A middleware-based approach to model refactoring at runtime

Model refactoring is emerging as a desirable means to improve design model by restructuring it while preserving the behavior properties. It applies the concept of refactoring to a higher level of abstraction and makes refactoring more convenient and effective. Model refactoring always arises at design phase, but unfortunately, 7(days) x 24(hours) high availability requires that refactoring takes effect at runtime without stopping the running systems. In this paper, we present a middleware-based approach to applying model refactoring for component based applications at runtime. First of all, ill-structures in an application are abstracted as bad patterns, each of which has at least one good pattern abstracting the refactored part in the application without the ill-structure. People can define the bad/good patterns using a MOF-based metamodel. After that, with the help of middleware, the ill-structures will be automatically detected and removed by refactoring the running application under the guide of predefined patterns.