SZTAKI - Department of Distributed Systems

S-Cube, the Software Services and Systems Network, aims to establish an integrated, multidisciplinary, vibrant research community which enables Europe to lead the software-services revolution, thereby helping shape the software-service based Internet which is the backbone of our future interactive society.

An integration of research expertise and an intense collaboration of researchers in the field of software services and systems are needed to address the following key problems:

• Research fragmentation: Current research activities are fragmented and each research community (e.g., grid computing or software engineering) concentrates mostly on its own specific techniques, mechanisms and methodologies. As a result the proposed solutions are not aligned with or influenced by activities in related research fields.
• Future Challenges: One challenge, as an example, is to build service-based systems in such a way that they can self-adapt while guaranteeing the expected level of service quality. Such an adaptation can be required due to changes in a system’s environment or in response to predicted and unpredicted problems.

Among others, we participated in the research of cross-layer adaptation in service-based applications. Cross-layer adaptation techniques combine adaptation methods on various layers, such as adaptation of the service infrastructure (e.g. speeding up service execution) or adaptation of the service composition (e.g. replacing a faulty service). The final goal of the adaptation is to help keeping the agreed Service Level Agreement (SLA) and to avoid SLA violations.

Another research topic was about SLA negotiation using negotiation brokers who help to establish the common environment which connect the negotiating parties. Before the negotiation can start, the negotiation protocol and other options must be set in a way that all parties are able to participate. This preparation phase is an important enabler of dynamic and ad-hoc negotations of SLA.