Since Thom already did the destruction test, I only chained 7 standbies,
just to see if I could reproduce his error.
In the process, I accidentally connected one standby to itself. This
failed, but the error message wasn't very helpful; it just gave me
"FATAL: could not connect, the database system is starting up". Surely
there's some way we could tell the user they've tried to connect a
standby to itself?
Anyway, I was unable to reproduce Thom's error. I did not see the
error message he did.
Without any read queries running on the standbys, lag from master to
replica7 averaged about 0.5 seconds, ranging between 0.1 seconds and 1.2
seconds.
--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com