DocumentCode :
260515
Title :
Revisiting Size-Based Scheduling with Estimated Job Sizes
Author :
Dell´Amico, Matteo ; Carra, Damiano ; Pastorelli, Mario ; Michiardi, Pietro
Author_Institution :
EURECOM, Sophia-Antipolis, France
fYear :
2014
fDate :
9-11 Sept. 2014
Firstpage :
411
Lastpage :
420
Abstract :
We study size-based schedulers, and focus on the impact of inaccurate job size information on response time and fairness. Our intent is to revisit previous results, which allude to performance degradation for even small errors on job size estimates, thus limiting the applicability of size-based schedulers. We show that scheduling performance is tightly connected to workload characteristics: in the absence of large skew in the job size distribution, even extremely imprecise estimates suffice to outperform size-oblivious disciplines. Instead, when job sizes are heavily skewed, known size-based disciplines suffer. In this context, we show - for the first time - the dichotomy of over-estimation versus under-estimation. The former is, in general, less problematic than the latter, as its effects are localized to individual jobs. Instead, under-estimation leads to severe problems that may affect a large number of jobs. We present an approach to mitigate these problems: our technique requires no complex modifications to original scheduling policies and performs very well. To support our claim, we proceed with a simulation-based evaluation that covers an unprecedented large parameter space, which takes into account a variety of synthetic and real workloads. As a consequence, we show that size-based scheduling is practical and outperforms alternatives in a wide array of use-cases, even in presence of inaccurate size information.
Keywords :
processor scheduling; queueing theory; inaccurate size information; job size distribution; job size estimation; simulation-based evaluation; size-based scheduling; workload characteristics; Context; Estimation error; Processor scheduling; Protocols; Shape; Time factors;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Modelling, Analysis & Simulation of Computer and Telecommunication Systems (MASCOTS), 2014 IEEE 22nd International Symposium on
Conference_Location :
Paris
ISSN :
1526-7539
Type :
conf
DOI :
10.1109/MASCOTS.2014.57
Filename :
7033679
Link To Document :
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