Re: cost based vacuum (parallel)

2019-11-17 Thread Masahiko Sawada
On Fri, 15 Nov 2019 at 11:54, Amit Kapila wrote: > > On Wed, Nov 13, 2019 at 10:02 AM Masahiko Sawada > wrote: > > > > I've done some tests while changing shared buffer size, delays and > > number of workers. The overall results has the similar tendency as the > > result shared by Dilip and

Re: cost based vacuum (parallel)

2019-11-15 Thread Dilip Kumar
On Thu, Nov 14, 2019 at 5:02 PM Mahendra Singh wrote: > > On Mon, 11 Nov 2019 at 17:56, Amit Kapila wrote: > > > > On Mon, Nov 11, 2019 at 5:14 PM Dilip Kumar wrote: > > > > > > On Mon, Nov 11, 2019 at 4:23 PM Amit Kapila > > > wrote: > > > > > > > > .. > > > > > I have tested the same with

Re: cost based vacuum (parallel)

2019-11-14 Thread Amit Kapila
On Wed, Nov 13, 2019 at 10:02 AM Masahiko Sawada wrote: > > I've done some tests while changing shared buffer size, delays and > number of workers. The overall results has the similar tendency as the > result shared by Dilip and looks reasonable to me. > Thanks, Sawada-san for repeating the

Re: cost based vacuum (parallel)

2019-11-14 Thread Mahendra Singh
On Mon, 11 Nov 2019 at 17:56, Amit Kapila wrote: > > On Mon, Nov 11, 2019 at 5:14 PM Dilip Kumar wrote: > > > > On Mon, Nov 11, 2019 at 4:23 PM Amit Kapila wrote: > > > > > > .. > > > > I have tested the same with some other workload(test file attached). > > > > I can see the same behaviour

Re: cost based vacuum (parallel)

2019-11-12 Thread Masahiko Sawada
On Tue, 12 Nov 2019 at 20:22, Masahiko Sawada wrote: > > On Tue, 12 Nov 2019 at 19:08, Amit Kapila wrote: > > > > On Tue, Nov 12, 2019 at 3:03 PM Dilip Kumar wrote: > > > > > > On Tue, Nov 12, 2019 at 10:47 AM Dilip Kumar > > > wrote: > > > > > > > > On Mon, Nov 11, 2019 at 4:23 PM Amit

Re: cost based vacuum (parallel)

2019-11-12 Thread Masahiko Sawada
On Tue, 12 Nov 2019 at 19:08, Amit Kapila wrote: > > On Tue, Nov 12, 2019 at 3:03 PM Dilip Kumar wrote: > > > > On Tue, Nov 12, 2019 at 10:47 AM Dilip Kumar wrote: > > > > > > On Mon, Nov 11, 2019 at 4:23 PM Amit Kapila > > > wrote: > > > > > > > > On Mon, Nov 11, 2019 at 12:59 PM Dilip Kumar

Re: cost based vacuum (parallel)

2019-11-12 Thread Amit Kapila
On Tue, Nov 12, 2019 at 3:03 PM Dilip Kumar wrote: > > On Tue, Nov 12, 2019 at 10:47 AM Dilip Kumar wrote: > > > > On Mon, Nov 11, 2019 at 4:23 PM Amit Kapila wrote: > > > > > > On Mon, Nov 11, 2019 at 12:59 PM Dilip Kumar > > > wrote: > > > > > > > > On Mon, Nov 11, 2019 at 9:43 AM Dilip

Re: cost based vacuum (parallel)

2019-11-12 Thread Dilip Kumar
On Tue, Nov 12, 2019 at 10:47 AM Dilip Kumar wrote: > > On Mon, Nov 11, 2019 at 4:23 PM Amit Kapila wrote: > > > > On Mon, Nov 11, 2019 at 12:59 PM Dilip Kumar wrote: > > > > > > On Mon, Nov 11, 2019 at 9:43 AM Dilip Kumar wrote: > > > > > > > > On Fri, Nov 8, 2019 at 11:49 AM Amit Kapila >

Re: cost based vacuum (parallel)

2019-11-11 Thread Dilip Kumar
On Mon, Nov 11, 2019 at 4:23 PM Amit Kapila wrote: > > On Mon, Nov 11, 2019 at 12:59 PM Dilip Kumar wrote: > > > > On Mon, Nov 11, 2019 at 9:43 AM Dilip Kumar wrote: > > > > > > On Fri, Nov 8, 2019 at 11:49 AM Amit Kapila > > > wrote: > > > > > > > > > > > > Yeah, I think it is difficult to

Re: cost based vacuum (parallel)

2019-11-11 Thread Amit Kapila
On Mon, Nov 11, 2019 at 5:14 PM Dilip Kumar wrote: > > On Mon, Nov 11, 2019 at 4:23 PM Amit Kapila wrote: > > > > .. > > > I have tested the same with some other workload(test file attached). > > > I can see the same behaviour with this workload as well that with the > > > patch 4 the

Re: cost based vacuum (parallel)

2019-11-11 Thread Dilip Kumar
On Mon, Nov 11, 2019 at 4:23 PM Amit Kapila wrote: > > On Mon, Nov 11, 2019 at 12:59 PM Dilip Kumar wrote: > > > > On Mon, Nov 11, 2019 at 9:43 AM Dilip Kumar wrote: > > > > > > On Fri, Nov 8, 2019 at 11:49 AM Amit Kapila > > > wrote: > > > > > > > > > > > > Yeah, I think it is difficult to

Re: cost based vacuum (parallel)

2019-11-11 Thread Amit Kapila
On Mon, Nov 11, 2019 at 12:59 PM Dilip Kumar wrote: > > On Mon, Nov 11, 2019 at 9:43 AM Dilip Kumar wrote: > > > > On Fri, Nov 8, 2019 at 11:49 AM Amit Kapila wrote: > > > > > > > > > Yeah, I think it is difficult to get the exact balance, but we can try > > > to be as close as possible. We

Re: cost based vacuum (parallel)

2019-11-10 Thread Dilip Kumar
On Mon, Nov 11, 2019 at 9:43 AM Dilip Kumar wrote: > > On Fri, Nov 8, 2019 at 11:49 AM Amit Kapila wrote: > > > > On Fri, Nov 8, 2019 at 9:39 AM Dilip Kumar wrote: > > > > > > I have done some experiments on this line. I have first produced a > > > case where we can show the problem with the

Re: cost based vacuum (parallel)

2019-11-10 Thread Dilip Kumar
On Fri, Nov 8, 2019 at 11:49 AM Amit Kapila wrote: > > On Fri, Nov 8, 2019 at 9:39 AM Dilip Kumar wrote: > > > > I have done some experiments on this line. I have first produced a > > case where we can show the problem with the existing shared costing > > patch (worker which is doing less I/O

Re: cost based vacuum (parallel)

2019-11-07 Thread Amit Kapila
On Fri, Nov 8, 2019 at 9:39 AM Dilip Kumar wrote: > > I have done some experiments on this line. I have first produced a > case where we can show the problem with the existing shared costing > patch (worker which is doing less I/O might pay the penalty on behalf > of the worker who is doing more

Re: cost based vacuum (parallel)

2019-11-07 Thread Dilip Kumar
On Fri, Nov 8, 2019 at 8:37 AM Amit Kapila wrote: >> On Fri, Nov 8, 2019 at 8:18 AM Masahiko Sawada > wrote: > > > > On Wed, 6 Nov 2019 at 15:45, Amit Kapila wrote: > > > > > > On Tue, Nov 5, 2019 at 11:28 AM Amit Kapila > > > wrote: > > > > > > > > On Mon, Nov 4, 2019 at 11:42 PM Andres

Re: cost based vacuum (parallel)

2019-11-07 Thread Amit Kapila
On Fri, Nov 8, 2019 at 8:18 AM Masahiko Sawada wrote: > > On Wed, 6 Nov 2019 at 15:45, Amit Kapila wrote: > > > > On Tue, Nov 5, 2019 at 11:28 AM Amit Kapila wrote: > > > > > > On Mon, Nov 4, 2019 at 11:42 PM Andres Freund wrote: > > > > > > > > > > > > > The two approaches to solve this

Re: cost based vacuum (parallel)

2019-11-07 Thread Masahiko Sawada
On Wed, 6 Nov 2019 at 15:45, Amit Kapila wrote: > > On Tue, Nov 5, 2019 at 11:28 AM Amit Kapila wrote: > > > > On Mon, Nov 4, 2019 at 11:42 PM Andres Freund wrote: > > > > > > > > > > The two approaches to solve this problem being discussed in that > > > > thread [1] are as follows: > > > > (a)

Re: cost based vacuum (parallel)

2019-11-06 Thread Dilip Kumar
On Wed, Nov 6, 2019 at 9:21 AM Stephen Frost wrote: > > Greetings, > > * Amit Kapila (amit.kapil...@gmail.com) wrote: > > On Tue, Nov 5, 2019 at 1:42 AM Stephen Frost wrote: > > > * Andres Freund (and...@anarazel.de) wrote: > > > > That's quite doable independent of parallelism, as we don't have

Re: cost based vacuum (parallel)

2019-11-05 Thread Amit Kapila
On Tue, Nov 5, 2019 at 11:28 AM Amit Kapila wrote: > > On Mon, Nov 4, 2019 at 11:42 PM Andres Freund wrote: > > > > > > > The two approaches to solve this problem being discussed in that > > > thread [1] are as follows: > > > (a) Allow the parallel workers and master backend to have a shared > >

Re: cost based vacuum (parallel)

2019-11-05 Thread Stephen Frost
Greetings, * Amit Kapila (amit.kapil...@gmail.com) wrote: > On Tue, Nov 5, 2019 at 1:42 AM Stephen Frost wrote: > > * Andres Freund (and...@anarazel.de) wrote: > > > That's quite doable independent of parallelism, as we don't have tables > > > or indexes spanning more than one tablespace. True,

Re: cost based vacuum (parallel)

2019-11-05 Thread Amit Kapila
On Wed, Nov 6, 2019 at 7:55 AM Andres Freund wrote: > > Hi, > > On 2019-11-06 07:53:09 +0530, Amit Kapila wrote: > > As per feedback in this thread, it seems that for now, it is better, > > if we can allow a parallel vacuum only when I/O throttling is not > > enabled. We can later extend it

Re: cost based vacuum (parallel)

2019-11-05 Thread Andres Freund
Hi, On 2019-11-06 07:53:09 +0530, Amit Kapila wrote: > As per feedback in this thread, it seems that for now, it is better, > if we can allow a parallel vacuum only when I/O throttling is not > enabled. We can later extend it based on feedback from the field once > the feature starts getting

Re: cost based vacuum (parallel)

2019-11-05 Thread Amit Kapila
On Tue, Nov 5, 2019 at 1:42 AM Stephen Frost wrote: > * Andres Freund (and...@anarazel.de) wrote: > > > That's quite doable independent of parallelism, as we don't have tables > > or indexes spanning more than one tablespace. True, you could then make > > the processing of an individual vacuum

Re: cost based vacuum (parallel)

2019-11-05 Thread Dilip Kumar
On Tue, Nov 5, 2019 at 8:49 PM Andres Freund wrote: > > Hi, > > On November 5, 2019 7:16:41 AM PST, Dilip Kumar wrote: > >On Tue, Nov 5, 2019 at 2:40 PM Amit Kapila > >wrote: > >> > >> On Mon, Nov 4, 2019 at 11:58 PM Andres Freund > >wrote: > >> > > >> > Hi, > >> > > >> > On 2019-11-04

Re: cost based vacuum (parallel)

2019-11-05 Thread Andres Freund
Hi, On November 5, 2019 7:16:41 AM PST, Dilip Kumar wrote: >On Tue, Nov 5, 2019 at 2:40 PM Amit Kapila >wrote: >> >> On Mon, Nov 4, 2019 at 11:58 PM Andres Freund >wrote: >> > >> > Hi, >> > >> > On 2019-11-04 12:59:02 -0500, Jeff Janes wrote: >> > > On Mon, Nov 4, 2019 at 1:54 AM Amit Kapila

Re: cost based vacuum (parallel)

2019-11-05 Thread Dilip Kumar
On Tue, Nov 5, 2019 at 2:40 PM Amit Kapila wrote: > > On Mon, Nov 4, 2019 at 11:58 PM Andres Freund wrote: > > > > Hi, > > > > On 2019-11-04 12:59:02 -0500, Jeff Janes wrote: > > > On Mon, Nov 4, 2019 at 1:54 AM Amit Kapila > > > wrote: > > > > > > > For parallel vacuum [1], we were discussing

Re: cost based vacuum (parallel)

2019-11-05 Thread Amit Kapila
On Tue, Nov 5, 2019 at 1:12 AM Andres Freund wrote: > On 2019-11-04 14:33:41 -0500, Stephen Frost wrote: > > > I've been wondering if the accounting system should consider the cost > > per tablespace when there's multiple tablespaces involved, instead of > > throttling the overall process without

Re: cost based vacuum (parallel)

2019-11-05 Thread Amit Kapila
On Mon, Nov 4, 2019 at 11:58 PM Andres Freund wrote: > > Hi, > > On 2019-11-04 12:59:02 -0500, Jeff Janes wrote: > > On Mon, Nov 4, 2019 at 1:54 AM Amit Kapila wrote: > > > > > For parallel vacuum [1], we were discussing what is the best way to > > > divide the cost among parallel workers but we

Re: cost based vacuum (parallel)

2019-11-04 Thread Amit Kapila
On Mon, Nov 4, 2019 at 11:42 PM Andres Freund wrote: > > > > The two approaches to solve this problem being discussed in that > > thread [1] are as follows: > > (a) Allow the parallel workers and master backend to have a shared > > view of vacuum cost related parameters (mainly VacuumCostBalance)

Re: cost based vacuum (parallel)

2019-11-04 Thread Stephen Frost
Greetings, * Andres Freund (and...@anarazel.de) wrote: > On 2019-11-04 14:33:41 -0500, Stephen Frost wrote: > > * Andres Freund (and...@anarazel.de) wrote: > > > On 2019-11-04 14:06:19 -0500, Stephen Frost wrote: > > > > With parallelization across indexes, you could have a situation where > > >

Re: cost based vacuum (parallel)

2019-11-04 Thread Andres Freund
Hi, On 2019-11-04 14:33:41 -0500, Stephen Frost wrote: > * Andres Freund (and...@anarazel.de) wrote: > > On 2019-11-04 14:06:19 -0500, Stephen Frost wrote: > > > With parallelization across indexes, you could have a situation where > > > the individual indexes are on different tablespaces with

Re: cost based vacuum (parallel)

2019-11-04 Thread Stephen Frost
Greetings, * Andres Freund (and...@anarazel.de) wrote: > On 2019-11-04 14:06:19 -0500, Stephen Frost wrote: > > * Jeff Janes (jeff.ja...@gmail.com) wrote: > > > On Mon, Nov 4, 2019 at 1:54 AM Amit Kapila > > > wrote: > > > > For parallel vacuum [1], we were discussing what is the best way to >

Re: cost based vacuum (parallel)

2019-11-04 Thread Andres Freund
Hi, On 2019-11-04 14:06:19 -0500, Stephen Frost wrote: > * Jeff Janes (jeff.ja...@gmail.com) wrote: > > On Mon, Nov 4, 2019 at 1:54 AM Amit Kapila wrote: > > > For parallel vacuum [1], we were discussing what is the best way to > > > divide the cost among parallel workers but we didn't get many

Re: cost based vacuum (parallel)

2019-11-04 Thread Stephen Frost
Greetings, * Jeff Janes (jeff.ja...@gmail.com) wrote: > On Mon, Nov 4, 2019 at 1:54 AM Amit Kapila wrote: > > For parallel vacuum [1], we were discussing what is the best way to > > divide the cost among parallel workers but we didn't get many inputs > > apart from people who are very actively

Re: cost based vacuum (parallel)

2019-11-04 Thread Andres Freund
Hi, On 2019-11-04 12:59:02 -0500, Jeff Janes wrote: > On Mon, Nov 4, 2019 at 1:54 AM Amit Kapila wrote: > > > For parallel vacuum [1], we were discussing what is the best way to > > divide the cost among parallel workers but we didn't get many inputs > > apart from people who are very actively

Re: cost based vacuum (parallel)

2019-11-04 Thread Andres Freund
Hi, On 2019-11-04 12:24:35 +0530, Amit Kapila wrote: > For parallel vacuum [1], we were discussing what is the best way to > divide the cost among parallel workers but we didn't get many inputs > apart from people who are very actively involved in patch development. > I feel that we need some

Re: cost based vacuum (parallel)

2019-11-04 Thread Jeff Janes
On Mon, Nov 4, 2019 at 1:54 AM Amit Kapila wrote: > For parallel vacuum [1], we were discussing what is the best way to > divide the cost among parallel workers but we didn't get many inputs > apart from people who are very actively involved in patch development. > I feel that we need some more

Re: cost based vacuum (parallel)

2019-11-04 Thread Masahiko Sawada
On Mon, 4 Nov 2019 at 19:26, Amit Kapila wrote: > > On Mon, Nov 4, 2019 at 1:51 PM Masahiko Sawada wrote: > > > > On Mon, Nov 4, 2019 at 3:54 PM Amit Kapila wrote: > > > > > > I think approach-2 is better in throttling the system as it doesn't > > > have the drawback of the first approach, but

Re: cost based vacuum (parallel)

2019-11-04 Thread Amit Kapila
On Mon, Nov 4, 2019 at 1:03 PM Darafei "Komяpa" Praliaskouski wrote: >> >> >> This is somewhat similar to a memory usage problem with a >> parallel query where each worker is allowed to use up to work_mem of >> memory. We can say that the users using parallel operation can expect >> more system

Re: cost based vacuum (parallel)

2019-11-04 Thread Amit Kapila
On Mon, Nov 4, 2019 at 1:51 PM Masahiko Sawada wrote: > > On Mon, Nov 4, 2019 at 3:54 PM Amit Kapila wrote: > > > > I think approach-2 is better in throttling the system as it doesn't > > have the drawback of the first approach, but it might be a bit tricky > > to implement. > > I might be

Re: cost based vacuum (parallel)

2019-11-04 Thread Masahiko Sawada
On Mon, Nov 4, 2019 at 3:54 PM Amit Kapila wrote: > > I think approach-2 is better in throttling the system as it doesn't > have the drawback of the first approach, but it might be a bit tricky > to implement. I might be missing something but I think that there could be the drawback of the

Re: cost based vacuum (parallel)

2019-11-03 Thread Komяpa
> > > This is somewhat similar to a memory usage problem with a > parallel query where each worker is allowed to use up to work_mem of > memory. We can say that the users using parallel operation can expect > more system resources to be used as they want to get the operation > done faster, so we