Detection and resolution of atomicity violation in service composition

Abstract

Atomicity is a desirable property that safeguards application consistency for service compositions. A service composition exhibiting this property could either complete or cancel itself without any side effects. It is possible to achieve this property for a service composition by selecting suitable web services to form an atomicity sphere. However, this property might still be breached at runtime due to the interference between various service compositions caused by implicit interactions. Existing approaches to addressing this problem by restricting concurrent execution of services to avoid all implicit interactions however compromise the performance of service compositions due to the long running nature of web services. In this paper, we propose a novel static approach to analyzing the implicit interactions a web service may interfere and their impacts on the atomicity property in each of its service compositions. By locating afflicted implicit interactions in a service composition, behavior constraints based on property propagation are formulated as local safety properties, which can then be enforced by the affected web services at runtime to suppress the impacts of the afflicted implicit interactions. We show that the satisfaction of these safety properties exempts the atomicity property of this service composition from being interfered by other services at runtime. The approach is illustrated using two service applications.

Data flow testing of service choreography

“…They proposed to link services and resource management to solve such problems. Ye et al [27] studied the atomicity of service composition. By using the encapsulated details, they analyzed the implicit interactions among services in service composition.…”

“…Software built on top of the service-oriented architecture (SOA) is increasingly popular [4][14] [27], and yet testing such software remains tedious and ill-understood. In these applications, primary components are typically known as services.…”

“…Through collaboration (e.g., parallel composition of processes in process algebra [27]), such sequences of process actions of one service can coordinate, albeit implicitly, with the sequences of process actions of other services in the same application. Techniques to test service orchestration have been proposed.…”

“…For instance, instead of using implicit collaboration sequences embedded in the parallel composition of processes [27], choreography explicitly defines the interactions among services by such means as Message Sequence Charts (MSCs) [19] [20], UML sequence diagrams, or the Web Services Choreography Description Language (WS-CDL) [22]. An application developed in this way is called a choreography application.…”

“…Existing research on service choreography focuses on service modeling [3], process flow modeling [2], synthesizing of models [21], verification using finite-state automata [7], and violation detection of properties such as atomicity and resource constraints [6] [27]. Not much public literature highlights the testing challenges.…”