# How to Schedule Near-Optimally under Real-World Constraints

@article{Scully2021HowTS, title={How to Schedule Near-Optimally under Real-World Constraints}, author={Ziv Scully and Mor Harchol-Balter}, journal={ArXiv}, year={2021}, volume={abs/2110.11579} }

Scheduling is a critical part of practical computer systems, and scheduling has also been extensively studied from a theoretical perspective. Unfortunately, there is a gap between theory and practice, as the optimal scheduling policies presented by theory can be difficult or impossible to perfectly implement in practice. In this work, we use recent breakthroughs in queueing theory to begin to bridge this gap. We show how to translate theoretically optimal policies—which provably minimize mean…

## One Citation

### The most common queueing theory questions asked by computer systems practitioners

- EducationSIGMETRICS Perform. Evaluation Rev.
- 2022

This document examines five performance questions which are repeatedly asked by practitioners in industry: (i) My system utilization is very low, so why are job delays so high? (ii) What should I do…

## References

SHOWING 1-10 OF 32 REFERENCES

### Simple Near-Optimal Scheduling for the M/G/1

- MathematicsSIGMETRICS Perform. Evaluation Rev.
- 2019

The problem of preemptively scheduling jobs to minimize mean response time of an M/G/1 queue is considered and the shortest expected remaining processing time (SERPT) policy is considered.

### PROPERTIES OF THE GITTINS INDEX WITH APPLICATION TO OPTIMAL SCHEDULING

- MathematicsProbability in the Engineering and Informational Sciences
- 2011

It turns out that the optimal policy always belongs to the family of multilevel processor sharing disciplines.

### Load Balancing Guardrails: Keeping Your Heavy Traffic on the Road to Low Response Times

- BusinessAbstracts of the 2019 SIGMETRICS/Performance Joint International Conference on Measurement and Modeling of Computer Systems
- 2019

The results yield the first analytical bounds on mean response time for load balancing systems with SRPT scheduling at the servers, and any dispatching policy, when augmented with guardrails, becomes heavy-traffic optimal.

### Minimizing slowdown in heterogeneous size-aware dispatching systems

- MathematicsSIGMETRICS '12
- 2012

The main contribution of this paper is to show the optimality of SPTP with respect to slowdown in a single server queue under Poisson arrivals, and to derive the so-called size-aware value functions for M/G/1-FIFO/LifO/SPTP with general holding costs to derive efficient dispatching policies so as to minimize the mean slowdown in an heterogeneous server system.

### The Gittins Policy is Nearly Optimal in the M/G/k under Extremely General Conditions

- Computer Science, MathematicsProc. ACM Meas. Anal. Comput. Syst.
- 2020

This work gives the first general analysis of Gittins in the M/G/k and shows that under extremely general conditions, Gittin's mean response time is at most itsmean response time in theM/g/1 plus an $O(łog(1/(1 - ρ)$ additive term, where ρ is the system load.

### Scheduling for today's computer systems: bridging theory and practice

- Business
- 2007

This thesis takes a step towards modernizing the theory of scheduling in order to provide results that apply to today's computer systems, and thus ease the burden on system designers, and provides new results that help to bridge each of the disconnects mentioned above.

### Approximating total flow time on parallel machines

- Computer ScienceSTOC '97
- 1997

It is proved that when preemption is allowed, Shortest Remaining Processing Time (SRPT) is an O(log(min{nm,P})) approximation algorithm for the total flow time, and it is shown that up to a constant factor SRPT is an optimal on-line algorithm.

### Performance Modeling and Design of Computer Systems: Queueing Theory in Action

- Computer Science
- 2013

Tackling the questions that systems designers care about, this book brings queueing theory decisively back to computer science and helps readers acquire the skills needed to model, analyze, and design large-scale systems with good performance and low cost.

### Nonclairvoyant scheduling to minimize the total flow time on single and parallel machines

- Computer ScienceJACM
- 2004

It is proved that a randomized version of the Multilevel Feedback algorithm is competitive for single and parallel machine systems, in the opinion providing one theoretical validation of the goodness of an idea that has proven effective in practice along the last two decades.