Horton

Re: speed up a logical replica setup

Euler Taveira <euler@eulerto.com>

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From: "Euler Taveira" <euler@eulerto.com>
To: "vignesh C" <vignesh21@gmail.com>, "Peter Eisentraut" <peter@eisentraut.org>
Cc: "Amit Kapila" <amit.kapila16@gmail.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>
Date: 2024-03-21T14:30:05Z
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 Thu, Mar 21, 2024, at 10:33 AM, vignesh C wrote:
> If we commit this we might not be able to change the way the option
> behaves once the customers starts using it. How about removing these
> options in the first version and adding it in the next version after
> more discussion.

We don't need to redesign this one if we want to add a format string in a next
version. A long time ago, pg_dump started to accept pattern for tables without
breaking or deprecating the -t option. If you have 100 databases and you don't
want to specify the options or use a script to generate it for you, you also
have the option to let pg_createsubscriber generate the object names for you.
Per my experience, it will be a rare case.

> Currently dry-run will do the check and might fail on identifying a
> few failures like after checking subscriber configurations. Then the
> user will have to correct the configuration and re-run then fix the
> next set of failures. Whereas the suggest-config will display all the
> optimal configuration for both the primary and the standby in a single
> shot. This is not a must in the first version, it can be done as a
> subsequent enhancement.

Do you meant publisher, right? Per order, check_subscriber is done before
check_publisher and it checks all settings on the subscriber before exiting. In
v30, I changed the way it provides the required settings. In a previous version,
it fails when it found a wrong setting; the current version, check all settings
from that server before providing a suitable error.

pg_createsubscriber: checking settings on publisher
pg_createsubscriber: primary has replication slot "physical_slot"
pg_createsubscriber: error: publisher requires wal_level >= logical
pg_createsubscriber: error: publisher requires 2 replication slots, but only 0 remain
pg_createsubscriber: hint: Consider increasing max_replication_slots to at least 3.
pg_createsubscriber: error: publisher requires 2 wal sender processes, but only 0 remain
pg_createsubscriber: hint: Consider increasing max_wal_senders to at least 3.

If you have such an error, you will fix them all and rerun using dry run mode
again to verify everything is ok. I don't have a strong preference about it. It
can be changed easily (unifying the check functions or providing a return for
each of the check functions).


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