Enabling JFR via the command line
After enabling JFR (with the -XX:+FlightRecorder option), there are two ways to control
how and when the actual recording should happen. The recording parameters can be con-
trolled when the JVM starts by using the -XX:+FlightRecorderOptions= string paramet-
er; this is most useful for reactive recordings. The string in that parameter is a list of
comma-separated name-value pairs taken from these options:
The name used to identify the recording.
Whether to start the recording initially. The default value is false ; for reactive analysis,
this should be set to true .
Name of the file containing the JFR settings (see next section).
The amount of time (e.g., 30s , 1h ) before the recording should start.
The amount of time to make the recording.
Name of the file to write the recording to.
Whether to compress (with gzip) the recording; the default is false .
Maximum time to keep recorded data in the circular buffer.
Maximum size (e.g., 1024K , 1M ) of the recording's circular buffer.