In this paper, we propose edge-cloud computing as a new framework for organizing the data pipeline functions, i.e., acquisition, processing and analytics, in the Internet of Things systems. Edge-cloud computing consists of three layers, namely smart edge devices, fog computing layer and cloud computing layer. Being an intrinsically hierarchical framework, edge-cloud computing is able to tackle the complexities of Internet of Things systems more fundamentally. In particular, we discuss the main roles of orchestration and intermediary that fog computing undertakes for microservices and cloud services, and the fundamental underpinning function – automated service provisioning in fog computing.