Re: Checkpoint sync pause

On 1/16/12 5:59 PM, Greg Smith wrote:
> 
> What I think is needed instead is a write-heavy benchmark with a think
> time in it, so that we can dial the workload up to, say, 90% of I/O
> capacity, but that spikes to 100% when checkpoint sync happens.  Then
> rearrangements in syncing that reduces caching pressure should be
> visible as a latency reduction in client response times.  My guess is
> that dbt-2 can be configured to provide such a workload, and I don't see
> a way forward here except for me to fully embrace that and start over
> with it.

You can do this with custom pgbench workloads, thanks to random and
sleep functions.  Somebody went and make pgbench programmable, I don't
remember who.

-- 
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com