OutFlank Routing: Increasing Throughput in Toroidal Interconnection Networks

We present a new, deadlock-free, routing scheme for toroidal interconnection networks, called OutFlank Routing (OFR). OFR is an adaptive strategy which exploits non-minimal links, both in the source and in the destination nodes. When minimal links are congested, OFR deroutes packets to carefully chosen intermediate destinations, in order to obtain travel paths which are only an additive constant longer than the shortest ones. Since routing performance is very sensitive to changes in the traffic model or in the router parameters, an accurate discrete-event simulator of the toroidal network has been developed to empirically validate OFR, by comparing it against other relevant routing strategies, over a range of typical real-world traffic patterns. On the 16x16x16 (4096 nodes) simulated network OFR exhibits improvements of the maximum sustained throughput between 14% and 114%, with respect to Adaptive Bubble Routing.Comment: 9 pages, 5 figures, to be presented at ICPADS 201

The k-ary n-direct s-indirect family of topologies for large-scale interconnection networks

The final publication is available at Springer via http://dx.doi.org/10.1007/s11227-016-1640-zIn large-scale supercomputers, the interconnection network plays a key role in system performance. Network topology highly defines the performance and cost of the interconnection network. Direct topologies are sometimes used due to its reduced hardware cost, but the number of network dimensions is limited by the physical 3D space, which leads to an increase of the communication latency and a reduction of network throughput for large machines. Indirect topologies can provide better performance for large machines, but at higher hardware cost. In this paper, we propose a new family of hybrid topologies, the k-ary n-direct s-indirect, that combines the best features from both direct and indirect topologies to efficiently connect an extremely high number of processing nodes. The proposed network is an n-dimensional topology where the k nodes of each dimension are connected through a small indirect topology of s stages. This combination results in a family of topologies that provides high performance, with latency and throughput figures of merit close to indirect topologies, but at a lower hardware cost. In particular, it doubles the throughput obtained per cost unit compared with indirect topologies in most of the cases. Moreover, their fault-tolerance degree is similar to the one achieved by direct topologies built with switches with the same number of ports.This work was supported by the Spanish Ministerio de Economa y Competitividad (MINECO) and by FEDER funds under Grant TIN2012-38341-C04-01 and by Programa de Ayudas de Investigacion y Desarrollo (PAID) from Universitat Politecnica de Valencia.Peñaranda Cebrián, R.; Gómez Requena, C.; Gómez Requena, ME.; López Rodríguez, PJ.; Duato Marín, JF. (2016). The k-ary n-direct s-indirect family of topologies for large-scale interconnection networks. Journal of Supercomputing. 72(3):1035-1062. https://doi.org/10.1007/s11227-016-1640-z10351062723Connect-IB. http://www.mellanox.com/related-docs/prod_adapter_cards/PB_Connect-IB.pdf . Accessed 3 Feb 2016Mellanox store. http://www.mellanoxstore.com . Accessed 3 Feb 2016Mellanox technology. http://www.mellanox.com . Accessed 3 Feb 2016Myricom. http://www.myri.com . Accessed 3 Feb 2016Quadrics homepage. http://www.quadrics.com . Accessed 22 Sept 2008TOP500 supercomputer site. http://www.top500.org . Accessed 3 Feb 2016Balkan A, Qu G, Vishkin U (2009) Mesh-of-trees and alternative interconnection networks for single-chip parallelism. IEEE Trans Very Large Scale Integr(VLSI) Syst 17(10):1419–1432. doi: 10.1109/TVLSI.2008.2003999Bermudez Garzon D, Gomez ME, Lopez P, Duato J, Gomez C (2014) FT-RUFT: a performance and fault-tolerant efficient indirect topology. In: 22nd Euromicro international conference on parallel, distributed and network-based processing (PDP). IEEE, pp 405–409Bhandarkar SM, Arabnia HR (1995) The Hough transform on a reconfigurable multi-ring network. J Parallel Distrib Comput 24(1):107–114Boku T, Nakazawa K, Nakamura H, Sone T, Mishima T, Itakura K (1996) Adaptive routing technique on hypercrossbar network and its evaluation. Syst Comput Jpn 27(4):55–64Dally W, Towles B (2004) Principles and practices of interconnection networks. Morgan Kaufmann, San FranciscoDas R, Eachempati S, Mishra A, Narayanan V, Das C (2009) Design and evaluation of a hierarchical on-chip interconnect for next-generation CMPs. In: IEEE 15th international symposium on high performance computer architecture (HPCA’09), pp 175–186. doi: 10.1109/HPCA.2009.4798252Mahdaly AI, Mouftah HT, Hanna NN (1990) Topological properties of WK-recursive networks. In: Proceedings of IEEE workshop on future trends of distributed computing systems, pp 374–380. doi: 10.1109/FTDCS.1990.138349Duato J (1996) A necessary and sufficient condition for deadlock-free routing in cut-through and store-and-forward networks. IEEE Trans Parallel Distrib Syst 7:841–854. doi: 10.1109/71.532115Duato J, Yalamanchili S, Lionel N (2002) Interconnection networks: an engineering approach. Morgan Kaufmann Publishers Inc., USAFlich J, Malumbres M, López P, Duato J (2000) Improving routing performance in Myrinet networks. In: International on parallel and distributed processing symposium, p 27. doi: 10.1109/IPDPS.2000.845961García M, Beivide R, Camarero C, Valero M, Rodríguez G, Minkenberg C (2015) On-the-fly adaptive routing for dragonfly interconnection networks. J Supercomput 71(3):1116–1142Gómez C, Gilabert F, Gómez M, López P, Duato J (2007) Deterministic versus adaptive routing in fat-trees. In: IEEE international on parallel and distributed processing symposium (IPDPS’07), pp 1–8. doi: 10.1109/IPDPS.2007.370482Gómez C, Gilabert F, Gómez M, López P, Duato J (2008) RUFT: simplifying the fat-tree topology. In: 14th IEEE international conference on parallel and distributed systems (ICPADS’08), pp 153–160. doi: 10.1109/ICPADS.2008.44Guo C, Lu G, Li D, Wu H, Zhang X, Shi Y, Tian C, Zhang Y, Lu S (2009) BCube: a high performance, server-centric network architecture for modular data centers. In: SIGCOMM ’09: proceedings of the ACM SIGCOMM 2009 conference on data communication. ACM, New York, pp 63–74. doi: 10.1145/1592568.1592577 . http://www.bibsonomy.org/bibtex/23a5da89fbf099e3c70f4559ab38082c5/chesteve . Accessed 22 Sept 2008Gupta A, Dally W (2006) Topology optimization of interconnection networks. Comput Arch Lett 5(1):10–13. doi: 10.1109/L-CA.2006.8Kim J, Dally W, Abts D (2007) Flattened butterfly: a cost-efficient topology for high-radix networks. In: Proceedings of the 34th annual international symposium on computer architecture (ISCA’07). ACM, New York, pp 126–137. doi: 10.1145/1250662.1250679Kim J, Dally W, Scott S, Abts D (2008) Technology-driven, highly-scalable dragonfly topology. In: Proceedings of the 35th annual international symposium on computer architecture (ISCA’08). IEEE Computer Society, Washington, DC, pp 77–88. doi: 10.1109/ISCA.2008.19Leighton F (1992) Introduction to parallel algorithms and architectures: arrays, trees, hypercubes v. 1. M. Kaufmann Publishers, San FranciscoLeiserson CE (1985) Fat-trees: universal networks for hardware-efficient supercomputing. IEEE Trans Comput 34(10):892–901Matsutani H, Koibuchi M, Amano H (2007) Performance, cost, and energy evaluation of fat H-tree: a cost-efficient tree-based on-chip network. In: IEEE international on parallel and distributed processing symposium (IPDPS’07), pp 1–10. doi: 10.1109/IPDPS.2007.370271Rahmati D, Kiasari A, Hessabi S, Sarbazi-Azad H (2006) A performance and power analysis of wk-recursive and mesh networks for network-on-chips. In: International conference on computer design (ICCD’06), pp 142–147. doi: 10.1109/ICCD.2006.4380807Towles B, Dally WJ (2002) Worst-case traffic for oblivious routing functions. In: Proceedings of the fourteenth annual ACM symposium on parallel algorithms and architectures (SPAA’02). ACM, New York, pp 1–8. doi: 10.1145/564870.564872Yang Y, Funahashi A, Jouraku A, Nishi H, Amano H, Sueyoshi T (2001) Recursive diagonal torus: an interconnection network for massively parallel computers. IEEE Trans Parallel Distrib Syst 12(7):701–715. doi: 10.1109/71.94074

Parallel computation on sparse networks of processors

SIGLELD:D48226/84 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Submicron Systems Architecture: Semiannual Technical Report

No abstract available

Submicron Systems Architecture: Semiannual Technical Report

No abstract available

Hardness of Exact Distance Queries in Sparse Graphs Through Hub Labeling

A distance labeling scheme is an assignment of bit-labels to the vertices of an undirected, unweighted graph such that the distance between any pair of vertices can be decoded solely from their labels. An important class of distance labeling schemes is that of hub labelings, where a node $v \in G$ stores its distance to the so-called hubs $S_v \subseteq V$, chosen so that for any $u,v \in V$ there is $w \in S_u \cap S_v$ belonging to some shortest $uv$ path. Notice that for most existing graph classes, the best distance labelling constructions existing use at some point a hub labeling scheme at least as a key building block. Our interest lies in hub labelings of sparse graphs, i.e., those with $|E(G)| = O(n)$, for which we show a lowerbound of $\frac{n}{2^{O(\sqrt{\log n})}}$ for the average size of the hubsets. Additionally, we show a hub-labeling construction for sparse graphs of average size $O(\frac{n}{RS(n)^{c}})$ for some $0 < c < 1$, where $RS(n)$ is the so-called Ruzsa-Szemer{\'e}di function, linked to structure of induced matchings in dense graphs. This implies that further improving the lower bound on hub labeling size to $\frac{n}{2^{(\log n)^{o(1)}}}$ would require a breakthrough in the study of lower bounds on $RS(n)$, which have resisted substantial improvement in the last 70 years. For general distance labeling of sparse graphs, we show a lowerbound of $\frac{1}{2^{O(\sqrt{\log n})}} SumIndex(n)$, where $SumIndex(n)$ is the communication complexity of the Sum-Index problem over $Z_n$. Our results suggest that the best achievable hub-label size and distance-label size in sparse graphs may be $\Theta(\frac{n}{2^{(\log n)^c}})$ for some $0<c < 1$

Investigation of reduced hypercube (RH) networks : embedding and routing capabilities

The choice of a topology for the interconnection of resources in a distributed-memory parallel computing system is a major design decision. The direct binary hypercube has been widely used for this purpose due to its low diameter and its ability to efficiently emulate other important structures. The aforementioned strong properties of the hypercube come at the cost of high VLSI complexity due to the increase in the number of communication ports and channels per node with an increase in the total number of nodes. The reduced hypercube (RH) topology, which is obtained by a uniform reduction in the number of links for each hypercube node, yields lower complexity interconnection networks compared to hypercubes with the same number of nodes, thus permitting the construction of larger parallel systems. Furthermore, it has been shown that the RH at a lower cost achieves performance comparable to that of a regular hypercube with the same number of nodes. A very important issue for the viability of the RH is to investigate the efficiency of embedding frequently used topologies into it. This thesis proposes embedding algorithms for three very important topologies, namely the ring, the torus and the binary tree. The performance of the proposed algorithms is analyzed and compared to that of equivalent embedding algorithms for the regular hypercube. It is shown that these topologies are emulated efficiently on the RH. Additionally, two already proposed routing algorithms for the RH are evaluated through simulation results