|shematic information flow of sinfo
The sinfo-system is split into two parts. A demon and a user program.
1.) The demon (sinfod) distributes system information using UDP
broadcasts on the local network. Each demon will also receive UDP
broadcasts of all other demons and manage a list of the most
2.) The user program (sinfo) connects to the demon via the local
loop-back interface and displays the up to date informations
using the ncurses library.
This scheme has the advantage that it produces minimal network
If each node broadcasts it's information in a cooperative
manner, the network load is O(N), where N is the number of nodes in
Other systems to monitor your cluster load (e.g. rup(1) ) are
using a polling scheme where every node has to ask every other node
for the system information: In that case the network load is
The Informations broadcasted include:
- The number of CPUs and their speed.
- The network node hostname, the hardware type, the host
processor type, the operating system name, the operating system
release, the operating system version. - Everything uname
- The uptime of the system.
- The load average.
- The current load - split by user, nice, system and idle
- The memory usage of the RAM and the swap space.
- The network traffic send and received by the network
- Informations of the TOP-5 processes.