How to select a JFR timeframe

Question

If I have a JFR recording, is there any tool that allows me to extract only a specific time frame from it as a separate file? Or better yet, is there a VM-style visualizer allowing me to inspect custom time frames?

Answer 1

There is the jfr disassemble [--max-size size] file command that can split a file into smaller ones. It can't extract a time frame, but you can easily write one with JDK 19, or later:

import jdk.jfr.consumer.RecordingFile;

...

public static void main(String... args) throws IOException {
  Instant start = Instant.parse(args[0]);
  Instant end = Instant.parse(args[1]);
  Path input = Path.of(args[2]);
  Path output = Path.of(args[3]);
  try (var r = new RecordingFile(input)) {
    r.write(output, e -> e.getStartTime().isAfter(start) &&
                         e.getEndTime().isBefore(end));
  }
}