Isaac ROS Mega Node Monitor

Overview

The Isaac ROS Mega Node Monitor provides a ROS 2 service to monitor the status of both regular and lifecycle nodes. It is particularly useful for:

• Verifying navigation stack components are running
• Checking system health
• Debugging node startup issues

Usage

1. Launch with Navigation Stack

The monitor is automatically launched with the navigation stack:

ros2 launch nova_carter_bringup navigation_in_mega.launch.py mode:=mega enable_navigation:=true enable_3d_lidar_costmap:=true enable_2d_lidar_costmap:=true enable_nvblox_costmap:=false

2. Check Node Status

Call the service to check node status:

ros2 service call /check_nodes_alive std_srvs/srv/Trigger

Response Format

The service returns a JSON-formatted response with two fields:

1. success (boolean):
   • true if all monitored nodes are alive and active
   • false if any nodes are dead or inactive
2. message (JSON string):

   {
     "status": "healthy",  // or "unhealthy"
     "dead_nodes": [],  // list of nodes that are not running
     "inactive_lifecycle_nodes": [],  // list of lifecycle nodes not in active state
     "alive_nodes": []  // list of healthy nodes
   }
   

Example responses:

success: False
message: {
  "status": "unhealthy",
  "dead_nodes": [
    "front_3d_lidar/flatscan_to_laserscan",
    "front_3d_lidar/pointcloud_to_flatscan",
    "global_costmap/global_costmap",
    "local_costmap/local_costmap"
  ],
  "inactive_lifecycle_nodes": [
    "behavior_server",
    "bt_navigator",
    "controller_server",
    "planner_server",
    "smoother_server",
    "velocity_smoother",
    "waypoint_follower"
  ],
  "alive_nodes": [
    "navigation_container",
    "nova_container"
  ]
}

Configuration

The nodes to monitor are configured in: config/node_monitor_config.yaml

mega_node_monitor_service:
  ros__parameters:
    # Regular nodes to monitor
    monitored_nodes:
      - "front_3d_lidar/flatscan_to_laserscan"
      - "front_3d_lidar/pointcloud_to_flatscan"
      - "navigation_container"
      - "nova_container"

    # Lifecycle nodes to monitor
    monitored_lifecycle_nodes:
      - "behavior_server"
      - "bt_navigator"
      - "controller_server"
      - "planner_server"
      - "smoother_server"