Symptom-first runtime diagnostics for JVM applications using JDK tools: jcmd, jstack, jmap, jstat, JFR, GC logs, async-profiler, Native Memory Tracking, and Eclipse MAT. Use when a Java app has high CPU, memory leaks or OutOfMemoryError, slow startup, deadlocks or thread starvation, long GC pauses, native memory growth, or slow requests. Includes permission tiers for safe use.
