Re: Support for N synchronous standby servers - take 2

On Sun, Jan 31, 2016 at 5:08 PM, Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
> On Sun, Jan 31, 2016 at 1:17 PM, Michael Paquier
> <michael(dot)paquier(at)gmail(dot)com> wrote:
>> On Thu, Jan 28, 2016 at 10:10 PM, Masahiko Sawada wrote:
>>> By the discussions so far, I'm planning to have several replication
>>> methods such as 'quorum', 'complex' in the feature, and the each
>>> replication method specifies the syntax of s_s_names.
>>> It means that s_s_names could have the number of sync standbys like
>>> what current patch does.
>>
>> What if the application_name of a standby node has the format of an integer?
>
> Even if the standby has an integer as application_name, we can set
> s_s_names like '2,1,2,3'.
> The leading '2' is always handled as the number of sync standbys when
> s_r_method = 'priority'.

Hm. I agree with Fujii-san here, having the number of sync standbys
defined in a parameter that should have a list of names is a bit
confusing. I'd rather have a separate GUC, which brings us back to one
of the first patches that I came up with, and a couple of people,
including Josh were not happy with that because this did not support
real quorum. Perhaps the final answer would be really to get a set of
hooks, and a contrib module making use of that.
--
Michael