7,186 research outputs found
Temporal specification and deductive verification of a distributed component model and its environment
In this paper we investigate the formalisation of distributed and long-running stateful systems using our normative temporal specification framework. We analyse aspects of a component-oriented Grid system, and the benefits of having a logic-based tool to perform automated and safe dynamic reconfiguration of its components. We describe which parts of this Grid system are involved in the reconfiguration process and detail the translation procedure into a state-based formal specification. Subsequently, we apply deductive verification to test whether dynamic reconfiguration can be performed. Finally, we analyse the procedure required to update our model for reconfiguration and justify the validity and the advantages of our methodology
COST Action IC 1402 ArVI: Runtime Verification Beyond Monitoring -- Activity Report of Working Group 1
This report presents the activities of the first working group of the COST
Action ArVI, Runtime Verification beyond Monitoring. The report aims to provide
an overview of some of the major core aspects involved in Runtime Verification.
Runtime Verification is the field of research dedicated to the analysis of
system executions. It is often seen as a discipline that studies how a system
run satisfies or violates correctness properties. The report exposes a taxonomy
of Runtime Verification (RV) presenting the terminology involved with the main
concepts of the field. The report also develops the concept of instrumentation,
the various ways to instrument systems, and the fundamental role of
instrumentation in designing an RV framework. We also discuss how RV interplays
with other verification techniques such as model-checking, deductive
verification, model learning, testing, and runtime assertion checking. Finally,
we propose challenges in monitoring quantitative and statistical data beyond
detecting property violation
Applying Formal Methods to Networking: Theory, Techniques and Applications
Despite its great importance, modern network infrastructure is remarkable for
the lack of rigor in its engineering. The Internet which began as a research
experiment was never designed to handle the users and applications it hosts
today. The lack of formalization of the Internet architecture meant limited
abstractions and modularity, especially for the control and management planes,
thus requiring for every new need a new protocol built from scratch. This led
to an unwieldy ossified Internet architecture resistant to any attempts at
formal verification, and an Internet culture where expediency and pragmatism
are favored over formal correctness. Fortunately, recent work in the space of
clean slate Internet design---especially, the software defined networking (SDN)
paradigm---offers the Internet community another chance to develop the right
kind of architecture and abstractions. This has also led to a great resurgence
in interest of applying formal methods to specification, verification, and
synthesis of networking protocols and applications. In this paper, we present a
self-contained tutorial of the formidable amount of work that has been done in
formal methods, and present a survey of its applications to networking.Comment: 30 pages, submitted to IEEE Communications Surveys and Tutorial
Integrating formal reasoning into component-based approach to reconfigurable distributed systems
Distributed computing is becoming ubiquitous in recent years in many areas, especially the
scientific and industrial ones, where the processing power - even that of supercomputers - never
seems to be enough. Grid systems were born out of necessity, and had to grow quickly to
meet requirements which evolved over time, becoming today’s complex systems. Even the
simplest distributed system nowadays is expected to have some basic functionalities, such as
resources and execution management, security and optimization features, data control, etc. The
complexity of Grid applications is also accentuated by their distributed nature, making them
some of the most elaborate systems to date. It is often too easy that these intricate systems
happen to fall in some kind of failure, it being a software bug, or plain simple human error; and
if such a failure occurs, it is not always the case that the system can recover from it, possibly
meaning hours of wasted computational power.
In this thesis, some of the problems which are at the core of the development and mainte-
nance of Grid software applications are addressed by introducing novel and solid approaches
to their solution. The difficulty of Grid systems to deal with unforeseen and unexpected cir-
cumstances resulting from dynamic reconfiguration can be identified. Such problems are often
related to the fact that Grid applications are large, distributed and prone to resource failures.
This research has produced a methodology for the solution of this problem by analysing the
structure of distributed systems and their reliance on the environment which they sit upon, often
overlooked when dealing with these types of scenarios. It is concluded that the way that Grid applications interact with the infrastructure is not sufficiently addressed and a novel approach
is developed in which formal verification methods are integrated with distributed applications
development and deployment in a way that includes the environment. This approach allows for
reconfiguration scenarios in distributed applications to proceed in a safe and controlled way, as
demonstrated by the development of a prototype application
Model-based dependability analysis : state-of-the-art, challenges and future outlook
Abstract: Over the past two decades, the study of model-based dependability analysis has gathered significant research interest. Different approaches have been developed to automate and address various limitations of classical dependability techniques to contend with the increasing complexity and challenges of modern safety-critical system. Two leading paradigms have emerged, one which constructs predictive system failure models from component failure models compositionally using the topology of the system. The other utilizes design models - typically state automata - to explore system behaviour through fault injection. This paper reviews a number of prominent techniques under these two paradigms, and provides an insight into their working mechanism, applicability, strengths and challenges, as well as recent developments within these fields. We also discuss the emerging trends on integrated approaches and advanced analysis capabilities. Lastly, we outline the future outlook for model-based dependability analysis
Dynamic reconfiguration of GCM components
We detail in this report past research and current/future developments in formal specification of Grid component systems by temporal logic and consequent resolution technique, for an automated dynamic reconfiguration of components. It is analysed the specification procedure of GCM (Grid Component Model) components and infrastructure in respect to their state behaviour, and the verification process in a dynamic and reconfigurable distributed system. Furthermore it is demonstrated how an automata based method is used to achieve the specification, as well as how the enrichment of the temporal specification language of Computation Tree Logic CTL with the ability to capture norms, allows to formally define the concept of reconfiguration
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