Java Flight Recorder (JFR)
Use JFR for deep JVM/runtime analysis with low overhead.
Start recordings with jcmd
jcmd <pid> JFR.start duration=60s filename=/data/recording1.jfr
jcmd <pid> JFR.start duration=300s filename=/data/recording2.jfr settings=profile
When to use
- Intermittent latency spikes.
- GC pauses not explained by basic metrics.
- CPU hotspots and lock contention.
Recommended practice
- Capture short focused recordings under realistic load.
- Correlate recording window with query/system telemetry from
sys.jobs*andsys.operations*.