Managing geo-distributed stream processing pipelines for the MoT with StreamPipes edge extensions

The industrial IoT and its promise to realize data-driven decision-making by analyzing industrial event streams is an important innovation driver in the industrial sector. Due to an enormous increase of generated data and the development of specialized hardware, new decentralized paradigms such as fog computing arised to overcome shortcomings of centralized cloud-only approaches. However, current undertakings are focused on static deployments of standalone services, which is insufficient for geo-distributed applications that are composed of multiple event-driven functions. In this paper, we present StreamPipes Edge Extensions (SEE), a novel contribution to the open source IIoT toolbox Apache StreamPipes. With SEE, domain experts are able to create stream processing pipelines in a graphical editor and to assign individual pipeline elements to available edge nodes, while underlying provisioning and deployment details are abstracted by the framework. The main contributions are (i) a fog cluster management model to represent computing node characteristics, (ii) a node controller for pipeline element life cycle management and (iii) a management framework to deploy event-driven functions to registered nodes. Our approach was validated in a real industrial setup showing low overall overhead of SEE as part of a robot-assisted product quality inspection use case.