Re: WIP/PoC for parallel backup

On Tue, Apr 21, 2020 at 4:50 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:

> On Tue, Apr 21, 2020 at 5:18 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
> wrote:
> >
> > On Tue, Apr 21, 2020 at 1:00 PM Asif Rehman <asifr(dot)rehman(at)gmail(dot)com>
> wrote:
> > >
> > > I did some tests a while back, and here are the results. The tests
> were done to simulate
> > > a live database environment using pgbench.
> > >
> > > machine configuration used for this test:
> > > Instance Type: t2.xlarge
> > > Volume Type : io1
> > > Memory (MiB) : 16384
> > > vCPU # : 4
> > > Architecture : X86_64
> > > IOP : 16000
> > > Database Size (GB) : 102
> > >
> > > The setup consist of 3 machines.
> > > - one for database instances
> > > - one for pg_basebackup client and
> > > - one for pgbench with some parallel workers, simulating SELECT loads.
> > >
> > > basebackup | 4 workers | 8 Workers
> | 16 workers
> > > Backup Duration(Min): 69.25 | 20.44 | 19.86 |
> 20.15
> > > (pgbench running with 50 parallel client simulating SELECT load)
> > >
> > > Backup Duration(Min): 154.75 | 49.28 | 45.27 |
> 20.35
> > > (pgbench running with 100 parallel client simulating SELECT load)
> > >
> >
> > Thanks for sharing the results, these show nice speedup! However, I
> > think we should try to find what exactly causes this speed up. If you
> > see the recent discussion on another thread related to this topic,
> > Andres, pointed out that he doesn't think that we can gain much by
> > having multiple connections[1]. It might be due to some internal
> > limitations (like small buffers) [2] due to which we are seeing these
> > speedups. It might help if you can share the perf reports of the
> > server-side and pg_basebackup side.
> >
>
> Just to be clear, we need perf reports both with and without patch-set.
>

These tests were done a while back, I think it would be good to run the
benchmark again with the latest patches of parallel backup and share the
results and perf reports.

>
> --
> With Regards,
> Amit Kapila.
> EnterpriseDB: http://www.enterprisedb.com
>
>
>

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