TY - GEN
T1 - Analyzing the impact of supporting out-of-order communication on in-order performance with iWARP
AU - Balaji, P.
AU - Feng, W.
AU - Bhagvat, S.
AU - Panda, D. K.
AU - Thakur, R.
AU - Gropp, W.
PY - 2007
Y1 - 2007
N2 - Due to the growing need to tolerate network faults and congestion in high-end computing systems, supporting multiple network communication paths is becoming increasingly important. However, multi-path communication comes with the disadvantage of out-of-order arrival of packets (because packets may traverse different paths). While modern networking stacks such as the Internet Wide-Area RDMA Protocol (iWARP) over 10-Gigabit Ethernet (10GE) support multi-path communication, their current implementations do not handle out-of-order packets primarily owing to the overhead on in-order communication that it adds. Specifically, in iWARP, supporting out-of-order packets requires every packet to carry additional information causing significant overhead on packets that arrive in-order. Thus, in this paper, we analyze the trade-offs in designing a feature-complete iWARP stack, i.e., one that provides support for out-of-order arriving packets, and thus, multi-path systems, while focusing on the performance of in-order communication. We propose three feature-complete designs of iWARP and analyze the pros and cons of each of these designs using performance experiments based on several micro-benchmarks as well as an iso-surface visual rendering application. Our analysis reveals that the iWARP design providing the best overall performance depends on the particular characteristics of the upper layers and that different designs are optimal based on the metric of interest. (c) 2007 ACM.
AB - Due to the growing need to tolerate network faults and congestion in high-end computing systems, supporting multiple network communication paths is becoming increasingly important. However, multi-path communication comes with the disadvantage of out-of-order arrival of packets (because packets may traverse different paths). While modern networking stacks such as the Internet Wide-Area RDMA Protocol (iWARP) over 10-Gigabit Ethernet (10GE) support multi-path communication, their current implementations do not handle out-of-order packets primarily owing to the overhead on in-order communication that it adds. Specifically, in iWARP, supporting out-of-order packets requires every packet to carry additional information causing significant overhead on packets that arrive in-order. Thus, in this paper, we analyze the trade-offs in designing a feature-complete iWARP stack, i.e., one that provides support for out-of-order arriving packets, and thus, multi-path systems, while focusing on the performance of in-order communication. We propose three feature-complete designs of iWARP and analyze the pros and cons of each of these designs using performance experiments based on several micro-benchmarks as well as an iso-surface visual rendering application. Our analysis reveals that the iWARP design providing the best overall performance depends on the particular characteristics of the upper layers and that different designs are optimal based on the metric of interest. (c) 2007 ACM.
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U2 - 10.1145/1362622.1362670
DO - 10.1145/1362622.1362670
M3 - Conference contribution
AN - SCOPUS:56749179551
SN - 9781595937643
T3 - Proceedings of the 2007 ACM/IEEE Conference on Supercomputing, SC'07
BT - Proceedings of the 2007 ACM/IEEE Conference on Supercomputing, SC'07
T2 - 2007 ACM/IEEE Conference on Supercomputing, SC'07
Y2 - 10 November 2007 through 16 November 2007
ER -