Microservices: Yesterday, Today, and Tomorrow

Abstract

Microservices is an architectural style inspired by service-oriented computing that has recently started gaining popularity. Before presenting the current state-of-the-art in the field, this chapter reviews the history of software architecture, the reasons that led to the diffusion of objects and services first, and microservices later. Finally, open problems and future challenges are introduced. This survey primarily addresses newcomers to the discipline, while offering an academic viewpoint on the topic. In addition, we investigate some practical issues and point out some potential solutions.

Research on Architecting Microservices: Trends, Focus, and Potential for Industrial Adoption

“…Dragoni et al performed an informal survey on microservices [2]. Our study differs from their study because (i) we specifically focus on architectural principles, method, and techniques, rather than on microservices in general; (ii) we apply a rigorous empirical method throughout the study (i.e., systematic mapping), thus providing evidence-based results and easing replication of the performed research; (iii) the objective of our study is to characterize existing research on architecting microservices, rather than on providing a narrative viewpoint on their historical, current, and future traits.…”

Aspect-driven Context-aware Services

“…The internal design of these components may differ based on their implementation. Properly implemented SOA emphasizes scalability and testability because it significantly reduces the complexity of services comparing to monolith applications [8]. On the other hand, it significantly reduces and complicates information reuse and enforces manual repetition instead, which easily leads to inconsistencies [3] and error-prone and expensive maintenance.…”

“…2 Microservices pattern suggests a use of a simple connection and smart endpoints [9], but we could also use more complex alternatives such as catalogs, service locators, and Enterprise Service Bus [5], [10]. It would be major overhead in this example plus conventional approaches highlight choreography over orchestration [8].…”

“…Next, it suggests the use of multiple agile teams and service communication through an independent, usually HTTP-based, protocol such as REST and SOAP. Finally, it stresses decentralization through choreography [8], [21]. Contrary, plain SOA often uses orchestration, e.g., Enterprise Service Bus, which brings centralization.…”

“…First, the services are orchestrated in a network with a director validating and forwarding messages, or the services know their dependencies and somehow they look up them themselves [8]. While the first more centric approach is known as an orchestration, the other is known as a choreography.…”