> You might want to try setting log_autovacuum_min_duration=0 in the
> postgresql.conf
Thanks, tried it. There is nothing in the log - the actual
vacuum/analyze commands are not run (as there is no query activity). I
suspect that autovacuum is checking each database if it should run - and
decides not to run. See the randomly catch process in ps
output/pg_stat_activity mentioned in earlier mail. I suspect that this
checking generates the load. Is it possible?
> With this many databases and this high of a statistics target
I've changed the default_statistics_target back to its default (100). No
change, still stats collector generates load.
> You're really pushing what you can do in a VM with this many
> databases of this size.
Yes, it's a VM but on our dedicated hardware - there are few other
containers running but they are not generating any load.
What's puzzling me is that there is no database activity (queries,
connections) and stats collector is still eating CPU.
Kuba
Dne 16.2.2010 8:29, Greg Smith napsal(a):
Jakub Ouhrabka wrote:
I've found similar reports but with older versions of postgres:
http://old.nabble.com/100--of-CPU-utilization-postgres-process-tt27302021.html
Those all looked like a FreeBSD issue, doubt it's related to yours.
The pgstat.stat is ~20MB. There are 650 databases, 140GB total.
default_statistics_target = 1000
The system is running Proxmox linux distribution. PostgreSQL is in
OpenVZ container.
With this many databases and this high of a statistics target, running
in a VM, suspecting autovacuum seems reasonable. You might want to try
setting log_autovacuum_min_duration=0 in the postgresql.conf, restarting
or signalling (pg_ctl reload) the server, and watching just what it's
doing. You might need to reduce how aggressively that runs, or limit the
higher target to only the tables that need it, to get this under
control. You're really pushing what you can do in a VM with this many
databases of this size.
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
