CLUE Based Load Balancing in Replicated Web Server

ABSTRACTThe performance of 3GPP long term evolution (LTE) network can be significantly influenced by unbalanced user distribution. In heavily loaded cells, users cannot obtain satisfied services because of shortage of resources, whereas in lightly loaded cells, there are plenty of unoccupied resources. Load balancing (LB) is proposed to deal with this problem, through which the load distribution among nearby cells can be greatly balanced. However, because of the usage of full frequency reuse in LTE, the cell‐edge throughput is severely deteriorated by strong intercell interference. Meanwhile, LTE network usually serves users with heterogenous quality‐of‐service (QoS) requirements, which requires LB to be aware of it. Furthermore, call admission control (CAC) is indispensable in the process of LB, and it depends heavily on the long‐term average performance of the scheduling scheme. Thus, design of an efficient LB algorithm with the consideration of intercell interference, QoS, CAC and scheduling together becomes an important issue. To deal with the previous problem, a multi‐objective optimisation problem is formulated in this paper. Its complexity is analysed, and a practical algorithm, which includes hybrid scheduling, QoS‐guaranteed CAC, QoS‐aware intracell and intercell LB, is proposed. Extensive simulations are conducted. Results show that the proposed algorithm can approximate the optimal solution efficiently, thus leading to significantly better performance, that is, a lower new call blocking rate for users with QoS requirement, a larger total utility and a higher cell‐edge throughput for users without QoS requirement, although the cost is a bit degradation of the total throughput. Copyright © 2013 John Wiley & Sons, Ltd.

A dominant factor for the success of an Internet based Web service is the Quality of Service (QoS) perceived by its users. The principal QoS attributes these users perceive include those related to the service "responsiveness", i.e. the service availability and timeliness. In this paper, we argue that QoS can be provided by distributing the processing load among replicated Web servers, and that these servers can be geographically distributed across the Internet. In this context, we discuss strategies for load distribution, and summarize a number of alternative architectures that can implement those strategies. The principal figure of merit we use in order to assess the effectiveness of the load distribution strategies we discuss is the response time experienced by the users.

Dynamic load balancing techniques prevents computer nodes from overloading unevenly while leaving other idle. It is considered as one of the most challenging topics in parallel computing. Moreover, it is essential for increasing the efficiency of highly parallel systems especially in solving multitask problems with unpredictable load estimates. Particularly, over each processor in the parallel systems and interconnection networks. This paper focuses on developing an efficient algorithm for load balancing on Hyper Hexa Cell (HHC) interconnection network, namely, HHCLB algorithm. Basically, the Dimension Exchange Method (DEM) approach is used in this paper to construct a new load balancing approach on the network of HHC interconnections. Thus, an algorithm was introduced and simulated using java threads, where the performance of the algorithm is evaluated both analytically and experimentally. The evaluation was in terms of various performance metrics, including, execution time, load balancing accuracy, communication cost. By implementing the proposed load balancing algorithm to the HHC network, a high degree of accuracy and minimal execution time was achieved. It is important to highlight that the algorithm recorded small gap between the execution time for small number of processors and large number of processors. For instance, the algorithm achieved 0.14 seconds for balancing the load of 6 processors while 0.59 seconds for balancing the load of 3072 processors. This proves how effective the algorithm is in balancing the load for different network sizes from small to large number of processors, with a slight difference in execution time.

3G wireless communication is the next version of mobile networks. Load balancing in networks causes efficient using of network resources. In this paper, we propose an efficient algorithm for load balancing of radio network controllers (RNCs) in radio access networks (RANs). As the characteristics of connections between RNCs and BTSs in a RAN are similar to those of graphs, we make use of graphs to solve our problem. The algorithm is based on the finding a path by which the RNCs could exchange their overloads. By using these paths the algorithm load balances the RNCs in an efficient and fast way. By testing our algorithm on networks with different topology and comparing the results, the efficiency and ability of our algorithm will be verified.

With the development of economics and the globalization of trade, the Multimedia Conference System is now widely used and the number of its users increases exponentially. But a single server can't handle the high concurrent user requests effectively. In this paper, we improved the Multimedia Conference System with load balance technology. With the load balance technology, the robustness and availability of the system can be enhanced significantly. Keywords-load balance, cluster, Nginx, Multimedia Conference System I. INTRODUCTION With the explosive popularity of the Internet and the World Wide Web, most popular web sites confronted with a problem that the server overloaded caused by the increasing number of concurrent accesses. In order to process the user requests timely, increase the network throughput and improve the quality of service, it's necessary to upgrade the hardware and software of the sever. But the the hardware is expensive and non-scalability. In this case, server cluster system appears. The sever cluster system refers to a server group which is composed of more than one homogeneous or heterogeneous severs and can provides services that are transparent for the external users. And it becomes a key point that how to achieve a reasonable distribution of load between multiple servers and avoid appearing one server with full load while other servers with little load. In this situation, the load balance technology was born. In recent years, cluster technology and load balance technology got fully developed and they have significant effect on solving the problem of overloading. As a web service, the Multimedia Conference System also has to face the problem that the overload of the server and uneven distribution of resources when there are too many users access the system. Using cluster and load balance technology, the requests the system received can be evenly distributed on each server, thus we can reduce the response time of the requests and improve the resource utilization. The Multimedia Conference System proposed in this paper contains Client Layer, Load Balancer Layer, Server Cluster Layer and Media Server Layer. The Client Layer receives the requests of the user including creating a conference and joining an existing conference. The Load Balancer Layer redirect the user's request to one of the application servers in the cluster according to the load balance algorithm and the different parameters from the Client Layer. The application servers in Server Cluster Layer call the Media Server resources and return them to the Client Layer. This implements a basic process of the system. The Load Balancer Layer contains four modules including User Authentication, Decision-Making, Redirecting and Log Parsing. With the Load Balancer Layer and its load balance algorithm, the user's request can be distributed on different servers and those who want to join the same conference can be allocated to the same application server. Thus we can minimize the response time of the request, improve the resource utilization and also ensure the conference can be held correctly. The rest of this paper is organized as follows: we describe related work in section II. Section III presents the architecture of the Multimedia Conference System. In section IV, we display the implementation of the Load Balancer Layer in detail. Some experiments of key features of load balancer in section V. We conclude in section VI.

Objectives: In this paper various task scheduling algorithm along with load distribution techniques investigated to ensure efficient mapping of tasks to resources and for coherent resource utilization in heterogeneous environment. Statistical Analysis: A detailed comparative approach is conferred for different job scheduling and load balancing algorithm available in the literature. Considered parameters for comparisons are scheduling approaches, techniques, findings, benefits, pros and cons. This study facilitates to identify the efficient scheduling and load balancing approach which optimizes resource use, minimizes completion time as well as task waiting time and balanced load among resources. Findings: Make span time and flow time are two important parameters to compute and minimize job execution time. This paper explores an intense survey of minimization of task execution time with minimum make span time and flow time. Apart from this a joint review on job scheduling, load balancing and minimizing job completion time using Expected Time to Compute (ETC) matrix is presented. At the end of this paper a research model is proposed which is a novel and hybrid approach with a combination of the efficiency of scheduling and load balancing. Application: The Load Balancing (LB) is an important feature of the grid environment. The efficient LB algorithm assures cost effective resource usage by the provisioning of resources to users on demand schedule in pay-as-you-say-manner.

The exponentially extensive and emerging expansion of the cloud computing network (CCN) and its prolific application result in an ample number of users/clients. The frugal superintend of the client’s requests for resources is troublesome due to a precise number of resources and to actualize the engrossment of Quality of Service (QOS). In aisle to achieve QOS, it is mandatory to maximize the efficiency and reliability of CNN resources. The zero-ground affair is to find an efficient load balancing (LB) algorithm (LBA) that obliged to parcel out data traffic amidst multitudinous resources. Here, in this paper, a multitudinous proposed scheme for QOS has been analyzed.

With the proliferation of Web services as a business solution to enterprise application integration, ranking and selecting the best Web services among the providers become an important factor in the success of the business solution. Quality of service (QoS) determines the quality and usability of a service including its price, performance, reliability, integrity, accessibility, availability, interoperability, and security. Given a set of QoS attributes from a variety of sources, it is a challenge to sort through all of them and be able to get the best services that meet QoS requirement. In this paper, we describe a novel method by which Web services can be ranked and selected automatically based on a number of observed QoS parameters and feedback responses learned from prior knowledge. This new approach treats the observed Web services QoS attributes and target Web services relationship, represented by a matrix, as a statistical problem. Using singular value decomposition (SVD) technique, and an user assisted weighting system, implicit higher order correlations among Web services and their associated QoS attributes are extracted and used to estimate the selection of recommended Web services.

Design of energy efficient load balancing models in cloud environments requires in-depth analysis of the cloud architecture and nature of requests served by the cloud. Depending upon these parameters, machine learning models are designed which aim at assigning best possible resource combination to serve the given tasks. This assignment varies w.r.t. multiple task and cloud parameters; which include task time, virtual machine (VM) performance, task deadline, energy consumption, etc. In order to perform this task, a wide variety of algorithms are developed by researchers cloud designers. Each of these algorithms aim at optimizing certain load balancing related parameters; for instance, a Genetic Algorithm (GA) designed for optimization of VM utilization might not consider task deadline before task allocation to the VMs. While, algorithms aimed at performing deadline aware load balancing might not provide effective cloud-to-task-mapping before allocation of tasks. Thus, it becomes difficult for researchers to select the best possible algorithms for their cloud deployment. In order to reduce this ambiguity, the underlying text compares different energy efficient cloud load balancing algorithms; and evaluates their performance in terms of computational complexity, and relative energy efficiency. This performance evaluation is further extended via inter architecture comparison; in order to evaluate the most optimum load balancer implementation for a given energy efficient application. Thus, after referring this text, researchers and cloud system designers will be able to select optimum algorithmic implementations for their given deployment. This will assist in reducing cloud deployment delay, and improving application specific load balancer performance.

In this paper, we propose a modification of the observe extension of CoAP to include Quality of Service (QoS) support for timeliness. The proposed QoS support is based on delivery priority. Nodes are able to express the priority order with which they wish to be notified. Furthermore, they are also able to specify which notification they want to receive. We classify the notifications in two categories: Critical and Non-Critical. The provided QoS is the result of a negotiation between the client and server. The client demands a certain degree of QoS according to its role. The server could accept or negotiate it. This choice depends on the availability of server and network resources. We evaluate our proposal in a real Wireless Sensor Network. An e-health application has been chosen as target of our tests. The performance evaluation is done in terms of average delay, energy consumption and delivery ratio.

The global optimal Web service selection based on quality of service (QoS) in cloud environment has become a research focus when there are lots of the same or similar services. In this environment, it is possible that many service users request the same or similar services at the same time, which will result in users' unsatisfied requirement and services' load imbalance. The existing service selection approaches usually suppose that service's load capacity is infinite and user always select the service with the best expected QoS despite the amount of user requests. Therefore, it is very important problem how to get a tradeoff between the users' satisfied requirement and service load balance. To solve this problem, this paper presents a global optimal service selection approach based on QoS and load-aware in cloud environment. In this approach, we first build a user QoS utility model which describes the relationship between user's request and services' QoS, and design a service's load capacity model to achieve the load capacity of a service. Then, we use 0-1 integer programming to build a global optimal model based on QoS utility of users and services' load capacity, and provide the optimal service selection algorithm for users. Finally, by conducting large-scale experiments based on a Web service dataset, we show that our approach can effectively help users to select high qualified services while keeping load balance of services in cloud environment.

A web service is an interface of the software component that can be accessed by standard Internet protocols. The web service technology enables an application to application communication and interoperability. The increasing number of web service providers throughout the globe have produced numerous web services providing the same or similar functionality. This necessitates the use of tools and techniques to search the suitable services available over the Web. UDDI (universal description, discovery and integration) is the first initiative to find the suitable web services based on the requester's functional demands. However, the requester's requirements may also include non-functional aspects like quality of service (QoS). In this paper, the authors define a QoS model for QoS aware and business driven web service publishing and selection. The authors propose a QoS requirement format for the requesters, to specify their complex demands on QoS for the web service selection. The authors define a tree structure called quality constraint tree (QCT) to represent the requester's variety of requirements on QoS properties having varied preferences. The paper proposes a QoS broker based architecture for web service selection, which facilitates the requesters to specify their QoS requirements to select qualitatively optimal web service. A web service selection algorithm is presented, which ranks the functionally similar web services based on the degree of satisfaction of the requester's QoS requirements and preferences. The paper defines web service provider qualities to distinguish qualitatively competitive web services. The paper also presents the modelling and selection mechanism for the requester's alternative constraints defined on the QoS. The authors implement the QoS broker based system to prove the correctness of the proposed web service selection mechanism.

To improve the global throughput of computational grid, effective and efficient load balancing algorithms are fundamentally important. A computational grid differs from traditional high-performance computing system in the heterogeneity of computing nodes, as well as the communication links that connect the different nodes together. In this paper, we propose a resource queue length based solution to the grid load balancing problem. The proposed algorithm will balance the load in the grid based on the queue length of each resource and transfer the job to the resource having minimum queue length. The simulation results show that our algorithm can achieve a better load balancing performance than its counterpart provided in simulation.

Bandwidth load balancing is a critical technique for improving the quality of service (QoS) in local area networks (LANs). Insufficient load balancing and QoS utilization can lead to network congestion, reduced performance, latency, packet loss, and an overall degradation of network performance. This paper presents an overview of load balancing techniques, load balancing algorithms, QoS parameters, load balancing strategies, and considerations for calculating bandwidth. The challenges of implementing load balancing algorithms and preferences for their implementation are discussed. Accurate network measurements and monitoring, coordination between network devices, security and privacy considerations, and careful evaluation of load balancing algorithms are among the challenges faced. The paper also discusses optimization and monitoring of bandwidth use, including options such as increasing bandwidth, bandwidth throttling, and data transfer throttling. The findings presented in this paper provide insights into the importance of load balancing and QoS in LANs and offer guidance for addressing related challenges.

A web service is a standards-based, language-agnostic software entity, that it accepts specially formatted requests from other software entities on remote machines via vendor and transport neutral communication protocols, producing application specific responses. Web services are used in every nook and corner of the world. The main strategy of web service is the availability of web service to all and its security over a distributed architecture. To ensure customer satisfaction web services must be available to all the users without any hindrance. The intrusion of attackers may be in any form such as a person or a program to cease the availability of the server. The Distributed Denial of Service attack is one of the severe attacks. The proposed system is an entropy based system which prevents the web service from the denial of service attack.