An Efficient Web Cluster with Content-Aware Request Distribution for Streaming Service

Abstract

As the advance of the web and multimedia technologies, the web sites usually can provide not only static and dynamic web page services but also multimedia stream-ing services. To serve various types and huge amount of ser-vice demands, nowadays the web cluster system has been popularly deployed because of the advantages of cost effec-tiveness, load sharing, scalability, and high availability. Traditionally, for providing the multimedia streaming ser-vice, the server needs to establish a streaming connection with the client at first and then transmits the streaming data. The servers need to maintain the connection until the entire streaming service is finished. In the process of providing streaming service, the servers cannot handoff the existing connection to the other server to continue the streaming ser-vice. This might cause load unbalance among servers and degrade the performance of the whole web cluster. In this paper, we have proposed and implemented the RTSP Handoff mechanism. Using our proposed mechanism, a long runtime film can be logically partitioned into several sections and each section of the film can be served by different real server. During the process, the client would not sense the change of servers. In this way, a web cluster can achieve better load balance when providing the streaming service. We have implemented our mechanism in the Linux kernel of the LVS-CAD web cluster. Experimental results demon-strate that the LVS-CAD web cluster with our proposed RTSP Handoff mechanism can reduce 34.35% average response time and achieve 37.19% better throughput than the one without our proposed mechanism when providing multiple web services.