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

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 reconfigurable 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 dynamically composed into event-dependent data-flow graphs. Again, generic mechanisms for such compositions correspond to calculus of functionals and relations. 1 Computations are coming back to "virtual"clouded mainframes Contemporary mainframes are huge data centers comprising tens or hundreds of thousands of interconnected physical servers and disk arrays. Usually, they are built according to cloud architecture where almost everything is virtualized starting with IaaS, PaaS and Saas. The next virtualizations are FaaS (Function as a Service) and BaaS (Backend as a Service) that constitute a new computing paradigm called Serverless. It is based on an execution model in which an application consists of interrelated individual functions and backend services that can be managed, scaled and executed by cloud provider by automatic and dynamic allocations of compute resources. Developers (of the applications) are charged for-only the compute resources and storage needed to execute a particular piece of code. Using FaaS and BaaS, developers can effectively implement micro-services that comprise the applications. Cloud providers are responsible for deploying the code, and for an application runtime environment. The book by Brendan Burns 2018 [6] (http:// www.istrsjournal.org/wp-content/uploads/2018/06/Designing_Distributed_Systems. pdf) may serve as a classic (now a bit obsolete) introduction to this subject.There are many serverless platforms provided by main players like Amazon Web Services, Microsoft Azure, Google Cloud Platform, IBM Cloud, Alibaba, etc. as well