FlightMemory
A java flight recording helper
Helper class for production profiling using java flight recorder (JFR)
FlightMemory.recordingAsZip(Duration.ofSeconds(10));
Returns a CompletableFuture<InputStream>
to a zipfile which contains:
- profile-XXX.jfr
- A java flight recorder file, open in jdk mission control (JMC)
- stacks-XXX.folded
- A folded stacktrace file, can be visualized with Flame graph tools like Brendan Greggs flame graph tools
- _coroutinesDump.txt
- A kotlin coroutines dump. Debug probes must be installed beforehand (at start), with
DebugProbes.install()
available in . If debug probes are not installed the file is empty.
- A kotlin coroutines dump. Debug probes must be installed beforehand (at start), with
Requires the app to run in a JVM with flight recorder classes available (jdk.jfr package), for example java8u262 or higher (jdk not jre) or java11
Depend on it in gradle or maven
repositories {
...
maven { url 'https://jitpack.io' }
}
implementation 'com.github.rrva:flightmemory:0.1.0'
Example usage in a spring boot application:
Here we do a ten second profiling, so we record and return the recording synchronously. For long recordings you might get a HTTP timeout so it might be better to return immediately with a link where the finished recording can be fetched.
Java usage:
import org.springframework.core.io.InputStreamResource;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import io.github.rrva.flightmemory.FlightMemory;
import java.time.LocalDateTime;
import java.time.Duration;
import java.util.concurrent.ExecutionException;
@RestController
public class FlightRecordingController {
@GetMapping("/profile.jfr.zip")
public ResponseEntity<InputStreamResource> flightRecorder() throws ExecutionException, InterruptedException {
LocalDateTime now = LocalDateTime.now();
InputStreamResource inputStreamResource =
new InputStreamResource(FlightMemory.recordingAsZip(Duration.ofSeconds(10)).get());
HttpHeaders httpHeaders = new HttpHeaders();
httpHeaders.setContentType(MediaType.APPLICATION_OCTET_STREAM);
httpHeaders.set("Content-Disposition", "attachment; filename=index-profile-"+now+".zip");
return new ResponseEntity<InputStreamResource>(inputStreamResource, httpHeaders, HttpStatus.OK);
}
}