Re: High cpu usage after many inserts - Mailing list pgsql-general

From Jordan Tomkinson
Subject Re: High cpu usage after many inserts
Date
Msg-id 6de2f13b0902222316s16476111j65905f253e8cc265@mail.gmail.com
Whole thread Raw
In response to Re: High cpu usage after many inserts  (Scott Marlowe <scott.marlowe@gmail.com>)
List pgsql-general


On Mon, Feb 23, 2009 at 4:03 PM, Scott Marlowe <scott.marlowe@gmail.com> wrote:
On Sun, Feb 22, 2009 at 11:55 PM, Jordan Tomkinson <jordan@moodle.com> wrote:
> Hi list,
>
> We are running postgresql 8.3.5 and are trying to stress test our LMS.
> The problem is when our stress tester (Jmeter) inserts around 10,000 rows
> (in 3 hours) over 2 tables (5000 rows each table) the CPU of the sql server
> hits 100% over all 4 cores for all future inserts.

And just to clarify, this is user / system CPU usage, not IO wait, right?

I am unable to post the jmeter file as it contains sensitive user/pass details, but they simply login to a forum and create a new forum post, then logout.
SQL wise this performs several SELECT's and 3 INSERT'S over 3 different tables.

How does one create an SQL test case?
LMS is Learning Management System, in this case Moodle (moodle.org)

Yes this is user space CPU usage.

Running iostat -k 2 shows:
Device:            tps    kB_read/s    kB_wrtn/s    kB_read    kB_wrtn
sda              31.50         0.00       456.00          0        912

so not alot of disk writes.

pgsql-general by date:

Previous
From: Scott Marlowe
Date:
Subject: Re: High cpu usage after many inserts
Next
From: Jordan Tomkinson
Date:
Subject: Re: High cpu usage after many inserts