Any action you take that reduces the peak, even if it involves just one component of that peak, will reduce all workload-based systems software charges that run during the peak. For example, if your peak four-hour rolling average is 1,000 MSUs and you can move 100 MSUs out of the peak period, you can save on every piece of workload-based systems software running on that machine.
The Role of Management Software
Capacity management software can give you a historical view of your utilization on a particular physical machine. If you wish to lower your peak by deferring, moving or consolidating workloads, then capacity management software will show you the effect on the workload response time and performance of those applications. Database maintenance on databases supporting business workloads generally runs during non-peak times. However, one large retailer looked at a usage report and saw that a particular machine actually peaked at 4 a.m. due to substantial batch database maintenance work. That’s the peak this retailer was paying for. In this case, more efficient DB2 management solutions could have saved money for that particular machine.
For almost every user, monitors consume more resources during peak processing. More is going on, so there are more activities to monitor. That means more efficient monitoring can also reduce the peak.
Both CICS and DB2 tend to have more processing intervals during peak processing periods. So, in general, anything you do to make CICS and DB2 more efficient around the clock makes them more efficient in peak periods. Even small efficiency gains across these various areas can add up to hundreds of thousands of dollars in savings each month.
Capping: Pro and Con
Many customers set a cap on peak usage as a cost-control measure. For example, if you decide you don’t want to pay for more than 1,000 MSUs, you can set a cap and the processor won’t let your system run above that level.
The drawback is obvious. If you set the cap too low, the systems will slow performance and you run the risk of hampering your revenue-generating potential. Business-critical online processing always gets the highest priority, so you set weighting factors for those online processes higher than for less critical processes and batch. There’s a point where you’re going to start constraining business if you exceed your cap.
If you can see a performance problem ahead, you can prevent it by raising the cap. However, you must do that before you exceed the cap, because the system will immediately start downward throttling performance, including the performance of business-critical services. This is another place where management software can help you. If your management software can monitor the rolling four-hour average utilization in real-time on specific machines, it can send you an alarm before you reach your cap.
There’s a growing challenge in managing the cap in this way: How will you recognize the patterns that indicate you will be exceeding your cap? In the old days of stable processing with known usage patterns, this was easier. In the modern environment of mobile-enabled business applications, those patterns are dynamic, driven by customer behaviors that change significantly and continuously. You will need to rely on systems management technology to automatically learn about the changing patterns and determine what constitutes the correct threshold for raising the alert.
Of course, software that’s efficient and intelligent is especially helpful in lowering IT-related costs. For example, efficient system monitoring software uses fewer resources, and efficient database utilities use less CPU time. Effective management software can help you more aggressively offload software to specialty processors, such as the System z Integrated Information Processor (zIIP), whenever appropriate.
Intelligent, “advisor-like” software can help you lower costs by determining whether you even have to do maintenance on parts of the system. For example, many customers routinely reorganize hundreds of databases every weekend, whether or not it’s necessary. Using good management software, you can determine that, say, only 20 databases need to be reorganized this weekend. The most efficient way of processing is not to process at all.