Petrenko O. Strategy development of service-oriented systems in a cloud environment

The dissertation is devoted to investigating necessary changes in service-oriented technologies due to the general tendency of transfer of applications in cloud environments, in particular, in the European open scientific cloud. The basic differences between the traditional first-generation SOA (based on Web-based services with unified communications protocols) and the cloud-based MSA of the new generation (based on microservices with containers) are explored, and the ways of their convergence are shown with the purpose of providing efficient virtualization of cloud hardware and OS resources. For this, SOA is recommended to switch to container-based interactions between services and to control a size of Web services, and MSA to apply a semantic description of the micro-services to automate their discovery in large-sized registries (an expedient search algorithm is described). It turns out that the application of SOA is effective for the integration of applications and information systems, MSA effectively acts at the level of a separate application, focusing on its structure and components. On the basis of the combination of Ontologically Oriented (OО) and Model-Managed (MD) approaches, the methodology for designing service systems has been developed as a process of successive transformation of conceptual models (CIM, PIM, and PSM) with a gradual increase in the influence of the parameters of the service platform, which is used to implement the service system. It is shown that for MSA you can create the same types of architectures (synchronous, asynchronous and mixed) that exist for SOA. The service-oriented architecture and the list of services for the mobile medical system of the state monitoring and assistance to elderly chronically ill people in the framework of the implementation of the national health care reform in Ukraine are described. Keywords: service-oriented architecture (SOA), microservice, virtualization, container, cloud, API interface, microservice architecture (MSA), ontology, semantics, model-driven approach, European open science cloud (EOSC).