David, thanks for the quick reply.

> Well, the server using it, in a slightly modified version from that
> message, remains in production, and has been continuously since July
> of 2007.  So it's certainly worked for its intended purpose for me -
> that is, offloading the SA database I/O to a dedicated thread to avoid
> any possible blocking in the main Twisted reactor thread.

That's good to hear.

> Probably the biggest change between my message and putting it in
> production was to stop using the ORM.

Yes, I've read other cautionary tales about mixing Twisted and the ORM. 
  Fortunately, I don't need it for my immediate needs.

> I always considered it a solution to a very specific usage pattern
> that worked for my particular case, but not necessarily something
> generalized enough for inclusion elsewhere.  It's pretty brute force;
> no ORM support (well, or be very careful if using the ORM), and each
> operation queued to the database thread needs to be self-contained
> (since ops from different twisted deferred chains could interleave
> over the same database connection).  But within those constraints it
> works just fine.

Hmmm, Could you elaborate a bit about the "self-contained"?  I do have 
some cases where I fire off a deferredList with several (independent) 
queries in it.  Might that be problematic?

> 
> As you can see from that older message, there's not too much involved.
> It's basically a standard worker thread pattern using queues, with
> only a single worker thread, some knowledge about the SA engine and
> the use of Twisted Deferreds to return the result.

Yes, it is nice and simple and clean.  It shouldn't be hard to work 
with, and extend if needed.

Thanks again,

-- 
Don Dwiggins
Advanced Publishing Technology


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