Re: Patch: Implement failover on libpq connect level.

On Mon, Nov 14, 2016 at 1:37 PM, Tsunakawa, Takayuki <tsunakawa.takay@jp.fujitsu.com> wrote:

 > No, there's no concern about compatibility.  Please look at this:

 > https://www.postgresql.org/docs/devel/static/protocol-flow.html#PROTOCOL-ASYNC

Thanks, my concern is suppose you have 3 server in cluster A(new version), B(new version), C(old version). If we implement as above only new servers will send ParameterStatus message to indicate what type of server we are connected. Server C will not send same. So we will not be able to use new feature "failover to new master" for such a kind of cluster.