Subject: State of pg_createsubscriber

From: Tom Lane <[email-masked]>
Date: Sun, 19 May 2024 13:30:17 -0400

I'm fairly disturbed about the readiness of pg_createsubscriber.
The 040_pg_createsubscriber.pl TAP test is moderately unstable
in the buildfarm [1], and there are various unaddressed complaints
at the end of the patch thread (pretty much everything below [2]).
I guess this is good enough to start beta with, but it's far from
being good enough to ship, IMO.  If there were active work going
on to fix these things, I'd feel better, but neither the C code
nor the test script have been touched since 1 April.

			regards, tom lane

[1] https://buildfarm.postgresql.org/cgi-bin/show_failures.pl?max_days=30&branch=HEAD&member=&stage=pg_basebackupCheck&filter=Submit
[2] https://www.postgresql.org/message-id/flat/3fa9ef0f-b277-4c13-850a-8ccc04de1406%40eisentraut.org#152dacecfc8f0cf08cbd8ecb79d6d38f

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From: "Euler Taveira" <[email-masked]>
Date: Sun, 19 May 2024 14:49:22 -0300

> nor the test script have been touched since 1 April.

My bad. :( I'll post patches soon to address all of the points.

--
Euler Taveira
EDB   https://www.enterprisedb.com/

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From: Amit Kapila <[email-masked]>
Date: Mon, 20 May 2024 12:12:26 +0530

> My bad. :( I'll post patches soon to address all of the points.

Just to summarize, apart from BF failures for which we had some
discussion, I could recall the following open points:

1. After promotion, the pre-existing replication objects should be
removed (either optionally or always), otherwise, it can lead to a new
subscriber not being able to restart or getting some unwarranted data.
[1][2].

2. Retaining synced slots on new subscribers can lead to unnecessary
WAL retention and dead rows [3].

3. We need to consider whether some of the messages displayed in
--dry-run mode are useful or not [4].

[1] - https://www.postgresql.org/message-id/CAA4eK1L6HOhT1qifTyuestXkPpkRwY9bOqFd4wydKsN6C3hePA%40mail.gmail.com
[2] - https://www.postgresql.org/message-id/flat/3fa9ef0f-b277-4c13-850a-8ccc04de1406%40eisentraut.org#152dacecfc8f0cf08cbd8ecb79d6d38f
[3] - https://www.postgresql.org/message-id/CAA4eK1KdCb%2B5sjYu6qCMXXdCX1y_ihr8kFzMozq0%3DP%3DauYxgog%40mail.gmail.com
[4] - https://www.postgresql.org/message-id/flat/3fa9ef0f-b277-4c13-850a-8ccc04de1406%40eisentraut.org#152dacecfc8f0cf08cbd8ecb79d6d38f

-- 
With Regards,
Amit Kapila.

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From: Michael Paquier <[email-masked]>
Date: Mon, 20 May 2024 16:29:24 +0900

> My bad. :( I'll post patches soon to address all of the points.

Please note that I have added an open item pointing at this thread.
--
Michael

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From: Robert Haas <[email-masked]>
Date: Wed, 22 May 2024 10:32:32 -0400

> --dry-run mode are useful or not [4].

Amit, thanks for summarzing your understanding of the situation. Tom,
is this list complete, to your knowledge? The original thread is quite
complex and it's hard to pick out what the open items actually are.
:-(

I would like to see this open item broken up into multiple open items,
one per issue.

Link [4] goes to a message that doesn't seem to relate to --dry-run.

-- 
Robert Haas
EDB: http://www.enterprisedb.com