Re: Minimal logical decoding on standbys

Bertrand Drouvot <bertranddrouvot.pg@gmail.com>

From: "Drouvot, Bertrand" <bertranddrouvot.pg@gmail.com>

To: Amit Kapila <amit.kapila16@gmail.com>, Jeff Davis <pgsql@j-davis.com>

Cc: Masahiko Sawada <sawada.mshk@gmail.com>, Andres Freund <andres@anarazel.de>, Robert Haas <robertmhaas@gmail.com>, Thomas Munro <thomas.munro@gmail.com>, Alvaro Herrera <alvherre@2ndquadrant.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: 2023-04-03T18:17:19Z

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 →

Reduce the log level in 035_standby_logical_decoding.pl.
- 3034dc56ef4b 16.0 landed
035_standby_logical_decoding: Add missing waits for replication
- 57411c82ce86 16.0 landed
For cascading replication, wake physical and logical walsenders separately
- e101dfac3a53 16.0 landed
Handle logical slot conflicts on standby
- 26669757b6a7 16.0 landed
Support invalidating replication slots due to horizon and wal_level
- be87200efd93 16.0 landed
Prevent use of invalidated logical slot in CreateDecodingContext()
- 4397abd0a2af 16.0 landed
Replace replication slot's invalidated_at LSN with an enum
- 15f8203a5975 16.0 landed
Pass down table relation into more index relation functions
- 61b313e47eb9 16.0 landed
Assert only valid flag bits are passed to visibilitymap_set()
- a88a18b1250b 16.0 landed
Remove unused _bt_delitems_delete() argument.
- dc43492e46c7 14.0 cited
Add xl_btree_delete optimization.
- d2e5e20e5711 13.0 cited

Attachments

v57-0006-Doc-changes-describing-details-about-logical-dec.patch (text/plain) patch v57-0006
v57-0005-New-TAP-test-for-logical-decoding-on-standby.patch (text/plain) patch v57-0005
v57-0004-Fixing-Walsender-corner-case-with-logical-decodi.patch (text/plain) patch v57-0004
v57-0003-Allow-logical-decoding-on-standby.patch (text/plain) patch v57-0003
v57-0002-Arrange-for-a-new-pg_stat_database_conflicts-and.patch (text/plain) patch v57-0002
v57-0001-Handle-logical-slot-conflicts-on-standby.patch (text/plain) patch v57-0001

Hi,

On 4/3/23 8:10 AM, Drouvot, Bertrand wrote:
> Hi,
> 
> On 4/3/23 7:35 AM, Amit Kapila wrote:
>> On Mon, Apr 3, 2023 at 4:26 AM Jeff Davis <pgsql@j-davis.com> wrote:
>>
>> Agreed, even Bertrand and myself discussed the same approach few
>> emails above. BTW, if we have this selective logic to wake
>> physical/logical walsenders and for standby's, we only wake logical
>> walsenders at the time of  ApplyWalRecord() then do we need the new
>> conditional variable enhancement being discussed, and if so, why?
>>
> 
> Thank you both for this new idea and discussion. In that case I don't think
> we need the new CV API and the use of a CV anymore. As just said up-thread I'll submit
> a new proposal with this new approach.
> 

Please find enclosed V57 implementing the new approach in 0004. With the new approach in place
the TAP tests (0005) work like a charm (no delay and even after a promotion).

Regards,

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