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: Euler Taveira <euler@eulerto.com>
Cc: Shlok Kyal <shlok.kyal.oss@gmail.com>, vignesh C <vignesh21@gmail.com>, Michael Paquier <michael@paquier.xyz>, Peter Eisentraut <peter@eisentraut.org>, pgsql-hackers@lists.postgresql.org, Andres Freund <andres@anarazel.de>, Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Date: 2024-01-11T06:41:03Z
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, Jan 11, 2024 at 7:59 AM Euler Taveira <euler@eulerto.com> wrote:
>
> On Wed, Jan 10, 2024, at 1:33 AM, Shlok Kyal wrote:
>
> Here the standby node would be waiting for the 'consistent_lsn' wal
> during recovery but this wal will not be present on standby if no
> physical replication is setup. Hence the command will be waiting
> infinitely for the wal.
>
>
> Hmm. Some validations are missing.
>
> To solve this added a timeout of 60s for the recovery process and also
> added a check so that pg_subscriber would give a error when it called
> for node which is not in physical replication.
> Have attached the patch for the same. It is a top-up patch of the
> patch shared by Euler at [1].
>
>
> If the user has a node that is not a standby and it does not set the GUCs to
> start the recovery process from a backup, the initial setup is broken. (That's
> the case you described.) A good UI is to detect this scenario earlier.
> Unfortunately, there isn't a reliable and cheap way to do it. You need to start
> the recovery and check if it is having some progress. (I don't have a strong
> opinion about requiring a standby to use this tool. It would reduce the
> complexity about checking if the setup has all requirements to run this tool.)
>

Right, such a check will reduce some complexity. So, +1 for the check
as proposed by Shlok. Also, what are your thoughts on a timeout during
the wait? I think it is okay to wait for 60s by default but there
should be an option for users to wait for longer.

-- 
With Regards,
Amit Kapila.