Facing the Unplanned Migration of Serverless Applications - A Study on Portability Problems, Solutions, and Dead Ends.

Serverless computing focuses on developing cloud applications that comprise components fully managed by providers. Function-as-a-Service (FaaS) service model is often associated with the term serverless as it allows developing entire applications by composing provider-managed, event-driven code snippets. However, such reduced control over the infrastructure and tight-coupling with provider's services amplify the various lock-in problems. In this work, we explore the challenges of migrating serverless, FaaS-based applications across cloud providers. To achieve this, we conduct an experiment in which we implement four prevalent yet intentionally simple serverless use cases and manually migrate them across three popular commercial cloud providers. The results show that even when migrating simple use cases, developers encounter multiple aspects of a lock-in problem. Moreover, we present a categorization of the problems and discuss the feasibility of possible solutions.