On Fri, Jan 17, 2020 at 11:39 AM Dilip Kumar <dilipbalaut@gmail.com> wrote:
I have performed cost delay testing on the latest test(I have used
same script as attahced in [1] and [2].
vacuum_cost_delay = 10
vacuum_cost_limit = 2000
Observation: As we have concluded earlier, the delay time is in sync
with the I/O performed by the worker
and the total delay (heap + index) is almost the same as the
non-parallel operation.
test1:[1]
Vacuum non-parallel
WARNING: VacuumCostTotalDelay=11332.320000
Vacuum 2 workers
WARNING: worker 0 delay=171.085000 total io=34288 hit=22208 miss=0 dirty=604
WARNING: worker 1 delay=87.790000 total io=17910 hit=17890 miss=0 dirty=1
WARNING: worker 2 delay=88.620000 total io=17910 hit=17890 miss=0 dirty=1
WARNING: VacuumCostTotalDelay=11505.650000
Vacuum 4 workers
WARNING: worker 0 delay=87.750000 total io=17910 hit=17890 miss=0 dirty=1
WARNING: worker 1 delay=89.155000 total io=17910 hit=17890 miss=0 dirty=1
WARNING: worker 2 delay=87.080000 total io=17910 hit=17890 miss=0 dirty=1
WARNING: worker 3 delay=78.745000 total io=16378 hit=4318 miss=0 dirty=603
WARNING: VacuumCostTotalDelay=11590.680000
test2:[2]
Vacuum non-parallel
WARNING: VacuumCostTotalDelay=22835.970000
Vacuum 2 workers
WARNING: worker 0 delay=345.550000 total io=69338 hit=45338 miss=0 dirty=1200
WARNING: worker 1 delay=177.150000 total io=35807 hit=35787 miss=0 dirty=1
WARNING: worker 2 delay=178.105000 total io=35807 hit=35787 miss=0 dirty=1
WARNING: VacuumCostTotalDelay=23191.405000
Vacuum 4 workers
WARNING: worker 0 delay=177.265000 total io=35807 hit=35787 miss=0 dirty=1
WARNING: worker 1 delay=177.175000 total io=35807 hit=35787 miss=0 dirty=1
WARNING: worker 2 delay=177.385000 total io=35807 hit=35787 miss=0 dirty=1
WARNING: worker 3 delay=166.515000 total io=33531 hit=9551 miss=0 dirty=1199
WARNING: VacuumCostTotalDelay=23357.115000
[1] https://www.postgresql.org/message-id/CAFiTN-tFLN%3Dvdu5Ra-23E9_7Z1JXkk5MkRY3Bkj2zAoWK7fULA%40mail.gmail.com
[2] https://www.postgresql.org/message-id/CAFiTN-tC%3DNcvcEd%2B5J62fR8-D8x7EHuVi2xhS-0DMf1bnJs4hw%40mail.gmail.com
--
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com