Horton

Re: Minimal logical decoding on standbys

Bertrand Drouvot <bertranddrouvot.pg@gmail.com>

View thread
From: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>, Jeff Davis <pgsql@j-davis.com>, Andres Freund <andres@anarazel.de>, 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: 2023-04-06T13:01:30Z
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 4/6/23 8:40 AM, Amit Kapila wrote:
> On Wed, Apr 5, 2023 at 9:27 PM Drouvot, Bertrand
> 
> 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. 
> For walsender, an ERROR will lead
> to its exit, so that is fine. If this understanding is correct, then
> if 'am_cascading_walsender' is false, we should set ProcDiePending
> apart from other parameters. Sorry, I haven't tested this, so I could
> be wrong here. 

Oops my bad. You are fully, right. Fixed in V62 posted up-thread

> Also, it seems you have removed the checks related to
> slots, is it because PROCSIG_RECOVERY_CONFLICT_LOGICALSLOT is only
> used for logical slots? If so, do you think an Assert would make
> sense?
> 

Yes, indeed adding an Assert makes sense: done in V62 posted up-thread.


> Another comment on 0001.
>   extern void CheckSlotRequirements(void);
>   extern void CheckSlotPermissions(void);
> +extern void ResolveRecoveryConflictWithLogicalSlots(Oid dboid,
> TransactionId xid, char *reason);
> 
> This doesn't seem to be called from anywhere.
>
Good catch, removed in V62 posted up-thread.

Regards,

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