Towards High-Availbility for Services Oriented Application

In services based applications, many inevitable factors, such as network fault, host exception, etc., will lead to the frequent failure of some component services. This paper presents a two phases approach for recovery of services based applications. The proposed approach can recover a services based application to provide both consistent function and consistent QoS by replacing its individual or multiple component services. In order to control overheads of recovery, the substitution group is introduced to reduce the number of services that need to be replaced in the phase of function recovery. In addition, the substitution factor is introduced to find the component services which are replaced to most likely achieve original overall QoS constraint. In this way, recovery overheads are lowered and service disruptions may be reduced. The prototype is implemented to validate the feasibility of our approach, and the test shows the effectiveness of our approach.