An Extensible Framework for Improving a Distributed Software System´s Deployment Architecture

A distributed system´s allocation of software components to hardware nodes (i.e., deployment architecture) can have a significant impact on its quality of service (QoS). For a given system, there may be many deployment architectures that provide the same functionality, but with different levels of QoS. The parameters that influence the quality of a system´s deployment architecture are often not known before the system´s initial deployment and may change at runtime. This means that redeployment of the software system may be necessary to improve the system´s QoS properties. This paper presents and evaluates a framework aimed at finding the most appropriate deployment architecture for a distributed software system with respect to multiple, possibly conflicting QoS dimensions. The framework supports formal modeling of the problem and provides a set of tailorable algorithms for improving a system´s deployment. We have realized the framework on top of a visual deployment architecture modeling and analysis environment. The framework has been evaluated for precision and execution-time complexity on a large number of simulated distributed system scenarios, as well as in the context of two third-party families of distributed applications.