[Twisted-Python] Moderately-long running processes timing out in Twisted

L. Daniel Burr ldanielburr at mac.com
Fri Sep 5 13:15:40 EDT 2008

Hi Steve,

On Fri, 05 Sep 2008 11:51:15 -0500, Steve Lewis  
<spiritualmechanic at yahoo.com> wrote:

> We're trying to use twisted as a sort of bus, a centralized place to  
> manage all of our SOA enpoints (mostly through XML-RPC). We have a few  
> services that access the Oracle DB directly (adbapi). In production  
> we're getting intermittent ConnectionLost exceptions from cx_Oracle.  
> Most of these are queries that take a couple of seconds.

Hmm, it is kind of hard to say what the problem could be, without
seeing the code that is using adbapi and cx_Oracle.

When you say you are receiving ConnectionLost exceptions from cx_Oracle,
are they *really* from cx_Oracle, i.e., "ORA-03135 - Connection lost...",
or are they just the result of adbapi calling its connectionLost method?

> Has anyone seen this kind of behavior before? What we're probably going  
> to do in the short term is just remove twisted from the equation for  
> these methods that seem to be timing out. But we're relatively new to  
> twisted and I wonder if we're doing something that's obviously wrong.

I've used cx_Oracle with twisted many times, with many different workloads,
including stored procedures with OUT parameters, and it has always worked
as expected.  If you are able to provide some code, this list might be
able to provide you with more prescriptive advice.

Hope this helps,

L. Daniel Burr

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