Distributed workload and response time management for web applications

Abstract-Managing workload for large scale web applications is a fundamental task for satisfactory quality of service, low management and operation cost. In this paper, we present SCOPS, a system of distributed workload management to achieve service differentiation and overload protection in such large scale deployment. Our system splits the workload management logic into distributed components on each back-end server and frontend proxy. The control solution is designed to protect the backend server from overloading and to achieve both efficient usage of system resource and service differentiation by employing a unique optimization target. The control components are automatically organized based on the flow of workloads, such that management overhead is minimized. SCOPS is extremely flexible because it requires no source code changes to host OS, application servers, or web applications. Additionally, the distributed design makes it scalable and robust for cloud scale server deployment. Experiments with our implementation confirm SCOPS's performance with dynamic heavy workload, incurring neglectable runtime overhead. More importantly, SCOPS also ensures fault-tolerance and fast convergence to system failures

A Comparison of wide area network performance using virtualized and non-virtualized client architectures

The goal of this thesis is to determine if there is a significant performance difference between two network computer architecture models. The study will measure latency and throughput for both client-server and virtualized client architectures. In the client server environment, the client computer performs a significant portion of the work and frequently requires downloading uploading files to and from a remote location. Virtual client architecture turns the client machine into a terminal, sending only keystrokes and mouse clicks and receiving only display pixel or sound changes. I accomplished the goal of comparing these architectures by comparing completion times for ping reply, file download, a small set of common work tasks, and a moderately large SQL database query. I compared these tasks using simulated wide area network, local area network, and virtual client network architectures. The study limits the architecture to one where the virtual client and server are in the same data center