The second "way" sounds interesting, but what is it filled with?
What does it matter? It’s an internal detail that apparently gets exposed as [unknown] appearing in your log file where the client ip address would normally be.
Because I'd hope that the log file would tell me the errant host name.
I added "log_hostname = on" to postgresql.conf earlier in the day. When I commented that out, the errors stopped happening.
This makes sense.
But is not explanatory. I want to see host names in the log file when possible, not just IP addresses.
In pg_hba.conf. all application servers are either IP addresses, or names that are explicitly defined in /etc/hosts.
