[ZODB-Dev] design issue: job queue is concurrency bottleneck

[Toby Dickenson]

On Thursday 04 March 2004 05:04, John Belmonte wrote:
> I finally got through the first round of concurrency testing on my app.
>     Despite being a high-write application, virtually no write conflicts
> occur-- with one major exception.  I have a job queue, which is a BTree
> keyed by scheduled job time.  It's the only BTree in my app that doesn't
> have random keys.  Incoming requests to my server tend to generate a few
> jobs, and unfortunately they must be scheduled at various constant time
> periods in the future.  As a result, simultaneous requests generate jobs
> scheduled for approximately the same time, mapping to the same area of
> the BTree, and causing write conflicts.

That makes sense for keys that are *exactly* the same time. For approximately 
the same time then surely conflict resolution would take care of the write 
conflict?

Or do you have read conflicts?


-- 
Toby Dickenson