def get_logging_nodes(service_list): 
    """
    Returns a list of all nodes which offer a logging_cmd service.
    """
    logging_srv_list = [srv for srv in service_list if 'logging_cmd' in srv.split('/')]
    logging_node_list = ['/'.join(srv.split('/')[:3]) for srv in logging_srv_list]
    return logging_node_list