Re: [HACKERS] [bug fix] PG10: libpq doesn't connect to alternative hosts when some errors occur

Michael Paquier <michael.paquier@gmail.com> writes:
> On Fri, May 12, 2017 at 1:28 PM, Tsunakawa, Takayuki
> <tsunakawa.takay@jp.fujitsu.com> wrote:
>> Likewise, when the first host has already reached max_connections, libpq doesn't attempt the connection aginst later
hosts.

> It seems to me that the feature is behaving as wanted. Or in short
> attempt to connect to the next host only if a connection cannot be
> established. If there is a failure once the exchange with the server
> has begun, just consider it as a hard failure. This is an important
> property for authentication and SSL connection failures actually.

I would not really expect that reconnection would retry after arbitrary
failure cases.  Should it retry for "wrong database name", for instance?
It's not hard to imagine that leading to very confusing behavior.
        regards, tom lane