Re: PG 8.3 and server load

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(at)squeakycode(dot)net> 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