Re: Determining server load from client

(forgot to send to list)
Dan Harris wrote:
> architecture of the server hardware. It would be very nice if I could
> check the load of the server at certain intervals to throttle the
> number of concurrent queries and mitigate load problems when other
> processes might be already inducing a significant load.
>
> I have seen some other nice back-end things exposed through PG
> functions ( e.g. database size on disk ) and wondered if there was
> anything applicable to this. Even if it can't return the load average
> proper, is there anything else in the pg_* tables that might give me a
> clue how "busy" the server is for a period of time?

I have installed munin (http://munin.projects.linpro.no/) on a few
systems. This lets you look at graphs of system resources/load etc. I
have also added python scripts which do sample queries to let me know if
performance/index size is changing dramatically. I have attached an
example script.

Hope that helps,

Joe

------------------------------------------------------------------------

#! /usr/bin/python
import psycopg
import sys

def fixName(name):
return name[:19]

if len(sys.argv) > 1 and sys.argv[1] == "config":
print """graph_title Postgresql Index Sizes
graph_vlabel Mb"""

con = psycopg.connect("host=xxx user=xxx dbname=xxx password=xxx")
cur = con.cursor()

cur.execute("select relname, relpages from pg_class where relowner > 10 and relkind='i' and relpages > 256 order by reltuples desc;")
results = cur.fetchall()
for name, pages in results:
print "%s.label %s" % (fixName(name), name)

else:
con = psycopg.connect("host=xxx user=xxx dbname=xxx password=xxx")
cur = con.cursor()

cur.execute("select relname, relpages from pg_class where relowner > 10 and relkind='i' and relpages > 256 order by reltuples desc;")
results = cur.fetchall()

for name, pages in results:
print "%s.value %.2f" % (name[:19], pages*8.0/1024.0)