Horton

Re: WIP/PoC for parallel backup

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: Asif Rehman <asifr.rehman@gmail.com>
Cc: Kashif Zeeshan <kashif.zeeshan@enterprisedb.com>, Robert Haas <robertmhaas@gmail.com>, Rajkumar Raghuwanshi <rajkumar.raghuwanshi@enterprisedb.com>, Jeevan Chalke <jeevan.chalke@enterprisedb.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2020-04-21T11:49:45Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Fix failures in incremental_sort due to number of workers

  2. In jsonb_plpython.c, suppress warning message from gcc 10.

  3. Fix minor problems with non-exclusive backup cleanup.

On Tue, Apr 21, 2020 at 5:18 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> On Tue, Apr 21, 2020 at 1:00 PM Asif Rehman <asifr.rehman@gmail.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.

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