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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
recent informations.
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
load.
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
your network.
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
O(N**2).
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
provides.
- The uptime of the system.
- The load average.
- The current load - split by user, nice, system and idle
times.
- The memory usage of the RAM and the swap space.
- The network traffic send and received by the network
card.
- Informations of the TOP-5 processes.
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