RRD4J inspector: How to use it

Hi folks,

during my upgrade process from OH 2 to OH 3 (great improvement!) I am struggeling with the rrd4j persistence. Therefore I wanted to look inside the newly created rrd4j data files. If you are using docker container (recommended…), these files are located here: …/openhab/userdata/persistence/rrd4j/.

There are some post in this forum about the usage of the inspector, but they are incomplete. So go to this site: https://repo1.maven.org/maven2/org/rrd4j/rrd4j/3.3.1/ and download these TWO files:

  • rrd4j-3.3.1-inspector.jar AND
  • rrd4j-3.3.1.jar

Put both files into the same directory. Use a CLI and change into this directory. Start the inspector with
java -cp rrd4j-3.3.1-inspector.jar org.rrd4j.inspector.RrdInspector
Select a rrd4j file for inspection. If you get an error like Exception in thread “main” java.lang.NoClassDefFoundError: org/rrd4j/core/RrdDb, then you are missing the 2nd .jar-file from above!

This should clarify the usage of the rrd4j inspector. Don’t use later versions of the inspector, the required class is not there anymore… Additionally the inspector requires a graphical interface (Windows-PC is fine) and does not work on headless systems.

Have fun!


Thanks for this input.
It used to work with the single (-inspector) jar file. However now you do need both.
Did my test with the 3.4 Version.