From: | Andres Freund <andres(at)2ndquadrant(dot)com> |
---|---|
To: | Robert Haas <robertmhaas(at)gmail(dot)com> |
Cc: | Josh Berkus <josh(at)agliodbs(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: Replication slots and footguns |
Date: | 2014-03-12 19:25:55 |
Message-ID: | 20140312192555.GB26328@awork2.anarazel.de |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
On 2014-03-12 15:18:04 -0400, Robert Haas wrote:
> On Wed, Mar 12, 2014 at 3:03 PM, Andres Freund <andres(at)2ndquadrant(dot)com> wrote:
> > Hi,
> >
> > On 2014-03-12 12:00:25 -0700, Josh Berkus wrote:
> >> I was just reading Michael's explanation of replication slots
> >> (http://michael.otacoo.com/postgresql-2/postgres-9-4-feature-highlight-replication-slots/)
> >> and realized there was something which had completely escaped me in the
> >> pre-commit discussion:
> >>
> >> select pg_drop_replication_slot('slot_1');
> >> ERROR: 55006: replication slot "slot_1" is already active
> >> LOCATION: ReplicationSlotAcquire, slot.c:339
> >>
> >> What defines an "active" slot?
> >
> > One with a connected walsender.
> >
> >> It seems like there's no way for a DBA to drop slots from the master if
> >> it's rapidly running out of disk WAL space without doing a restart, and
> >> there's no way to drop the slot for a replica which the DBA knows is
> >> permanently offline but was connected earlier. Am I missing something?
> >
> > It's sufficient to terminate the walsender and then drop the slot. That
> > seems ok for now?
>
> Urgh. That error message looks susceptible to improvement. How about:
>
> replication slot "%s" cannot be dropped because it is currently in use
I think that'd require duplicating some code between acquire and drop,
but how about "replication slot "%s" is in use by another backend"?
Greetings,
Andres Freund
--
Andres Freund http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services
From | Date | Subject | |
---|---|---|---|
Next Message | Andres Freund | 2014-03-12 19:26:46 | Re: Replication slots and footguns |
Previous Message | Josh Berkus | 2014-03-12 19:23:01 | Re: Replication slots and footguns |