Estimate EDM_SKELETON_POOL size for V9 migration?

Gary Martin

Estimate EDM_SKELETON_POOL size for V9 migration?
We had a rude awakening after migrating a busy subsystem to V9 CM.
Once the workload increased to prime-time levels, we saw performance
degradation with these symptoms:
• I/O delays on SPT01
• high # of PKG Loads
We had relied on the install clist calculation for EDM_SKELETON_POOL of
10MB, but after a few painful hours of troubleshooting, increased it to
100MB. This made a significant improvement in reducing PKG Loads.
We’ve subsequently increased it 120MB for another incremental
performance improvement.

Has anyone else suffered this experience?
I’m wondering what process you are using to estimate the size of this pool?

I’ve since seen the recommendation to size EDM_SKELETON_POOL at
least as large as V8 EDM Pool SKCT & SKCT while under peak load. I’m
curious to know if other techniques have been used & how effective they
have been.

Thanks,
Gary

_____________________________________________________________________

* IDUG North America * Tampa, Florida, * May 10-14 2010 * http://IDUG.ORG/NA *
_____________________________________________________________________

http://www.idug.org/rug/index.html - with almost 150 IDUG Regional User Groups,
there is probably one near you!
Regional User Groups are your local connection to the Worldwide DB2 User Community
_____________________________________________________________________

If you need to change settings, http://www.idug.org/cgi-bin/wa?A0=DB2-L is the home of IDUG's DB2-L

Phil McLaren

Re: Estimate EDM_SKELETON_POOL size for V9 migration?
(in response to Gary Martin)
Gary,

I can't say I relied on the install clist, but then I had the flexibility to go high on the value for the new EDM-SKEL_POOL value and tune afterwards. I ended up with an approximate split, halving the original EDMPOOL and giving the other half to the new SKEL_POOL. If I remember correctly, much of the new pool was not consumed until we rebound. Final results we ended up with were as below (for the main production subsystem)

EDMPOOL=80000,
EDM_SKELETON_POOL=70000,

It would be interesting to know what others have found here, though of course there are a lot of variables.

I used much the same erm...'intelligence' (!) to handle the DSNDB07 rebalance for the 4K and 32K pagesets. In our case about 70% moved into the 32K pagesets from almost zero use before.

Regards
Phil


-----Original Message-----
From: IDUG DB2-L [mailto:[login to unmask email] On Behalf Of Gary Martin
Sent: 23 November 2009 19:36
To: [login to unmask email]
Subject: [DB2-L] Estimate EDM_SKELETON_POOL size for V9 migration?

We had a rude awakening after migrating a busy subsystem to V9 CM.
Once the workload increased to prime-time levels, we saw performance
degradation with these symptoms:
• I/O delays on SPT01
• high # of PKG Loads
We had relied on the install clist calculation for EDM_SKELETON_POOL of
10MB, but after a few painful hours of troubleshooting, increased it to
100MB. This made a significant improvement in reducing PKG Loads.
We’ve subsequently increased it 120MB for another incremental
performance improvement.

Has anyone else suffered this experience?
I’m wondering what process you are using to estimate the size of this pool?

I’ve since seen the recommendation to size EDM_SKELETON_POOL at
least as large as V8 EDM Pool SKCT & SKCT while under peak load. I’m
curious to know if other techniques have been used & how effective they
have been.

Thanks,
Gary

_____________________________________________________________________

* IDUG North America * Tampa, Florida, * May 10-14 2010 * http://IDUG.ORG/NA *
_____________________________________________________________________

http://www.idug.org/rug/index.html - with almost 150 IDUG Regional User Groups,
there is probably one near you!
Regional User Groups are your local connection to the Worldwide DB2 User Community
_____________________________________________________________________

If you need to change settings, http://www.idug.org/cgi-bin/wa?A0=DB2-L is the home of IDUG's DB2-L

The AXA Winterthur Wealth Management proposition is offered by companies within the AXA UK group of companies. AXA Sun Life Services plc distributes financial products and services for these companies and is issuing this item on their behalf. Details of the companies offering specific products are contained within the related material. AXA Sun Life Services plc is authorised and regulated by the Financial Services Authority and is a company limited by shares, registered in England No. 3424940, registered office: 5 Old Broad Street, London, EC2N 1AD. As part of our commitment to quality service, telephone calls will be recorded