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

Chris Withers chrisw at
Thu Oct 23 14:05:05 EDT 2003

Bo M. Maryniuck wrote:

> On Thursday 23 October 2003 15:47, Chris Withers wrote:
>>What do you mean by 'needed' here?
> I mean I have in production huge cache (10.000 objects or more, 20 threads 
> etc). So I really dislike this idea to flush everything from the Cache...

Why do you have so many threads?

>>Well, it could catch the exception oracle throws and re-connect, surely?
> Yup.

That's what I want to implement ;-)

> Well, yes. So C code of dco2 SHOULD have timeout feature. Though I am not sure 
> it has (should see one day). But I am a bit timecontstrained...

If you can tell me what to write, I can write it :-)
(Matt, that goes for you too :-P)

> Connection is da whole Zope approach by sharing connectors between threads 
> using volatile attributes. In this case we sometimes have large amount of 
> connections, while we usually need one-two-three maximum...

I'm currently looking at how the other DA's do this, the only idea that's popped 
into my head so far is a module-level variable storing the connection pool.

ZOracleDA threads can then retrieve a connection from this pool is a section of 
code protected by a python Lock and put it back when they're done.

If there are no connections available, then a new one would be opened, up to a 
maximum equal to the number of Zope threads.

What problems/weaknesses can people see with this approach?



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