161-java-profiling-detect

# Java Profiling Workflow / Step 1 / Collect data to measure potential issues Set up the Java profiling detection phase: automated environment setup with async-profiler v4.0, problem-driven interactive profiling scripts, and comprehensive data collection for CPU hotspots, memory leaks, lock contention, GC issues, and I/O bottlenecks. Uses JEP 518 (Cooperative Sampling) and JEP 520 (Method Timing) for reduced overhead. **What is covered in this Skill?** - Run application with profiling JVM flags (run-java-process-for-profiling.sh) - Interactive profiling script (profiler/scripts/profile-java-process.sh) — copy exact template - Directory structure: profiler/scripts/, profiler/results/, profiler/current/ - Automated OS/architecture detection and async-profiler download - CPU, memory, lock, GC, I/O profiling modes - Flamegraph and JFR output with timestamped results **Scope:** Use the exact bash script templates without modification or interpretation. ## Constraints Copy bash scripts exactly from templates. Ensure JVM flags are applied for profiling compatibility. Verify Java processes are running before attaching profiler. - **CRITICAL**: Copy the bash script templates exactly — do not modify, interpret, or enhance - **SETUP**: Create profiler directory structure: profiler/scripts, profiler/results - **EXECUTABLE**: Make scripts executable with chmod +x - **BEFORE APPLYING**: Read the reference for exact script templates and setup instructions ## When to use this skill - Review Java code for profiling - Add profiling support ## Reference For detailed guidance, examples, and constraints, see [references/161-java-profiling-detect.md](references/161-java-profiling-detect.md).