=20
> Thanks in advance for any input.
>=20
> Jeff Nielsen / UgoFast
> http://www.UgoFast.com
> Jeff@UgoFast.com
> =20
>=20
>=20
>=20
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>=20