Web serverclusters has become a popular solutionto achieve high performance duetotheirlow price, highreliability,and good scalability. One ofthe key technologiesis “request dispatching”, which is to centrallyaccept...Web serverclusters has become a popular solutionto achieve high performance duetotheirlow price, highreliability,and good scalability. One ofthe key technologiesis “request dispatching”, which is to centrallyacceptallthe incoming HTTPrequests and dispatchthem to the serversinthe clusterto achieve parallelism .The research showsthatthe efficiency ofrequest dispatching is determined by whetherthe serverloads are balanced duringthe dispatching.This paper studies the characteristics ofthe load generated by HTTPrequests,gives anefficient method ofloadsampling,and presentsa novelrequestdispatching algorithm which can predicttheload andbalanceit.The method can be usedto build Web serverclusters ofheterogeneous machines.展开更多
Recently,the fundamental problem with Hybrid Mobile Ad-hoc Net-works(H-MANETs)is tofind a suitable and secure way of balancing the load through Internet gateways.Moreover,the selection of the gateway and overload of th...Recently,the fundamental problem with Hybrid Mobile Ad-hoc Net-works(H-MANETs)is tofind a suitable and secure way of balancing the load through Internet gateways.Moreover,the selection of the gateway and overload of the network results in packet loss and Delay(DL).For optimal performance,it is important to load balance between different gateways.As a result,a stable load balancing procedure is implemented,which selects gateways based on Fuzzy Logic(FL)and increases the efficiency of the network.In this case,since gate-ways are selected based on the number of nodes,the Energy Consumption(EC)was high.This paper presents a novel Node Quality-based Clustering Algo-rithm(NQCA)based on Fuzzy-Genetic for Cluster Head and Gateway Selection(FGCHGS).This algorithm combines NQCA with the Improved Weighted Clus-tering Algorithm(IWCA).The NQCA algorithm divides the network into clusters based upon node priority,transmission range,and neighbourfidelity.In addition,the simulation results tend to evaluate the performance effectiveness of the FFFCHGS algorithm in terms of EC,packet loss rate(PLR),etc.展开更多
Aiming at the load imbalance and poor scalability in single-tier Web server clusters, an efficient load balancing ap- proach is proposed for constructing an N-hierarchical （multi-tier） Web server cluster. In each la...Aiming at the load imbalance and poor scalability in single-tier Web server clusters, an efficient load balancing ap- proach is proposed for constructing an N-hierarchical （multi-tier） Web server cluster. In each layer, multiple load balancers are set to receive the user requests simultaneously, and different load bal- ancing algorithms are used to construct the high-scalable Web cluster system. At the same time, an improved load balancing al- gorithm is proposed, which can dynamically calculate weights according to the utilization of the server resources, and reasonably distribute the loads for each server according to the load status of the servers. The experimental results show that the proposed ap- proach can greatly decrease the load imbalance among the Web servers and reduce the response time of the entire Web cluster system.展开更多
The real problem in cluster of workstations is the changes in workstation power or number of workstations or dynmaic changes in the run time behavior of the application hamper the efficient use of resources. Dynamic l...The real problem in cluster of workstations is the changes in workstation power or number of workstations or dynmaic changes in the run time behavior of the application hamper the efficient use of resources. Dynamic load balancing is a technique for the parallel implementation of problems, which generate unpredictable workloads by migration work units from heavily loaded processor to lightly loaded processors at run time. This paper proposed an efficient load balancing method in which parallel tree computations depth first search (DFS) generates unpredictable, highly imbalance workloads and moves through different phases detectable at run time, where dynamic load balancing strategy is applicable in each phase running under the MPI(message passing interface) and Unix operating system on cluster of workstations parallel platform computing.展开更多
分析Web服务器集群技术,研究负载均衡算法,提出基于临界加速递减的一致性哈希负载均衡算法CHMDC(Consistent hash load balancing algorithm based on the Multiplicative Decrease in Critical area)。一方面,该算法采用了加权一致性...分析Web服务器集群技术,研究负载均衡算法,提出基于临界加速递减的一致性哈希负载均衡算法CHMDC(Consistent hash load balancing algorithm based on the Multiplicative Decrease in Critical area)。一方面,该算法采用了加权一致性哈希算法,引入了虚拟化的设计思路,采用虚拟节点进行真实服务器节点分配;另一方面,该算法提出了基于请求反馈时间计算机服务器节点负载率的方法,引入了临界因子的概念,采用了临界因子加速递减来防止服务器过载。通过实验测试证明,该算法应用于Web服务器集群的负载均衡效果突出。展开更多
Web Cluster is an effective mechanism used in Web site construction to deal with the system capacity prob-lem. Researchers proposed several strategies or algorithms, which improve the performance and scalability of th...Web Cluster is an effective mechanism used in Web site construction to deal with the system capacity prob-lem. Researchers proposed several strategies or algorithms, which improve the performance and scalability of the Webcluster system. In this paper, a content-based load distribution algorithm is proposed. It takes the processing ability ofback-end severs and the request load weight into account, and ensure the request locality. The emulation results illus-trate that this algorithm performs better in different kinds of Web site, comparing with other relative algorithms.展开更多
文摘Web serverclusters has become a popular solutionto achieve high performance duetotheirlow price, highreliability,and good scalability. One ofthe key technologiesis “request dispatching”, which is to centrallyacceptallthe incoming HTTPrequests and dispatchthem to the serversinthe clusterto achieve parallelism .The research showsthatthe efficiency ofrequest dispatching is determined by whetherthe serverloads are balanced duringthe dispatching.This paper studies the characteristics ofthe load generated by HTTPrequests,gives anefficient method ofloadsampling,and presentsa novelrequestdispatching algorithm which can predicttheload andbalanceit.The method can be usedto build Web serverclusters ofheterogeneous machines.
文摘Recently,the fundamental problem with Hybrid Mobile Ad-hoc Net-works(H-MANETs)is tofind a suitable and secure way of balancing the load through Internet gateways.Moreover,the selection of the gateway and overload of the network results in packet loss and Delay(DL).For optimal performance,it is important to load balance between different gateways.As a result,a stable load balancing procedure is implemented,which selects gateways based on Fuzzy Logic(FL)and increases the efficiency of the network.In this case,since gate-ways are selected based on the number of nodes,the Energy Consumption(EC)was high.This paper presents a novel Node Quality-based Clustering Algo-rithm(NQCA)based on Fuzzy-Genetic for Cluster Head and Gateway Selection(FGCHGS).This algorithm combines NQCA with the Improved Weighted Clus-tering Algorithm(IWCA).The NQCA algorithm divides the network into clusters based upon node priority,transmission range,and neighbourfidelity.In addition,the simulation results tend to evaluate the performance effectiveness of the FFFCHGS algorithm in terms of EC,packet loss rate(PLR),etc.
基金Supported by the National Natural Science Foundation of China(61073063,61173029,61272182 and 61173030)the Ocean Public Welfare Scientific Research Project of State Oceanic Administration of China(201105033)National Digital Ocean Key Laboratory Open Fund Projects(KLDO201306)
文摘Aiming at the load imbalance and poor scalability in single-tier Web server clusters, an efficient load balancing ap- proach is proposed for constructing an N-hierarchical （multi-tier） Web server cluster. In each layer, multiple load balancers are set to receive the user requests simultaneously, and different load bal- ancing algorithms are used to construct the high-scalable Web cluster system. At the same time, an improved load balancing al- gorithm is proposed, which can dynamically calculate weights according to the utilization of the server resources, and reasonably distribute the loads for each server according to the load status of the servers. The experimental results show that the proposed ap- proach can greatly decrease the load imbalance among the Web servers and reduce the response time of the entire Web cluster system.
基金Natural Science Foundation of China (No.60 173 0 3 1)
文摘The real problem in cluster of workstations is the changes in workstation power or number of workstations or dynmaic changes in the run time behavior of the application hamper the efficient use of resources. Dynamic load balancing is a technique for the parallel implementation of problems, which generate unpredictable workloads by migration work units from heavily loaded processor to lightly loaded processors at run time. This paper proposed an efficient load balancing method in which parallel tree computations depth first search (DFS) generates unpredictable, highly imbalance workloads and moves through different phases detectable at run time, where dynamic load balancing strategy is applicable in each phase running under the MPI(message passing interface) and Unix operating system on cluster of workstations parallel platform computing.
文摘分析Web服务器集群技术,研究负载均衡算法,提出基于临界加速递减的一致性哈希负载均衡算法CHMDC(Consistent hash load balancing algorithm based on the Multiplicative Decrease in Critical area)。一方面,该算法采用了加权一致性哈希算法,引入了虚拟化的设计思路,采用虚拟节点进行真实服务器节点分配;另一方面,该算法提出了基于请求反馈时间计算机服务器节点负载率的方法,引入了临界因子的概念,采用了临界因子加速递减来防止服务器过载。通过实验测试证明,该算法应用于Web服务器集群的负载均衡效果突出。
文摘Web Cluster is an effective mechanism used in Web site construction to deal with the system capacity prob-lem. Researchers proposed several strategies or algorithms, which improve the performance and scalability of the Webcluster system. In this paper, a content-based load distribution algorithm is proposed. It takes the processing ability ofback-end severs and the request load weight into account, and ensure the request locality. The emulation results illus-trate that this algorithm performs better in different kinds of Web site, comparing with other relative algorithms.
