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Last update: June 23, 2021

Java Flight Recorder

Java Flight Recorder (JFR) is a monitoring tool that collects information about the Java Virtual Machine (JVM) when Hyperledger Besu is running. Use the JFR as a tool to analyze Besu performance.

Enabling Java Flight Recorder

To enable JFR, set BESU_OPTS to the JFR tags as follows:

export BESU_OPTS=-XX:StartFlightRecording=disk=true,delay=15s,dumponexit=true,\


When recording, cleanly exiting Besu results in better data. If not possible to cleanly exit, the file may be missing some information not flushed to disk.

Inspect the file written to /tmp/recording.jfr with tools such as Mission Control.


If providing the output file to ConsenSys Quorum support, be aware that while JFR files don’t contain secrets such as private keys, some details about the user configuration can be inferred from the JFR output.

Questions or feedback? You can discuss issues and obtain free support on Hyperledger Besu chat channel.
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