[Diagnostics] - A non active controller should not be reported as error

[firesurfer]

Describe the bug

Currently controllers that are loaded but are deactivated are reported as errors via ROS diagnostics.

I think this should be a warning. In my system for example I regularly switch controllers (e.g. from a compliant controller to the jtc and back). The other controller being inactive is desired behavior in that case and should not be reported as an error.

To Reproduce

Load a controller and deactivate it

Expected behavior

Report nothing or just a warning via ROS diagnostics

Environment (please complete the following information):

• OS: Ubuntu 22.04
• Version iron

[saikishor]

Hello @firesurfer!

Yes, it makes sense that it shouldn't be reported as an error if the controllers are loaded but are deactivated. Feel free to open a PR fixing this part of the code:

ros2_control/controller_manager/src/controller_manager.cpp

Lines 2539 to 2563 in 65353ff

	void ControllerManager::controller_activity_diagnostic_callback(
	diagnostic_updater::DiagnosticStatusWrapper & stat)
	{
	// lock controllers
	std::lock_guard<std::recursive_mutex> guard(rt_controllers_wrapper_.controllers_lock_);
	const std::vector<ControllerSpec> & controllers = rt_controllers_wrapper_.get_updated_list(guard);
	bool all_active = true;
	for (size_t i = 0; i < controllers.size(); ++i)
	{
	if (!is_controller_active(controllers[i].c))
	{
	all_active = false;
	}
	stat.add(controllers[i].info.name, controllers[i].c->get_state().label());
	}
	if (all_active)
	{
	stat.summary(diagnostic_msgs::msg::DiagnosticStatus::OK, "All controllers are active");
	}
	else
	{
	stat.summary(diagnostic_msgs::msg::DiagnosticStatus::ERROR, "Not all controllers are active");
	}
	}

.

I would say it would be an OK state to be in the inactive state, if you are interested, you can also log the information of the controller stats like their update_rate and if they are async or not etc.

Thank you

[firesurfer]

@saikishor I created a PR which just makes the switch from Error to Warn. Not sure if there is any other error information to report about controller (such as ros2 control could not active the controller)

[christophfroehlich]

Is this fixed with #1184?

[saikishor]

@christophfroehlich yes it should be fixed. Now it won't report it as an error