Part 3: Diagnosing memory-related issues

In the previous part, we looked at problems tied to CPU and execution flow. But another major source of trouble lies in how an application uses memory. Memory issues can creep in slowly. They cause the app to slow down, pause unpredictably, or even crash. And they can appear suddenly in high-load scenarios.

This part is all about spotting these memory-related problems. We’ll start by profiling the heap to see which parts of the code are allocating objects and in what quantities. Then we’ll move on to heap dumps, which are snapshots of everything in memory. We’ll use them to find leaks, unexpected object retention, or bloated data structures. Finally, we’ll look at garbage collection logs to understand how the JVM is reclaiming memory, and how tuning or fixing code can help reduce GC pauses and improve stability.

By the end of this part, you’ll know how to measure memory usage, uncover leaks, and interpret JVM behavior so you can keep your application running smoothly.