Abstract:
Web container conforming to J2EE specification, which provides runtime environment for servlet and JSP and adopts best-effort service mode, has become an effective platform to deploy enterprise Web applications on Internet. However, complex business Web applications require Web container to provide differentiated services that traditional Web container does not provide for requests from different clients according to role or payment etc. Some approaches such as admission control and priority scheduling have been applied to provide differentiated services for Web container, but they do not consider differentiated services in finer granularity so that they can only provide monotone and static strategy of differentiated services. To improve the deficiencies of traditional Web container, the requirement of differentiated services is analyzed and a differentiated service Web container (DSWC) based on self-management unit (SMU) is brought forward. In DSWC, process modules are encapsulated into SMUs, which are connected to compose a SMU chain. DSWC provides SMU-based and SMU chain-based differentiated services for requests according to SLA (service level agreement). At the same time, an adaptive strategy selection algorithm is also presented, which can adaptively select different strategies of differentiated services based on the dynamic environment. The experiments of prototype show DSWC can effectively provide differentiated services according to SLA for different type of requests.