Migration of a Chosen Architectural Pattern to Service Oriented ...

Chapter 3. Architectural Patterns 48ViewControllerModelFigure 3.10: Example usage of MVC pattern7. MicrokernelOverview – This architectural pattern provides a solution for problemsthat need systems characterised by high adaptivity.ElementsMicrokernel – It is called also Message Bus or just Kernel. Kernel receivesmessages through external API from clients, forwards them to specific serviceand returns the result to calling client.Service – It encapsulates business logic. Can invoke other services (acts asa client)Client – Sends request to Kernel.Relationships – a service does not know location of other services andcannot invoke other service directly. A service can invoke only Kernel. Kernelknows location of all the services and can invoke them(see figure 3.12 ).8. ReflectionOverview – This very unusual pattern enables rapid evolution of system.This evolution is ensured by a “self – aware” meta–layerElementsMeta Layer – consists of Meta ObjectsMeta Object – contains information about structure of the system and itsbehavior including knowledge about operations that should be invoked ifan element from Base Layer invokes an action.Base Layer – contains elements of the system.Element – each element calls Meta Layer in order to execute an action.