beostat_get_net_rate will get the current network usage rate in bytes per second across all interfaces on that node.
printf ("Node 3 is currently transfering %d bytes / second.\n", beostat_get_net_rate (3));
This function can give erroneous results for its transfer counts during the moment of rollover of each interface.
Returns an unsigned long, which represents the network transfer rate. If an error occurs, it will return -1.0.
This function relies on the Beostat subsystem, which consists of the proc filesystem on the remote node, the sendstatsdaemon on the remote node, the recvstats daemon on the master node, and two shared memory files in the directory /var/shm. If any part of the system breaks down, this function could fail.