Re: pg_basebackup blocking all queries with horrible performance

Magnus Hagander <magnus@hagander.net>

From: Magnus Hagander <magnus@hagander.net>

To: Tom Lane <tgl@sss.pgh.pa.us>

Cc: Fujii Masao <masao.fujii@gmail.com>, Lonni J Friedman <netllama@gmail.com>, Craig Ringer <ringerc@ringerc.id.au>, Jerry Sievers <gsievers19@comcast.net>, pgsql-admin@postgresql.org

Date: 2012-06-10T10:43:32Z

Lists: pgsql-hackers

On Sat, Jun 9, 2012 at 2:51 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Fujii Masao <masao.fujii@gmail.com> writes:
>> This seems a bug. I think we should prevent pg_basebackup from
>> becoming synchronous standby. Thought?
>
> Absolutely.  If we have replication clients that are not actually
> capable of being standbys, there *must* be a way for the master
> to know that.

I thought we fixed this already by sending InvalidXlogRecPtr as flush
location? And that this only applied in 9.2?

Are you saying we picked pg_basebackup *in backup mode* (not log
streaming) as synchronous standby? If so then yes, that is
*definitely* a bug that should be fixed. We should never select a
connection that's not even streaming log as standby!

-- 
 Magnus Hagander
 Me: http://www.hagander.net/
 Work: http://www.redpill-linpro.com/