Enabling Proactive Adaptation through Just-in-Time Testing of Conversational Services

Abstract

Abstract. Service-based applications (SBAs) will increasingly be composed of third-party services available over the Internet. Reacting to failures of those third-party services by dynamically adapting the SBAs will become a key enabler for ensuring reliability. Determining when to adapt an SBA is especially challenging in the presence of conversational (aka. stateful) services. A conversational service might fail in the middle of an invocation sequence, in which case adapting the SBA might be costly; e.g., due to the necessary state transfer to an alternative service. In this paper we propose just-in-time testing of conversational services as a novel approach to detect potential problems and to proactively trigger adaptations, thereby preventing costly compensation activities. The approach is based on a framework for online testing and a formal test-generation method which guarantees functional correctness for conversational services. The applicability of the approach is discussed with respect to its underlying assumptions and its performance. The benefits of the approach are demonstrated using a realistic example.

Model based testing of service oriented applications

“…In stateful services, the studies focus on conformance testing supported by test case generation (Bertolino et al, 2004;Frantzen et al, 2008;Belli and Linschulte, 2008;Keum et al, 2006;Dranidis et al, 2007;Ramollari et al, 2009;Paradkar et al, 2007;Kourtesis et al, 2010;Dranidis et al, 2010). Bertolino et al (2008) propose on the generation of stubs using a state model and QoS properties.…”

“…Chakrabarti and Rodriquez (2010) present a formal approach to test RESTful web services. Dranidis et al (2010) propose an automated technique for just-in-time testing of stateful services.…”

“…These techniques are: Labeled Transition System (LTS) and extensions (Mei et al, 2009a;Bertolino et al, 2004Bertolino et al, , 2008Frantzen et al, 2008;Bentakouk et al, 2009;Wieczorek et al, 2009Wieczorek et al, , 2010Rabhi, 2012;Escobedo et al, 2010;De Angelis et al, 2010), timed automaton and extensions (Lallali et al, 2008;Morales et al, 2010;Cavalli et al, 2010;Gao and Li, 2011), Stream X-Machine (SXM) (Dranidis et al, 2007;Ramollari et al, 2009;Kourtesis et al, 2010;Dranidis et al, 2010), extensions of FSMs (Benharref et al, 2006;Keum et al, 2006;Dong et al, 2010), finite state automaton (Baldoni et al, 2005), and Web Service Automaton (WSA) (Zheng et al, 2007). The modeling techniques are used to describe the control flow, data flow, timing, and stochastic properties.…”

A Two-Phase Online Prediction Approach for Accurate and Timely Adaptation Decision

“…[9] presents the PROSA framework, which defines key activities to initiate online testing either on the binding level or on the service composition level, and thereby proactively triggers the adaptation process. [10] investigates how to guarantee functional correctness of conversational services. The authors propose a novel approach to enables proactive adaptations through just-in-time testing.…”

Cross - layer monitoring and adaptation of multi - cloud service - based applications

“…On the same wavelength, [Dranidis et al 2010] proposes an approach for "justin-time" (i.e., shortly before a conversational service is invoked for the first time) proactive adaptation, utilizing test cases grounded in the formal theory of Stream X-machines (SXMs) [Dranidis et al 2007]. Most of the costly test preparation ac-…”