共查询到19条相似文献,搜索用时 562 毫秒
1.
2.
针对OCS (online charging system)服务器,提出了一种新的请求调度算法,算法的基本思想是利用系统队列的长度、请求的到达率以及预先分配的时延区分参数作为调度的优先级依据,在调度时采用概率的方式选取需要服务的队列请求.实验结果表明,在考虑服务时延的情况下,新算法性能总是优于一些传统的PDD(proportional delay differentiation)调度算法,当请求服务时延增加和彼此差别很大时,性能优势相对更大,并且有效地满足了内容计费环境下提出的6点QoS(quality of service)要求. 相似文献
3.
4.
负载均衡是大规模基于对象存储系统必须要考虑的重要问题.探讨了几种经典的负载均衡调度算法,介绍了它们的算法流程及其优缺点,最后根据INSS存储系统结构模型及其I/O请求流程,提出了一种二级动态反馈负载均衡模型,能最大程度的减少系统的平均总响应时间. 相似文献
5.
一种HSDPA系统中依赖负载的正比公平调度算法 总被引:1,自引:0,他引:1
研究和仿真了HSDPA系统中分组调度算法(RR,Max C/I和PF)的系统吞吐量和用户公平性,仿真结果与理论分析表明在HSDPA系统中RR算法调度结果的公平性略逊于PF算法.为了补偿正比公平调度算法公平性,提出了依赖负载的正比公平(LDPF)调度算法.该算法旨在通过低负载时牺牲系统吞吐量换取用户间公平性.然后用扩展了爱立信EUPLANE模块的NS2网络仿真软件对LDPF算法进行了仿真.仿真结果表明LDPF调度算法在系统低负载时有效地补偿了先前的低速率用户,通过这种低负载和高负载时的时间分集,改善用户间的长时公平性. 相似文献
6.
一种基于优先级队列的集群动态反馈调度算法 总被引:1,自引:0,他引:1
在分析现有面向LVS集群的负载均衡调度算法优缺点的基础上,提出了一种新的调度算法—基于优先级队列的动态反馈调度算法。该算法根据定期采集到的各服务器负载信息动态地调整各服务器的权值,并根据权值建立优先级调度队列借以实现连接的调度。算法可保证良好的负载均衡性,且时间复杂度降低至O(1)。 相似文献
7.
8.
在多控制器管理的软件定义网络(SDN)中,时延和负载是控制器放置问题(CPP)要考虑的重要因素。该文以降低控制器之间的传播时延、流请求的传播时延和排队时延、均衡控制器间负载为目标,提出一种控制器放置及动态调整的策略,其中包括用于初始控制器放置的负载均衡算法(BCRA)和遗传算法(GA),用于动态调整控制器负载的在线调整算法(ADOA)。以上算法均考虑网络连通性。仿真结果表明:在初始控制器放置时,在保证流请求的传播时延、排队时延和控制器传播时延较低的情况下,BCRA部署在中小型网络中时,其负载均衡性能与GA相近且优于k-center和k-means算法;GA部署在大型网络中时,与BCRA, k-center和k-means算法相比,使得负载均衡率平均提高了49.7%。在动态情况下,与现有动态调整算法相比,ADOA可以保证较低排队时延和运行时间的同时,仍能使负载均衡参数小于1.54。 相似文献
9.
针对无线虚拟化网络在时间域上业务请求的动态变化和信息反馈时延导致虚拟资源分配的不合理,该文提出一种基于长短时记忆(LSTM)网络的流量感知算法,该算法通过服务功能链(SFC)的历史队列信息来预测未来负载状态。基于预测的结果,联合考虑虚拟网络功能(VNF)的调度问题和相应的计算资源分配问题,提出一种基于最大最小蚁群算法(MMACA)的虚拟网络功能动态部署方法,在满足未来队列不溢出的最低资源需求的前提下,采用按需分配的方式最大化计算资源利用率。仿真结果表明,该文提出的基于LSTM神经网络预测模型能够获得很好的预测效果,实现了网络的在线监测;基于MMACA的VNF部署方法有效降低了比特丢失率的同时也降低了整体VNF调度产生的平均端到端时延。 相似文献
10.
针对网络控制系统(Network Control Systems, NCS)节点中的非周期任务,设计了一种FC-ABS调度算法.该调度算法可以根据非周期任务的时间特性采取不同的调度方式,并通过反馈调度减小非周期任务调度对周期任务的影响.仿真实验证明了算法的正确性. 相似文献
11.
12.
13.
Several scheduling techniques were designed for the base station (BS) of IEEE 802.16e wireless interoperability of microwave access networks. However, depending on the BS scheduler alone to determine the servicing order of each connection might affect the accuracy of the scheduling process because the BS does not necessarily have enough up‐to‐date information about the current state of the connections at the subscriber station. In this paper, we propose a preemption‐based scheduling algorithm that focuses on improving the quality of service requirements of real‐time service flow classes. The proposed algorithm incorporates two schedulers, one at the BS and another one at the subscriber station. We have implemented and integrated the proposed algorithm with the network simulator NS2 using the Network and Distributed Systems Laboratory wireless interoperability of microwave access module. Simulation results have shown that the proposed approach outperforms other scheduling algorithms in terms of enhancing the throughput and the average delay of real‐time quality of service classes. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
14.
ZHANG Qi-zhi 《中国邮电高校学报(英文版)》2008,15(1):43-47
After analyzing the features of the Parlay application server(AS), which provides many services with different time constraints in the next generation network(NGN), a selfadapted overload control algorithm implemented in Parlay AS is proposed. In this algorithm, the service process module in parlay AS uses the earliest deadline first (EDF) serving rule to serve messages, and the overload control mechanism, using the Leaky Bucket algorithm to control message flows, is triggered by estimating the queue waiting time of a newly arriving message. By simulation it shows that this algorithm is a simple, easy-to-use, and available algorithm. 相似文献
15.
提出了一种新的应用于集群计算环境的文件分配算法,即启发式文件分类分配算法(Heuristic FileSorted Assignment algorithm,HFSA),它在保证系统负载基本均衡的前提下,按相似的访问服务时间对每个待分配的数据文件进行磁盘分配.具体实现时,首先对待分配文件按它们的服务时间大小进行排序,然后从集群中选择一个结点的磁盘,将有序的若干文件连续地分配到该磁盘上,直接该磁盘达到最大负载时为止.通过对新策略与已有的贪婪文件分配法进行实验比较,结果表明:在访问响应时间方面,系统轻负载时,缩短了20.2%,系统重负载时,缩短了31.6%,并且数据访问的速率越高,由启发式文件分类分配策略所改善的性能就越明显. 相似文献
16.
The increasing demand for interactive mobile multimedia service is causing the integration of 3rd generation (3G) cellular systems and wireless broadcast systems. The key challenge is to support data dissemination with low response time, request drop rate, and the unfairness of request drop. This article proposes a novel scheduling algorithm called DAG (on-demand scheduling utilizing analytic hierarchy process (AHP) and grey relational analysis (GRA)), which takes multiple factors-waiting time, number of active requests, deadline-into consideration, and models the data scheduling process as a multiple factors' decision-making and best option-selecting process. The proposed approach comprises two parts. The first part applies AHP to decide the relative weights of multiple decision factors according to user requests, while the second adopts GRA to rank the data item alternatives through the similarity between each option and the ideal option. Simulation results are presented to demonstrate that DAG performs well in the multiple criterions mentioned above. 相似文献
17.
In this paper, we proposed an improved hybrid semantic matching algorithm combining Input/Output (I/O) semantic matching with
text lexical similarity to overcome the disadvantage that the existing semantic matching algorithms were unable to distinguish
those services with the same I/O by only performing I/O based service signature matching in semantic web service discovery
techniques. The improved algorithm consists of two steps, the first is logic based I/O concept ontology matching, through
which the candidate service set is obtained and the second is the service name matching with lexical similarity against the
candidate service set, through which the final precise matching result is concluded. Using Ontology Web Language for Services
(OWL-S) test collection, we tested our hybrid algorithm and compared it with OWL-S Matchmaker-X (OWLS-MX), the experimental
results have shown that the proposed algorithm could pick out the most suitable advertised service corresponding to user’s
request from very similar ones and provide better matching precision and efficiency than OWLS-MX. 相似文献
18.
An ant colony optimization task scheduling algorithm based on multiple quality of service constraint (QoS-ACO) for SWIM was proposed.Focusing on the multiple quality of service (QoS) requirements for task requests completed in system-wide information management (SWIM),considering the task execution time,security and reliability factors,a new evaluate user satisfaction utility function and system task scheduling model were constructed.Using the QoS total utility evaluation function of SWIM service scheduling to update the pheromone of the ant colony algorithm.The simulation results show that under the same conditions,the QoS-ACO algorithm is better than the traditional Min-Min algorithm and particle swarm optimization (PSO) algorithm in terms of task completion time,security,reliability and quality of service total utility evaluation value,and it can ensure that the user's task scheduling quality of service requirements are met,and can better complete the scheduling tasks of the SWIM. 相似文献
19.
Broadcast is becoming an increasingly attractive data-dissemination method for large client populations. In order to effectively utilize a broadcast medium for such a service, it is necessary to have efficient on-line scheduling algorithms that can balance individual and overall performance and can scale in terms of data set sizes, client populations, and broadcast bandwidth. We propose an algorithm, called R×W, that provides good performance across all of these criteria and can be tuned to trade off average and worst-case waiting time. Unlike previous work on low overhead scheduling, the algorithm does not use estimates of the access probabilities of items, but rather, it makes scheduling decisions based on the current queue state, allowing it to easily adapt to changes in the intensity and distribution of the workload. We demonstrate the performance advantages of the algorithm under a range of scenarios using a simulation model and present analytical results that describe the intrinsic behavior of the algorithm 相似文献