Saga continues ([Zope-DB] DCOracle2: close connection doesn't)

[Dario Lopez-Kästen]

This is a me-too mail to indicate that there are more people experiencing
the same problems. Further comments are inline below.

From: "Paul Browning" <paul.browning at bristol.ac.uk>
>
> Me too. BUT ...... we have been having a torrid time over the
> summer with Zope and Oracle.
>
> We have several Zope instances, many Oracle instances and
> and a lot Z Oracle Database Connection objects.

Same here, although we have cut down the number of Z Oracle Database
Connection object to only one per schema. This *seems* to lower the risk of
having hanging connections. Our main problem though is with long running
queries that seems to loose connection with zope, and the fact that
eventueally, of the 4 trheads that are available 3 are hanging leaving only
one thread for zope to work with.

> I will observe the following: the many Oracle instances are
> also used by Java and Perl apps. There have been, I understand,
> no problems with database connectivity with the non-Zope apps.

Exactly. The same situation is here.

> The circumstantial evidence therefore points very strongly
> to some bit of the Zope side of things being to blame.

+1. I wouls also like to say the following: The performance of Zope
effectively using only 1 of it's 4 threads is realtively good (not lightning
fast, but it works). This means that zope is reasonably good
performance-wise. I would love to see the performance of Zope when it
effectively runs with 4 threads on ur db-apps.

RDBMS connection, with Oracle in particular, is a big thing where I work and
I am sure that it is a big thing for other organsiations as well, so I'd
like to really put emphasis (sp?) on the importance of this matter.
Re-designing using ZODB is usually not an option for many of the
applications we build.

Unfortunately, I have no cash to put behind my emphasis, so I know that i
can scream all I want with little result :-), but still - the idea of good
Oracle conectivity helps Zope gain mindshare as a stable platform for
building applications that connect to mainstream databases.

>
> So, Bo, keep digging. You may not be on the right path but
> you are in the right forest IMHO.
>

If I can help in anyway, please let me know.

/dario