Re: A change in the Debian install

rob stone <floriparob(at)gmail(dot)com> writes:
> Upgraded to version 9.6.2-2 and these are the log entries on start-up:-

> 2017-04-05 08:03:29 AESTLOG:  test message did not get through on
> socket for statistics collector

This is not something that would be affected by any Postgres setting;
the stats collector always depends on a loopback TCP connection to
"localhost", and has done so since day one. If it was working before,
you need to look at what you changed related to network and firewall
configuration. These symptoms looks like some kernel firewall rule
deciding to block local-loopback TCP traffic, for what that's worth.

(But ... these statements are based on an assumption of out-of-the-
box Postgres behavior. I would not exactly put it past the Debian
packagers to have decided to change this for reasons of their own,
and their track record of telling us about such decisions is many
miles south of abysmal. So you might look at whatever patches
are in the Debian package to see if there's anything touching
pgstat.c's socket-setup logic.)

regards, tom lane