Re: pgbench vs. wait events

On Thu, Oct 6, 2016 at 02:38:56PM -0400, Robert Haas wrote:
> Hi,
>
> I decided to do some testing on hydra (IBM-provided community
> resource, POWER, 16 cores/64 threads, kernel 3.2.6-3.fc16.ppc64) using
> the newly-enhanced wait event stuff to try to get an idea of what
> we're waiting for during pgbench. I did 30-minute pgbench runs with
> various configurations, but all had max_connections = 200,
> shared_buffers = 8GB, maintenance_work_mem = 4GB, synchronous_commit =
> off, checkpoint_timeout = 15min, checkpoint_completion_target = 0.9,
> log_line_prefix = '%t [%p] ', max_wal_size = 40GB, log_checkpoints =
> on. During each run, I ran this psql script in another window and
> captured the output:

This is a great study that shows how the new instrumentation has given
us a new window into performance. I am frankly surprised we got as far
as we did in finding performance bottlenecks before we had this
instrumentation.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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