On demand and DB2 V10 performance

[leodejong]

Hi,

I's like to share some experiences we had with Ondemand since we implemented DB2 V10.
A few months ago we installed V10 on our production system with OnDemand. After a few weeks we noticed a large increase of CPU-usage of the ARSSOCK task. The CPU almost tripled. Soon we found out it was all CPU executing SQL.
We did all of the standard recommendations in the V10 books like RUNSTATS with all the new options. Rebind the ODBC packages and the ARS* packages. But no improvement.

But the solution at the end was to bind the DSNCLINF package with the REOPT(ALWAYS) option. CPU consumption went back to normal.
We also tried REOPT(AUTO). But then we struck an open APAR (which might be solved in the meantime).

I don't know if other sites have the same experience.

Vriendelijke Groeten / Kind Regards,

Leo de Jong

[Greg Ira]

Thanks, that's good to know.  We'll be going to DB2 10 within a year.

[Ed_Arnold]

Also, if you're on CMOD 8.5 or 9.0 make sure you have PM73809 installed.

ERROR DESCRIPTION:                                           
High CPU in ARSSOCKD started task after upgrade to V8.5.0   
The high CPU involves retrieving AFP or PDF resource objects.
The bigger the uncompressed size of the resource object, the
greater the CPU consumption.                                 
                                                             

[cmodpuser]

Leo,
Was the IBM APAR opened for OnDemand or DB2?
We have DSNCLINF bound with REOPT(NONE) which is a default.
Thanks,
Margaret

[jeffs42885]

Is this only if you are running CMOD (zOS) 8.5+ and DB2 Version 10?

[leodejong]

Hi,
Sorry for late reply:

Ed_arnold: Thanks for the tip. We are going to migrate to 9.0 from 8.4

cmodpuser: I did not open a PMR with IBM. I just rebound the package.
Found the tip in a presentattion about DB2 V10 installation experiences.
But they had the same increase with a LDAP server they ran on z/OS.
The thing which is common with CMOD is the use of ODBC on  z/OS.

jeffs42885:
I don't think it has anything to do with the release of CMOD. Just the way DB2 handles ODBC type work. And in most cases CMOD is the user of ODBC interface to DB2 on the z/OS system.  So you will only notice the increase there.

Leo