Citation: Abdelfattah, A.S.; Cerny, T.
Roadmap to Reasoning in
Microservice Systems: A Rapid
Review. Appl. Sci. 2023, 13, 1838.
https://doi.org/10.3390/app13031838
Academic Editors: Sanjay Misra,
Robertas Damaševiˇcius and Bharti
Suri
Received: 22 December 2022
Revised: 19 January 2023
Accepted: 24 January 2023
Published: 31 January 2023
Copyright: © 2023 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/).
Article
Roadmap to Reasoning in Microservice Systems:
A Rapid Review
Amr S. Abdelfattah and Tomas Cerny *
Computer Science, ECS, Baylor University, One Bear Place #97141, Waco, TX 76798-7356, USA
* Correspondence: tomas_cerny@baylor.edu
Abstract:
Understanding software systems written by others is often challenging. When we want to
assess systems to reason about them, i.e., to understand dependencies, analyze evolution trade-offs,
or to verify conformance to the original blueprint, we must invest broad efforts. This becomes
difficult when considering decentralized systems. Microservice-based systems are mainstream
these days; however, to observe, understand, and manage these systems and their properties, we
are missing fundamental tools that would derive various simplified system abstract perspectives.
Microservices architecture characteristics yield many advantages to system operation; however, they
bring challenges to their development and deployment lifecycles. Microservices urge a system-centric
perspective to better reason about the system evolution and its quality attributes. This process review
paper considers the current system analysis approaches and their possible alignment with automated
system assessment or with human-centered approaches. We outline the necessary steps to accomplish
holistic reasoning in decentralized microservice systems. As a contribution, we provide a roadmap
for analysis and reasoning in microservice-based systems and suggest that various process phases
can be decoupled through the introduction of system intermediate representation as the trajectory to
provide various system-centered perspectives to analyze various system aspects. Furthermore, we
cover different technical-based reasoning strategies and metrics in addition to the human-centered
reasoning addressed through alternative visualization approaches. Finally, a system evolution is
discussed from the perspective of such a reasoning process to illustrate the impact analysis evaluation
over system changes.
Keywords:
architecture reconstruction; microservices visualization; architecture degradation; evolution
1. Introduction
Microservices architecture is a specific style of service-oriented architecture. It is built
of microservices that are relatively small and loosely coupled, running in their processes
and communicating through lightweight communication protocols [
1
,
2
]. This architec-
ture promotes dynamic and independent development, scaling, and deployment [
1
,
3
].
Therefore, several organizations, such as Netflix, Amazon, and Spotify, have adopted
microservice architecture to build scalable, maintainable software systems [
4
,
5
]. This ar-
chitecture style influences the structure of organizations, such that individual components
are typically developed by a specific team; dependencies between components lead to
dependencies between teams [
1
]. Moreover, multiple surveys (https://martinfowler.com/
articles/microservices.html accessed on 1 January 2023) [
6
,
7
] identified and highlighted
the following microservices characteristics,
1.
Autonomous: Separately and independently developed and deployed within their
own lifecycle.
2.
Scalability: Horizontally scaling up and down per the need, while they are small and
stateless components.
3.
Heterogeneity: Various programming languages and technologies can involve the
same system.
Appl. Sci. 2023, 13, 1838. https://doi.org/10.3390/app13031838 https://www.mdpi.com/journal/applsci
