Performance modeling for service oriented architectures

We present a tool for performance modeling of Service Oriented Architectures (SOAs). As mission-critical use of whole-of-government SOAs become pervasive, the capability to model and predict the performance of interdependent composite applications is critical. The tool can be used by architects early in the software engineering lifecycle to predict performance and scalability, to evaluate architectural alternatives, to provide guidance for capacity planning and the negotiation of Service Level Agreements (SLAs). It directly models and produces metrics for SOA applications in terms that are familiar to architects (services, workflows, and compositions of services). The tool enables the performance model to be generated from available architectural artifacts and performance data, making it easy to use. It is highly dynamic to facilitate interactive evaluation of alternative architectural choices. The tool can model complex deployment scenarios, including hosting multiple services on shared fixed or virtual servers. Development and evaluation of the tool was carried out in the context of architectural modeling for large-scale SOA-based Australian e-Government systems. The tool radically simplified the construction and execution of SOA performance models, and contributed critical architectural insights for the software engineering of these systems. 1