public inbox for [email protected]
help / color / mirror / Atom feedFrom: Amit Kapila <[email protected]>
To: Masahiko Sawada <[email protected]>
Cc: Peter Smith <[email protected]>
Cc: [email protected] <[email protected]>
Cc: [email protected] <[email protected]>
Cc: PostgreSQL Hackers <[email protected]>
Subject: Re: Perform streaming logical transactions by background workers and parallel apply
Date: Tue, 10 May 2022 14:28:59 +0530
Message-ID: <CAA4eK1KJmdhxDxPyfpc61cp4gpnNXL6racTXFVUBfUUYT-0FYA@mail.gmail.com> (raw)
In-Reply-To: <CAD21AoB8YTFSXcA0OGUN4DOvqyUzgkcUKYZuME5nmme9eOT1JQ@mail.gmail.com>
References: <CAA4eK1+wyN6zpaHUkCLorEWNx75MG0xhMwcFhvjqm2KURZEAGw@mail.gmail.com>
<OS0PR01MB57160DFDEF5B1C4668346B7D94E99@OS0PR01MB5716.jpnprd01.prod.outlook.com>
<CAD21AoB9UqvozzFuSaQ12r7-Vg+gY-kA4D7kzkwuyLU-A6bo1g@mail.gmail.com>
<CAA4eK1+4qAc8vbma3obtzrzJOTx_w-DJvBzxY9JuUG_uCP9OiQ@mail.gmail.com>
<CAD21AoDPHstj+jD3ODS-bd1uM+ZE=cpDKf8npeNFZD+YdM28fA@mail.gmail.com>
<CAA4eK1LYWZ+reJ-jSz7naM6GwdS2VqydmJaHmL_mpjbtMC9vgg@mail.gmail.com>
<CAHut+PvPwTQ_GpVMw3JgZzhWcwTrAiT-_5M-XzEO7GUnHH8hGA@mail.gmail.com>
<CAHut+PsP6WMHeui5WsGbabZqZNj5+hUp=ivxFJLLKD0Zi5QfVw@mail.gmail.com>
<CAD21AoB8YTFSXcA0OGUN4DOvqyUzgkcUKYZuME5nmme9eOT1JQ@mail.gmail.com>
On Tue, May 10, 2022 at 10:39 AM Masahiko Sawada <[email protected]> wrote:
>
> On Wed, May 4, 2022 at 8:44 AM Peter Smith <[email protected]> wrote:
> >
> > On Tue, May 3, 2022 at 5:16 PM Peter Smith <[email protected]> wrote:
> > >
> > ...
> >
> > > Avoiding unexpected differences like this is why I suggested the
> > > option should have to be explicitly enabled instead of being on by
> > > default as it is in the current patch. See my review comment #14 [1].
> > > It means the user won't have to change their existing code as a
> > > workaround.
> > >
> > > ------
> > > [1] https://www.postgresql.org/message-id/CAHut%2BPuqYP5eD5wcSCtk%3Da6KuMjat2UCzqyGoE7sieCaBsVskQ%40mail...
> > >
> >
> > Sorry I was wrong above. It seems this behaviour was already changed
> > in the latest patch v5 so now the option value 'on' means what it
> > always did. Thanks!
>
> Having it optional seems a good idea. BTW can the user configure how
> many apply bgworkers can be used per subscription or in the whole
> system? Like max_sync_workers_per_subscription, is it better to have a
> configuration parameter or a subscription option for that? If so,
> setting it to 0 probably means to disable the parallel apply feature.
>
Yeah, that might be useful but we are already giving an option while
creating a subscription whether to allow parallelism, so will it be
useful to give one more way to disable this feature? OTOH, having
something like max_parallel_apply_workers/max_bg_apply_workers at the
system level can give better control for how much parallelism the user
wishes to allow for apply work. If we have such a new parameter then I
think max_logical_replication_workers should include apply workers,
parallel apply workers, and table synchronization? In such a case,
don't we need to think of increasing the default value of
max_logical_replication_workers?
--
With Regards,
Amit Kapila.
view thread (627+ messages) latest in thread
reply
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: [email protected]
Cc: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
Subject: Re: Perform streaming logical transactions by background workers and parallel apply
In-Reply-To: <CAA4eK1KJmdhxDxPyfpc61cp4gpnNXL6racTXFVUBfUUYT-0FYA@mail.gmail.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox