sloretz / ros-world-2021-demo

Demo for ROS World 2021 talk: Tracing ROS 2 with ros2_tracing

ros-world-2021-demo

Demo for ROS World 2021 talk: Tracing ROS 2 with ros2_tracing (video, slides).

Demo

In the demo, we trace a ping node and a pong node. See launch file. The nodes exchange N messages (ping then pong) every M milliseconds T times, and then exit. The ping node publishes its pings on the /ping topic and the pong node publishes its pongs on the /pong topic, with each node subscribing to the other's messages. We trace the nodes and analyze the trace data using a Jupyter notebook to show timer & subscription callbacks, publications, and timer & subscriptions & publisher creations over time.

Instructions

1. Setup system to build ROS 2 Rolling and trace
   • https://docs.ros.org/en/rolling/Installation/Ubuntu-Development-Setup.html
   • https://gitlab.com/ros-tracing/ros2_tracing
2. Clone tracetools_analysis and this repo, and install dependencies

   cd ws/src
   git clone https://gitlab.com/ros-tracing/tracetools_analysis.git
   git clone https://github.com/christophebedard/ros-world-2021-demo.git
   cd ..
   pip3 install notebook bokeh

3. Build

   colcon build --packages-up-to ros_world_2021_demo

4. Source and launch

   source install/setup.bash
   ros2 launch ros_world_2021_demo demo.launch.py

   • it should exit by itself
   • alternatively, instead of executing the launch file, use the sample trace by extracting the contents of trace.zip into your ~/.ros/tracing/ directory
5. Analyze

   pip3 install notebook bokeh
   jupyter notebook src/ros-world-2021-demo/ros_world_2021_demo/analysis/demo.ipynb

   • run the whole notebook

Results

Overall results:

Single ping-pong sequence: