Horton

Re: Logical replication timeout problem

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>, "wangw.fnst@fujitsu.com" <wangw.fnst@fujitsu.com>, "shiy.fnst@fujitsu.com" <shiy.fnst@fujitsu.com>, "houzj.fnst@fujitsu.com" <houzj.fnst@fujitsu.com>, Peter Smith <smithpb2250@gmail.com>, Fabrice Chapuis <fabrice636861@gmail.com>, Euler Taveira <euler@eulerto.com>, Masahiko Sawada <sawada.mshk@gmail.com>, "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>, Simon Riggs <simon.riggs@enterprisedb.com>, Petr Jelinek <petr.jelinek@enterprisedb.com>, "tanghy.fnst@fujitsu.com" <tanghy.fnst@fujitsu.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Ajin Cherian <itsajin@gmail.com>
Date: 2023-02-08T18:30:37Z
Lists: pgsql-hackers 
Hi,

On 2023-02-08 10:18:41 -0800, Andres Freund wrote:
> I don't think the syncrep logic in WalSndUpdateProgress really works as-is -
> consider what happens if e.g. the origin filter filters out entire
> transactions. We'll afaics never get to WalSndUpdateProgress(). In some cases
> we'll be lucky because we'll return quickly to XLogSendLogical(), but not
> reliably.

Is it actually the right thing to check SyncRepRequested() in that logic? It's
quite common to set up syncrep so that individual users or transactions opt
into syncrep, but to leave the default disabled.

I don't really see an alternative to making this depend solely on
sync_standbys_defined.

Greetings,

Andres Freund

Commits

  1. Fix the logical replication timeout during large DDLs.

  2. Fix the logical replication timeout during large transactions.

  3. Rethink the delay-checkpoint-end mechanism in the back-branches.

  4. Revert "Logical decoding of sequences"

  5. Skip empty transactions for logical replication.

  6. Allow specifying column lists for logical replication

  7. Add decoding of sequences to built-in replication

  8. Fix ABI break introduced by commit 4daa140a2f.

  9. Lag tracking for logical replication