Re: Synchronous Standalone Master Redoux

On Thu, Jul 12, 2012 at 12:17 PM, Bruce Momjian <bruce@momjian.us> wrote:
> On Thu, Jul 12, 2012 at 11:33:26AM +0530, Amit Kapila wrote:
>> > From: pgsql-hackers-owner@postgresql.org
>> [mailto:pgsql-hackers-owner@postgresql.org]
>> > On Behalf Of Jose Ildefonso Camargo Tolosa
>>
>> > Please, stop arguing on all of this: I don't think that adding an
>> > option will hurt anybody (specially because the work was already done
>> > by someone), we are not asking to change how the things work, we just
>> > want an option to decided whether we want it to freeze on standby
>> > disconnection, or if we want it to continue automatically... is that
>> > asking so much?
>>
>> I think this kind of decision should be done from outside utility or
>> scripts.
>> It would be better if from outside it can be detected that stand-by is down
>> during sync replication, and send command to master to change its mode or
>> change settings appropriately without stopping master.
>> Putting this kind of more and more logic into replication code will make it
>> more cumbersome.
>
> We certainly would need something external to inform administrators that
> the system is no longer synchronous.

That is *mandatory*, just as you monitor DRBD, or disk arrays: if a
disk fail, and alert have to be issued, to fix it as soon as possible.

But such alerts can wait 30 seconds to be sent out, so, any monitoring
system would be able to handle that, we just need to get current
system status from the monitoring system, and create corresponding
rules: a simple matter, actually.