Horton

Re: speed up a logical replica setup

Euler Taveira <euler@eulerto.com>

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From: "Euler Taveira" <euler@eulerto.com>
To: "Amit Kapila" <amit.kapila16@gmail.com>, "kuroda.hayato@fujitsu.com" <kuroda.hayato@fujitsu.com>
Cc: "Peter Eisentraut" <peter@eisentraut.org>, "pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>, "Shlok Kyal" <shlok.kyal.oss@gmail.com>, "vignesh C" <vignesh21@gmail.com>, "Michael Paquier" <michael@paquier.xyz>, "Andres Freund" <andres@anarazel.de>, "Ashutosh Bapat" <ashutosh.bapat.oss@gmail.com>
Date: 2024-01-23T23:44:15Z
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. pg_createsubscriber: Remove obsolete comment

  2. pg_createsubscriber: Fix an unpredictable recovery wait time.

  3. Fix unstable test in 040_pg_createsubscriber.

  4. Fix the testcase introduced in commit 81d20fbf7a.

  5. Further weaken new pg_createsubscriber test on Windows.

  6. Temporarily(?) weaken new pg_createsubscriber test on Windows.

  7. Make pg_createsubscriber warn if publisher has two-phase commit enabled.

  8. Make pg_createsubscriber more wary about quoting connection parameters.

  9. pg_createsubscriber: Remove failover replication slots on subscriber

  10. pg_createsubscriber: Remove replication slot check on primary

  11. pg_createsubscriber: Only --recovery-timeout controls the end of recovery process

  12. pg_createsubscriber: creates a new logical replica from a standby server

  13. Add some const decorations

  14. Add option force_initdb to PostgreSQL::Test::Cluster:init()

  15. Remove MSVC scripts

On Mon, Jan 22, 2024, at 6:22 AM, Amit Kapila wrote:
> On Mon, Jan 22, 2024 at 2:38 PM Hayato Kuroda (Fujitsu)
> <kuroda.hayato@fujitsu.com> wrote:
> > >
> > > > Yet other options could be
> > > > pg_buildsubscriber, pg_makesubscriber as 'build' or 'make' in the name
> > > > sounds like we are doing some work to create the subscriber which I
> > > > think is the case here.
> > >
> > > I see your point here.  pg_createsubscriber is not like createuser in
> > > that it just runs an SQL command.  It does something different than
> > > CREATE SUBSCRIBER.
> 
> Right.

Subscriber has a different meaning of subscription. Subscription is an SQL
object. Subscriber is the server (node in replication terminology) where the
subscription resides. Having said that pg_createsubscriber doesn't seem a bad
name because you are creating a new subscriber. (Indeed, you are transforming /
converting but "create" seems closer and users can infer that it is a tool to
build a new logical replica.

>   So a different verb would make that clearer.  Maybe
> > > something from here: https://www.thesaurus.com/browse/convert
> >
> > I read the link and found a good verb "switch". So, how about using "pg_switchsubscriber"?
> >
> 
> I also initially thought on these lines and came up with a name like
> pg_convertsubscriber but didn't feel strongly about it as that would
> have sounded meaningful if we use a name like
> pg_convertstandbytosubscriber. Now, that has become too long. Having
> said that, I am not opposed to it having a name on those lines. BTW,
> another option that occurred to me today is pg_preparesubscriber. We
> internally create slots and then wait for wal, etc. which makes me
> sound like adding 'prepare' in the name can also explain the purpose.

I think "convert" and "transform" fit for this case. However, "create",
"convert" and "transform" have 6, 7 and 9 characters,  respectively. I suggest
that we avoid long names (subscriber already has 10 characters). My preference
is pg_createsubscriber.


--
Euler Taveira
EDB   https://www.enterprisedb.com/