Towards Dynamic Updates in Service Composition
Résumé
We survey our work on choreographies and behavioural contracts in multiparty interactions. In particular theories of behavioural contracts are presented which enable reasoning about correct service composition (contract compliance) and service substitutability (contract refinement preorder) under different assumptions concerning service communication: synchronous communication with patient non-preemptable or impatient invocations, or asynchronous communication. Correspondingly, relations concerning behavioural contracts and choreographic descriptions are considered, where a contract for each communicating party is, e.g., derived by projection.
Contract refinement relations are induced as the maximal preoders which preserve contract compliance and global traces. The obtained preorders are then characterized in terms of a new form of testing, called compliance testing (where not only tests must succeed but also the system under test), and compared with classical preorders. Moreover, recent work about adaptable choreographies and behavioural contracts is presented, where the theory above is extended to update mechanisms allowing choreographies/contracts to be modified at run-time by internal (self-adaptation) or external intervention.