Introducing Self-Adaptability into Transaction Processing

In a database system, the scheduler has the goal of synchronizing operations belonging to several concurrent transactions. In order to achieve its goal, the scheduler implements a concurrency control protocol, which may have either conservative or aggressive behavior. This paper presents a self-adaptable scheduler, called Intelligent Transaction Scheduler (ITS), which has the ability of dynamically changing its behavior (from conservative to aggressive and vice-versa) to adapt itself to the characteristics of the computing environment (e.g., the aborted transaction rate and conflicting operation rate). The proposed scheduler adapts its behavior without any human interference by using an expert system based on fuzzy logic. In order to evaluate ITS, it was applied in a Mobile Database Community (MDBC). An MDBC can be characterized as a dynamically configurable environment, since an MDBC is a dynamic collection of autonomous mobile databases, interconnected through a mobile ad hoc network (MANET). Therefore, self-adaptability plays a key role for schedulers running in dynamically configurable environments. The experimentation results show the efficiency of ITS for synchronizing transactions in MDBCs