@inproceedings {23558,
	title = {SlimUpdate: Minimal Routing Update for Performance-based Reconfigurations in Fat-Trees},
	journal = {1st IEEE International Workshop on High-Performance Interconnection Networks Towards the Exascale and Big-Data Era (HiPINEB 2015)},
	year = {2015},
	month = {10/2015},
	pages = {849-856},
	publisher = {IEEE Computer Society},
	abstract = {As the size of high-performance computing systems grows, the number of events requiring a network\&nbsp;reconfiguration, as well as the complexity of each reconfiguration, is likely to increase.\&nbsp;In large systems, the probability of component failure is high. At the same time, with more\&nbsp;network components, ensuring high utilization of network resources becomes challenging.\&nbsp;Reconfiguration in interconnection networks,\&nbsp;like InfiniBand (IB), typically involves computation and distribution of a new set of routes in order\&nbsp;to maintain connectivity and performance. In general, current routing algorithms do not consider the\&nbsp;existing routes in a network when calculating new ones. Such configuration-oblivious routing\&nbsp;might result in substantial modifications to the existing paths, and the reconfiguration\&nbsp;becomes costly as it potentially involves a large number of source-destination pairs.\&nbsp;In this paper, we propose a novel routing algorithm for IB based fat-tree topologies, SlimUpdate.\&nbsp;SlimUpdate employs techniques to preserve existing forwarding entries in switches to ensure a minimal\&nbsp;routing update, without any performance penalty, and with minimal computational overhead.\&nbsp;We present an implementation of SlimUpdate in OpenSM,\&nbsp;and compare it with the current de facto fat-tree routing algorithm. Our experiments and simulations show\&nbsp;a decrease of up to 80\% in the number of total path modifications when using SlimUpdate routing, while achieving\&nbsp;similar or even better performance than the fat-tree routing in most reconfiguration scenarios.},
	isbn = {978-1-4673-6598-7},
	doi = {10.1109/CLUSTER.2015.142},
	author = {Zahid, Feroz and Ernst Gunnar {Gran} and Bogdanski, Bartosz and Bj{\o}rn Dag {Johnsen} and Skeie, Tor}
}
