Java Flight Recorder - find file descriptor leak

Question

M Java application probably has a file descriptor leak, since I'm getting a Too many open files exception.

I'm running my application with JFR, and when I inspect File I/OI barely see any I/O count. Is it possible to use JFR for finding code which open files but not closes them?

Answer 1

No, JFR can't track file handles.

You can change the threshold of the File Read and File Write event to 0 ns, so you will see every read and write, but there will be a lot of events. Not sure if it will help though.

You can change the threshold in the Recording Wizard, or Window -> Template Manager if you don't start the recording from JMC.