Too Many Open Files in Java: File Descriptor Leaks Fixed
java.io.IOException: Too many open files means you hit the descriptor limit. How to count FDs, find the leak with /proc and lsof, and set limits that hold.
troubleshooting
3 PostsFinding Java Memory Leaks with Heap Dumps, Step by Step
Heap keeps climbing after every full GC? How to confirm a Java memory leak, take the right heap dumps, compare them, and walk from the leak back to the code.
Java OutOfMemoryError: Every Message and What It Means
Java heap space, Metaspace, GC overhead, direct buffer, native thread: every OutOfMemoryError message, the memory area behind it, and where to look first.