Web services support software architectures that can evolve dynamically. In particular, in this paper the focus is on architectures where services are composed (orchestrated) through a workflow described in the business process execution language (BPEL). It is assumed that the resulting composite service refers to external services through assertions that specify their expected functional and non-functional properties. On the basis of these assertions, the composite service may be verified at design time by checking that it ensures certain relevant properties. Because of the dynamic nature of web services and the multiple stakeholders involved in their provision, however, the external services may evolve dynamically, and even unexpectedly. They may become inconsistent with respect to the assertions against which the workflow was verified during development. As a consequence, validation of the composition must extend to run time. In this work, an assertion language, called assertion language for BPEL process interactions (ALBERT), is introduced; it can be used to specify both functional and non-functional properties. An environment which supports design-time verification of ALBERT assertions for BPEL workflows via model checking is also described. At run time, the assertions can be turned into checks that a software monitor performs on the composite system to verify that it continues to guarantee its required properties. A TeleAssistance application is provided as a running example to illustrate our validation framework

Many software engineering activities process the events contained in log files. However, before performing any processing activity, it is necessary to parse the entries in a log file, to retrieve the actual events recorded in the log. Each event is denoted by a log message, which is composed of a fixed part-called (event) template-that is the same for all occurrences of the same event type, and a variable part, which may vary with each event occurrence. The formats of log messages, in complex and evolving systems, have numerous variations, are typically not entirely known, and change on a frequent basis; therefore, they need to be identified automatically.The log message format identification problem deals with the identification of the different templates used in the messages of a log. Any solution to this problem has to generate templates that meet two main goals: generating templates that are not too general, so as to distinguish different events, but also not too specific, so as not to consider different occurrences of the same event as following different templates; however, these goals are conflicting.In this paper, we present the MoLFI approach, which recasts the log message identification problem as a multi-objective problem. MoLFI uses an evolutionary approach to solve this problem, by tailoring the NSGA-II algorithm to search the space of solutions for a Pareto optimal set of message templates. We have implemented MoLFI in a tool, which we have evaluated on six real-world datasets, containing log files with a number of entries ranging from 2K to 300K. The experiments results show that MoLFI extracts by far the highest number of correct log message templates, significantly outperforming two state-of-the-art approaches on all datasets. CCS CONCEPTS• Software and its engineering → Search-based software engineering;

Specification patterns have proven to help developers to state precise system requirements, as well as formalize them by means of dedicated specification languages. Most of the past work has focused its applicability area to the specification of concurrent and real-time systems, and has been limited to a research setting. In this paper we present the results of our study on specification patterns for service-based applications (SBAs). The study focuses on industrial SBAs in the banking domain. We started by performing an extensive analysis of the usage of specification patterns in published research case studies -representing almost ten years of research in the area of specification, verification, and validation of SBAs. We then compared these patterns with a large body of specifications written by our industrial partner over a similar time period. The paper discusses the outcome of this comparison, indicating that some needs of the industry, especially in the area of requirements specification languages, are not fully met by current software engineering research.

This article follows up on Lionel Briand's 2012 Sounding Board article on the significant disconnect between research and industrial needs in software engineering [1]. Here, we argue that for software engineering research to increase its impact and steer our community toward a more successful future, it must change. Specifically, we see the need to foster context-driven research. By that, we mean research focused on problems defined in collaboration with industrial partners and driven by concrete needs in specific domains and development projects. By analyzing publications from the top software engineering research venues, anyone could easily conclude that only a small proportion of the papers stem from such research. Context-driven research doesn't try to frame a general problem and devise universal solutions. Rather, it makes clear working assumptions, given a precise context, and relies on trade-offs that make sense in that context to achieve practicality and scalability. This research paradigm applies to any topic in software engineering and isn't meant to highlight any particular research area. Because context-driven research doesn't produce results that generalize easily to any arbitrary software development environment, the following questions arise: Does it have value? How so? Is it (engineering) science? This is what we discuss in the rest of this article.

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Abstract-Trace checking is a procedure for evaluating requirements over a log of events produced by a system. This paper deals with the problem of performing trace checking of temporal properties expressed in TemPsy, a pattern-based specification language. The goal of the paper is to present a scalable and practical solution for trace checking, which can be used in contexts where relying on model-driven engineering standards and tools for property checking is a fundamental prerequisite.The main contributions of the paper are: a model-driven trace checking procedure, which relies on the efficient mapping of temporal requirements written in TemPsy into OCL constraints on a meta-model of execution traces; the implementation of this trace checking procedure in the TEMPSY-CHECK tool; the evaluation of the scalability of TEMPSY-CHECK, applied to the verification of real properties derived from a case study of our industrial partner, including a comparison with a state-of-theart alternative technology based on temporal logic. The results of the evaluation show the feasibility of applying our modeldriven approach for trace checking in realistic settings: TEMPSY-CHECK scales linearly with respect to the length of the input trace and can analyze traces with one million events in about two seconds.

Prohibiting unauthorized access to critical resources and data has become a major requirement for enterprises. Access control (AC) mechanisms manage requests from users to access system resources; the access is granted or denied based on authorization policies defined within the enterprise. One of the most used AC paradigms is role-based access control (RBAC). In RBAC, access rights are determined based on the user's role, e.g., her job or function in the enterprise.Many different types of RBAC authorization policies have been proposed in the literature, each one accompanied by the corresponding extension of the original RBAC model. However, there is no unified framework that can be used to define all these types of RBAC policies in a coherent way, using a common model. Moreover, these types of policies and their corresponding models are scattered across multiple sources and sometimes the concepts are expressed ambiguously. This situation makes it difficult for researchers to understand the state of the art in a coherent manner; furthermore, practitioners may experience severe difficulties when selecting the relevant types of policies to be implemented in their systems based on the available information. There is clearly a need for organizing the various types of RBAC policies systematically, based on a unified framework, and to formalize them to enable their operationalization.In this paper we propose a model-driven engineering (MDE) approach, based on UML and the Object Constraint Language (OCL), to enable the precise specification and verification of such policies. More specifically, we first present a taxonomy of the various types of RBAC authorization policies proposed in the literature. We also propose the GemRBAC model, a generalized model for RBAC that includes all the entities required to define the classified policies. This model is a conceptual model that can also serve as data model to operationalize data collection and verification. Lastly, we formalize the classified RBAC policies as OCL constraints on the GemRBAC model. To facilitate such operationalization, we make publicly available online the Ecore version of the GemRBAC model and the OCL constraints corresponding to the classified RBAC policies.

Modern complex software systems produce a large amount of execution data, often stored in logs. These logs can be analyzed using trace checking techniques to check whether the system complies with its requirements specifications. Often these specifications express quantitative properties of the system, which include timing constraints as well as higher-level constraints on the occurrences of significant events, expressed using aggregate operators.In this paper we present an algorithm that exploits the MapReduce programming model to check specifications expressed in a metric temporal logic with aggregating modalities, over large execution traces. The algorithm exploits the structure of the formula to parallelize the evaluation, with a significant gain in time. We report on the assessment of the implementation-based on the Hadoop framework-of the proposed algorithm and comment on its scalability.