ROS2 Custom QoS

[yoelbassin]

Hey!
My robotic system works in a lossy wi-fi environment where we must use our custom QoS profiles for controlled throughput and reliability. We want to use foxglove, or at least the foxglove bridge, but this is a really big issue for us. I will be happy to create needed pull requests for supporting this matter, but wanted to hear the community and the devs thoughts :)

[achim-k]

When subscribing, Foxglove bridge tries to choose a QoS that matches the available publishers, similar to how ros2 topic echo does it. If your publishers use your custom QoS profile, then this might just work. Or is there anything special about your QoS profile that causes issues?

[yoelbassin]

Or maybe there are no publishers and you would like to specify the default publishing QoS profile?

Yes that's exactly the issue! What do you think can be done in that case?

[achim-k]

I guess the easiest would be to create a simple script with a simple ROS node and publishers with the QoS profile that you want. The script does nothing else than instantiating the publishers and spinning, no messages are published. This should allow foxglove bridge to pick up the desired QoS profile for publishing.

Alternatively, feel free to submit a PR to the foxglove bridge repo which adds fallback QoS parameters for publishing.

[defunctzombie]

Or maybe there are no publishers and you would like to specify the default publishing QoS profile?

@achim-k That logic is for advertising from the bridge - when subscribing to messages the bridge would still use the QoS of the publisher does it not? So for the above request of working with lossy networks it still seems like the ROS publisher side should have its QoS updated?

[achim-k]

Not sure if I understand correctly, but the request is about advertising from the bridge and not for subscribing topics.

[defunctzombie]

👍 I missed that part of the clarification in the thread (the original post did not specify this was about publishing behavior from the bridge or app).