@inproceedings {34107,
	title = {Adaptive Routing in InfiniBand Hardware},
	journal = {The 22nd IEEE/ACM International Symposium on Cluster, Cloud and Internet Computing},
	year = {2022},
	pages = {463-472},
	publisher = {IEEE},
	abstract = {Interconnection networks are the communication\&nbsp;backbone of modern high-performance computing systems and\&nbsp;an optimised interconnection network is crucial for the performance and utilisation of the system as a whole. One element of the interconnection network is the routing algorithm, which directly influences how we are able to utilise the physical network topology. InfiniBand is one of the most common network architectures used in high-performance computing and\&nbsp;traditionally it only supported static routing. For multi-path networks such as Fat-trees, static routing is inefficient because it cannot balance traffic in real-time nor utilise multiple paths\&nbsp;efficiently under adversarial traffic. This again potentially leads\&nbsp;to unnecessary contention and an underutilised network, which\&nbsp;has led to numerous proposals on how to avoid this by using\&nbsp;adaptive routing. Adaptive routing has recently\&nbsp; been introduced\&nbsp;in InfiniBand and in this paper we evaluate to what extent\&nbsp;the expected benefits of adaptive routing is true for InfiniBand.\&nbsp;Through a set of experiments on HDR InfiniBand equipment we\&nbsp;describe the basic behaviour of adaptive routing in InfiniBand,\&nbsp;its benefits in Fat tree topologies and the unfortunate side effects\&nbsp;related to unfairness that adaptive routing in general might\&nbsp;introduce, including such phenomena as the reverse parking lotproblem and congestion spreading.},
	author = {Rocher-Gonzalez, Jose and Ernst Gunnar {Gran} and Reinemo, Sven-Arne and Skeie, Tor and Escudero-Sahuquillo, Jes{\'u}s and Pedro Javier {Garc{\'\i}a} and Francisco Jos{\'e} {Quiles}}
}
@inproceedings {23935,
	title = {A New Fault-Tolerant Routing Methodology for KNS Topologies},
	journal = {2nd IEEE International Workshop on High-Performance Interconnection Networks in the Exascale and Big-Data Era (HiPINEB)},
	year = {2016},
	month = {03/2016},
	pages = {1-8},
	publisher = {IEEE},
	abstract = {Exascale computing systems are being built with thousands of nodes. A key component of these systems is the interconnection network. The high number of components significantly increases the probability of failure. If failures occur in the interconnection network, they may isolate a large fraction of the machine. For this reason, an efficient fault-tolerant mechanism is needed to keep the system interconnected, even in the presence of faults. A topology recently proposed for these large systems is the hybrid KNS family that provides good performance and connectivity at a reduced hardware cost. This paper present a fault-tolerant routing methodology for the KNS topology that degrades performance gracefully in the presence of faults and tolerates a reasonably large number of faults without disabling any healthy node. In order to tolerate network failures, the methodology uses a simple mechanism: for some sourcedestination pairs, only if necessary, packets are forwarded to the destination node through a set of intermediate nodes (without being ejected from the network) which allow avoiding faults. The evaluation results shows that the methodology tolerates a large number of faults. Furthermore, the methodology offers a gracious performance degradation. For instance, performance degrades only 1\% for a 2D-network with 1024 nodes and 1\% faulty links.},
	isbn = {978-1-5090-2121-5},
	doi = {10.1109/HIPINEB.2016.9},
	author = {Pe{\~n}aranda, Roberto and Ernst Gunnar {Gran} and Skeie, Tor and Maria Engracia {G{\'o}mez} and Lopez, Pedro},
	editor = {Pedro J. {Garcia} and Escudero-Sahuquillo, Jes{\'u}s}
}
@article {Simula.simula.2620,
	title = {Efficient and Cost-Effective Hybrid Congestion Control for HPC Interconnection Networks},
	journal = {IEEE Transactions on Parallel and Distributed Systems},
	volume = {26},
	number = {pp},
	year = {2015},
	pages = {107-119},
	publisher = {IEEE},
	abstract = {Interconnection networks are key components in High-Performance Computing (HPC) systems, their performance having a strong influence on the overall system one. However, at high load, congestion and its negative effects (e.g. Head-of-line blocking) threaten the performance of the network, and so the one of the entire system. Congestion control (CC) is crucial to ensure an efficient utilization of the interconnection network during congestion situations. As one major trend is to reduce the effective wiring in interconnection networks to reduce cost and power consumption, the network will operate very close to its capacity. Thus, congestion control becomes essential. Existing CC techniques can be divided into two general approaches. One is to throttle traffic injection at the sources that contribute to congestion, and the other is to isolate the congested traffic in specially designated resources. However, both approaches have different, but non-overlapping weaknesses: injection throttling techniques have a slow reaction against congestion, while isolating traffic in special resources may lead the system to run out of those resources. In this paper we propose EcoCC, a new Efficient and Cost-Effective CC technique, that combines injection throttling and congested-flow isolation to minimize their respective drawbacks and maximize overall system performance. This new strategy is suitable for current commercial switch architectures, where it could be implemented without requiring significant complexity. Experimental results, using simulations under synthetic and real tracebased traffic patterns, show that this technique improves by up to 55\% over some of the most successful congestion control techniques.},
	doi = {10.1109/TPDS.2014.2307851},
	author = {Escudero-Sahuquillo, Jes{\'u}s and Ernst Gunnar {Gran} and Pedro J. {Garcia} and Flich, Jos{\'e} and Skeie, Tor and Lysne, Olav and Francisco Jos{\'e} {Quiles} and Duato, Jose}
}
@article {Simula.simula.2218,
	title = {A New Proposal to Deal With Congestion in InfiniBand-Based Fat-Trees},
	journal = {Journal of Parallel and Distributed Computing},
	volume = {74},
	number = {1},
	year = {2014},
	month = {January},
	pages = {1802-1819},
	publisher = {Elsevier},
	abstract = {The overall performance of High-Performance Computing applications may depend largely on the performance achieved by the network interconnecting the end-nodes, thus high-speed interconnect technologies like InfiniBand are used to provide high throughput and low latency. Nevertheless, network performance may be degraded due to congestion, thus using techniques to deal with the problems derived from congestion has become practically mandatory. In this paper we propose a straightforward congestion-management method suitable for fat-tree topologies built from InfiniBand components. Our proposal is based on a traffic-flow-to-service-level mapping that prevents, as much as possible with the resources available in current InfiniBand components (basically Virtual Lanes), the negative impact of the two most common problems derived from congestion: head-of-line blocking and buffer-hogging. We also provide a mathematical approach to analyze the efficiency of our proposal and several ones, by means of a set of analytical metrics. In certain traffic scenarios, we observe up to a 68\% of the ideal performance gain that could be achieved in HoL-blocking and buffer-hogging prevention.},
	keywords = {Congestion management, Fat-trees, High-performance computing, InfiniBand, Interconnection networks},
	doi = {http://dx.doi.org/10.1016/j.jpdc.2013.09},
	author = {Escudero-Sahuquillo, Jes{\'u}s and Pedro Javier {Garc{\'\i}a} and Francisco Jos{\'e} {Quiles} and Reinemo, Sven-Arne and Skeie, Tor and Lysne, Olav and Duato, Jose}
}
@inproceedings {Simula.simula.834,
	title = {Combining Congested-Flow Isolation and Injection Throttling in HPC Interconnection Networks},
	journal = {International Conference on Parallel Processing, ICPP 2011},
	year = {2011},
	month = {September},
	pages = {662-672},
	publisher = {IEEE Computer Society},
	type = {Conference},
	abstract = {Existing congestion control mechanisms in interconnects can be divided into two general approaches. One is to throttle traffic injection at the sources that contribute to congestion, and the other is to isolate the congested traffic in specially designated resources. These two approaches have different, but non-overlapping weaknesses. In this paper we present in detail a method that combines injection throttling and congested-flow isolation. Through simulation studies we first demonstrate the respective flaws of the injection throttling and of flow isolation. Thereafter we show that our combined method extracts the best of both approaches in the sense that it gives fast reaction to congestion, it is scalable and it has good fairness properties with respect to the congested flows.},
	isbn = {978-1-4577-1336-1},
	doi = {10.1109/ICPP.2011.80},
	author = {Escudero-Sahuquillo, Jes{\'u}s and Ernst Gunnar {Gran} and Pedro Javier {Garc{\'\i}a} and Flich, Jos{\'e} and Skeie, Tor and Lysne, Olav and Francisco Jos{\'e} {Quiles} and Duato, Jose},
	editor = {Bilof, Randall}
}
