Horton

Re: replication_slots usability issue

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Michael Paquier <michael@paquier.xyz>
Cc: Alvaro Herrera <alvherre@2ndquadrant.com>, "Joshua D. Drake" <jd@commandprompt.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2018-11-01T17:54:23Z
Lists: pgsql-hackers 
On 2018-11-01 09:34:05 +0900, Michael Paquier wrote:
> 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()?

That has absolutely nothing to do with the issue at hand though, so I
don't think it'd have made much sense to do it at the same time. Nor do
I think it's particularly important.


> 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.

Cool. And yes, I don't think a cosmetic log level adjustment that could
affect people's scripts should be backpatched without need. Even if not
particularly likely to break something.


> 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"

Darnit. Fixed. Thanks.

Greetings,

Andres Freund

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