Friday, June 6, 2008

Building Application Management into Your Capacity Plan

One of the most common questions that I get asked when showing Oracle Enterprise Manager to customers is the amount of processing overhead the tool introduces to the environment. It is a valid concern. After all, you don't want a management tool that is supposed to help prevent performance problems to introduce new performance problems of its own. However, treating management as purely “overhead” may not be a productive way to think about the problem either.

First, let me state that it does take resource to run management tools. It takes CPU cycles, memory, disk space and I/O bandwidth to collect and process information about the health of an application environment. Since all these resources cost money, it means that it costs money to use management tools. But costs isn't the problem. It is whether you recuperate the costs through the benefits that the tools deliver. In other words, it is about return on investment.

What would be the alternative of not incurring the management costs? You would have to try managing the systems manually with no data. You would have to sit in front of the terminal yourself to watch everything to make sure things are working. If something breaks, you would have to take many guesses to try to fix the problems, which would probably take you much longer, forcing you to stay longer at work and missing other important things in life. Meanwhile, your application's availability goes down, your end users productivity are impacted, and your organization might even lose business because of that. Would you rather incur these costs over the 5% or even 10% of CPU cycles that you dedicate to running your shop properly?

So as you do capacity planning for deploying or upgrading an application, build in a capacity budget for management as well. You'll be glad you did.