Context and Motivation
Context
LEMMA is rooted in the domain of Microservice Architecture (MSA), which is an architectural style targeting distributed, service-oriented software systems.
MSA promotes to decompose a software system into microservices, which are components that
- provide a single, distinct functional or infrastructure capability to other architecture components by means of well-defined interfaces,
- are as independent as possible from other components w.r.t. implementation, data management, testing, deployment, and operation,
- are fully accountable for all aspects related to their interaction with other components,
- are owned by exactly one team, which takes full responsibility for design, implementation, and operation issues related to their microservices.
Given the above characteristics of a microservice, MSA aims to particularly increase the scalability and maintainability of software systems.
Motivation
While the adoption of MSA is expected to yield several benefits, it also comes with an increased degree of complexity compared to monolithic applications and their usual multitier architecture:
- Design Complexity: Typical challenges in MSA design comprise the identification of microservices, the determination of their granularity, and the design of their APIs.
- Implementation Complexity: The increased independence of microservices enables teams to employ the most suitable technologies to realize their services. These technologies may concern, e.g., programming languages, database systems, communication protocols, and data formats. However, the resulting technology heterogeneity bears a greater risk for technical debt, additional maintainability costs, and steeper learning curves. Consequently, it calls for dedicated management activities.
- Operation Complexity: MSA emphasizes loose coupling of architecture components, which increases scalability but also requires dedicated components that provide microservices with capabilities such as service discovery, API provisioning, load balancing, and monitoring. These components require regular maintenance and management, which may be aggravated again by an increased technology heterogeneity.
- Organizational Complexity: MSA is most effective when the structure of the organization is also aligned towards the architectural style. That is, the organization or parts thereof are also decomposed along the communication structures of the eventual software architecture. In particular, MSA fosters DevOps practices so that teams should be composed of members with heterogeneous professional backgrounds. However, the introduction of a DevOps culture also requires the automation of manual tasks and sharing of knowledge across team boundaries1.
With LEMMA, we study the support of Model-driven Engineering, and especially the abstraction power of models and modeling languages, to mitigate the impact of the aforementioned degrees of MSA complexity.