On Fri, Apr 14, 2017 at 9:38 AM, Michael Paquier <michael.paqu...@gmail.com> wrote: > On Fri, Apr 14, 2017 at 2:47 AM, Fujii Masao <masao.fu...@gmail.com> wrote: >> I'm thinking that it's less confusing to report always 0 as the priority of >> async standby whatever the setting of synchronous_standby_names is. >> Thought? > > Or we could have priority being reported to NULL for async standbys as > well, the priority number has no meaning for them anyway...
I agree to set the same thing (priority or NULL) to all sync standby in a quorum set. As Fujii-san mentioned, I also think that it means all standbys in a quorum set can be chosen equally. But to less confusion for current user I'd not like to change current behavior of the priority of async standby. > >> If we adopt this idea, in a quorum-based sync replication, I think that >> the priorities of all the standbys listed in synchronous_standby_names >> should be 1 instead of NULL. That is, those standbys have the same >> (highest) priority, and which means that any of them can be chosen as >> sync standby. Thought? > > Mainly my fault here to suggest that standbys in a quorum set should > have a priority set to NULL. My 2c on the matter is that I would be > fine with either having the async standbys having a priority of NULL > or using a priority of 1 for standbys in a quorum set. Though, > honestly, I find that showing a priority number for something where > this has no real meaning is even more confusing.. This is just a thought but we can merge sync_priority and sync_state into one column. The sync priority can have meaning only when the standby is considered as a sync standby or a potential standby in priority-based sync replication. For example, we can show something like 'sync:N' as states of the sync standby and 'potential:N' as states of the potential standby in priority-based sync replication, where N means the priority. In quorum-based sync replication it is just 'quorum'. It breaks backward compatibility, though. Regards, -- Masahiko Sawada NIPPON TELEGRAPH AND TELEPHONE CORPORATION NTT Open Source Software Center -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
