Migrating monolithic software systems into microservices requires the application of decomposition techniquesto find and select appropriate service boundaries. These techniques are often based on domain knowledge, static code analysis, and non-functional requirements such as maintainability. In this paper, we present our experience with an approach that extends static analysis with dynamic analysis of a legacy software system's runtime behavior, including the live trace visualization to support the decomposition into microservices. Overall, our approach combines established analysis techniques for microservice decomposition, such as the bounded context pattern of domain-driven design, and enriches the collected information via dynamic software visualization to identify appropriate microservice boundaries. In collaboration with the German IT service provider adesso SE, we applied our approach to their real-word, legacy lottery application in|FOCUS to identify good microservice decompositions for this layered monolithic Enterprise Java system.
Microservices' architecture is getting attention in the academic community and the industry, and mostly is compared with monolithic architecture. Plenty of the results of these research papers contradict each other regarding the performance of these architectures. Therefore, these two architectures are compared in this paper, and some specific configurations of microservices' applications are evaluated as well in the term of service discovery. Monolithic architecture in concurrency testing showed better performance in throughput by 6% when compared to microservices architecture. The load testi…
One of the most challenging problems in the migration of a monolith to a microservices architecture is the identification of the microservices boundaries. Several approaches have been recently proposed for the automatic identification of microservices, which, even though following the same basic steps, diverge on how data of the monolith system is collected and analysed. In this paper, we compare the decompositions generated for two monolith systems into a set of candidate microservices, when static and dynamic analysis data collection techniques are used. The decompositions are generated usin…
Monolithic applications are being decomposed to a microservices architecture, aiming to improve maintainability, performance and modularization. Although such decompositions have now been widely carried out in the industry, little is reported in the literature about the impacts of these decompositions. This work, therefore, reports a case study carried out to investigate the impacts of the decomposition of a real industry application for microservices architecture. The target application of the study refers to a raid operation, performed by a financial institution, which was extracted from a m…
Background. The migration from monolithic systems to microservices involves deep refactoring of the systems. Therefore, the migration usually has a big economic impact and companies tend to postpone several activities during this process, mainly to speed-up the migration itself, but also because of the need to release new features. Objective. We monitored the Technical Debt of a small and medium enterprise while migrating a legacy monolithic system to an ecosystem of microservices to analyze changes in the code technical debt before and after the migration to microservices. Method. We conducte…
Microservice architecture refers to the use of numerous small-scale and independently deployed services, instead of encapsulating all functions into one monolith. It has been a challenge in software engineering to decompose a monolithic system into smaller parts. In this paper, we propose the Feature Table approach, a structured approach to service decomposition based on the correlation between functional features and microservices: (1) we defined the concept of {\em Feature Cards} and 12 instances of such cards; (2) we formulated {\em Decomposition Rules} to decompose monolithic applications;…
Linear-infrastructure Mission Control (LiMiC) is an application for autonomous Unmanned Aerial Vehicle (UAV) infrastructure inspection mission planning developed in monolithic software architecture. The application calculates routes along the infrastructure based on the users' inputs, the number of UAVs participating in the mission, and UAVs' locations. LiMiC1.0 is the latest application version migrated from monolith to microservices, continuously integrated, and deployed using DevOps tools to facilitate future features development, enable better traffic management, and improve the route calc…
Migrating a monolith application into a microservices architecture can benefit from automation methods, which speed up the migration and improve the decomposition results. One of the current approaches that guide software architects on the migration is to group monolith domain entities into microservices, using the sequences of accesses of the monolith functionalities to the domain entities. In this paper, we enrich the sequence of accesses solution by applying code vectorization to the monolith, using the \textit{Code2Vec} neural network model. We apply \textit{Code2Vec} to vectorize the mono…
Context. Re-architecting monolithic systems with Microservices-based architecture is a common trend. Various companies are migrating to Microservices for different reasons. However, making such an important decision like re-architecting an entire system must be based on real facts and not only on gut feelings. Objective. The goal of this work is to propose an evidence-based decision support framework for companies that need to migrate to Microservices, based on the analysis of a set of characteristics and metrics they should collect before re-architecting their monolithic system. Method. We de…
We propose Sliceable Monolith, a new methodology for developing microservice architectures and perform their integration testing by leveraging most of the simplicity of a monolith: a single codebase and a local execution environment that simulates distribution. Then, a tool compiles a codebase for each microservice and a cloud deployment configuration. The key enabler of our approach is the technology-agnostic service definition language offered by Jolie.
The agility inherent to today's business promotes the definition of software architectures where the business entities are decoupled into modules and/or services. However, there are advantages in having a rich domain model, where domain entities are tightly connected, because it fosters an initial quick development. On the other hand, the split of the business logic into modules and/or services, its encapsulation through well-defined interfaces and the introduction of inter-service communication introduces a cost in terms of performance. In this paper we analyze the stepwise migrating of a mon…
Microservices Architecture (MSA) has become a de-facto standard for designing cloud-native enterprise applications due to its efficient infrastructure setup, service availability, elastic scalability, dependability, and better security. Existing (monolithic) systems must be decomposed into microservices to harness these characteristics. Since manual decomposition of large scale applications can be laborious and error-prone, AI-based systems to detect decomposition strategies are gaining popularity. However, the usefulness of these approaches is limited by the expressiveness of the program repr…
Migrating from monolithic systems into microservice is a very complex task. Companies are commonly decomposing the monolithic system manually, analyzing dependencies of the monolith and then assessing different decomposition options. The goal of our work is two-folded: 1) we provide a microservice measurement framework to objectively evaluate and compare the quality of microservices-based systems; 2) we propose a decomposition system based on business process mining. The microservice measurement framework can be applied independently from the decomposition process adopted, but is also useful t…
Recent research has proposed different approaches on the automated identification of candidate microservices on monolith systems, which vary on the monolith representation, similarity criteria, and quality metrics used. On the other hand, they are generally limited in the number of codebases and decompositions evaluated, and few comparisons between approaches exist. Considering the emerging trend in software engineering in techniques based on the analysis of codebases' evolution, we compare a representation based on the monolith code structure, in particular the sequences of accesses to domain…
In migrating production workloads to cloud, enterprises often face the daunting task of evolving monolithic applications toward a microservice architecture. At IBM, we developed a tool called Mono2Micro to assist with this challenging task. Mono2Micro performs spatio-temporal decomposition, leveraging well-defined business use cases and runtime call relations to create functionally cohesive partitioning of application classes. Our preliminary evaluation of Mono2Micro showed promising results. How well does Mono2Micro perform against other decomposition techniques, and how do practitioners perc…
While the recently emerged Microservices architectural style is widely discussed in literature, it is difficult to find clear guidance on the process of refactoring legacy applications. The importance of the topic is underpinned by high costs and effort of a refactoring process which has several other implications, e.g. overall processes (DevOps) and team structure. Software architects facing this challenge are in need of selecting an appropriate strategy and refactoring technique. One of the most discussed aspects in this context is finding the right service granularity to fully leverage the …
The microservice architectural style has many advantages such as scalability, reusability, and easy maintainability. Microservices have therefore become a popular architectural choice when developing new applications. Reaping these benefits requires redesigning the monolithic application and moving them to a microservices-based architecture. This process is inherently complex and costly, so automating this task is critical. This project proposes a method by which potential microservices can be identified from a given monolithic application while treating this problem as a clustering thematic. …
Proposing and implementing software systems, especially web applications for e-commerce using the traditional monolithic approach has been the norm, however, as new user requirements force organisations and developers to add more functionalities to their systems, and as user demands increases, the performance of monolith applications decreases, and maintenance costs rise. These issues have necessitated a need for a better system and that is where Microservices event-driven applications come in. This thesis investigates the scopeand impact of migrating to Microservices, using agile frameworks, …
Monolithic software encapsulates all functional capabilities into a single deployable unit. But managing it becomes harder as the demand for new functionalities grow. Microservice architecture is seen as an alternate as it advocates building an application through a set of loosely coupled small services wherein each service owns a single functional responsibility. But the challenges associated with the separation of functional modules, slows down the migration of a monolithic code into microservices. In this work, we propose a representation learning based solution to tackle this problem. We u…
In recent years, microservice architecture has become a popular architectural style in software engineering, with its natural support for DevOps and continuous delivery, as well as its scalability and extensibility, which drive industry practitioners to migrate to microservice architecture. However, there are many challenges in adopting a microservice architecture, the most important of which is how to properly decomposition a monolithic system into microservices. Currently, microservice decomposition decisions for monolithic systems rely on subjective human experience, which is a costly, time…
Continuous Architecture (CA) is an approach that supports companies in decreasing the time between deliveries. Migration to microservices is one of the most common situations when companies adopt continuous architecting processes [4]. Companies commonly adopt an initial migration strategy to extract some components from the monolithic system as microservices, making use of simplified microservices patterns [5][4]. As an example, companies commonly directly connect the microservices to the legacy monolithic system and do not adopt any message bus at the beginning. When the system starts to grow…
The microservice software architecture is more scalable and efficient than its monolithic predecessor. Despite its increasing adoption, microservices might expose security concerns and issues that are distinct from those associated with monolithic designs. We propose Microusity, a tool that performs RESTful API testing on a specific type of microservice pattern called back end for front end (BFF). We design a novel approach to trace BFF requests using the port mapping between requests to BFF and the sub-requests sent to back-end microservices. Furthermore, our tool can pinpoint which of the ba…
In the last few years, the cloudification of applications requires new concepts and techniques to fully reap the benefits of the new computing paradigm. Among them, the microservices architectural style, which is inspired by service-oriented architectures, has gained attention from both industry and academia. However, decomposing a monolith into multiple microservices also creates several challenges across the application's lifecycle. In this work, we focus on the operation aspect of microservices, and present our novel proposal to enable self-optimizing microservices systems based on grid sea…
It is well recognized that design patterns improve system development and maintenance in many aspects. While we commonly recognize these patterns in monolithic systems, many patterns emerged for cloud computing, specifically microservices. Unfortunately, while various patterns have been proposed, available quality assessment tools often do not recognize many. This article performs a grey literature review to find and catalog available tools to detect microservice API patterns (MAP). It reasons about mechanisms that can be used to detect these patterns. Furthermore, the results indicate gaps an…
Microservices are supporting digital transformation; however, fundamental tools and system perspectives are missing to better observe, understand, and manage these systems, their properties, and their dependencies. Microservices architecture leans toward decentralization, which yields many advantages to system operation; it, however, brings challenges to their development. Microservices lack a system-centric perspective to better cope with system evolution and quality assessment. In this work, we explore microservice-specific architecture reconstruction based on static analysis. Such reconstru…
Microservices bring various benefits to software systems. They also bring decentralization and lose coupling across self-contained system parts. Since these systems likely evolve in a decentralized manner, they need to be monitored to identify when possibly poorly designed extensions deteriorate the overall system quality. For monolith systems, such tasks have been commonly addressed through static analysis. However, given the decentralization and possible language diversity across microservices, static analysis tools are lacking. On the other hand, there are available tools commonly used by p…
The microservice architectural style has gained much attention from both academia and industry recently as a novel way to design, develop, and deploy cloud-native applications. This concept encourages the decomposition of a monolith into multiple independently deployable units. A typical microservices-based application is formed of two service types: functional services, which provide the core business logic, and infrastructure services, which provide essential functionalities for a microservices ecosystem. To improve developers' productivity, many software frameworks have been developed to pr…
In traditional SaaS enterprise applications, microservices are an essential ingredient to deploy machine learning (ML) models successfully. In general, microservices result in efficiencies in software service design, development, and delivery. As they become ubiquitous in the redesign of monolithic software, with the addition of machine learning, the traditional applications are also becoming increasingly intelligent. Here, we propose a portable ML microservice framework Minerva (microservices container for applied ML) as an efficient way to modularize and deploy intelligent microservices in t…
The evolution of decentralized microservice-based systems is challenging. These challenges are classified into static and dynamic categories. Regarding the static perspective, documenting and visualizing the fluid application topology is something few have been able to accomplish. Building an architecture map of services design is a complicated task in its interpretation rather than construction. Therefore, the system-centric and up-to-date view became essential for such distributed systems. The dynamic perspective considers the process of investigation and service path detection. Therefore pe…
