Обсуждение: PGbackrest very slow!

Hi Pär,

On Thu, Oct 23, 2025 at 10:59 AM Pär Mattsson <par.x.mattsson@gmail.com> wrote:
>
> Hi!
> I have  3 node postgres cluster with repmgr and pgpool.
>
> Pgbackrest is configed like this
> We use pgbackrest with this config
> =======================================

It is a quite basic config,

> It is not a network issue. I tested to transfer 2GB between two host and it took 4 sec.
>
>
> I think backup-standby=y slows down the backup out of all minds.
>

so if you are sure it is not a network issue, your guess could be
right. You can try to compare with backup from primary and if it is
faster, it could be archiving process on standby which slows you down.
You can try to improve it with more processes [1] and with better zst
compression [2]. Async archiving [3] could also help

>
> Br Pär
>
>

[1] https://pgbackrest.org/configuration.html#section-general/option-process-max
[2] https://pgbackrest.org/configuration.html#section-general/option-compress
[3] https://pgbackrest.org/configuration.html#section-archive/option-archive-async


best regards,
Ilya Kosmodemiansky
CEO, Founder

Data Egret GmbH
Your remote PostgreSQL DBA team
T.: +49 6821 919 3297
ik@dataegret.com

> On Oct 23, 2025, at 2:59 AM, Pär Mattsson <par.x.mattsson@gmail.com> wrote:
>
> ...
> The backup of 50GB took 40 min.
> It is not a network issue. I tested to transfer 2GB between two host and it took 4 sec.
>
> I think backup-standby=y slows down the backup out of all minds.
>
> Br Pär

pgbackrest defaults to gzip compression, which is slow--try lz4 and see what happens

On Thu, Oct 23, 2025 at 10:21:37AM -0400, Ron Johnson wrote:
> On Thu, Oct 23, 2025 at 9:14 AM Scott Ribe <scott_ribe@elevated-dev.com>
> wrote:
> 
> > > On Oct 23, 2025, at 2:59 AM, Pär Mattsson <par.x.mattsson@gmail.com>
> > wrote:
> > >
> > > ...
> > > The backup of 50GB took 40 min.
> > > It is not a network issue. I tested to transfer 2GB between two host and
> > it took 4 sec.
> > >
> > > I think backup-standby=y slows down the backup out of all minds.
> > >
> > > Br Pär
> >
> > pgbackrest defaults to gzip compression, which is slow--try lz4 and see
> > what happens
> >
> 
> lz4 is faster, but not 1440x faster.
> 

But it might be 24x faster, using 2s/GB. :)

--Ken