عرض عملي: إيجاد نقطة الاختناق في نقطة نهاية بطيئة باستخدام JFR

خطوة بخطوة

1. Reproduce: /orders/report has p95 of 900 ms under load.
2. Record 2 minutes with JFR (profile settings) during the load test.
3. In JMC, Method Profiling and flame graph: find the dominant frame (a regex compiled on every call).
4. Hypothesis: precompile the pattern. Change only that.
5. Planned mistake: "optimize" a different method that looked suspicious in code review. Show it was 1% of samples. Fix: follow the profile.
6. Re-measure under the same load; p95 drops; record before/after in the log.