Once upon a time enterprise software systems used to be monolithic, “siloed” and barely scalable. This has radically changed with the advent of cloud computing that enabled software applications to exploit the scalability, elasticity and capacity of the cloud. Furthermore, the architectures of cloud-based software systems have evolved in-line with new modular and flexible paradigms such as the microservices paradigm.
Microservices refer to a novel architectural style for enterprise software systems in which small services are built and deployed in a modular fashion. Specifically, each module of a microservices architecture runs in its own process and communicates with other modules based on lightweight mechanisms such asHyperText Transmission Protocol(HTTP)based Application Programming Interfaces (APIs). These services are built around business capabilities and are independently deployable. There is a bare minimum of centralized management of these services, which may be written in different programming languages and use different data storage technologies. Microservices architectures can be seen as the next evolutionary step in legacy enterprise architectures like popular Service-Oriented Architectures (SOA).
Microservices provide a host of benefits to software developers and enterprises, especially, when compared with traditional monolithic architectures. One of their main benefits is that they can be used to quickly break large systems into manageable pieces that are easier to reimagine using modern practices and technology. This boosts the flexibility of software developments and the overall agility of modern enterprises.
The Benefits of Microservices
Some of the most prominent benefits of microservices based architectures are:
- Frequent Deployment and Less Bugs: Microservices allow engineers to deploy changes more frequently and with fewer bugs, while also scaling their applications more efficiently. Therefore, they enable enterprise software architectures that are more flexible and more cost-effective at the same time.
- Effective Continuous Integration and Continuous Deployment (CI/CD) for Complex Enterprise Applications: Microservices architectures enable the continuous delivery and continuous deployment of large, complex applications. This is because they are based on a modular approach to development, in which an application consists of many services. These services are built around business capabilities and are independently deployable by fully automated deployment systems.
- Efficient Process Orchestration: Most microservices architectures come with tools that enable the orchestration of multiple autonomous services into adapted business processes. In this direction, microservices tools incorporate domain specific design patterns and orchestration patterns, notably proven and efficient patterns.
- Programming Flexibility: Microservices architectures are structured as a set of loosely coupled, autonomous services that interact with each other through lightweight application programming interfaces. This is based on clearly defined APIs, which are aligned with straightforward business capabilities that are easily understood by all stakeholders. In this way, microservices facilitate developers to streamline their programming efforts with the needs of their business.
Microservices Development and Deployment Tools
In recent years a significant number of microservices tools have emerged. These are destined to facilitate and accelerate the development and deployment of microservices applications. They span different areas including programming languages, architectural frameworks, messaging middleware platforms, tools for containerization and workload management, cloud deployment tools, application monitoring utilities, as well as API testing and management environments. A rich set of different tools falls in each one of the above categories. Take programming languages as an example. It is nowadays possible to write microservices applications in Java, Javascript, Python, and other programming languages. Each of these languages is paired with some microservices execution environment like Elixir, which is based on the Erlang virtual machine. As another example, different architectural frameworks can be used to develop microservices applications in different platforms. Such frameworks include for example spring cloud, goa and kong.
Nowadays, containerization is considered the most important technological infrastructure for microservices deployment. Containers enable the packaging of all files and configuration artifacts that comprise an application in a single portable package that can be flexibly deployed in different environments. As such they enable a principle of building, shipping, and executing any application anywhere. Likewise, it eliminates the notorious “it worked in my machine” problem, where developers complain about applications that work properly in their development environments yet cannot gracefully execute in the production environment. The most popular technologies for containerizing applications and for managing containers’ workloads are Docker and Kubernetes respectively. Specifically, Docker enables the development of a container for a microservices application, while Kubernetes ensures the resource efficient and elastic scaling and descaling of containers. Moreover, various Kubernetes services provide the means for container load balancing towards efficient workload management.
Microservices and Business Agility
From a business perspective, the merit of using microservices architectures lies in their flexibility and their ability to make businesses more agile. This is very important in today’s fast-paced business environment, where the time it takes an organization to innovate and respond to changing market conditions is becoming an increasingly important determiner of whether that company is able to thrive. Despite this importance, most businesses are still struggling with traditional enterprise architectures, which tend to be monolithic, inflexible and heavy. Microservices architectures help organizations alleviate the drawbacks of traditional architectures. They enable large, complex applications to evolve more flexibly and to be built through the collaboration of many autonomous, cross-functional teams. In this way microservices architectures allow organizations to boost their business agility, with scalable, independently deployable services that can be written using the common language and stack of their respective micro-service. A microservices approach maintains a much finer granularity of management control, capitalizing on existing tools and processes to support DevOps (Development and Operations) and other Agile methodologies.
Container technologies such as Docker and Kubernetes make microservices more practical for leveraging non-differentiated capabilities within an organization. Hence, organizations can use microservices to speed development and deploy new features faster. They can also leverage microservices to update their services independently, without redeploying the entire application. This independency is yet another element of business agility.
Overall, microservices architectures enable modern enterprises to write code and develop applications that focus on their business domain instead of their infrastructure. This enables them to ship software systems faster than ever before, to give better support, and to implement changes in different aspects of their applications based on simple and separate services. During the next decade, a massive shift from monolithic architectures to microservices will be realized. This is a good reason for Chief Information Officers (CIOs) to understand microservices architectures and how to best use them to the benefit of their companies.
