IBM Systems Magazine, Mainframe Edition - November/December 2012 - (Page 8)

Insider Insights from the industry What’s Really Driving Peak CPU Usage? In many cases, batch processing accounts for as much as 40 percent By Martin Wills During my tenure with MVS Solutions, I often asked customers what they thought drove their usage peaks. Typically, they’d say the peaks were entirely dependent on online processing. However, I’ve long suspected that batch processing also plays a significant role. So I decided to see if my suspicions were justified. Some colleagues and I devised a way to analyze monthly usage and calculate both the overall four-hour rolling average and the four-hour rolling average for batch. The results among the participants in our study indicated that batch processing accounted for a surprising 30 to 40 percent of the peaks in many cases. That’s a significant contributor to usage and ultimately results in increased costs. M any installations using some form of subcapacity pricing believe their peak CPU usage is driven by their online workload. But is that really true? At the Source Instantaneous spikes in usage, however, aren’t really the issue, other than the fact they drive the four-hour rolling average higher. Peaks on a given LPAR aren’t usually the problem either, because most costs are based on the highest four-hour average usage of the month on each physical machine or central electronic complex (CEC). Of course, all LPARs contribute to this average, so any approach to controlling your peaks has to take this into account. To help control four-hour rolling averages, IBM provides a mechanism, known as soft capping, in which you can specify a limit for the four-hour rolling average. All workloads running on the CEC are affected to some degree when capping causes usage to be 8 NOVEMBER/DECEMBER 2012 ILLUSTRATION BY DANIEL BEJAR / THEISPOT.COM http://www.THEISPOT.COM

Table of Contents for the Digital Edition of IBM Systems Magazine, Mainframe Edition - November/December 2012

IBM Systems Magazine, Mainframe Edition - November/December 2012
Table of Contents
Editor's Desk: Been There, Done That
IBM Perspective: Not All Clouds Are Designed Equal
Insider: What's Really Driving Peak CPU Usage?
Focus on Storage: The DS8870 Provides up to Three Times the Performance of Its Predecessor
Case Study: A Capital Investment: DTCC implements tools to ensure its networking infrastructure is ready for anything
Cover Story: A Clear Vision for Cloud: System z GM Doug Balog on why zEnterprise provides a firm foundation for a secure cloud
Feature: Overcoming Cloud Obstacles: The benefits far outweigh the challenges associated with cloud integration
Tech Corner: From Silicon to Architecture, zEC12 Innovations Push the Envelope
Administrator: IBM zAware Extends z/OS Resilience to Another Level
Solutions: Attach Facility; DataSniff; AutoPilot; Eclipse; Correlog Enterprise Server 5.1
Advertisers Index
Stop Run: IBM Distinguished Engineer Joe Temple Reflects on His Juggling Past
Reference Point - Global Events, Education, Resources for Power Systems
Smarter Computing
2013 Mainframe Buyer's Guide Index

IBM Systems Magazine, Mainframe Edition - November/December 2012