Re: Mutex wait
Hi,
We have tried to set NUMFDSERVERS to 1 on 11.50 but it did not help. Now, we
trying to upgrade to 11.70.
________________________________
From: VIKAS HIVARKAR <vikas.hivarkar@gmail.com>
To: ids@iiug.org
Sent: Wednesday, September 21, 2011 4:20 PM
Subject: Re: Mutex wait [24980]
Hello All,
One important observation:
When Guardium (monitoring tool from IBM) is stoped I do not see this bad mutex
behaviour!
@Madison Pruet:
Yes, nsf.lock waits are a problem, however in my case If I see 200 mutex waits
(onstat -g ath |grep mutex / onstat -g lmx)then only 3-5 are nsf.lock hence
not sure if the performance issue is only because of these 3 to 4 nsf.locks.
https://www-304.ibm.com/support/docview.wss?uid=swg21145897
says that if we see lots of nsf.locks then setting NUMFDSERVERS to 1 for
11.50. could resolve the issue.
I see large number of other types of mutex waits, should I try setting this
parameter( it requires instance restart)?
@Art:
concurrent sessions: 350+
BUFFERPOOL
size=2K,buffers=7200000,lrus=512,lru_min_dirty=1.000000,lru_max_dirty=5.000000
BUFFERPOOL
size=4K,buffers=3000000,lrus=512,lru_min_dirty=10.000000,lru_max_dirty=20.000000
BUFFERPOOL
size=16K,buffers=750000,lrus=512,lru_min_dirty=10.000000,lru_max_dirty=20.000000
AUTO_LRU_TUNING 1
Number of CPUs = 16
Clock speed = 1598 MHz
Bus speed = 533 MT/s
processor family: 32 Intel(R) Itanium 2 9000 series
VPCLASS cpu,num=12,noage
RESIDENT 1
MULTIPROCESSOR 1
@Joe:
We take the backup during night time, during day time only logical log backup
is running, so will check the bug you shared.
@Fernando:
I do see couple of threads and many waiter threads against each holder,
however I am not able to trace them further as the old onces are replaced by
new onces faster than my tracking speed.
Any suggestions for further investigation.
Regards,
Vikas
*******************************************************************************
Forum Note: Use "Reply" to post a response in the discussion forum.