Re: found xmin from before relfrozenxid on pg_catalog.pg_authid - Mailing list pgsql-hackers

From Matheus de Oliveira
Subject Re: found xmin from before relfrozenxid on pg_catalog.pg_authid
Date
Msg-id CAJghg4LczhD72zE6vfgvN_g+ZHtFNkbR8G-EiWeOqaKQRv8caA@mail.gmail.com
Whole thread Raw
In response to Re: found xmin from before relfrozenxid on pg_catalog.pg_authid  (Andres Freund <andres@anarazel.de>)
Responses Re: found xmin from before relfrozenxid on pg_catalog.pg_authid
List pgsql-hackers


On Tue, Jun 19, 2018 at 12:53 PM, Andres Freund <andres@anarazel.de> wrote:
Hi,

On 2018-06-19 10:26:26 -0300, Matheus de Oliveira wrote:
> Hello friends.
>
> On Tue, Jun 12, 2018 at 3:31 PM, Andres Freund <andres@anarazel.de> wrote:
>
> >
> > On 2018-06-11 17:39:14 -0700, Andres Freund wrote:
> > > I plan to go over the change again tomorrow, and then push. Unless
> > > somebody has comments before then, obviously.
> >
> > Done.
> >
> >
> Sorry to bother about this, but do you have any plan to do the minor
> release before planned due to this bug?

Unclear at this point.  There's been discussion about it, without coming
to a conclusion.


Ok. Thank you for the information.

I really hope you decide to release it soon, I'm very afraid about the users that have hit the bug but haven't noticed the issue.
 

> I'm pondering what is the best option to avoid a forced shutdown of this
> server:
> - should I just wait for a release (if it is soon, I would be fine)?
> - build PG from the git version by myself?
> - or is there a safer workaround to the problem? (not clear to me if
> deleting the `global/pg_internal.init` file is really the way to go, and
> the details, is it safe? Should I stop the server, delete, start?)

You should first make sure it's actually this problem - which tables are
holding back the xmin horizon?

How can I be sure? The tables are `pg_authid` and `pg_auth_members`, the following message is logged every minute (which I belive is due to `autovacuum_naptime`, which is using the default of 1 minute):

    ERROR:  found xmin 3460221635 from before relfrozenxid 1245633870
    CONTEXT:  automatic vacuum of table "template0.pg_catalog.pg_authid"
    ERROR:  found xmin 3460221635 from before relfrozenxid 1245633870
    CONTEXT:  automatic vacuum of table "template0.pg_catalog.pg_auth_members"

Do you need controldata or more info to validate it?
 
  After that, yes, deleting the
global/pg_internal.init file is the way to go, and I can't think of a
case where it's problematic, even without stopping the server.


I'll try that and get back to you if it worked or not. Thank you for the confirmation.

And thank you for all clarifications.

Best regards,
--
Matheus de Oliveira


pgsql-hackers by date:

Previous
From: Bruce Momjian
Date:
Subject: Re: Add necessary package list to ldap TAP's README
Next
From: Andres Freund
Date:
Subject: Re: Invisible Indexes