Paper Info
Title
vFtree - A Fat-Tree Routing Algorithm Using Virtual Lanes to Alleviate Congestion
Abstract
It is a well known fact that multiple virtual lanes can improve performance in interconnection networks, but this knowledge has had little impact on real clusters. Currently, a large number of clusters using InfiniBand is based on fat-tree topologies that can be routed deadlock-free using only one virtual lane. Consequently, all the remaining virtual lanes are left unused. In this paper we suggest an enhancement to the fat-tree algorithm that utilizes virtual lanes to improve performance when hot-spots are present. Even though the bisection bandwidth in a fat-tree is constant, hot-spots are still possible and they will degrade performance for flows not contributing to them due to head-of-line blocking. Such a situation may be alleviated through adaptive routing or congestion control, however, these methods are not yet readily available in InfiniBand technology. To remedy this problem, we have implemented an enhanced fat-tree algorithm in OpenSM that distributes traffic across all available virtual lanes without any configuration needed. We evaluated the performance of the algorithm on a small cluster and did a large-scale evaluation through simulations. In a congested environment, results show that we are able to achieve throughput increases up to 38% on a small cluster and from 221% to 757% depending on the hot-spot scenario for a 648-port simulated cluster.
Year
DOI
Venue
2011
10.1109/IPDPS.2011.28
IPDPS
Keywords
Field
DocType
congestion control,enhanced fat-tree algorithm,opensm,multiprocessor interconnection networks,virtual lanes,vftree,alleviate congestion,real cluster,fat-tree routing algorithm,virtual lane,congestion alleviation,remaining virtual lane,telecommunication congestion control,multiple virtual lane,interconnection networks,adaptive routing,648-port simulated cluster,fat-tree algorithm,available virtual lane,small cluster,workstation clusters,fat-tree topology,telecommunication network routing,infiniband,network topology,routing,topology,hardware,bandwidth,hot spot
InfiniBand,Computer science,Computer network,Network topology,Bisection bandwidth,Bandwidth (signal processing),Network congestion,Throughput,Fat tree,Interconnection,Distributed computing
Conference
ISSN
ISBN
Citations 
1530-2075 E-ISBN : 978-0-7695-4385-7
978-0-7695-4385-7
22
PageRank 
References 
Authors
0.79
15
5
Name
Order
Citations
PageRank
Wei Lin Guay1322.35
Bartosz Bogdanski2414.53
Sven-Arne Reinemo318412.64
Olav Lysne479754.53
Tor Skeie5110374.67