عرض عملي: اكتشاف تسرّب بلقطتين للـ Heap

خطوة بخطوة

1. Start Shop with GC logging and the planted cache; run steady load.
2. Confirm in the log that the post-GC floor keeps rising.
3. Take dump A (jcmd <pid> GC.heap_dump a.hprof), run load a few more minutes, take dump B.
4. Open both in Eclipse MAT or VisualVM; compare histograms and find the class with growing instance count.
5. Planned mistake: raise -Xmx first and declare it fixed because the crash is later. Fix: follow the path to GC roots (dominator tree, "path to GC roots") to the static map.
6. Bound the cache (size limit/eviction), rerun, and show a flat floor.