On Thu, Mar 16, 2017 at 8:35 PM, David Steele <da...@pgmasters.net> wrote:
> On 2/21/17 9:54 AM, Bernd Helmle wrote: > > Am Dienstag, den 14.02.2017, 15:53 +0300 schrieb Alexander Korotkov: > >> +1 > >> And you could try to use pg_wait_sampling > >> <https://github.com/postgrespro/pg_wait_sampling> to sampling of wait > >> events. > > > > I've tried this with your example from your blog post[1] and got this: > > > > (pgbench scale 1000) > > > > pgbench -Mprepared -S -n -c 100 -j 100 -T 300 -P2 pgbench2 > > > > SELECT-only: > > > > SELECT * FROM profile_log ; > > ts | event_type | event | count > > ----------------------------+---------------+---------------+------- > > 2017-02-21 15:21:52.45719 | LWLockNamed | ProcArrayLock | 8 > > 2017-02-21 15:22:11.19594 | LWLockTranche | lock_manager | 1 > > 2017-02-21 15:22:11.19594 | LWLockNamed | ProcArrayLock | 24 > > 2017-02-21 15:22:31.220803 | LWLockNamed | ProcArrayLock | 1 > > 2017-02-21 15:23:01.255969 | LWLockNamed | ProcArrayLock | 1 > > 2017-02-21 15:23:11.272254 | LWLockNamed | ProcArrayLock | 2 > > 2017-02-21 15:23:41.313069 | LWLockNamed | ProcArrayLock | 1 > > 2017-02-21 15:24:31.37512 | LWLockNamed | ProcArrayLock | 19 > > 2017-02-21 15:24:41.386974 | LWLockNamed | ProcArrayLock | 1 > > 2017-02-21 15:26:41.530399 | LWLockNamed | ProcArrayLock | 1 > > (10 rows) > > > > writes pgbench runs have far more events logged, see the attached text > > file. Maybe this is of interest... > > > > > > [1] http://akorotkov.github.io/blog/2016/03/25/wait_monitoring_9_6/ > > This patch applies cleanly at cccbdde. It doesn't break compilation on > amd64 but I can't test on a Power-based machine > > Alexander, have you had a chance to look at Bernd's results? > Bernd's results look good. But it seems that his machine is not big enough, so effect of patch isn't huge. I will get access to big enough Power8 machine in Monday 27 March. I will run benchmarks there and post results immediately. ------ Alexander Korotkov Postgres Professional: http://www.postgrespro.com The Russian Postgres Company
