B Cluster Interconnect Topology; Fat Tree Topology - HP Cluster Platform Introduction v2010 Introduction Manual

B Cluster Interconnect Topology

Methods of connecting individual servers into clusters are referred to as cluster topologies. The
HP Cluster Platform uses a fat tree topology. This topology is represented by a network tree
where the network capacity increases closest to the root of the tree than at its leaves, thereby
making the network nonblocking. Figure B-1 shows an example of one implementation of a fat
tree topology for a 128-node cluster.
Figure B-1 Fat Tree Topology
In Figure B-1, the 128 cluster nodes are represented by the blocks at the bottom of the illustration.
Each line represents a potential route, or data pathway, from one node to any other node in the
network. The circles represent the high-speed switch ASICs (chips) of the interconnect architecture.
In this example, each switch ASIC contains eight links. The topmost circles represent the spine
(backplane) of the interconnect.
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