Carlos Eduardo da Silva

Dynamic plans for integration testing of self-adaptive software systems

Self-adaptive software systems are able to modify their own structure and/or behaviour at run-time in order to cope with changes. During software self-adaptation, new components may be incorporated to the software system. One crucial aspect when incorporating new components is to test them for guaranteeing that they can interoperate as specified. However, this aspect has been often neglected when considering architectural reconfiguration. To deal with this problem, this paper presents an approach for the dynamic generation of plans for conducting the integration testing of self-adaptive software systems. In order to evaluate our approach, we have developed a prototype application that has been used to conduct some experiments, and to demonstrate the feasibility of our approach.

Using dynamic workflows for coordinating self-adaptation of software systems

The self-adaptation of a software system is a complex process that depends on the system requirements, its operational state and environment, which may change during the system operational lifetime. Hence, the process for coordinating the self-adaptation should also be adaptable to changes that may occur during run-time. As a means for coordinating the self-adaptation process of software systems, the proposed approach employs workflows that are dynamically generated for dealing with the variability associated with the self-adaptation process. In this context, our aim is to define and develop techniques for automatically generate workflows for coordinating the self-adaptation of software systems. For demonstrating the feasibility of the proposed approach, architectural reconfiguration of software systems is used as an example, whereby the reconfiguration is managed by workflows that are dynamically generated depending on the availability of resources.

Definition of a Component Selection Process Based on QoS Criteria and Its Application to Self-adaptive Software Systems

Nowadays, self-adaptive systems use the concept of feedback loops. This approach is based on the selection of components that conform to the expected requirements. The selection became increasingly complex in such systems due to the variety of criteria. This paper proposes a process for dynamic selection of components using multi-attribute utility theory based on Quality of Service (QoS) criteria. Furthermore, it defines a model that can be used to represent the current needs of an application, and that is used by the proposed selection process for evaluating the candidate components. As a proof of concept, its presented the AnaMoC module that performs the selection of components based on the proposed process.

Towards the use of dynamic workflows for coordinating self-adaptation of software systems

The self-adaptation of software system is a complex process that depends on several factors that may change during the system operational lifetime. Hence, the process for coordinating the self-adaptation should also be adaptable to changes that may occur during run-time. As the means for coordinating the self-adaptation process of software systems, we are applying workflows that are dynamically generated for dealing with the variability associated with the self-adaptation process. In this context, this research aims to define and develop techniques for automatically generate workflows for coordinating the self-adaptation of software systems. For demonstrating the feasibility of the proposed approach, architectural reconfiguration of software systems is used as an example, whereby the reconfiguration is managed by workflows that are dynamically generated depending on the availability of resources.

A Model for the Transmission of Multimedia Data Flow Based on the Use of Shared Memory Mechanism

The communication between multimedia components located on the same physical machine, but in different address space, uses mechanisms designed for distributed environments. The present paper proposes an inter-component communication model in this context through the use of a shared memory mechanism. This model is based on the shared memory primitives offered by different operating systems. The model can be used in different middleware platforms. To evaluate the model, an application written in Java was developed, that, through functions written in C language, has access to the primitives of manipulation of the shared address space.

Poster: Reengineering Legacy Systems for Supporting SOA: A Case Study on the Brazilian's Secretary of State for Taxation

The migration of legacy systems to a service-oriented architecture (SOA) allows to deal with the demand for interoperability and the need to provide a robust high-available service interface. However, such migration presents a considerable risk, as it often involves the use of different techniques on systems with elevated technical debt and high maintenance costs. For this purpose, a process is instantiated to provide an appropriate set of techniques that will minimize risks and at the same time ensure quality improvement of the systems throughout the migration process. In this sense, this work reports on a case study of the application of a process for the reengineering of legacy systems to support the implementation of SOA project. This study has been applied to the evolution of legacy systems of the Secretariat of State for Taxation of Rio Grande do Norte (SET/RN), Brazil, providing significant results regarding the achievement of important quality goals.

Extracting and Evolving a Software Product Line from Existing Web-based Systems: An Experience Report

This paper presents an experience report of extraction and evolution of software product lines (SPLs) from existing web-based systems. We describe the activities to succesfully refactor and evolve an web-based system of management of university rooms and laboratories by promoting the management and modularization of their variabilities. Several lessons learned are derived from that experience, includying the proposal of a method for the extraction and evolution of SPLs, as well as strategies for variability refactoring.

Self-adaptive authorisation in OpenStack cloud platform

Although major advances have been made in protection of cloud platforms against malicious attacks, little has been done regarding the protection of these platforms against insider threats. This paper looks into this challenge by introducing self-adaptation as a mechanism to handle insider threats in cloud platforms, and this will be demonstrated in the context of OpenStack. OpenStack is a popular cloud platform that relies on Keystone, its identity management component, for controlling access to its resources. The use of self-adaptation for handling insider threats has been motivated by the fact that self-adaptation has been shown to be quite effective in dealing with uncertainty in a wide range of applications. Insider threats have become a major cause for concern since legitimate, though malicious, users might have access, in case of theft, to a large amount of information. The key contribution of this paper is the definition of an architectural solution that incorporates self-adaptation into OpenStack Keystone in order to handle insider threats. For that, we have identified and analysed several insider threats scenarios in the context of the OpenStack cloud platform, and have developed a prototype that was used for experimenting and evaluating the impact of these scenarios upon the self-adaptive authorisation system for the cloud platforms.

A new approach to deploy a self-adaptive distributed firewall

Abstract■■■Distributed firewall systems emerged with the proposal of protecting individual hosts against attacks originating from inside the network. In these systems, firewall rules are centrally created, then distributed and enforced on all servers that compose the firewall, restricting which services will be available. However, this approach lacks protection against software vulnerabilities that can make network services vulnerable to attacks, since firewalls usually do not scan application protocols. In this sense, from the discovery of any vulnerability until the publication and application of patches there is an exposure window that should be reduced. In this context, this article presents Self-Adaptive Distributed Firewall (SADF). Our approach is based on monitoring hosts and using a vulnerability assessment system to detect vulnerable services, integrated with components capable of deciding and applying firewall rules on affected hosts. In this way, SADF can respond to vulnerabilities discovered in these hosts, helping to mitigate the risk of exploiting the vulnerability. Our system was evaluated in the context of a simulated network environment, where the results achieved demonstrate its viability.

Self-adaptive role-based access control for business processes

We present an approach for dynamically reconfiguring the role-based access control (RBAC) of information systems running business processes, to protect them against insider threats. The new approach uses business process execution traces and stochastic model checking to establish confidence intervals for key measurable attributes of user behaviour, and thus to identify and adaptively demote users who misuse their access permissions maliciously or accidentally. We implemented and evaluated the approach and its policy specification formalism for a real IT support business process, showing their ability to express and apply a broad range of self-adaptive RBAC policies.