Josh Berkus <josh(at)agliodbs(dot)com> wrote:
> when we last had the argument about time synchronization,
> Kevin Grittner (I believe) pointed out that unsynchronized
> replication servers have an assortment of other issues ... like
> any read query involving now().
I don't remember making that point, although I think it's a valid
one.
What I'm sure I pointed out is that we have one central router which
synchronizes to a whole bunch of atomic clocks around the world
using the normal "discard the outliers and average the rest"
algorithm, and then *every singe server and workstation on our
network synchronizes to that router*. Our database servers are all
running on Linux using ntpd. Our monitoring spams us with email if
any of the clocks falls outside nominal bounds. (It's been many
years since we had a misconfigured server which triggered that.)
I think doing anything in PostgreSQL around this beyond allowing
DBAs to trust their server clocks is insane. The arguments for
using and trusting ntpd is pretty much identical to the arguments
for using and trusting the OS file systems.
-Kevin