Significant discrepancy in V$OSSTAT since upgrading to 10.2.0.5

From: Mladen Gogala <no_at_email.here.invalid>
Date: Wed, 21 Jul 2010 15:51:33 +0000 (UTC)
Message-ID: <pan.2010.07.21.15.51.33_at_email.here.invalid>

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:

SQL> column stat_name format a20
SQL> select stat_name,value from v$osstat   2 where stat_name like '%TIME';

STAT_NAME VALUE

-------------------- ----------
IDLE_TIME	       80163480
BUSY_TIME	       42444869
USER_TIME	       32543474
SYS_TIME		7838644
IOWAIT_TIME		8463912
NICE_TIME		      1
RSRC_MGR_CPU_WAIT_TI	      0

ME

SQL> select 42444869/80163480 from dual;

42444869/80163480

---

       .529478872

SQL> !sar -u 3 5
Linux 2.6.9-22.ELsmp (oracle13) 07/21/2010

11:45:27 AM       CPU     %user     %nice   %system   %iowait     %idle
11:45:30 AM       all     17.83      0.00      8.08      6.00     68.08
11:45:33 AM       all     19.23      0.00      8.83      2.66     69.28
11:45:36 AM       all     14.51      0.00      6.67      0.83     77.98
11:45:39 AM       all     19.67      0.00      8.25      1.58     70.50
11:45:42 AM       all     13.33      0.00      7.00      1.25     78.42
Average:          all     16.92      0.00      7.77      2.47     72.85

SQL> 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.

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Received on Wed Jul 21 2010 - 10:51:33 CDT