Parses Java garbage collection logging and analyzes collectors, safepoint triggers, JVM version, JVM options, and OS information and reports error/warn/info level analysis and recommendations to support JVM tuning and troubleshooting for OpenJDK derivatives: (e.g. Adoptium, Azul, Microsoft, Oracle, Red Hat, etc.).

littleMock is an easy-to-install demo environment for Java performance tuning. Runs on Windows/Mac/Linux.

PerfUnit is Java Agent which helps to take control over applications bottlenecks, expensive calls, or simply control your performance SLO budget.

CyBench IntelliJ IDEA plugin for benchmarking APIs, Java code

Turn any unit or integration test into benchmark

CyBench plugin for Eclipse for benchmarking APIs, Java code

JVM Options Analyzer

A comparison of C++/Java/Scala/Go runtime speed for the Havlak algorithm, updated to run with the current versions of compilers / build tools.

This app has all java performance issue BuggyApp is an opensource chaos engineering program that can simulate various performance problems like Memory Leak, OutOfMemoryError, CPU spike, thread leak StackOverflowError, deadlock, unresponsiveness.

Donnacha on GitHub (Blogs & Posts, Lectures and Code)