# The JDK Flight Recorder File Format

DevFeed: [The JDK Flight Recorder File Format](<https://devfeed.tech/articles/the-jdk-flight-recorder-file-format-18840.md>)

Original publisher: [Read original article](<https://www.morling.dev/blog/jdk-flight-recorder-file-format/>)

Published: 2022-02-20T20:15:00Z

Content type: tutorial

Language: en

Sources: [Gunnar Morling](<https://devfeed.tech/sources/gunnar-morling.md>)

Topics: [JDK Flight Recorder](<https://devfeed.tech/topics/jdk-flight-recorder.md>), [Java](<https://devfeed.tech/topics/java.md>), [openjdk](<https://devfeed.tech/topics/openjdk.md>), [Parser](<https://devfeed.tech/topics/parser.md>)

Tags: [format](<https://devfeed.tech/tags/format.md>), [java](<https://devfeed.tech/tags/java.md>), [jdk](<https://devfeed.tech/tags/jdk.md>), [jdk-flight-recorder](<https://devfeed.tech/tags/jdk-flight-recorder.md>), [openjdk](<https://devfeed.tech/tags/openjdk.md>), [parsing](<https://devfeed.tech/tags/parsing.md>)

## AI overview

This article examines the JDK Flight Recorder file format. It explains that JFR records high-performance runtime events in recording files, notes that the format has no official specification and is an OpenJDK implementation detail, and describes investigating its structure through JDK and JDK Mission Control source code.

## Source excerpt

The JDK Flight Recorder (JFR) is one of Java's secret weapons; deeply integrated into the Hotspot VM, it's a high-performance event collection framework, which lets you collect metrics on runtime aspects like object allocation and garbage collection, class loading, file and network I/O, and lock contention, do method profiling, and much more. JFR data is persisted in recording files (since Java 14, also "realtime" event streaming is supported), which can be loaded for analysis into tools like JDK Mission Control (JMC), or the jfr utility coming with OpenJDK itself.