11 Analyzing potential JVM issues with GC logs
This chapter covers
- Enabling and accessing Garbage Collector (GC) logs
- Understanding the GC logs structure and content
- Using GC logs to identify issue root causes
- Analyzing large volume GC logs with AI assistance
Let’s embark on a journey into the often misunderstood yet indispensable world of Garbage Collection (GC) logs. If you’ve ever stared at a stream of cryptic JVM output and thought, “This looks like the Matrix, but with less Keanu and more confusion,” you’re not alone. Fear not, for by the end of this chapter, GC logs will transform from chaotic hieroglyphics into an invaluable troubleshooting ally.
But before we dive in, let me set the stage with a little story—a cautionary tale of what happens when GC logs are ignored.
Alex is a senior developer at an e-commerce startup, known for their love of coffee, code, and, unfortunately, cutting corners. One fateful Friday afternoon, Alex deployed a major update to the production environment—an update heralded as the solution to all scalability woes. But as the weekend wore on, the reality was anything but celebratory.
By Sunday morning, the site was slower than a dial-up modem from the '90s. The server logs painted a picture of doom: memory spikes, sluggish response times, and CPU usage hovering at 99%. The worst part? The system was spawning threads faster than it could clean them up, leading to what Alex dubbed "zombie threads."