[Beowulf] Differenz between a Grid and a Cluster???

[leduc at lri.fr]

> Hello,
>
> i really need your help to this question. What is the differenz between a
> Grid (or Grid Computing) and a Cluster?

My definition: a cluster is an homogeneus set of nodes, while a grid is an
heterogeneus set of clusters.

By homogeneus, it depends on your interest, if you indend to do
computation, it is related to administrative domains or the high bandwidth
network habilities of a set of computers...

Defining a grid depends on your point of view: if you have a cluster with
2 switches, if you make computations that are not networking intensive,
you can see it as a cluster: a complete set of nodes you can use without
caring of the network topology. But if your needs are network driven, you
can split this physical cluster into 2 sub sets of nodes, and use it at
another level on the application side, it means that you use a cluster as
you would use a grid, adding a tree dimension: it is not flat anymore.

That is why it is often confusing, depending on an application, a grid can
be seen as a flat cluster: java parametric applications are well known for
this.


> There is very much literature in the net but mostly it is quite different
> among each other.

Grids are very young and, to what I see in the HPC world, most of the
time, it is only a trendy word for saying flat big cluster.
A cluster can be huge, but it does not implies that it becomes a grid with
a certain amount of nodes...

> What are the main points for Grid and Cluster?

Cluster=easy (up to 200 nodes, tricky at 500), Grids mean intricated
problems and increased complexity.


Julien Leduc