Bassem Nasser

Platform-as-a-Service Architecture for Real-Time Quality of Service Management in Clouds

Cloud computing offers the potential to dramatically reduce the cost of software services through the commoditization of information technology assets and on-demand usage patterns. However, the complexity of determining resource provision policies for applications in such complex environments introduces significant inefficiencies and has driven the emergence of a new class of infrastructure called Platform-as-a-Service (PaaS). In this paper, we present a novel PaaS architecture being developed in the EU IST IRMOS project targeting real-time Quality of Service (QoS) guarantees for online interactive multimedia applications. The architecture considers the full service lifecycle including service engineering, service level agreement design, provisioning and monitoring. QoS parameters at both application and infrastructure levels are given specific attention as the basis for provisioning policies in the context of temporal constraints. The generic applicability of the architecture is being verified and validated through implemented scenarios from three important application sectors (film post-production, virtual augmented reality for engineering design, collaborative e-Learning in virtual worlds).

A business-oriented Cloud federation model for real-time applications

Cloud federation can allow individual Cloud providers working collaboratively to offer best-effort services to service customers. However, the current federated Cloud computing model is not appropriate for computationally intensive Real-time Online Interactive Applications (ROIA). This paper discusses how we propose and develop a business-oriented federated Cloud computing model where multiple independent infrastructure providers can cooperate seamlessly to provide scalable IT infrastructure and QoS-assured hosting services for ROIA. The distinct features of this proposed Cloud federation model is its business layer that can provide an enhanced security features and can trigger the on-demand resource provisioning across multiple infrastructure providers, hence helping to maximize the customer satisfaction, business benefits and resources usage.

Maintaining trustworthiness of socio-technical systems at run-time

Trustworthiness of dynamical and distributed socio-technical systems is a key factor for the success and wide adoption of these systems in digital businesses. Different trustworthiness attributes should be identified and accounted for when such systems are built, and in order to maintain their overall trustworthiness they should be monitored during run-time. Trustworthiness monitoring is a critical task which enables providers to significantly improve the systems’ overall acceptance. However, trustworthiness characteristics are poorly monitored, diagnosed and assessed by existing methods and technologies. In this paper, we address this problem and provide support for semi-automatic trustworthiness maintenance. We propose a trustworthiness maintenance framework for monitoring and managing the system’s trustworthiness properties in order to preserve the overall established trust during run-time. The framework provides an ontology for run-time trustworthiness maintenance, and respective business processes for identifying threats and enacting control decisions to mitigate these threats. We also present use cases and an architecture for developing trustworthiness maintenance systems that support system providers.

Run-Time Risk Management in Adaptive ICT Systems

We will present results of the SERSCIS project related to risk management and mitigation strategies in adaptive multi-stakeholder ICT systems. The SERSCIS approach involves using semantic threat models to support automated design-time threat identification and mitigation analysis. The focus of this paper is the use of these models at run-time for automated threat detection and diagnosis. This is based on a combination of semantic reasoning and Bayesian inference applied to run-time system monitoring data. The resulting dynamic risk management approach is compared to a conventional ISO 27000 type approach, and validation test results presented from an Airport Collaborative Decision Making (A-CDM) scenario involving data exchange between multiple airport service providers.

Towards a Linked Data Vocabulary for the Certification of Software Properties

In order to cater for a growing user base that requires varied functionalities and owns multiple devices, software providers are using cloud solutions as the preferred technical means. In fact, all major operating systems come with a tight integration to cloud services. Software solutions that have such integration with cloud services should disclose (transparency) this to the consumer. Furthermore, with mounting concerns over the security of software, consumers are demanding assurance over the software being used. Software certification can address both issues: security and transparency of software, thereby providing comprehensive assurance to consumers. However current software certifications are tailored for human consumption and represented in natural language, a major issue that hinders automated reasoning to be performed on them. Focused research efforts in the past few years have resulted in a Digital Certification concept, a machine process able representation of certifications, that can cater to different software provisioning models. We extend the notion of a Digital Certification by using the Linked Data vocabulary to express general characteristics of software systems that benefits from existing and future knowledge from the Linked Data community. This greatly increases the usability of such Digital Certifications and has a wider impact on the Software certification landscape.

Supporting Coordinated Maintenance of System Trustworthiness and User Trust at Runtime

In addition to design-time considerations, user trust and the trustworthiness of software-intensive socio-technical systems (STS) need to be maintained during runtime. Especially trust can only be monitored based on the actual usage of the system in operation. Service providers should be able to make informed decisions about runtime adaptation based on trust and trustworthiness, as well as respective essential relations. In this paper we present a unified approach to support the coordination of trust and trustworthiness maintenance. Trustworthiness maintenance is based on measuring objective system qualities, while trust maintenance considers two complementary measures of trust, i.e., the user behavior, and an estimation of the perceived system trustworthiness. A prototype tool demonstrates the feasibility of our approach. Furthermore, we illustrate specific functionalities of the tool by means of an application example.

The edutain@grid Portals --- Providing User Interfaces for Different Kinds of Actors

In recent years grid computing has evolved from simple batch processing systems to highly interactive applications. One approach heading in that direction is the edutain@grid project. This project aims to enable the computing power of current grid systems to the area of online computer games and e-learning applications. The shift from traditional scientific computing applications into the domain of business oriented applications has led to the involvement of a variety of actors. All of these organisations and persons have different needs considering the access to the system. To communicate with the edutain@grid system a novel combination of portals had to be developed. Three types of portals allow the stakeholders to get access to this system. These portals allow a unified and consistent interface approach hiding the complexity of traditional grid applications in order to support users from all different fields to work with edutain@grid in an intuitive way.