Web server support for tiered services

TLDR

The evolving needs of conducting commerce on the Internet require more than just network QoS; overloaded servers and FIFO scheduling can negate network QoS, making server QoS essential for predictable, tiered services. This article describes our research and results for WebQoS, an architecture for supporting server QoS. We use classification, admission control, and scheduling to provide distinct performance levels for different user classes. Our approach maintains predictable performance even when the client request rate exceeds the server’s maximum processing rate by several times.

Abstract

The evolving needs of conducting commerce using the Internet requires more than just network quality of service mechanisms for differentiated services. Empirical evidence suggests that overloaded servers can have significant impact on user perceived response times. Furthermore, FIFO scheduling done by servers can eliminate any QoS improvements made by network-differentiated services. Consequently, server QoS is a key component in delivering end to end predictable, stable, and tiered services to end users. This article describes our research and results for WebQoS, an architecture for supporting server QoS. We demonstrate that through classification, admission control, and scheduling, we can support distinct performance levels for different classes of users and maintain predictable performance even when the server is subjected to a client request rate that is several times greater than the server's maximum processing rate.