Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published May 1, 2007 | public
Thesis Open

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

Wierman, Adam

Abstract

Scheduling is a fundamental technique for improving performance in computer systems. From web servers to routers to operating systems, how the bottleneck device is scheduled has an enormous impact on the performance of the system as a whole. Given the immense literature studying scheduling, it is easy to think that we already understand enough about scheduling. But, modern computer system designs have highlighted a number of disconnects between traditional analytic results and the needs of system designers. In particular, the idealized policies, metrics, and models used by analytic researchers do not match the policies, metrics, and scenarios that appear in real systems. The goal of this thesis is to take 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. To accomplish this goal, we provide new results that help to bridge each of the disconnects mentioned above. We will move beyond the study of idealized policies by introducing a new analytic framework where the focus is on scheduling heuristics and techniques rather than individual policies. By moving beyond the study of individual policies, our results apply to the complex hybrid policies that are often used in practice. For example, our results enable designers to understand how the policies that favor small job sizes are affected by the fact that real systems only have estimates of job sizes. In addition, we move beyond the study of mean response time and provide results characterizing the distribution of response time and the fairness of scheduling policies. These results allow us to understand how scheduling affects QoS guarantees and whether favoring small job sizes results in large job sizes being treated unfairly. Finally, we move beyond the simplified models traditionally used in scheduling research and provide results characterizing the effectiveness of scheduling in multiserver systems and when users are interactive. These results allow us to answer questions about the how to design multiserver systems and how to choose a workload generator when evaluating new scheduling designs.

Additional Information

Thesis Committee: Mor Harchol-Balter, chair; John Lafferty; Bruce Maggs; Alan Scheller-Wolf; Ward Whitt. This research was supported, in part, by an NSF Graduate Research Fellowship and a Siebel Scholar award. Additional funding was provided by a grant from the Pittsburgh Digital Greenhouse and NSF grants CCR-0133077, CCR-0311383, and CCR-9457766.

Files

thesis.pdf
Files (7.1 MB)
Name Size Download all
md5:fe2ba8890ac94c41392591e720ed1b24
3.2 MB Preview Download
md5:ac663b5aa8f1122ffe5b5d74c40ff253
3.8 MB Download

Additional details

Created:
August 22, 2023
Modified:
October 16, 2023