Re: Minimal logical decoding on standbys

Bertrand Drouvot <bertranddrouvot.pg@gmail.com>

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

To: Andres Freund <andres@anarazel.de>

Cc: 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: 2023-02-13T15:27:20Z

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

v50-0006-Doc-changes-describing-details-about-logical-dec.patch (text/plain) patch v50-0006
v50-0005-New-TAP-test-for-logical-decoding-on-standby.patch (text/plain) patch v50-0005
v50-0004-Fixing-Walsender-corner-case-with-logical-decodi.patch (text/plain) patch v50-0004
v50-0003-Allow-logical-decoding-on-standby.patch (text/plain) patch v50-0003
v50-0002-Handle-logical-slot-conflicts-on-standby.patch (text/plain) patch v50-0002
v50-0001-Add-info-in-WAL-records-in-preparation-for-logic.patch (text/plain) patch v50-0001

Hi,

On 2/7/23 4:29 PM, Drouvot, Bertrand wrote:
> Hi,
> 
> On 1/19/23 10:43 AM, Drouvot, Bertrand wrote:
>> Hi,
>>
>> On 1/19/23 3:46 AM, Andres Freund wrote:
>>> Hi,
>>>
>>> On 2023-01-18 11:24:19 +0100, Drouvot, Bertrand wrote:
>>>> On 1/6/23 4:40 AM, Andres Freund wrote:
>>>>> Hm, that's quite expensive. Perhaps worth adding a C helper that can do that
>>>>> for us instead? This will likely also be needed in real applications after all.
>>>>>
>>>>
>>>> Not sure I got it. What the C helper would be supposed to do?
>>>
>>> Call LogStandbySnapshot().
>>>
>>
>> Got it, I like the idea, will do.
>>
> 
> 0005 in V49 attached is introducing a new pg_log_standby_snapshot() function
> and the TAP test is making use of it.
> 
> Documentation about this new function is also added in the "Snapshot Synchronization Functions"
> section. I'm not sure that's the best place for it but did not find a better place yet.
> 

Attaching V50, tiny update in the TAP test (aka 0005) to make use of the wait_for_replay_catchup()
wrapper just added in a1acdacada.

Regards,

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