Horton

Re: speed up a logical replica setup

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: Noah Misch <noah@leadboat.com>
Cc: Peter Eisentraut <peter@eisentraut.org>, Euler Taveira <euler@eulerto.com>, Shlok Kyal <shlok.kyal.oss@gmail.com>, "kuroda.hayato@fujitsu.com" <kuroda.hayato@fujitsu.com>, Tomas Vondra <tomas.vondra@enterprisedb.com>, "pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>, Michael Paquier <michael@paquier.xyz>, Andres Freund <andres@anarazel.de>, Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>, Fabrízio de Royes Mello <fabriziomello@gmail.com>, vignesh C <vignesh21@gmail.com>
Date: 2024-06-24T06:38:59Z
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 Sun, Jun 23, 2024 at 11:52 AM Noah Misch <noah@leadboat.com> wrote:
>
> > +static char *
> > +create_logical_replication_slot(PGconn *conn, struct LogicalRepInfo *dbinfo)
> > +{
> > +     PQExpBuffer str = createPQExpBuffer();
> > +     PGresult   *res = NULL;
> > +     const char *slot_name = dbinfo->replslotname;
> > +     char       *slot_name_esc;
> > +     char       *lsn = NULL;
> > +
> > +     Assert(conn != NULL);
> > +
> > +     pg_log_info("creating the replication slot \"%s\" on database \"%s\"",
> > +                             slot_name, dbinfo->dbname);
> > +
> > +     slot_name_esc = PQescapeLiteral(conn, slot_name, strlen(slot_name));
> > +
> > +     appendPQExpBuffer(str,
> > +                                       "SELECT lsn FROM pg_catalog.pg_create_logical_replication_slot(%s, 'pgoutput', false, false, false)",
>
> This is passing twophase=false, but the patch does not mention prepared
> transactions.  Is the intent to not support workloads containing prepared
> transactions?  If so, the documentation should say that, and the tool likely
> should warn on startup if max_prepared_transactions != 0.
>

The other point to note in this regard is that if we don't support
two_phase in the beginning during subscription/slot setup, users won't
be able to change it as we don't yet support changing it via alter
subscription (though the patch to alter two_pc is proposed for PG18).

-- 
With Regards,
Amit Kapila.