* Josh Berkus (josh@agliodbs.com) wrote:
> 1. you're almost out of disk space due to a replica falling behind, like
> down to 16mb left. Or maybe you are out of disk space.
This right here is a real issue. What I'd personally like to see is an
option which says "you have X GB of disk space. Once it's gone, forget
about all replicas or failing archive commands or whatever, and just
stop holding on to ancient WAL that you no longer need to operate."
Perhaps there would be a warning threshold there too, where you start
getting complaints in the log if things are falling too far behind.
Ideally, you'd have a monitoring system which is checking for that, but
it'd be trivial to include and could be useful for environments that
don't have proper monitoring yet.
Having this work on the replicas would be nice too. I realize we have
time-based constraints there which say "kill off queries which are
blocking us from moving forward after X time", but it'd be awful nice to
have a size-based way too, to avoid having PG crash when it runs out of
space. I have to admit that I'm getting quite tired of the ways in
which PG can crash due to out of memory (yes, I know, it's the OOM
killer because of a misconfigured Linux box, but still), out of disk
space on the master, out of space on the replica, etc, etc.
Thanks!
Stephen