Mariam Lahami

Towards a TTCN-3 Test System for Runtime Testing of Adaptable and Distributed Systems

Today, adaptable and distributed component based systems need to be checked and validated in order to ensure their correctness and trustworthiness when dynamic changes occur. Traditional testing techniques can not be used since they are applied during the development phase. Therefore, runtime testing is emerging as a novel solution for the validation of highly dynamic systems at runtime. In this paper, we illustrate how a platform independent test system based on the TTCN-3 standard can be used to execute runtime tests. The proposed test system is called TT4RT: TTCN-3 test system for Runtime Testing. A case study in the telemedicine field is used as an illustration to show the relevance of the proposed test system.

Using Knapsack Problem Model to Design a Resource Aware Test Architecture for Adaptable and Distributed Systems

This work focuses on testing the consistency of distributed and adaptable systems. In this context, Runtime Testing which is carried out on the final execution environment is emerging as a new solution for quality assurance and validation of these systems. This activity can be costly and resource consuming especially when execution environment is shared between the software system and the test system. To overcome this challenging problem, we propose a new approach to design a resource aware test architecture. We consider the best usage of available resources (such as CPU load, memory, battery level, etc.) in the execution nodes while assigning the test components to them. Hence, this work describes basically a method for test component placement in the execution environment based on an existing model called Multiple Multidimensional Knapsack Problem. A tool based on the constraint programming Choco library has been also implemented.

Safe and efficient runtime testing framework applied in dynamic and distributed systems

This paper provides a standard-based and resource aware Runtime Testing Framework For Adaptable and Distributed Systems (RTF4ADS). Based on the runtime testing approach, RTF4ADS performs safely and efficiently tests on the final operational environment of such dynamic systems. Indeed, our proposal (1) looks for a minimal set of tests to re-execute written in a standardized notation, (2) assigns the involved test components in execution nodes while respecting resources and connectivity constraints and finally (3) performs distributed testing at runtime while it prevents test processes from interfering with business processes. Implementation details of the proposed research prototype are presented. To demonstrate the validity and the usefulness of RTF4ADS, a case study in the healthcare domain implemented using the Open Services Gateway Initiative (OSGi) platform is illustrated. The experiments that we conducted show a reasonable overhead introduced by RTF4ADS. They also demonstrate the efficiency of this framework in testing dynamic and distributed systems while reducing side effects of this validation technique.

Test Isolation Policy for Safe Runtime Validation of Evolvable Software Systems

Runtime testing of dynamically evolvable systems is known as a complex and challenging activity. Undesired side effects may be introduced as the interference between test cases and business functionalities of the components under test. To handle such problem, test isolation strategies are used to execute runtime tests safely. In this proposal, we discuss the need to adapt the well known test isolation mechanisms to cope with heterogeneity of the components under test. For doing this, we define a Test Isolation Policy that produces the suitable test isolation solution depending on the testability degree of each component under test. We show its usefulness by the means of a case study in the healthcare domain, called Teleservices and Remote Medical Care System (TRMCS). Some experiments are carried out to show the efficiency of our approach and the low overhead it introduces.

Runtime testing framework for improving quality in dynamic service-based systems

Service-based systems are operating in dynamic environments characterized by continual changes such as requirement evolution, service crash or service unavailability. In this context, improving the quality of these systems after such evolution is highly demanded. With the aim of checking their behaviors at runtime and detecting faults introduced after dynamic changes, a runtime testing approach is applied. An effective Runtime Testing Framework For Adaptable and Distributed Systems called RTF4ADS is then proposed. This framework is conceived in order to reduce runtime testing side effects as timing and resource usage costs, interference risks while improving its fault finding capabilities. To show the relevance of RTF4ADS prototype, a case study in the healthcare domain implemented in the OSGi platform is given.

Distributed and Resource-Aware Load Testing of WS-BPEL Compositions.

One important type of testing Web services compositions is load testing, as such applications solicit concurrent access by multiple users simultaneously. In this context, load testing of these applications seems an important task in order to detect problems under elevated loads. For this purpose, we propose a distributed and resource aware test architecture aiming to study the behavior of WS-BPEL compositions considering load conditions. The major contribution of this paper consists of (i) looking for the best node hosting the execution of each tester instance, then (ii) running a load test during which the composition under test is monitored and performance data are recorded and finally (iii) analyzing in a distributed manner the resulting test logs in order to identify problems under load. We also illustrate our approach by means of a case study in the healthcare domain considering the context of resource aware load testing.

Towards a Model-Based Testing Framework for the Security of Internet of Things for Smart City Applications

This is a work in progress in which we are interested in testing security aspects of Internet of Things for Smart Cities. For this purpose we follow a Model-Based approach which consists in: modeling the system under investigation with an appropriate formalism; deriving test suites from the obtained model; applying some coverage criteria to select suitable tests; executing the obtained tests; and finally collecting verdicts and analyzing them in order to detect errors and repair them.

Selective Test Generation Approach for Testing Dynamic Behavioral Adaptations

This paper presents a model-based black-box testing approach for dynamically adaptive systems. Behavioral models of such systems are formally specified using timed automata. With the aim of obtaining the new test suite and avoiding its regeneration in a cost effective manner, we propose a selective test generation approach. The latter comprises essentially three modules: 1 a model differencing module that detects similarities and differences between the initial and the evolved behavioral models, 2 an old test classification module that identifies reusable and retestable tests from the old test suite, and finally 3 a test generation module that generates new tests covering new behaviors and adapts old tests that failed during animation. To show its efficiency, the proposed technique is illustrated through the Toast application and compared to the classical Regenerate All and Retest All approaches.

Runtime testing approach of structural adaptations for dynamic and distributed systems

Adaptable and distributed component-based systems need to be checked and validated in order to ensure their correctness and trustworthiness when structural dynamic changes occur. Runtime testing, seen as an online validation technique, is used in this work for this aim. Indeed, we propose a generic and resource aware test platform that: 1 looks for a minimal set of tests to re-execute written in the TTCN-3 standard notation; 2 assigns the involved test components in execution nodes while respecting resources and connectivity constraints and finally; 3 performs runtime tests with reducing interference risks by supplying different test isolation strategies depending on testability degrees of each component under test. To show the relevance of our solution, a prototype is proposed and illustrated via a case study in the healthcare domain implemented using the OSGi platform.

A generic process to build reliable distributed software components from early to late stages of software development

In this paper, we propose an incremental software development process that addresses reliability concerns, from early to late stages of software development. Contrary to existing techniques, in our proposal we merge two dependability means: fault prevention and fault forecasting techniques in order to build reliable distributed software systems. The design stage is focused on obtaining coherent specification of each individual component using an incremental refinement technique. After obtaining a consistent specification of each component, we deal with generating its code safely. In addition, we define consistent component assemblies by checking their compatibility at the integration level. The runtime testing stage is based on the fault forecasting technique which allows an emprirical estimation of the overall system reliability. Such process is used to get confidence that the obtained system behaves correctly according to its specification and fulfils all requirements and expectations. As an example, this paper introduces B formal method and Fractal component model to build reliable and trustworthy Fractal based applications.