On Thu, 2009-07-30 at 23:55 -0700, poifgh wrote:
[...]
> I was measuring how quickly could SA [spam assassin] process spams when
> several SA processes are run in parallel over separate mbox files. I used a
> 8 core machine. Below are the numbers when I forked different number of
> processes.
>
> Fork = 8;
> Rate = 57 msgs/sec
>
> Fork = 4;
> Rate = 44 msgs/sec
>
> Fork = 1;
> Rate = 22 msgs/sec
>
>
> I ran freshly build SA with Bayes and DNSBL turned off. Why am I not seeing
> a linear increase in the throughput? Is a file locking creating the
Because the bottleneck is not (only) the CPUs?
Run `vmstat 1` or similar to see (or at least get an idea;-) if the
workload is I/O bound or CPU-bound or ....
> bottleneck? If yes, which particular file is being locked? If no, what could
Maybe. The default "store in files" drivers locks the DBs exclusively
for each access.
> be the reason for this?
Switch the DB backend to some MySQL or PostgreSQL (or whatever you like
using from the "supported" ones). Run that on the very same machine and
compare the numbers with the above.
Bernd
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