Recording a Running Application
Table of Contents
Thanks to JFR and jcmd, you can make a recording to file from a running application if you have terminal access to the environment where the application is running.
Starting a Recording
Start a recording for a running application on the same host and userid as the Java process under analysis, by running the following command:
$ jcmd JVMID JFR.start filename=rec.jfr
Where JVMID is either the process ID or the classname assigned with the java process as shown when running jcmd without parameters.
Stopping a Recording
Use the JFR.stop command to stop a JFR recording, either by its name or ID. If no name or ID is specified, the first recording which is found, is stopped.
$ jcmd JVMID JFR.stop name=1
Modifying a Recording
Change the settings of a running JFR recording with the JFR.config command:
jcmd <PID> JFR.config filename=new_file.jfr
Options
See JFR Command Line Options for a complete overview of the available options.