Configuring Cloud-Service Interfaces Using Flow Inheritance
This addresses the need for flexible and provably consistent service composition in cloud computing, offering an incremental improvement over existing technologies like WS-CDL and session types.
The paper tackles the problem of configuring cloud-service interfaces for modular web service composition by introducing a novel mechanism that focuses on data format consistency with subtyping, polymorphism, and flow inheritance, resulting in a toolchain that automatically derives and configures interfaces without raising security issues despite global availability.
Technologies for composition of loosely-coupled web services in a modular and flexible way are in high demand today. On the one hand, the services must be flexible enough to be reused in a variety of contexts. On the other hand, they must be specific enough so that their composition may be provably consistent. The existing technologies (WS-CDL, WSCI and session types) require a behavioural contract associated with each service, which is impossible to derive automatically. Furthermore, neither technology supports flow inheritance: a mechanism that automatically and transparently propagates data through service pipelines. This paper presents a novel mechanism for automatic interface configuration of such services. Instead of checking consistency of the behavioural contracts, our approach focuses solely on that of data formats in the presence of subtyping, polymorphism and flow inheritance. The paper presents a toolchain that automatically derives service interfaces from the code and performs interface configuration taking non-local constraints into account. Although the configuration mechanism is global, the services are compiled separately. As a result, the mechanism does not raise source security issues despite global service availability in adaptable form.