Today's data centers face extreme challenges in providing low latency. However, fair sharing, a principle commonly adopted in current congestion control protocols, is far from optimal for satisfying latency requirements. We propose Preemptive Distributed Quick (PDQ) flow scheduling, a protocol designed to complete flows quickly and meet flow deadlines. PDQ enables flow preemption to approximate a range of scheduling disciplines. For example, PDQ can emulate a shortest job first algorithm to give priority to the short flows by pausing the contending flows. PDQ borrows ideas from centralized scheduling disciplines and implements them in a fully distributed manner, making it scalable to today's data centers. Further, we develop a multipath version of PDQ to exploit path diversity. Through extensive packet-level and flow-level simulation, we demonstrate that PDQ significantly outperforms TCP, RCP and D3 in data center environments. We further show that PDQ is stable, resilient to packet loss, and preserves nearly all its performance gains even given inaccurate flow information.
Finishing flows quickly with preemptive scheduling
C. Hong,M. Caesar,Brighten Godfrey
Published 2012 in CCRV
ABSTRACT
PUBLICATION RECORD
- Publication year
2012
- Venue
CCRV
- Publication date
2012-06-10
- Fields of study
Computer Science
- Identifiers
- External record
- Source metadata
Semantic Scholar
CITATION MAP
EXTRACTION MAP
CLAIMS
CONCEPTS
- d3
A deadline-aware data center transport protocol used as a comparison baseline in the evaluation.
- flow preemption
The mechanism of pausing a contending flow so that another flow can receive service first.
- multipath pdq
A PDQ variant that uses multiple network paths to carry traffic.
- packet-level and flow-level simulation
A simulation setup that evaluates behavior at both packet granularity and flow granularity.
- path diversity
The presence of multiple alternative routes between endpoints in the data center network.
- pdq
A preemptive distributed quick flow scheduling protocol for data centers that aims to complete flows rapidly and respect deadlines.
Aliases: Preemptive Distributed Quick
- rcp
Rate Control Protocol, included as a comparison baseline in the evaluation.
Aliases: Rate Control Protocol
- shortest job first
A scheduling discipline that prioritizes shorter flows ahead of longer ones.
Aliases: SJF
- tcp
The conventional transport protocol used as a comparison baseline in the simulations.
REFERENCES
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