Utilization of nonclairvoyant online schedules
نویسندگان
چکیده
This paper addresses the analysis of nondelay, nonpreemptive, nonclairvoyant online schedules for independent jobs onm identical machines. In our online model, all jobs are submitted over time. We show that the commonly used makespan criterion is not well suited to describe utilization for this online problem. Therefore, we directly address utilization and determine themaximum deviation from the optimal utilization for the given scheduling problem. © 2006 Elsevier B.V. All rights reserved.
منابع مشابه
New utilization criteria for online scheduling
In the classical scheduling problems, it has been assumed that complete knowledge of the problem was available when it was to be solved. However, scheduling problems in the real world face the possibility of the lack of the knowledge. Uncertainties frequently encountered in scheduling environments include the appearance of new jobs and unknown processing times. In this work, we take into accoun...
متن کاملMinimizing Maximum Flowtime of Jobs with Arbitrary Parallelizability
We consider the problem of nonclairvoyantly scheduling jobs, which arrive over time and have varying sizes and degrees of parallelizability, with the objective of minimizing the maximum flow. We give essentially tight bounds on the achievable competitiveness. More specifically we show that the competitive ratio of every deterministic nonclairvoyant algorithm is high, namely Ω( √ n). But there i...
متن کاملAn Owner-centric Metric for the Evaluation of Online Job Schedules
The paper presents a metric that is well suited to evaluate online job schedules for massively parallel processors. We point out the disadvantages of commonly used metrics like makespan or machine utilization. We suggest to use the well known total weighted completion time metric with an appropriate selection of job weights and show that this metric exhibits many properties that are similar to ...
متن کاملTowards Memory-Optimal Schedules for SDF
The Synchronous Data Flow (SDF) programming model is an established programming paradigm for stream processing applications. SDF programs are expressed by actors and streams that establish communication among actors. Streams are implemented as FIFO buffers, and the size of the FIFO buffers depends on the steady-state schedule. Finding a steady-state schedule that minimizes the sizes of FIFO buf...
متن کاملEvery Deterministic Nonclairvoyant Scheduler has a Suboptimal Load Threshold
We prove a surprising lower bound for resource augmented nonclairvoyant algorithms for scheduling jobs with sublinear nondecreasing speed-up curves on multiple processors with the objective of average response time. Edmonds in STOC99 shows that the algorithm Equi-partition is a (2+ǫ)-speed Θ( ǫ )-competitive algorithm. We define its speed threshold to be 2 because it is constant competitive whe...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Theor. Comput. Sci.
دوره 362 شماره
صفحات -
تاریخ انتشار 2006