Microsoft launched a new blog called “The Power of Software.” This looks like a site you should add to your rss feeds. I am.
Welcome to The Power of Software blog, a new undertaking by the patterns & practices team. As you may know, our traditional focus has been on building guidance that helps software architects and developers successfully design and build applications.
This blog is a slight departure from that. We’re exploring ideas relating to Green IT and the ways we, as a company, can use energy more efficiently. Some currently planned subjects include ways to save energy through the use of software and ways to optimize datacenters. All posts will be written or reviewed by subject matter experts, just like other patterns & practices projects.
We hope this starts a dialog with the community—please let us know the topics that interest you.
The first entry is by Christian Belady and Mike Manos on Microsoft’s experience using PUE in their data centers.
Microsoft’s PUE Experience—Years of Experience, Reams of Data
This short series of articles describes how Microsoft uses Power Usage Effectiveness (PUE), an industry standard metric for the efficiency of a datacenter. Being able to measure and monitor the effective power consumption of a datacenter in terms of the computing power it contains provides a way to ensure that you make best use of resources while minimizing your environmental footprint. This first article introduces PUE and looks at the issues that it can help you to resolve.
Part 1—"What Color is your Datacenter?"
Imagine if a child were to draw a picture of your datacenter. Does it look green, or is it a glowing orange or even as black as night? Look at the individual pieces of equipment in your datacenter—are any of them green?
If you want the picture of your datacenter to look greener (more energy efficient), you could try upgrading items to more energy-efficient equivalents, as if they were pieces of a puzzle that can simply be replaced. This upgrade method is what many companies are using as a way to convince themselves that they are reducing energy costs. The problem is that, unless you look at the big picture and understand how the pieces fit together, you could end up being disappointed with the outcome.
Figure 1 shows an example of how the painter Seurat demonstrated a scientific approach to painting called pointillism, where the artist uses combination of color dots to create an image that is harmonious and effective, while minimizing the number of colors used. This approach is analogous to management telling their datacenter team, “I want a good looking picture where everything works together and uses as few resources as possible.”
A simple idea needs a simple metric to work. In Seurat's paintings, it is a visual test. For a datacenter, it is an efficiency value—"Tell me what the energy overhead is to run the IT equipment". Microsoft has been using this approach as long as anyone can remember, and when industry groups like The Green Grid started promoting a metric for datacenter efficiency, Microsoft was an early supporter and contributor to the standard as they had years of experience with their own datacenter efficiency metrics.