Proxy-Monitor: An Integration of Runtime Verification with Passive Conformance Testing

This paper proposes a conformance testing method combining two well-known testing approaches, runtime verification and passive testing. Runtime verification addresses the monitoring of a system under test to check whether formal properties hold, while passive testing aims at checking the conformance of the system in the long-term. The method, proposed in this paper, checks whether an implementation conforms to its specification with reference to the ioco test relation. While passively checking if ioco holds, it also checks whether the implementation meets safety properties, which informally state that "nothing bad ever happens". This paper also tackles the trace extraction problem, which is common to both runtime verification and passive testing. The authors define the notion of Proxy-monitors for collecting traces even when the implementation environment access rights are restricted. Then, they apply and specialise this approach on Web service compositions. A Web service composition deployed in different Clouds is experimented to assess the feasibility of the method.