Identifying Indicators of Performance Issues

So far, you have an understanding of what performance is. You also know which system bottlenecks lead to performance issues and how they do so. Now, we're ready to talk about how to identify these problems. 

Different implementations of the same functionality can impact the performance of the whole application in different ways. It's hard to make the right choice between several approaches if you're guided by your assumptions. Therefore, we should measure performance but not make our choice based on a guess.

Measurement is a significant part of everyday management and technical activities. It's important because measurement gives us the numbers—the objective information—that we need to make informed decisions that improve performance. From the developer's point of view, performance measurement is the process of collecting, analyzing, and reporting information about the performance of an application. This is a vast topic, but a software engineer should know how to detect and recognize performance issues during the testing and post-release stages. That's why we'll touch on the topics most related to developers.

In this chapter, we'll cover the following topics:

• Benchmarking
• General performance metrics