A Model for Adaptable Systems for Transaction Processing

There is a need for adaptable systems that can change as requirements change, both in the long and the short term. Adaptability can reduce software costs and improve reliability and performance. Adaptability includes design techniques that support enhancement, retargeting to new projects, restructuring during different phases of a mission, and changing algorithms as external conditions. change. These techniques are particularly important for projects with stringent performance or reliability requirements. We model algorithmic adaptability, and develop techniques for switching between classes of schedulers in distributed transaction systems. RAID is an experimental system implemented to support experimentation in adaptability. We study adaptability features in RAID, including algorithmic adaptability, fault-tolerance, and implementation techniques for an adaptable server-based design. Adaptability is an essential tool for the future to manage escalating software costs and build high-reliability, high-performance systems.