| From: | Andres Freund <andres(at)2ndquadrant(dot)com> |
|---|---|
| To: | Heikki Linnakangas <hlinnakangas(at)vmware(dot)com> |
| Cc: | Rajeev rastogi <rajeev(dot)rastogi(at)huawei(dot)com>, "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Standalone synchronous master |
| Date: | 2014-01-08 09:48:57 |
| Message-ID: | 20140108094857.GM14280@awork2.anarazel.de |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On 2014-01-08 11:07:48 +0200, Heikki Linnakangas wrote:
> I'm going to say right off the bat that I think the whole notion to
> automatically disable synchronous replication when the standby goes down is
> completely bonkers. If you don't need the strong guarantee that your
> transaction is safe in at least two servers before it's acknowledged to the
> client, there's no point enabling synchronous replication in the first
> place.
I think that's likely caused by the misconception that synchronous
replication is synchronous in apply, not just remote write/fsync. I have
now seen several sites that assumed that and just set up sync rep to
maintain that goal to then query standbys instead of the primary after
the commit finished.
If that assumption were true, supporting a timeout that way would
possibly be helpful, but it is not atm...
Greetings,
Andres Freund
--
Andres Freund http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Dean Rasheed | 2014-01-08 10:19:57 | Re: WIP patch (v2) for updatable security barrier views |
| Previous Message | Christoph Berg | 2014-01-08 09:40:17 | Re: extra_float_digits and casting from real to numeric |