WorldCat Identities

Wierman, Adam

Overview
Works: 10 works in 11 publications in 1 language and 15 library holdings
Publication Timeline
Key
Publications about  Adam Wierman Publications about Adam Wierman
Publications by  Adam Wierman Publications by Adam Wierman
Most widely held works by Adam Wierman
Special issue on the 2010 HotMetrics workshop ( )
2 editions published in 2010 in English and held by 4 WorldCat member libraries worldwide
Bounds on a fair policy with near optimal performance by Adam Wierman ( Book )
1 edition published in 2003 in English and held by 2 WorldCat member libraries worldwide
Abstract: "Providing fairness and providing good response times are often viewed as conflicting goals in scheduling. Scheduling policies that provide low response times, such as Shortest Running Processing Time (SRPT), are sometimes not fair, while fair policies like Processor Sharing (PS) provide response times far worse than SRPT. This seemingly inevitable tension between providing fairness and providing good response times was eliminated at last year's ACM Sigmetrics conference with the introduction of a new scheduling policy, Fair Sojourn Protocol (FSP), that appears to provide both [9]. The FSP policy is provably fair, as seen directly from its definition, and simulations show that FSP has a very low mean response time, close to that of SRPT in many cases [9]. Unfortunately, analyzing the mean response time of the FSP policy has proven to be difficult, and thus the queueing performance of FSP has only be [sic] assessed via simulation. In this work, we present the first queueing analysis of FSP. This analysis yields close upper and lower bounds on the mean response time and mean slowdown of the M/GI/1/FSP queue. Our upper bound shows that the improvement of FSP over PS is substantial: for all job size distributions, the mean response time and mean slowdown under FSP are a fraction (1 - [rho]/2) of that under PS, where [rho] is the system load. For distributions with decreasing failure rate the improvement is even greater. We also prove that the mean response time of SRPT and FSP are quite close. Lastly, our bounds reveal that FSP has yet another desirable property: similarly to PS, the FSP policy is largely insensitive to the variability of the job size distribution."
The foreground-background queue: a survey by Misja Nuyens ( Book )
1 edition published in 2006 in English and held by 2 WorldCat member libraries worldwide
Competitive analysis of M/GI/1 queueing policies by Nikhil Bansal ( Book )
1 edition published in 2002 in English and held by 1 WorldCat member library worldwide
Abstract: "We propose a framework for comparing the performance of two queueing policies. Our framework is motivated by the notion of competitive analysis, widely used by the computer science community to analyze the performance of online algorithms. We apply our framework to compare M/GI/1/FB and M/GI/1/SJF with M/GI/1/SRPT, and obtain new results about the performance of M/GI/1/FB and M/GI/1/SJF."
A unified framework for modeling TCP-Vegas, TCP-SACK, and TCP-Reno by Adam Wierman ( Book )
1 edition published in 2003 in English and held by 1 WorldCat member library worldwide
Abstract: "We present a general analytical framework for the modeling and analysis of TCP variations. The framework is quite comprehensive and allows the modeling of multiple variations of TCP, i.e. TCP-Vegas, TCP-SACK, and TCP-Reno, under very general network situations. In particular, the framework allows us to propose the first analytical model of TCP-Vegas under on-off traffic -- all existing analytical models of TCP-Vegas assume bulk transfer only. All TCP models are validated against event driven simulations (ns-2) and existing state-of-the-art analytical models. Finally, the analysis provided by our framework leads to many interesting observations with respect to both the behavior of bottleneck links that are shared by TCP sources and the effectiveness of the design decisions in TCP-SACK and TCP-Vegas."
A note on comparing response times in the M/GI/1/FB and M/GI/1/PS queues by Adam Wierman ( Book )
1 edition published in 2002 in English and held by 1 WorldCat member library worldwide
Abstract: "Two widely used scheduling policies used in the absence of knowledge of job sizes are Processor Sharing (PS) and Feedback (FB). While a lot of work has been done on comparing their performance on particular job size distributions, a general comparison has not been done. We compare the overall mean response time (a.k.a. sojourn time) of the PS and FB queues under an M/GI/1 system. We show that FB outperforms PS when the service distribution has a decresing failure rate; but that when the failure rate of the service distribution is increasing, PS outperforms FB. This answers a question posed by Coffman and Denning [1]."
Asymptotic convergence of scheduling policies with respect to slowdown by Mor Harchol-Balter ( Book )
1 edition published in 2002 in English and held by 1 WorldCat member library worldwide
Abstract: "We explore the performance of an M/GI/1 queue under various scheduling policies from the perspective of a new metric: the slowdown experienced by largest jobs. We consider scheduling policies that bias against large jobs, towards large jobs, and those that are fair, e.g., Processor-Sharing. We prove that as job size increases to infinity, all work conserving policies converge almost surely with respect to this metric to no more than 1/(1-[rho]), where [rho] denotes load. We also find that the expected slowdown under any work conserving policy can be made arbitrarily close to that under Processor-Sharing, for all job sizes that are sufficiently large."
Simple bounds on SMART scheduling by Adam Wierman ( Book )
1 edition published in 2003 in English and held by 1 WorldCat member library worldwide
Abstract: "We define the class of SMART scheduling policies. These are policies that bias towards jobs with short remaining service times, jobs with small original sizes, or both, with the motivation of minimizing mean response time and/or mean slowdown. Examples of SMART policies include PSJF, SRPT, and hybrid policies such as RS (which biases according to the product of the response time and size of a job. For many policies in the SMART class, the mean response time and mean slowdown are not known or have complex representations involving multiple nested integrals, making evaluation difficult. In this work, we prove three main results. First, for all policies in the SMART class, we prove simple upper and lower bounds on mean response time. In particular, we focus on the SRPT and PSJF policies and prove even tighter bounds in these cases. Second, we show that all policies in the SMART class, surprisingly, have very similar mean response times. Third, we show that the response times of SMART policies are largely invariant to the variability of the job size distribution."
Analyzing the effect of prioritized background tasks in multiserver systems ( Book )
1 edition published in 2003 in English and held by 1 WorldCat member library worldwide
Abstract: "Computer systems depend on high priority background processes to provide both reliability and security. This is especially true in multiserver systems where many such background processes are required for data coherence, fault detection, intrusion detection, etc. From a user's perspective, it is important to understand the effect that these many classes of high priority, backround tasks have on the performance of lower priority user-level tasks. We model this situation as an M/GI/k queue with m preemptive-resume priority classes, presenting the first analysis of this system with more than two priority classes under a general phase-type service distribution. (Prior analyses of the M/GI/k with more than two priority classes are approximations that, we show, can be highly inaccurate.) Our analytical method is very different from the prior literature: it combines the technique of dimensionality reduction [10] with Neuts' technique for determining busy periods in multiserver systems [21], and then uses a novel recursive iteration technique. Our analysis is approximate, but, unlike prior techniques, can be made as accurate as desired, and is verified via simulation."
Preventing large sojourn times using SMART scheduling by M Nuyens ( Book )
1 edition published in 2005 in English and held by 1 WorldCat member library worldwide
 
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Languages
English (11)