Write your own Java Profiler in 240 lines of pure Java By Johannes Bechberger

Profilers help to analyze performance bottlenecks of your application if you know how to use them. To get to grips with profilers, it helps to understand how they work: Profilers aren't rocket science. A usable Java profiler can be written in 240 lines of pure Java code, helping you to fix performance issues and add custom features fast. This talk will give the fundamentals of Java profiling and how Java profilers typically work, followed by a detailed explanation of how to develop a functioning profiler in a few lines of Java code. This talk will also explain how you can use it in production to analyze performance issues and show briefly how to work with a widely used open-source profiler that is based on the same principles. JOHANNES BECHBERGER Johannes Bechberger is a JVM developer working on profilers and their underlying technology in the SapMachine team at SAP. This includes improvements to async-profiler and its ecosystem, a website to view the different JFR event types, and improvements to the FirefoxProfiler, making it usable in the Java world. He started at SAP in 2022 after two years of research studies at the KIT in Java security analyses. His work today comprises many open-source contributions and his blog, where he writes regularly on in-depth profiling and debugging topics and works on his JEP Candidate 435 to add a new profiling API to the OpenJDK.