Resumen
In this paper, the authors, based on a case study of the Polish healthcare IT system being deployed to the cloud, show the possibilities for limiting the computing resources consumption of rarely used services. The architecture of today?s developed application systems is often based on the architectural style of microservices, where individual groups of services are deployed independently of each other. This is also the case with the system under discussion. Most often, the nature of the workload of each group of services is different, which creates some challenges but also provides opportunities to make optimizations in the consumption of computing resources, thus lowering the environmental footprint and at the same time gaining measurable financial benefits. Unlike other scaling methods, such as those based on MDP and reinforcement learning in particular, which focus on system load prediction, in this paper, the authors propose a reactive approach in which any, even unpredictable, change in system load may result in a change (autoscaling) in the number of instances of computing processes so as to adapt the system to the current demand for computing resources as soon as possible. The authors? main motivation for undertaking the study is to observe the growing interest in implementing FaaS technology in systems deployed to production in many fields, but with relatively little adoption in the healthcare field. Thus, as part of the research conducted here, the authors propose a solution for infrequently used services enabling the so-called scale-to-zero feature using the FaaS model implemented by the Fission tool. This solution is at the same time compatible with the cloud-agnostic approach which in turn helps avoid so-called cloud computing vendor lock-in. Using the example of the system in question, quantitative experimental results showing the savings achieved are presented, proving the justification for this novel implementation in the field of healthcare IT systems.