Functionals in the Clouds: An abstract architecture of serverless Cloud-Native Apps

TL;DR

This paper presents a theoretical framework for modeling serverless cloud-native applications using functionals and higher-order type theory, aiming to enable dynamic reconfiguration and composition of microservices.

Contribution

It introduces an abstract architecture of cloud-native apps based on functionals, connecting microservice reconfiguration with higher-order type theory, inspired by Backus's programming at the function level.

Findings

Provides a formal abstract architecture for CNApps

Links reconfiguration mechanisms to higher-order functions

Lays groundwork for a non-von Neumann programming language

Abstract

Cloud Native Application CNApp (as a distributed system) is a collection of independent components (micro-services) interacting via communication protocols. This gives rise to present an abstract architecture of CNApp as dynamically re-configurable acyclic directed multi graph where vertices are microservices, and edges are the protocols. Generic mechanisms for such reconfigurations evidently correspond to higher-level functions (functionals). This implies also internal abstract architecture of microservice as a collection of event-triggered serverless functions (including functions implementing the protocols) that are composed into event-dependent data-flow graphs, and dynamically reconfigured at the runtime. Again, generic mechanisms for such compositions and reconfigurations correspond to functionals and higher order type theory like Coq https://coq.inria.fr/about-coq. Our contribution is strictly theoretical and relies on the abstract architecture of CNApp that is closely related to the calculus of functionals and relations. The proposed theoretical approach is an attempt to implement the original idea of programming at the function level postulated by John Backus 1978 \cite{Backus}; the idea that is still waiting to be implemented as a non-von Neumann programming language.