TY - JOUR

T1 - Buffer Management for Colored Packets with Deadlines

AU - Azar, Yossi

AU - Feige, Uriel

AU - Gamzu, Iftah

AU - Moscibroda, Thomas

AU - Raghavendra, Prasad

N1 - Funding Information:
An extended abstract of this paper appeared in Proceedings of the 21st Annual ACM Symposium on Parallel Algorithms and Architectures, pp. 319–327, 2009. Y. Azar was partially supported by the Israeli Science Foundation (grant No. 1404/10).

PY - 2011/11

Y1 - 2011/11

N2 - We consider buffer management of unit packets with deadlines for a multi-port device with reconfiguration overhead. The goal is to maximize the throughput of the device, i.e., the number of packets delivered by their deadline. For a single port or with free reconfiguration, the problem reduces to the well-known packets scheduling problem, where the celebrated earliest-deadline-first (EDF) strategy is optimal 1-competitive. However, EDF is not 1-competitive when there is a reconfiguration overhead. We design an online algorithm that achieves a competitive ratio of 1-o(1) when the ratio between the minimum laxity of the packets and the number of ports tends to infinity. This is one of the rare cases where one can design an almost 1-competitive algorithm. One ingredient of our analysis, which may be interesting on its own right, is a perturbation theorem on EDF for the classical packets scheduling problem. Specifically, we show that a small perturbation in the release and deadline times cannot significantly degrade the optimal throughput. This implies that EDF is robust in the sense that its throughput is close to the optimum even when the deadlines are not precisely known.

AB - We consider buffer management of unit packets with deadlines for a multi-port device with reconfiguration overhead. The goal is to maximize the throughput of the device, i.e., the number of packets delivered by their deadline. For a single port or with free reconfiguration, the problem reduces to the well-known packets scheduling problem, where the celebrated earliest-deadline-first (EDF) strategy is optimal 1-competitive. However, EDF is not 1-competitive when there is a reconfiguration overhead. We design an online algorithm that achieves a competitive ratio of 1-o(1) when the ratio between the minimum laxity of the packets and the number of ports tends to infinity. This is one of the rare cases where one can design an almost 1-competitive algorithm. One ingredient of our analysis, which may be interesting on its own right, is a perturbation theorem on EDF for the classical packets scheduling problem. Specifically, we show that a small perturbation in the release and deadline times cannot significantly degrade the optimal throughput. This implies that EDF is robust in the sense that its throughput is close to the optimum even when the deadlines are not precisely known.

KW - Buffer management

KW - DRAM scheduling

KW - Earliest deadline first

KW - Online algorithms

KW - Packets scheduling

UR - http://www.scopus.com/inward/record.url?scp=80053445323&partnerID=8YFLogxK

U2 - 10.1007/s00224-011-9346-3

DO - 10.1007/s00224-011-9346-3

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AN - SCOPUS:80053445323

SN - 1432-4350

VL - 49

SP - 738

EP - 756

JO - Theory of Computing Systems

JF - Theory of Computing Systems

IS - 4

ER -