Re: "mode" and varios processes sharing the same queue for writting

["Iñaki Baz Castillo" <ibc@aliax.net>]

El Sábado, 9 de Enero de 2010, Eric Wong escribió:
> > It's really great for me. It works really well by having different
> > writers  processes and different reader processes sharing the same mqueue
> > (load balancing out of the box) :)
> 
> Good to know, I've yet to test them under high load myself :)

I've done some benchmarks as follows:

- Unicorn with 8 workers and each worker also writting in a shared mq 
(maxmsg=50) for each HTTP request (non-blocking writting).

- Other 8 processes acting as mq readers in parallel (blocking reading). For 
each message the reader simulates some work by sleeping during 0.002 seconds.

- Apache ab test with 5000 requests and concurrency 10.

With these settings there are no errors (the queue is always available). By 
incrementing a bit the sleeping time then some errors occur since the queue 
buffer gets full sometimes (totally expected of course).

But the more great thing is the fact that each mq reader process receives a 
similar ammount of messages, so the kernel gives us a perfect load balancing 
system :)



-- 
Iñaki Baz Castillo <ibc@aliax.net>