IDS Forum

RE: Mutex wait

Posted By: Plugge, Joe R.
Date: Wednesday, 21 September 2011, at 1:53 a.m.

In Response To: Re: Mutex wait (Art Kagel)

we are running on AIX and ran into this issue on FC8W2 ... maybe it is the same issue?

IC75072: RACE CONDITION BETWEEN ONTAPE AND SQLEXEC THREAD CAN CAUSE DEADLOCK ON DBS MUTEX.

Support informed us that it was fixed in 11.50.FC9

________________________________________
From: ids-bounces@iiug.org [ids-bounces@iiug.org] On Behalf Of Art Kagel [art.kagel@gmail.com]
Sent: Wednesday, September 21, 2011 12:13 AM
To: ids@iiug.org
Subject: Re: Mutex wait [24977]

How many concurrent sessions do you normally have?
How many LRU queues are configured?
How many physical processor cores on the system? How fast are they?
Itanium or PA-RISC?
How many CPU VPs are configured?
What are your settings for:
VPCLASS cpu
MULTIPROCESSOR
RESIDENT

Art

Art S. Kagel
Advanced DataTools (www.advancedatatools.com)
Blog: http://informix-myview.blogspot.com/

Disclaimer: Please keep in mind that my own opinions are my own opinions and
do not reflect on my employer, Advanced DataTools, the IIUG, nor any other
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inference. Neither do those opinions reflect those of other individuals
affiliated with any entity with which I am affiliated nor those of the
entities themselves.

On Tue, Sep 20, 2011 at 11:58 PM, VIKAS HIVARKAR
<vikas.hivarkar@gmail.com>wrote:

> Hello All,
>
> IDS 11.50.FC8W2 on HP-Unix
>
> Reposting this issue as I did not got any response for my earlier thread
> and
> yesterday we again saw a near outage due to mutex waits in the database.
>
> We experinced some dip in our performance(load jobs) and while checking the
> user I saw quite many sessions with S- flag indicating these were waiting
> on
> mutex.
>
> I checked in onstat -g ath and found the following different waits:
> 8815514 c000000a2ee36030 c000000a8fa7db48 1 mutex wait pt_940000a 12cpu
> sqlexec
> 9376796 c000000a54e18c10 c000000a865a1550 1 mutex wait nsf.lock 11cpu*
> sqlexec
> 9331804 c000000a2e8c1720 c000000a7ddc4888 1 mutex wait hash 0 175 10cpu
> sqlexec
> 8660524 c000000a3511a030 c000000a7ddf58d8 1 mutex wait <unknown> 9cpu
> sqlexec
> 8897413 c000000a511d3ae0 c000000a3777d370 1 mutex wait netnorm 1cpu sqlexec
> 8660524 c000000a3511a030 c000000a7ddf58d8 1 mutex wait hash 0 286 5cpu
> sqlexec
>
> Not all of these are waiting for nsf.lock! and I dont know what the others
> mean(hash 0 175, pt_940000a) ?
>
> Drilling down from ath - users - ses I saw the SQLs waiting for mutex,
> however
> these are normal SQLs running almost all the time while loading jobs run.
>
> onstat -lmx shows some holding and lots of waiters.
>
> Any comments and suggestions, why this could be happening in my system?
>
> Regards,
> Vikas
>
>
>
>
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>

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Messages In This Thread

• Mutex wait
  VIKAS HIVARKAR -- Tuesday, 20 September 2011, at 11:58 p.m.
  • Re: Mutex wait
    Madison Pruet -- Wednesday, 21 September 2011, at 12:31 a.m.
  • Re: Mutex wait
    Art Kagel -- Wednesday, 21 September 2011, at 1:13 a.m.
    • RE: Mutex wait
      Plugge, Joe R. -- Wednesday, 21 September 2011, at 1:53 a.m.
  • Re: Mutex wait
    Fernando Nunes -- Wednesday, 21 September 2011, at 3:50 a.m.
    • Re: Mutex wait
      VIKAS HIVARKAR -- Wednesday, 21 September 2011, at 5:20 a.m.
      • Re: Mutex wait
        Art Kagel -- Wednesday, 21 September 2011, at 8:04 a.m.
      • Re: Mutex wait
        jak aka -- Thursday, 22 September 2011, at 11:02 a.m.

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