chapter five
5 Identifying resource consumption problems using profiling techniques
This chapter covers
- Evaluating resource consumption
- Identifying problems with resource consumption
- Installing and configuring a profiling tool
- Simplifying profiling techniques with AI assistance
“And for you, Frodo Baggins, I give you the light of Eärendil, our most beloved star. May it be a light to you in dark places when all other lights go out.” —Galadriel (The Fellowship of the Ring, by J.R.R. Tolkien)
This chapter introduces a profiling tool, and we’ll continue the discussion in chapter 6. A profiling tool (or profiler) may not be as powerful as the light of Eärendil, but it is definitely a source of light in dark cases when all the other lights go out. A profiler is a powerful tool that has helped me understand the root cause of an app’s strange behavior in many difficult situations. I consider learning to use a profiler a must for all developers, as it can guide you to the cause of a seemingly hopeless problem. As you’ll learn in this chapter, the profiler intercepts the executing JVM processes and offers extremely useful details, such as:
- How the app consumes resources such as the CPU and memory
- The threads in execution and their current status
- The code in execution and the resources spent by a given piece of code (e.g., the duration of each method’s execution)