The Python module hostlist.py knows how to expand and collect LLNL hostlists, as used by SLURM, pdsh, powerman, and genders, among other projects.
The nodes utility builds upon the python-hostlist module and allows you to define node groups in /etc/nodes.conf. The node groups can then be used to answer question about nodes and groups.
The coping utility wraps fping to ping several destinations continuosly (approximately once per second) and report on up and down events.