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Denna rapport behandlar en undersökning av olika lastbalanseringsalgoritmer i Linux Virtual Server. Undersökningen har gjorts i ett webbkluster (Apache var webbservern som användes) med tre heterogena noder, där operativsystemet var den detalj som skiljde dem åt. Operativsystemen som ingick i undersökningen var Windows Server 2008 R2, CentOS 6.2 och FreeBSD 9.0. De faktorer som undersöktes mellan de olika algoritmerna var klustrets genomsnittliga svarstid vid olika belastning och hur många anslutningar som kunde hanteras av klustret, detta gjordes med verktyget httperf. Undersökningen ger svar på hur ett heterogent webbklusters genomsnittligasvarstid och arbetskapacitet kan skilja sig åt beroende på vilken algoritm som används för lastbalansering. Resultatet visar att den genomsnittliga svarstiden håller sig låg tills en hastig stigning inträffar. Shortest Expected Delay och Weighted Least-Connection Scheduling kunde hantera störst antal anslutningar. / This report covers an investigation of different load balancing algorithms in Linux Virtual Server. The investigation was done in a web cluster (with Apache as the software being used) consisting of three heterogeneous nodes, where the operating system was the detail that differentiated the nodes. The operating systems that were used in the investigation were Windows Server 2008 R2, CentOS 6.2 and FreeBSD 9.0. The factors examined were average response time at different load and how many connections the cluster could cope with, these factors were examined by measurements taken with the tool httperf. The investigation gives an answer to how a heterogeneous web clustersaverage response time and working capacity can be affected by the choice of load balancing algorithm. The result shows that the average response time stays low until a sudden rise occurs. Shortest Expected Delay and Weighted Least-Connection Scheduling could handle the largest number of connections.

The goal of this master thesis is to analyze Open Source resources for loadbalancing and high availability, with aim on areas of its typical usage. These areas are particularly solutions of network infrastructure (routers, loadbalancers), generally network and internet services and parallel filesystems. Next part of this thesis is analysis of design, implementation and plans of subsequent advancement of an fast growing Internet project. The effect of this growth is necessity of solving scalability on all levels. The last part is performance analysis of individual loadbalancing methods in the Linux Virtual Server project.