Re: connections and cpu consumption

On 11/09/11 10:35 AM, Gauthier, Dave wrote:
>
> I'm using "selcet procpid,current_query from pg_stat_activity" to
> monitor activity during times when "top" is showing many PG procs with
> very high cpu usage numbers (all cores at or above 90%).  Some of
> these are procs that map to PG connections with current_query = <IDLE>.
>
> What scenarios could explain a process identified as IDLE consuming
> lots of CPU?
>
> More clues... In parallel with these was a user that was making a
> series of insert/delete/update commands that fire off triggers that
> generate more DML recursively.  Some of the idles are "<IDLE> in
> transaction".
>

perhaps you just happened to sample pg_stat_activity in between queries?
<IDLE> should be just that. <IDLE> in transaction is equally idle, but
there's an open transaction.   if these processes STAY idle in
transaction for too long they can cause vacuum to get behind, thats
typically hours-to-days before this is a problem in most scenarios.


--
john r pierce                            N 37, W 122
santa cruz ca                         mid-left coast