Re: Significant discrepancy in V$OSSTAT since upgrading to 10.2.0.5
From: Charles Hooper <hooperc2000_at_yahoo.com>
Date: Wed, 21 Jul 2010 10:48:58 -0700 (PDT)
Message-ID: <99a15aed-e2ba-4341-801c-a8ddef5f5e21_at_i28g2000yqa.googlegroups.com>
On Jul 21, 11:51 am, Mladen Gogala <n..._at_email.here.invalid> wrote:
> I used V$OSSTAT for monitoring in 10.2.0.4 and it was much more accurate
> than is the case with 10.2.0.5. Look at this:
>
(Snip)
> So, V$OSSTAT tells me that my CPU resources are 52.9% busy while sar
> tells me that those very same resources are 70% idle. The "top" monitor
> confirms that "sar" is right and not Oracle.
Date: Wed, 21 Jul 2010 10:48:58 -0700 (PDT)
Message-ID: <99a15aed-e2ba-4341-801c-a8ddef5f5e21_at_i28g2000yqa.googlegroups.com>
On Jul 21, 11:51 am, Mladen Gogala <n..._at_email.here.invalid> wrote:
> I used V$OSSTAT for monitoring in 10.2.0.4 and it was much more accurate
> than is the case with 10.2.0.5. Look at this:
>
(Snip)
> So, V$OSSTAT tells me that my CPU resources are 52.9% busy while sar
> tells me that those very same resources are 70% idle. The "top" monitor
> confirms that "sar" is right and not Oracle.
Just a couple of quick calculations:
IDLE_TIME: 80163480
BUSY_TIME: 42444869
Total Time: 122608349
If the total available CPU time is 122,608,349: Busy Percent = 42444869/(42444869+80163480) Busy Percent = 42444869/122608349
Since the database was brought online:
34.62 Busy
65.38 Idle
sar output:
72.852% for 15 second time period
The problem is that the current average CPU usage does not match the historical CPU usage.
Charles Hooper
Co-author of "Expert Oracle Practices: Oracle Database Administration
from the Oak Table"
http://hoopercharles.wordpress.com/
IT Manager/Oracle DBA
K&M Machine-Fabricating, Inc.
Received on Wed Jul 21 2010 - 12:48:58 CDT