Interesting - in this quick snapshot there is no I/O happening at all. What happens when you track the activity for a longer period of time? How about just capturing vmstat during a period when the queries are slow? Has the load average been this high forever or are you experiencing a growth in workload? 463 processes all doing CPU work will take 100x as long as one query on a 4 CPU box, have you worked through how long you should expect the queries to take? - Luke > -----Original Message----- > From: Willo van der Merwe [mailto:willo@xxxxxxxxxxxxxxxxxxxx] > Sent: Wednesday, August 30, 2006 4:35 AM > To: Luke Lonergan > Cc: Merlin Moncure; pgsql-performance@xxxxxxxxxxxxxx > Subject: Re: [PERFORM] PostgreSQL performance issues > > Luke Lonergan wrote: > >> Currently the load looks like this: > >> Cpu0 : 96.8% us, 1.9% sy, 0.0% ni, 0.3% id, 0.0% wa, > 0.0% hi, > >> 1.0% si > >> Cpu1 : 97.8% us, 1.6% sy, 0.0% ni, 0.3% id, 0.0% wa, > 0.0% hi, > >> 0.3% si > >> Cpu2 : 96.8% us, 2.6% sy, 0.0% ni, 0.3% id, 0.0% wa, > 0.0% hi, > >> 0.3% si > >> Cpu3 : 96.2% us, 3.2% sy, 0.0% ni, 0.3% id, 0.0% wa, > 0.0% hi, > >> 0.3% si > >> > > > > All four CPUs are hammered busy - check "top" and look for runaway > > processes. > > > > - Luke > > > > > > > Yes, the first 463 process are all postgres. In the meanwhile > I've done: > Dropped max_connections from 500 to 250 and Upped > shared_buffers = 50000 > > Without any apparent effect. > >
