Re: 11g kokc latching problem??

Some good inputs by Tanel Poder on how to tune latches on his blog: http://blog.tanelpoder.com/2008/07/23/advanced-oracle-troubleshooting-guide-part-8-even-more-detailed-latch-troubleshooting-using-latchprofx/

Regards,

Jaffar

On Wed, Oct 15, 2008 at 3:10 PM, Sriram Kumar <k.sriramkumar_at_gmail.com>wrote:

> Hi Gurus,
> We had started some online performance testing of our application on 11g (
> 11.1.0.7) . There seems to be a severe latching problem on kokc descriptor
> latch. I understand that this is a new latch in 11g and not able to find
> anything beyond that. The same test went fine on 10g R2. Metalink has no
> hits on this have any one of you faced a similar problem in 11g and any
> possible hints/undocumented parameters that can help?
>
> have copied relevant sections from AWR
>
> Top 5 Timed Foreground Events
>
> *Event*
>
> *Waits*
>
> *Time(s)*
>
> *Avg wait (ms)*
>
> *% DB time*
>
> *Wait Class*
>
> latch free
>
> 566,894
>
> 184,570
>
> 326
>
> 93.68
>
> Other
>
> DB CPU
>
>
>
> 10,676
>
>
>
> 5.42
>
>
>
> log file sync
>
> 76,340
>
> 1,184
>
> 16
>
> 0.60
>
> Commit
>
> library cache: mutex X
>
> 2,283,183
>
> 360
>
> 0
>
> 0.18
>
> Concurrency
>
> SQL*Net more data from client
>
> 105,660
>
> 117
>
> 1
>
> 0.06
>
> Network
>
>
>
> Latch Statistics
>
>
>
> Latch Name
>
> Get Requests
>
> Pct Get Miss
>
> Avg Slps /Miss
>
> Wait Time (s)
>
> NoWait Requests
>
> Pct NoWait Miss
>
> kokc descriptor allocation latch
>
> 3,968,130
>
> 18.59
>
> 0.88
>
> 174283
>
> 0
>
>
>
>
>
> Latch Miss Source
>
>
>
> *Latch Name*
>
> *Where*
>
> *NoWait Misses*
>
> *Sleeps*
>
> *Waiter Sleeps*
>
> kokc descriptor allocation latch
>
> kokcdlt: regular free
>
> 0
>
> 327,851
>
> 265,626
>
> kokc descriptor allocation latch
>
> kokcdlt: allocation
>
> 0
>
> 321,646
>
> 383,871
>
> * *
> Best Regards,
>
> Sriram Kumar
>

-- 
Best Regards,

Syed Jaffar Hussain
Oracle Certified Master (10g)
http://www.oracle.com/technology/ocm/shussain.html
Oracle ACE
http://apex.oracle.com/pls/otn/f?p=19297:4:1579866181463918::NO:4:P4_ID:126
OCP 8i,9i & 10g DBA
RAC Certified Expert
Official Oracle RAC SIG Representative for Saudi Arabian region  (
http://www.oracleracsig.org/)
I blog at
http://jaffardba.blogspot.com/
--------------------
"Winners don't do different things. They do things differently."

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