Event-Based Runtime Verification of Temporal Properties Using Time Basic Petri Nets

Discrete Event Dyn Syst

Capra

2021

Self Cite

Engineering distributed self-adaptive systems is challenging due to multiple interacting components, some of which monitor and possibly modify the behavior of managed components that operate in highly dynamic settings. Formalizing such systems having a decentralized adaptation control has been recognized as a hard task. In this article, we introduce a formal framework based on Symmetric Nets (a well-established subclass of Colored Petri nets) for modeling and analyzing distributed self-adaptive discrete-event systems. Even though Petri Nets represent a sound and expressive formal model of concurrency and distribution, they cannot specify in a natural way structural changes enacted by adaptation procedures. We overcome this limitation by means of a two-layer modeling approach that enables clear separation of concerns and allows multiple decentralized adaptation procedures to be specified, validated, and verified against formal requirements. Validation and verification techniques are supported by powerful off-the-shelf tools tailored to Symmetric Nets. A self-healing manufacturing system case study is used to show applicability, advantages, and shortcomings of the approach. In particular, complexity issues are thoroughly discussed and mitigated by adopting complementary approaches based on interleaving reduction and behavioral symmetries exploitation.

Section: Related Workmentioning

confidence: 99%

Formal specification and verification of decentralized self-adaptive systems using symmetric nets

Discrete Event Dyn Syst

Capra

2021

Self Cite

“…Preliminary results are promising. In particular, work presented in [27] introduces MahaRAJA, i.e., an event-based runtime verification framework that makes use of TB Petri nets. Experiments show that MahaRAJA is highly scalable and it introduces bounded overhead and effectively reduces the involvement of the monitor at run time by using negligible auxiliary memory [77].…”

Section: Discussionmentioning

confidence: 99%

“…It would be therefore possible to verify properties of the feedback loops under time constraints. To this last purpose, we want to combine the proposed zone-based TB net formalism with the run-time verification framework already presented in [27].…”

Section: Discussionmentioning

confidence: 99%

“…Furthermore, aspects such as messaging, communication protocols, which are commonly used in concurrent or distributed systems, can be difficult to model with the language primitives of timed-automata [22,21]. Moreover, TB nets are supported by powerful off-the-shelf open source software tools able to perform simulation, model checking [23,24,25,26], model-based testing, and runtime verification [27,28].…”

Section: Time Basic Petri Netsmentioning

confidence: 99%

See 1 more Smart Citation

Zone-based formal specification and timing analysis of real-time self-adaptive systems

Science of Computer Programming

Gargantini

Scandurra

2018

Self Cite

Self-adaptive software systems are able to autonomously adapt their behavior at run-time to react to internal dynamics and to uncertain and changing environment conditions. Formal specification and verification of self-adaptive systems are tasks generally very difficult to carry out, especially when involving time constraints. In this case, in fact, the system correctness depends also on the time associated with events.This article introduces the Zone-based Time Basic Petri nets specification formalism. The formalism adopts timed adaptation models to specify self-adaptive behavior with temporal constraints, and relies on a zone-based modeling approach to support separation of concerns. Zones identified during the modeling phase can be then used as modules either in isolation, to verify intra-zone properties, or all together, to verify inter-zone properties over the entire system. In addition, the framework allows the verification of (timed) robustness properties to guarantee self-healing capabilities when higher levels of reliability and availability are required to the system, especially when dealing with time-critical systems. This article presents also the ZAFETY tool, a Java software implementation of the proposed framework, and the validation and experimental results obtained in modeling and verifying two time-critical self-adaptive systems: the Gas Burner system and the Unmanned Aerial Vehicle system.

“…The TB nets formalism is nicely supported by powerful off-the-shelf software tools covering both modeling and verification phases [7,8]. The RV technique is currently implemented as a prototypal Java library, built on top of MahaRAJA [9], a lightweight pluggable tool supporting the verification of behavioral and temporal aspects of Java programs.…”

Section: Introductionmentioning

confidence: 99%

Design-Time to Run-Time Verification of Microservices Based Applications

Software Engineering and Formal Methods

Bellettini

Capra

2018

Self Cite

Microservice based architectures have started to gain in popularity and are often adopted in the implementation of modern cloud, IoT, and large-scale distributed applications. Software life cycles, in this context, are characterized by short iterations, where several updates and new functionalities are continuously integrated many times a day. This paradigm shift calls for new formal approaches to systematic verification and testing of applications in production infrastructures. We introduce an approach to continuous, design-to run-time verification, of microservice based applications. This paper describes our envisioned approach, the current stage of this ongoing work, and the challenges ahead.