Kazuaki Obana

A Web Access SHaping method to improve the performance of congested servers

This paper proposes WASH, a Web Access SHaping method, to realize overload-tolerant and highly accessible web sites. Due to the explosive spread of the Internet and emerging sophisticated web applications, servers will become the bottlenecks of the Web. WASH works as a reverse proxy with load balancing and improves the service quality of popular servers. WASH provides two innovative mechanisms: load control with active process limit and application-aware request scheduling. Comparative experiments against current load balancers demonstrate the following superiority of WASH in handling heavy congestion: a) WASH keeps the response time for single page display to below 5 seconds and b) WASH maximizes the throughput of completed page displays and sessions.

Evaluation of the MXQ mechanism by audio and video applications

This work discusses the congestion problems that may be caused by video and audio applications. These applications commonly use UDP to convey their data. Unlike TCP,UDP does not have any standard mechanisms for congestion control. Therefore, they might lead to severe congestion that would significantly damage all of the flows in the same traffic class and degrade network utilization. To overcome this problem, we propose the MXQ (MaXimal Queuing) mechanism which represents a new flow-aware forwarding policy. We evaluate this mechanism using UDP video and UDP audio applications. We also evaluate the mechanism using a TCP video application with outputs of hundreds of Mbps. The results show that the dynamic arbitration control realized by the MXQ mechanism can effectively control the congestion and enhance the efficiency of best-effort networks.