Extending TOSCA for Edge and Fog Deployment Support

Andreas Tsagkaropoulos,Gregoris Mentzas,Dimitris Apostolou,Maxime Compastié,Yiannis Verginadis

doi:10.3390/electronics10060737

Abstract

The emergence of fog and edge computing has complemented cloud computing in the design of pervasive, computing-intensive applications. The proximity of fog resources to data sources has contributed to minimizing network operating expenditure and has permitted latency-aware processing. Furthermore, novel approaches such as serverless computing change the structure of applications and challenge the monopoly of traditional Virtual Machine (VM)-based applications. However, the efforts directed to the modeling of cloud applications have not yet evolved to exploit these breakthroughs and handle the whole application lifecycle efficiently. In this work, we present a set of Topology and Orchestration Specification for Cloud Applications (TOSCA) extensions to model applications relying on any combination of the aforementioned technologies. Our approach features a design-time “type-level” flavor and a run time “instance-level” flavor. The introduction of semantic enhancements and the use of two TOSCA flavors enables the optimization of a candidate topology before its deployment. The optimization modeling is achieved using a set of constraints, requirements, and criteria independent from the underlying hosting infrastructure (i.e., clouds, multi-clouds, edge devices). Furthermore, we discuss the advantages of such an approach in comparison to other notable cloud application deployment approaches and provide directions for future research.

Highlights

Cloud computing has become a widely valued commodity with constantly increasing popularity among large and small to mid-sized enterprises (SMEs), as well as public organizations
The lack of common standards and the heterogeneity of cloud provider solutions put at risk the portability of data and applications, as moving to a technology supported by a different provider may be associated with high costs [2]
Based on our experience working on the PrEstoCloud framework [14], we argue that in such dynamic environments there is an urgent need to shift some of the core responsibilities of Development and Operations (DevOps) to an appropriate middleware

Summary

Introduction

Cloud computing has become a widely valued commodity with constantly increasing popularity among large and small to mid-sized enterprises (SMEs), as well as public organizations. According to the report by Gartner, an 18.4% increase in total public cloud computing revenue is expected for 2021 compared to 2020, reaching 304.9 billion USD [1]. The lack of common standards and the heterogeneity of cloud provider solutions put at risk the portability of data and applications, as moving to a technology supported by a different provider may be associated with high costs [2]. The need for a common and interoperable standard is further augmented due to the appearance of fog computing, which relies on edge devices to complement cloud resources. An advanced common standard can contribute towards provider-agnostic orchestration, but can fill gaps in the management of application assets in fog environments

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Conclusion