Re: Synchronous replication

On Mon, Aug 2, 2010 at 7:06 AM, Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
> On Mon, Aug 2, 2010 at 7:53 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>> Let's not get *the manner of specifying the policy* confused with *the
>> need to update the policy when the master changes*.  It doesn't seem
>> likely you would want the same value for  synchronous_standbys on all
>> your machines.  In the most common configuration, you'd probably have:
>>
>> on A: synchronous_standbys=B
>> on B: synchronous_standbys=A
>
> Oh, true. But, what if we have another synchronous standby called C?
> We specify the policy as follows?:
>
> on A: synchronous_standbys=B,C
> on B: synchronous_standbys=A,C
> on C: synchronous_standbys=A,B
>
> We would need to change the setting on both A and B when we want to
> change the name of the third standby from C to D, for example. No?

Sure. If you give the standbys names, then if people change the
names, they'll have to update their configuration. But I can't see
that as an argument against doing it. You can remove the possibility
that someone will have a hassle if they rename a server by not
allowing them to give it a name in the first place, but that doesn't
seem like a win from a usability perspective.

--
Robert Haas
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