Repository logo
 

Search Results

Now showing 1 - 2 of 2
  • Towards compensation correctness in interactive systems
    Publication . Vaz, Cátia; Ferreira, Carla
    One fundamental idea of service-oriented computing is that applications should be developed by composing already available services. Due to the long running nature of service interactions, a main challenge in service composition is ensuring correctness of failure recovery. In this paper, we use a process calculus suitable for modelling long running transactions with a recovery mechanism based on compensations. Within this setting, we discuss and formally state correctness criteria for compensable processes compositions, assuming that each process is correct with respect to failure recovery. Under our theory, we formally interpret self-healing compositions, that can detect and recover from failures, as correct compositions of compensable processes.
  • Dynamic recovering of long running transactions
    Publication . Vaz, Cátia; Ferreira, Carla; Ravara, António
    Most business applications rely on the notion of long running transaction as a fundamental building block. This paper presents a calculus for modelling long running transactions within the framework of the π-calculus, with support for compensation as a recovery mechanism. The underlying model of this calculus is the asynchronous polyadic π-calculus, with transaction scopes and dynamic installation of compensation processes. We add to the framework a type system which guarantees that transactions are unequivocally identified, ensuring that upon a failure the correct compensation process is invoked. Moreover, the operational semantics of the calculus ensures both installation and activation of the compensation of a transaction.