Re: Minimal logical decoding on standbys

Andres Freund <andres@anarazel.de>

From: Andres Freund <andres@anarazel.de>
To: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com>
Cc: Noah Misch <noah@leadboat.com>, Amit Kapila <amit.kapila16@gmail.com>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Jeff Davis <pgsql@j-davis.com>, Robert Haas <robertmhaas@gmail.com>, Thomas Munro <thomas.munro@gmail.com>, Ibrar Ahmed <ibrar.ahmad@gmail.com>, Amit Khandekar <amitdkhan.pg@gmail.com>, fabriziomello@gmail.com, tushar <tushar.ahuja@enterprisedb.com>, Rahila Syed <rahila.syed@2ndquadrant.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2023-04-11T20:10:57Z
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. Reduce the log level in 035_standby_logical_decoding.pl.

  2. 035_standby_logical_decoding: Add missing waits for replication

  3. For cascading replication, wake physical and logical walsenders separately

  4. Handle logical slot conflicts on standby

  5. Support invalidating replication slots due to horizon and wal_level

  6. Prevent use of invalidated logical slot in CreateDecodingContext()

  7. Replace replication slot's invalidated_at LSN with an enum

  8. Pass down table relation into more index relation functions

  9. Assert only valid flag bits are passed to visibilitymap_set()

  10. Remove unused _bt_delitems_delete() argument.

  11. Add xl_btree_delete optimization.

Hi,

On 2023-04-11 11:04:50 +0200, Drouvot, Bertrand wrote:
> On 4/11/23 10:55 AM, Drouvot, Bertrand wrote:
> > Hi,
> > 
> > I think we might want to add:
> > 
> > $node_primary->wait_for_replay_catchup($node_standby);
> > 
> > before calling the slot creation.
> > 
> > It's done in the attached, would it be possible to give it a try please?
> 
> Actually, let's also wait for the cascading standby to catchup too, like done in the attached.

Pushed. Seems like a clear race in the test, so I didn't think it was worth
waiting for testing it on hoverfly.

I think we should lower the log level, but perhaps wait for a few more cycles
in case there are random failures?

I wonder if we should make the connections in poll_query_until to reduce
verbosity - it's pretty annoying how much that can bloat the log. Perhaps also
introduce some backoff? It's really annoying to have to trawl through all
those logs when there's a problem.

Greetings,

Andres Freund