h. Common Errors

MongoDB

The MongoDB packages (rosplan_scene_database, and rosplan_scene_message_store nodes) are used to store and retrieve real data. For instance, pose data is stored in MongoDB and retrieved by the MoveBase interface component. For more information about MongoDB, please visit: ROS MongoDB Tutorial.

Common MongoDB Errors

The user needs to stop the MongoDB service running in the background by default. If you run the simulation without killing the default MongoDB service, the rosplan_scene_database node will die.
To stop default MongoDB service: sudo service mongodb stop.
To prevent MongoDB from starting by default: sudo update-rc.d -f mongodb remove.

When MongoDB is not shutdown properly, it may fail to start. You will see a “Unclean shutdown detected” error. In this case, you need to delete the MongoDB lock file: "rosplan_knowledge_base/common/mongodb.lock" to clean up database. For more information, please visit: MongoDB Repair Homepage

On some systems there is an error MongoDB creating huge files. This can be fixed by switching off journaling. To disable this option, you must edit (Hydro) "/opt/ros/hydro/lib/mongodb_store/mongodb_server.py" to change the line:
cmd = ["mongod","--dbpath",self._db_path,"--port",str(self._mongo_port)]
adding the argument
cmd = ["mongod","--dbpath",self._db_path,"--port",str(self._mongo_port), "--nojournal"]