Horton

Re: replication_slots usability issue

Michael Paquier <michael@paquier.xyz>

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From: Michael Paquier <michael@paquier.xyz>
To: Andres Freund <andres@anarazel.de>
Cc: Alvaro Herrera <alvherre@2ndquadrant.com>, "Joshua D. Drake" <jd@commandprompt.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2018-11-01T00:34:05Z
Lists: pgsql-hackers 
HI Andres,

On Wed, Oct 31, 2018 at 03:48:02PM -0700, Andres Freund wrote:
> And done.  Thanks for the report JD.

Shouldn't we also switch the PANIC to a FATAL in RestoreSlotFromDisk()?
I don't mind doing so myself if you agree with the change, only on
HEAD as you seemed to disagree about changing that on back-branches.

Also, from 691d79a which you just committed:
+       ereport(FATAL,
+               (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+                errmsg("logical replication slots \"%s\" exists, but wal_level < logical",
+                       NameStr(cp.slotdata.name)),
I can see one grammar mistake here, as you refer to only one slot here.
The error messages should read:
"logical replication slot \"%s\" exists, but wal_level < logical"
and:
"physical replication slot \"%s\" exists, but wal_level < replica"

Thanks,
--
Michael

Commits

  1. Fix copy-paste error in errhint() introduced in 691d79a07933.

  2. Lower error level from PANIC to FATAL when restoring slots at startup

  3. Fix error message typo introduced 691d79a07933.

  4. Disallow starting server with insufficient wal_level for existing slot.

  5. Allow replication slots to be dropped in single-user mode