Tutorial about computer clusters

R. Ballisti

What are clusters?

(From http://www.linuxnetworx.com/Linux NetworX

Clustering is a method of connecting multiple computers (called nodes) together to form one large system dedicated to a particular task or series of tasks.

How they work?

Clusters are comparable to massive parallel processing (MPP) machines.
Because the cluster's processor, disk, power and memory systems are distributed among the various nodes, if one happens to fail, the other nodes immediately divide up the work of the failed node.

we have to distinguish between two kind of clusters:
computational OR high availability systems.

In our laboratory we are interested on the former one:
Computational clusters are designed to do the complex computational calculations of supercompuetrs. A quality high speed netwrok is an important feature of computational clusters. The high speed network allows nodes to communicate quickly and finish calculations in less time.