Functionalities, Challenges and Enablers for a generalized FaaS based architecture as the realizer of Cloud/Edge continuum interplay

The availability of decentralized edge computing locations as well as their combination with more centralized Cloud solutions enables the investigation of various tradeoffs for application component placement in order to optimize application behavior and resource usage. In this paper, the goal is to investigate key functionalities and operations needed by a middleware layer so that it can serve as a generalized architectural and computing framework in the implementation of a Cloud/Edge computing continuum. As a primary candidate, FaaS frameworks are taken under consideration, given their significant benefits such as flexibility in execution, maturity of the underlying tools, event driven nature and enablement of incorporation of arbitrary and legacy application components triggered by diverse actions and rules. Related work, gaps and enablers for three different layers (application design and implementation, semantically enriched runtime adaptation/configuration and deployment optimization) are highlighted. These aid in detecting necessary building blocks of a proposed generalized architecture in order to enclose the needed functionalities, covering aspects such as diverse service environments and links with the underlying platforms for orchestration.