- Fat tree
The fat tree network, invented by
Charles E. Leiserson ofMIT , is a universal network for provably efficient communication. Unlike an ordinarycomputer scientist 's notion of a tree, which has "skinny" links all over, the links in a fat-tree become "fatter" as one moves up the tree towards the root. By judiciously choosing the fatness of links, the network can be tailored to efficiently use any bandwidth made available by packaging and communications technology. In contrast, other communications networks, such ashypercube s and meshes, have communication requirements that follow a prespecified mathematical law, and therefore cannot be tailored to specific packaging technologies.Uses
The
Connection Machine Model CM5 supercomputer (circa 1990) used a fat tree interconnection network.Mercury Computer Systems used ahypertree network , a variant of fat trees, in theirmulticomputer . From 2 to 360 compute nodes would reside in a circuit switched fat tree network, with each node having local memory that could be mapped by any other node. Each node in this heterogeneous system could be anIntel i860 , aPowerPC , or a group of three SHARC DSPs. The fat tree network was particularly well suited to theFFT , which customers used forsignal processing tasks likeradar ,sonar ,medical imaging , and so on.A fat tree network is now preferred for the
Infiniband cluster architecture.In late August 2008, a team of computer scientists at
UCSD published a scalable design for network architecture that uses a variant of the fat tree topology to realize networks with uplinks that scale better than those of hierarchical networks with commodity switches that are cheaper and more power-efficient than high-end modular data center switches.Al-Fares, Loukissas, Vahdat, [http://ccr.sigcomm.org/online/?q=node/378 "A Scalable, Commodity Data Center Network Architecture"] , proceedings ofSIGCOMM , 2008.]ee also
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Network topology Further reading
Advanced Computer Architectures: A Design Space Approach, D. Sima, T. Fountain and P. Kacsuk, Addison-Wesley, 1997.
References
Wikimedia Foundation. 2010.
