• Title/Summary/Keyword: Task Scheduling

Search Result 483, Processing Time 0.028 seconds

A Task Scheduling Method after Clustering for Data Intensive Jobs in Heterogeneous Distributed Systems

  • Hajikano, Kazuo;Kanemitsu, Hidehiro;Kim, Moo Wan;Kim, Hee-Dong
    • Journal of Computing Science and Engineering
    • /
    • v.10 no.1
    • /
    • pp.9-20
    • /
    • 2016
  • Several task clustering heuristics are proposed for allocating tasks in heterogeneous systems to achieve a good response time in data intensive jobs. However, one of the challenging problems is the process in task scheduling after task allocation by task clustering. We propose a task scheduling method after task clustering, leveraging worst schedule length (WSL) as an upper bound of the schedule length. In our proposed method, a task in a WSL sequence is scheduled preferentially to make the WSL smaller. Experimental results by simulation show that the response time is improved in several task clustering heuristics. In particular, our proposed scheduling method with the task clustering outperforms conventional list-based task scheduling methods.

Analysis Task Scheduling Models based on Hierarchical Timed Marked Graph

  • Ro, Cheul-Woo;Cao, Yang
    • International Journal of Contents
    • /
    • v.6 no.3
    • /
    • pp.19-24
    • /
    • 2010
  • Task scheduling is an integrated component of computing with the emergence of grid computing. In this paper, we address two different task scheduling models, which are static Round-Robin (RR) and dynamic Fastest Site First (FSF) task scheduling method, using extended timed marked graphs, which is a special case of Stochastic Petri Nets (SPN). Stochastic reward nets (SRN) is an extension of SPN and provides compact modeling facilities for system analysis. We build hierarchical SRN models to compare two task scheduling methods. The upper level model simulates task scheduling and the lower level model implements task serving process for different sites with multiple servers. We compare these two models and analyze their performances by giving reward measures in SRN.

Dynamic Task Scheduling Via Policy Iteration Scheduling Approach for Cloud Computing

  • Hu, Bin;Xie, Ning;Zhao, Tingting;Zhang, Xiaotong
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.11 no.3
    • /
    • pp.1265-1278
    • /
    • 2017
  • Dynamic task scheduling is one of the most popular research topics in the cloud computing field. The cloud scheduler dynamically provides VM resources to variable cloud tasks with different scheduling strategies in cloud computing. In this study, we utilized a valid model to describe the dynamic changes of both computing facilities (such as hardware updating) and request task queuing. We built a novel approach called Policy Iteration Scheduling (PIS) to globally optimize the independent task scheduling scheme and minimize the total execution time of priority tasks. We performed experiments with randomly generated cloud task sets and varied the performance of VM resources using Poisson distributions. The results show that PIS outperforms other popular schedulers in a typical cloud computing environment.

Task Scheduling Algorithm for the Communication, Ocean, and Meteorological Satellite

  • Lee, Soo-Jeon;Jung, Won-Chan;Kim, Jae-Hoon
    • ETRI Journal
    • /
    • v.30 no.1
    • /
    • pp.1-12
    • /
    • 2008
  • In this paper, we propose an efficient single-resource task scheduling algorithm for the Communication, Ocean, and Meteorological Satellite. Among general satellite planning functions such as constraint check, priority check, and task scheduling, this paper focuses on the task scheduling algorithm, which resolves conflict among tasks which have an exclusion relation and the same priority. The goal of the proposed task scheduling algorithm is to maximize the number of tasks that can be scheduled. The rationale of the algorithm is that a discarded task can be scheduled instead of a previously selected one depending on the expected benefit acquired by doing so. The evaluation results show that the proposed algorithm enhances the number of tasks that can be scheduled considerably.

  • PDF

Schedulability Test using task utilization in Real-Time system (실시간 시스템에서 태스크 이용율을 이용한 스케줄링 가능성 검사)

  • Lim Kyung-Hyun;Seo Jae-Hyeon;Park Kyung-Woo
    • Journal of Internet Computing and Services
    • /
    • v.6 no.2
    • /
    • pp.25-35
    • /
    • 2005
  • The Rate Monotonic(RM) scheduling algorithm and Earliest Deadline First(EDF) scheduling algorithm are normally used in Real-Time scheduling algorithm. In those scheduling algorithm, we could predict the performance possibility with total utilization value of task group. But. it had problems with prediction of the boundedness in individual task when the utilization value was over in temporary task. In this paper, the suggested scheduling algorithm can predict task when the utilization value was over and it suggested the method of predicting scheduling possibility based on the utilization value of individual task as well. it predicted the boundedness of scheduling possibility test through simulation In Real-Time scheduling algorithm and analyzed the result.

  • PDF

Task Scheduling and Resource Management Strategy for Edge Cloud Computing Using Improved Genetic Algorithm

  • Xiuye Yin;Liyong Chen
    • Journal of Information Processing Systems
    • /
    • v.19 no.4
    • /
    • pp.450-464
    • /
    • 2023
  • To address the problems of large system overhead and low timeliness when dealing with task scheduling in mobile edge cloud computing, a task scheduling and resource management strategy for edge cloud computing based on an improved genetic algorithm was proposed. First, a user task scheduling system model based on edge cloud computing was constructed using the Shannon theorem, including calculation, communication, and network models. In addition, a multi-objective optimization model, including delay and energy consumption, was constructed to minimize the sum of two weights. Finally, the selection, crossover, and mutation operations of the genetic algorithm were improved using the best reservation selection algorithm and normal distribution crossover operator. Furthermore, an improved legacy algorithm was selected to deal with the multi-objective problem and acquire the optimal solution, that is, the best computing task scheduling scheme. The experimental analysis of the proposed strategy based on the MATLAB simulation platform shows that its energy loss does not exceed 50 J, and the time delay is 23.2 ms, which are better than those of other comparison strategies.

A Fault-tolerant Task Scheduling Algorithm Supporting the Minimum Schedule Length (최소의 스케줄 길이를 유지하는 결함 허용 태스크 스케줄링 알고리즘)

  • Min, Byeong-Jun
    • The Transactions of the Korea Information Processing Society
    • /
    • v.7 no.4
    • /
    • pp.1201-1210
    • /
    • 2000
  • In order to tolerate faults which may occur during the execution of distributed tasks in high-performance parallel computer systems, tasks are duplicated on different processors. In this paper, by utilizing the task duplication based scheduling algorithm, a new task scheduling algorithm which duplicates each task on more than two different processors with the minimum schedule length is presented, and the number of processors required for the duplication is analyzed with the ratio of communication cost to computation time and the workload of the system. A simulation with various task graphs reveals that the number of processors required for the full-duplex fault-tolerant task scheduling with the obtainable minimum schedule length increases about 30% to 75% when compared with that of the task duplication based scheduling algorithm.

  • PDF

Efficient Duplication Based Task Scheduling with Communication Cost in Heterogeneous Systems (이질 시스템에서 통신 시간을 고려한 효율적인 복제 기반 태스크 스케줄링)

  • Yoon, Wan-Oh;Baek, Jueng-Kuy;Shin, Kwang-Sik;Cheong, Jin-Ha;Choi, Sang-Bang
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.33 no.3C
    • /
    • pp.219-233
    • /
    • 2008
  • Optimal scheduling of parallel tasks with some precedence relationship, onto a parallel machine is known to be NP-complete. The complexity of the problem increases when task scheduling is to be done in a heterogeneous environment, where the processors in the network may not be identical and take different amounts of time to execute the same task. This paper introduces a Duplication based Task Scheduling with Communication Cost in Heterogeneous Systems (DTSC), which provides optimal results for applications represented by Directed Acyclic Graphs (DAGs), provided a simple set of conditions on task computation and network communication time could be satisfied. Results from an extensive simulation show significant performance improvement from the proposed techniques over the Task duplication-based scheduling Algorithm for Network of Heterogeneous systems(TANH) and General Dynamic Level(GDL) scheduling algorithm.

A Study on the Efficient Task Scheduling by the Reconstructed Task Graph (태스크 그래프의 재구성에 의한 효율적 태스크 스케줄링에 관한 연구)

  • Byun, Seung-Hwan;Yoo, Kwan-Jong
    • The Transactions of the Korea Information Processing Society
    • /
    • v.4 no.9
    • /
    • pp.2235-2246
    • /
    • 1997
  • This paper presents an effective heuristic task scheduling algorithm for multiprocessor systems. To execute task scheduling effectively which is defined as an allocation of m's tasks onto n's processors(m > n), several problems almost at NP-hard should be cleaned up. The purpose of the task scheduling obtains the minimum execution time by mapping the tasks on a system topology or reduces the total execution time to give a minimum system topology. In order to solve this problem, in this paper, the task scheduling is done by redefining a task graph to a reconstructed task graph (RTG). An RTG is obtained by merging or copying nodes to equal the number of nodes on each level of the task graph to the number of processors of the system topology and then directly scheduled to the system topology. This method obtains a fast scheduling time and a simple scheduling method, and near-optimal execution time without executing steps such as the refinement step and the duplication step after the task scheduling.

  • PDF

Task-Technology Fit in Construction Scheduling

  • Yang, Juneseok;Arditi, David
    • International conference on construction engineering and project management
    • /
    • 2015.10a
    • /
    • pp.117-121
    • /
    • 2015
  • Construction managers use scheduling methods to improve the outcome of their project. Despite the many obvious advantages of the critical path method (CPM), its use in construction has been limited. Understanding the reasons why CPM is not used as extensively as expected could improve its level of acceptance in the construction industry. The link between construction scheduling methods and the tasks expected to be performed by schedulers has been an on-going concern in the construction industry. This study proposes a task-technology fit model to understand why CPM is not used as extensively as expected in construction scheduling. A task-technology fit model that aims to measure the extent to which a construction scheduling method functionally matches the tasks expected to be performed by the scheduling staff. The model that is proposed is an answer to the lack of proper instruments for evaluating the extent to which scheduling methods are used in the industry.

  • PDF