Modellbasiertes Service-level-Management verteilter Anwendungssysteme

In order to reduce costs, many enterprises have started to focus on their core business processes. As a consequence non-central business processes more and more are outsourced to external service providers. The relelationships between service providers and the service consumers are laid down in legal contracts called Service Level Agreements (SLAs). It is the task of the Service Level Management (SLM) to monitor all agreed upon service level parameters and make sure that they are not violated. For an automated management of SLAs, a formal representation is required. The big number of different SLM tools spawned by the market cause problems due to proprietary SLA formats and missing specification methodologies. This leads to a dependency on SLM tools and a very limited reusability of previously specified SLAs. As a solution, this thesis proposes a platform independent approach for Service Level Management. Its goal is a unification of the modelling process in order to integrate different management tools. This enables a separation of the technology domain from the problem domain, resulting in stable and persistent models. Further goals of this thesis are to provide reusability of modeled SLAs and to establish a process-oriented modelling methodology. The automatic deployment of modelled SLAs is important for the practical applicability of the approach. This thesis applies the principles of the Model Driven Architecture (MDA) to the problem domain of Service Level Management. The central idea of this thesis is the definition of SLA patterns which represent configuration independent abstractions of real SLAs. These SLA patterns correspond to the Platform-Independent Model (PIM) of the MDA. By using an appropriate model transformation, a concrete SLA instance is generated from an SLA pattern. Such an SLA instance includes all necessary configuration information and is already represented in the SLA format of the target management platform. Thus, an SLA instance corresponds to the Platform-Specific Model (PSM) of the MDA. Finally, the deployment of the SLA instance sets up the management platform for automatically managing the SLA conformance. The deployment of the SLA instance corresponds to the Platform-Specific Code (PSC) of the MDA. As part of this thesis, a UML extension was defined which enables the specification of SLA patterns using a UML modeling tool. SLA patterns can be specified as purely graphical UML models and additionally with the Object Constraint Language (OCL). For practical application of the approach, a management architecture was developed and prototypically implemented. The overall solution has been evaluated in a case study.