On Tue, Oct 29, 2019 at 1:59 PM Masahiko Sawada <sawada.mshk@gmail.com> wrote:
> Actually after increased shared_buffer I got expected results:
>
> * Test1 (after increased shared_buffers)
> normal : 2807 ms (hit 56295, miss 2, dirty 3, total 56300)
> 2 workers : 2840 ms (hit 56295, miss 2, dirty 3, total 56300)
> 1 worker : 2841 ms (hit 56295, miss 2, dirty 3, total 56300)
>
> I updated the patch that computes the total cost delay shared by
> Dilip[1] so that it collects the number of buffer hits and so on, and
> have attached it. It can be applied on top of my latest patch set[1].
I tried to repeat the test to see the IO delay with
v32-0004-PoC-shared-vacuum-cost-balance.patch [1]. I tried with
shared memory 4GB. I recreated the database and restarted the server
before each run. But, I could not see the same I/O delay and cost is
also not the same. Can you please tell me how much shared buffers did
you set?
Test1 (4GB shared buffers)
normal: stats delay 1348.160000, hit 68952, miss 2, dirty 10063,
total 79017
1 worker: stats delay 1821.255000, hit 78184, miss 2, dirty 14095, total 92281
2 workers: stats delay 2224.415000, hit 86482, miss 2, dirty 17665, total 104149
[1] https://www.postgresql.org/message-id/CAD21AoAqT17QwKJ_sWOqRxNvg66wMw1oZZzf9Rt-E-zD%2BXOh_Q%40mail.gmail.com
--
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com