Towards a General Model for Adapting Structure while Maintaining Topology: Pipelines.

Large scale information systems are increasingly structured around flexible workflows of services providing a range of functionalities that are configured to suit particular needs, yet this flexibility can bring a lack of organisation in the ways in which services are combined. Particular system structures bring different benefits to an application in terms of efficacy and efficiency but sometimes need to reorganise as their circumstances change. In this context, this paper seeks to establish techniques for reorganisation that preserve particular topologies in support of their recognised benefit for the target applications. The contributions are twofold: first, a general vision of reorganisation of defined topologies, in which topology is preserved but efficiency and efficacy are optimised; and second, a specific solution for the case of pipelines, reorganising to optimise key application-specific metrics, while preserving topology. The paper is thus the starting point for a more ambitious general programme of research.