The node 'lifecycle_manager' should be added to the LaunchDescription before the nodes that are managed by the 'lifecycle_manager.'

[bluebird]

The node ‘lifecycle_manager’ should be added to the LaunchDescription before the nodes that are managed by the ‘lifecycle_manager.’ If we add the sub-nodes first, they will run before the manager can manage them.
The figure in lecture:

The official example:
https://github.com/ros-planning/navigation2_tutorials/blob/master/nav2_costmap_filters_demo/launch/costmap_filter_info.launch.py

[rtellez]

Well actually it doesn’t matter, because the node start in un-configured state, so they will do nothing, waiting there for a lifecycle manager to make them change state.