The Performance of Multithreading and Scheduling on Client-server Systems

Two approaches to the improvement of the performance of client-server systems, multithreading and scheduling of servers, are investigated. Both of these approaches are observed to have a significant impact on system performance. The use of multithreading improves throughput characteristics of systems whereas the deployment of appropriate scheduling strategies at servers can produce a significant improvement in mean client response times. Based on a simulation model a number of basic questions that are important in the context of scheduling on non-multithreaded as well as multithreaded systems are analyzed. Two factors, monopolization of servers by large requests and software bottlenecking, are observed to be important in scheduling on client server systems. Both server scheduling as well as multithreading can be used to control these effects and lead to a higher system performance. Scheduling policies based on request characteristics are observed to perform well. A new request characteristic that is useful in the scheduling of client-server systems in the presence of software bottlenecks is presented.