Re: Implement support for TCP_KEEPCNT, TCP_KEEPIDLE, TCP_KEEPINTVL

Tom Lane wrote:

> I'm not sure if we can issue a notice that will be seen on the client
> side at this point in the startup cycle.  I seem to recall the protocol
> document advising against sending NOTICEs during the authentication
> cycle.

As currently written the setsockopt() calls are done very early, well
before even ProcessStartupPacket() has run -- so we can't really send
anything at all to the client because we don't even know which protocol
to use.

Delaying the setsockopt() introduces the danger that you could lose the
network at just the wrong time and have a backend sitting around for an
extended period waiting on a startup packet (but not holding locks,
admittedly).

-O