How do you monitor your robot diagnostics (topic rates)?

[christophebedard]

@jak

The ros2_tracing package on paper looks like a suitable approach. However, I didn’t manage to get it even running on Humble by following the documentation and tutorials. The documentation has room for improvement and the ROS 2 tutorial page seems to have some errors in the guide.

Please open an issue and mention what doesn’t work for you or what you think needs improvement, otherwise we don’t know about it and can’t improve whatever doesn’t work!

@jak

In Humble, the package also requires a huge number of dependencies to be built from the source.

Starting from Iron, tracing instrumentation is included by default on Linux, so it’s much easier to use. If something doesn’t work for you with Humble, please open an issue.

@jak

I got it running on Jazzy, but even after looking a lot through the documentation and examples, I couldn’t find if it supports live monitoring. In all the examples I found, the data is always logged on the disk and then analyzed afterwards offline.

Indeed, it was mainly built for offline processing (for example, see the tool I mentioned in this recent comment). However, live trace data processing is possible using a live tracing session, although you currently have to enable it directly using the lttng CLI since it’s not exposed through ros2 trace or the Trace launch action yet. I just opened an issue for it: Allow creating a live tracing session with `ros2 trace`/`Trace` · Issue #149 · ros2/ros2_tracing · GitHub.

I actually talked to @emersonknapp after ROSCon about this and shared a simple starter script to do live trace data processing. I included it in the issue above. This will require you to implement your own (live) trace data analysis in Python, but, depending on your use-case, it might be simpler than you think. I believe it could be quite powerful. If you’d like to go down this road, let me know and I can try to help you.