Abstract
Designing low-latency network topologies of switches is a key objective for next-generation large-scale clusters. Low latency is preconditioned on low hop counts, but existing network topologies have hop counts much larger than theoretical lower bounds. To alleviate this problem, we propose building network topologies based on uni-directional graphs that are known to have hop counts close to theoretical lower bounds. A practical difficulty with uni-directional topologies is switch-by-switch flow control, which we resolve by using hot-potato routing. Cycle-Accurate network simulation experiments for various traffic patterns on uni-directional topologies show that hot-potato routing achieves performance comparable to that of conventional deadlock-free routing. Similar experiments are used to compare several uni-directional topologies to bi-directional topologies, showing that the former achieve significantly lower latency and higher throughput. We quantify end-To-end application performance for parallel application benchmarks via discrete-even simulation, showing that uni-directional topologies can lead to large application performance improvements over their bi-directional counterparts. Finally, we discuss practical issues for uni-directional topologies such as cabling complexity and cost, power consumption, and soft-error tolerance. Our results make a compelling case for considering uni-directional topologies for upcoming large-scale clusters.
| Original language | English |
|---|---|
| Title of host publication | Proceedings - 2017 IEEE International Conference on Cluster Computing, CLUSTER 2017 |
| Publisher | Institute of Electrical and Electronics Engineers Inc. |
| Pages | 178-187 |
| Number of pages | 10 |
| Volume | 2017-September |
| ISBN (Electronic) | 9781538623268 |
| DOIs | |
| Publication status | Published - 2017 Sep 22 |
| Event | 2017 IEEE International Conference on Cluster Computing, CLUSTER 2017 - Honolulu, United States Duration: 2017 Sep 5 → 2017 Sep 8 |
Other
| Other | 2017 IEEE International Conference on Cluster Computing, CLUSTER 2017 |
|---|---|
| Country | United States |
| City | Honolulu |
| Period | 17/9/5 → 17/9/8 |
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Keywords
- Hot-potato routing
- HPC clusters
- Interconnection networks
- Uni-directional network topologies
ASJC Scopus subject areas
- Software
- Hardware and Architecture
- Signal Processing
Cite this
A Case for Uni-directional Network Topologies in Large-Scale Clusters. / Koibuchi, Michihiro; Totoki, Tomohiro; Matsutani, Hiroki; Amano, Hideharu; Chaix, Fabien; Fujiwara, Ikki; Casanova, Henri.
Proceedings - 2017 IEEE International Conference on Cluster Computing, CLUSTER 2017. Vol. 2017-September Institute of Electrical and Electronics Engineers Inc., 2017. p. 178-187 8048929.Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
}
TY - GEN
T1 - A Case for Uni-directional Network Topologies in Large-Scale Clusters
AU - Koibuchi, Michihiro
AU - Totoki, Tomohiro
AU - Matsutani, Hiroki
AU - Amano, Hideharu
AU - Chaix, Fabien
AU - Fujiwara, Ikki
AU - Casanova, Henri
PY - 2017/9/22
Y1 - 2017/9/22
N2 - Designing low-latency network topologies of switches is a key objective for next-generation large-scale clusters. Low latency is preconditioned on low hop counts, but existing network topologies have hop counts much larger than theoretical lower bounds. To alleviate this problem, we propose building network topologies based on uni-directional graphs that are known to have hop counts close to theoretical lower bounds. A practical difficulty with uni-directional topologies is switch-by-switch flow control, which we resolve by using hot-potato routing. Cycle-Accurate network simulation experiments for various traffic patterns on uni-directional topologies show that hot-potato routing achieves performance comparable to that of conventional deadlock-free routing. Similar experiments are used to compare several uni-directional topologies to bi-directional topologies, showing that the former achieve significantly lower latency and higher throughput. We quantify end-To-end application performance for parallel application benchmarks via discrete-even simulation, showing that uni-directional topologies can lead to large application performance improvements over their bi-directional counterparts. Finally, we discuss practical issues for uni-directional topologies such as cabling complexity and cost, power consumption, and soft-error tolerance. Our results make a compelling case for considering uni-directional topologies for upcoming large-scale clusters.
AB - Designing low-latency network topologies of switches is a key objective for next-generation large-scale clusters. Low latency is preconditioned on low hop counts, but existing network topologies have hop counts much larger than theoretical lower bounds. To alleviate this problem, we propose building network topologies based on uni-directional graphs that are known to have hop counts close to theoretical lower bounds. A practical difficulty with uni-directional topologies is switch-by-switch flow control, which we resolve by using hot-potato routing. Cycle-Accurate network simulation experiments for various traffic patterns on uni-directional topologies show that hot-potato routing achieves performance comparable to that of conventional deadlock-free routing. Similar experiments are used to compare several uni-directional topologies to bi-directional topologies, showing that the former achieve significantly lower latency and higher throughput. We quantify end-To-end application performance for parallel application benchmarks via discrete-even simulation, showing that uni-directional topologies can lead to large application performance improvements over their bi-directional counterparts. Finally, we discuss practical issues for uni-directional topologies such as cabling complexity and cost, power consumption, and soft-error tolerance. Our results make a compelling case for considering uni-directional topologies for upcoming large-scale clusters.
KW - Hot-potato routing
KW - HPC clusters
KW - Interconnection networks
KW - Uni-directional network topologies
UR - http://www.scopus.com/inward/record.url?scp=85032626894&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85032626894&partnerID=8YFLogxK
U2 - 10.1109/CLUSTER.2017.33
DO - 10.1109/CLUSTER.2017.33
M3 - Conference contribution
AN - SCOPUS:85032626894
VL - 2017-September
SP - 178
EP - 187
BT - Proceedings - 2017 IEEE International Conference on Cluster Computing, CLUSTER 2017
PB - Institute of Electrical and Electronics Engineers Inc.
ER -