Phoenix Kiula wrote:
Thanks, but swap is not changing, there is no idle transaction, and
number of connections are 28/29.
Here are some command line stamps...any other ideas?
[MYSITE] ~ > date && vmstat
Wed Aug 19 10:00:37 CDT 2009
procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
3 1 20920 25736 60172 7594988 0 0 74 153 0 3 10 5 74 12
[MYSITE] ~ > date && vmstat
Wed Aug 19 10:00:40 CDT 2009
procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
0 1 20920 34696 60124 7593996 0 0 74 153 0 3 10 5 74 12
[MYSITE] ~ > ps ax|grep postgres
25302 ? Ss 0:00 postgres: logger process
25352 ? Ss 0:07 postgres: writer process
25353 ? Ss 4:21 postgres: stats collector process
23483 ? Ds 0:00 postgres: snipurl_snipurl snipurl
127.0.0.1(51622) UPDATE
23485 pts/12 S+ 0:00 grep postgres
[MYSITE] ~ > date && vmstat
Wed Aug 19 10:00:55 CDT 2009
procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
0 0 20920 49464 60272 7597748 0 0 74 153 0 3 10 5 74 12
[MYSITE] ~ > ps ax|grep http|wc --lines
28
[MYSITE] ~ > ps ax|grep http|wc --lines
29
[MYSITE] ~ > ps ax|grep postgres
25302 ? Ss 0:00 postgres: logger process
25352 ? Ss 0:07 postgres: writer process
25353 ? Ss 4:21 postgres: stats collector process
24718 pts/12 S+ 0:00 grep postgres
[MYSITE] ~ > date && vmstat
Wed Aug 19 10:01:23 CDT 2009
procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
0 0 20920 106376 59220 7531016 0 0 74 153 0 3 10 5 74 12
On Wed, Aug 19, 2009 at 10:01 PM, Andy Colson<andy@xxxxxxxxxxxxxxx> wrote:
Phoenix Kiula wrote:
I'm on a CentOS 5 OS 64 bit, latest kernel and all of that.
PG version is 8.3.7, compiled as 64bit.
The memory is 8GB.
It's a 2 x Dual Core Intel 5310.
Hard disks are Raid 1, SCSI 15 rpm.
The server is running just one website. So there's Apache 2.2.11,
MySQL (for some small tasks, almost negligible).
And then there's PG, which in the "top" command shows up as the main
beast.
My server load is going to 64, 63, 65, and so on.
Where should I start debugging? What should I see? TOP command does
not yield anything meaningful. I mean, even if it shows that postgres
user for "postmaster" and nobody user for "httpd" (apache) are the
main resource hogs, what should I start with in terms of debugging?
1) check if you are using swap space. Use free and make sure swap/used is a
small number. Check vmstat and see if swpd is moving up and down. (Posting
a handful of lines from vmstat might help us).
2) check 'ps ax|grep postgres' and make sure nothing says "idle in
transaction"
3) I had a web box where the number of apache clients was set very high, and
the box was brought to its knees by the sheer number of connections. check
"ps ax|grep http|wc --lines" and make sure its not too big. (perhaps less
than 100)
-Andy
the first line of vmstat is an average since bootup. Kinda useless.
run it as: 'vmstat 4'
it will print a line every 4 seconds, which will be a summary of
everything that happened in the last 4 seconds.
since boot, you've written out an average of 153 blocks (the bo column).
Thats very small, so your not io bound.
but... you have average 74% idle cpu. So your not cpu bound either?
Ahh? I'm not sure what that means. Maybe I'm reading something wrong?
-Andy
--
Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-performance
