http://dacxzjk3kq5mmepbdd3ai2ifynlzxsnpl2cnkfhridqfywihrfftapid.onion/help/administration/postgresql/database_load_balancing.md
For example, if the TTL of the A record is 90 seconds, then service
discovery waits at least 90 seconds before checking the A record again.
When the list of hosts is updated, it might take a while for the old connections
to be terminated. The disconnect_timeout setting can be used to enforce an
upper limit on the time it takes to terminate all old database connections.