Building Green Software

Chapter 9. Measurement

An experiment is a question which science poses to Nature and a measurement is the recording of Nature’s answer.

Max Planck

Metrics, measurements, or monitoring—whatever you choose to call it, software practitioners like numbers and charts that indicate our progress. Perhaps this is due to the intangible nature of our field? Or maybe all types of professionals who dedicate their time to building things are just as obsessed with measurements. Whatever the reason, here are some very commonly asked questions when talking about green software: How can I measure it? How do I know my impact? Which part of my software has the biggest impact? In this chapter, we will dive deeper into these questions and offer you some options for how to answer them.

In a perfect world, every item would have a neat carbon price attached to it, clearly showing the climate impact of each action we took or each product we purchased. That way we could always make informed choices with regard to climate. But as you have noticed in shops, that is not the case today. However, in this chapter, we will go through what “as close to perfect as you can get” would mean for software. Because we are opinionated people, we will also tell you what we would like to see the industry move toward: the real-time monitoring of carbon emissions. And for good measure, we will also tell you what the “good enough” measures are and when and how you can use them.

As with most things, we are of course not the ...