[PERFORM] autovacuum fringe case?

2013-01-23 Thread AJ Weber
I have a server that is IO-bound right now (it's 4 cores, and top indicates the use rarely hits 25%, but the Wait spikes above 25-40% regularly). The server is running postgresql 9.0 and tomcat 6. As I have mentioned in a previous thread, I can't alter the hardware to add disks

Re: [PERFORM] autovacuum fringe case?

2013-01-23 Thread Evgeniy Shishkin
On 23.01.2013, at 20:53, AJ Weber awe...@comcast.net wrote: I have a server that is IO-bound right now (it's 4 cores, and top indicates the use rarely hits 25%, but the Wait spikes above 25-40% regularly). The server is running postgresql 9.0 and tomcat 6. As I have mentioned in a

Re: [PERFORM] autovacuum fringe case?

2013-01-23 Thread Jeff Janes
On Wed, Jan 23, 2013 at 8:53 AM, AJ Weber awe...@comcast.net wrote: I have a server that is IO-bound right now (it's 4 cores, and top indicates the use rarely hits 25%, but the Wait spikes above 25-40% regularly). How long do the spikes last? The server is running postgresql 9.0 and tomcat

Re: [PERFORM] autovacuum fringe case?

2013-01-23 Thread Kevin Grittner
AJ Weber wrote: Is it possible that some spikes in IO could be attributable to the autovacuum process? Is there a way to check this theory? Taking a look at the ps aux listing, pg_stat_activity, and pg_locks should help establish a cause, or at least rule out a number of possibilities. There

Re: [PERFORM] autovacuum fringe case?

2013-01-23 Thread AJ Weber
On 1/23/2013 2:13 PM, Jeff Janes wrote: On Wed, Jan 23, 2013 at 8:53 AM, AJ Weberawe...@comcast.net wrote: I have a server that is IO-bound right now (it's 4 cores, and top indicates the use rarely hits 25%, but the Wait spikes above 25-40% regularly). How long do the spikes last? From

Re: [PERFORM] autovacuum fringe case?

2013-01-23 Thread Alvaro Herrera
AJ Weber escribió: On 1/23/2013 2:13 PM, Jeff Janes wrote: Scheduling a manual vacuum should be fine (but keep in mind that vacuum has very different default cost_delay settings than autovacuum does. If the server is completely idle that shouldn't matter, but if it is only mostly idle, you

Re: [PERFORM] autovacuum fringe case?

2013-01-23 Thread Jeff Janes
On Wednesday, January 23, 2013, AJ Weber wrote: Is there a skinny set of instructions on loading pg_stat_statements? Or should I just log them and review them from there? Make sure you have installed contrib. (How you do that depends on how you installed PostgreSQL in the first place. If