The various node daemon modules are described below
The TCP listener listens to a port for tcp connections. You need this daemon if your scheduler is configured to send commands over TCP. NOTE: you also currently need this even if you're using multicast for stopping the node daemon. This module has its own thread to run inside.
The UDP/multicast listener listens to a port for multicast connections. You need this daemon if your scheduler is configured to send commands over multicast. This module has its own thread to run inside.
The
Node Updater module sends a node status update each time the
main loop invokes it. You could subclass it to return your own
additional status updates. In addition this class is default
configured to execute the checknode.sh script to make sure
the node is OK. If this script returns a nonzero exit status
the updater marks the node as being Down.