Horton

Re: Minimal logical decoding on standbys

Bertrand Drouvot <bertranddrouvot.pg@gmail.com>

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From: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>, Andres Freund <andres@anarazel.de>
Cc: 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: 2023-04-07T04:58:21Z
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.

On 4/7/23 3:59 AM, Amit Kapila wrote:
> On Fri, Apr 7, 2023 at 6:55 AM Andres Freund <andres@anarazel.de> wrote:
>>
>> On 2023-04-06 12:10:57 +0530, Amit Kapila wrote:
>>> After this, I think for backends that have active slots, it would
>>> simply cancel the current query. Will that be sufficient? Because we
>>> want the backend process should exit and release the slot so that the
>>> startup process can mark it invalid.
>>
>> We don't need them to exit, we just need them to release the slot. Which does
>> happen when the query is cancelled. Imagine if that weren't the case - if a
>> cancellation of pg_logical_slot_* wouldn't release the slot, we couldn't call
>> it again before disconnecting. I also did verify that indeed the slot is
>> released upon a cancellation.
>>
> 
> makes sense. Thanks for the clarification!
> 

+1, thanks Andres!

Regards,

-- 
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com