Providing QoS strategies and cloud-integration to web servers by means of aspects

摘要

The main responsibilities of a web server are to listen from the communication channel and to preparernreplies to requests. Additional responsibilities include adapting processing activities, for example, throughrnscheduling or request filtering, so as to satisfy Quality of Service (QoS) requirements. Typical QoS-relatedrnconcerns address behavioural constraints (e.g. response time bounds, satisfiable by scheduling the mostrnurgent requests first) and resource monitoring, for optimal use. Although such concerns are spread acrossrnseveral web server components, they should be handled separately from communication-related ones, forrnthe sake of modularity.