Re: Support for N synchronous standby servers - take 2 - Mailing list pgsql-hackers

From Robert Haas
Subject Re: Support for N synchronous standby servers - take 2
Date
Msg-id CA+TgmoZ0F=takLNEMXeKcdfx-H4Q27U=tBti65R-cMDfqg5fJA@mail.gmail.com
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In response to Re: Support for N synchronous standby servers - take 2  (Michael Paquier <michael.paquier@gmail.com>)
Responses Re: Support for N synchronous standby servers - take 2  (Simon Riggs <simon@2ndQuadrant.com>)
List pgsql-hackers
On Wed, Jul 15, 2015 at 5:03 AM, Michael Paquier
<michael.paquier@gmail.com> wrote:
>> Group labels are essential.
>
> OK, so this is leading us to the following points:
> - Use a JSON object to define the quorum/priority groups for the sync state.
> - Store it as a GUC, and use the check hook to validate its format,
> which is what we have now with s_s_names
> - Rely on SIGHUP to maintain an in-memory image of the quorum/priority
> sync state
> - Have the possibility to define group labels in this JSON blob, and
> be able to use those labels in a quorum or priority sync definition.
> - For backward-compatibility, use for example s_s_names = 'json' to
> switch to the new system.

Personally, I think we're going to find that using JSON for this
rather than a custom syntax makes the configuration strings two or
three times as long for no discernable benefit.

But I just work here.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company



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