An Introduction to Hybrid Microservices
Microservices, which have evolved as an architectural idea in the past five years, has been revolutionizing the way software is created and delivered, offering advantages such as enhanced agility, better resilience, and increased application scalability. It is changing how software is developed, deployed, and managed.
Microservices architecture is a collection of small, self-contained services that can be developed, deployed, and scaled on their own. In recent times microservices architecture has been instrumental in building and deploying business applications with greater agility and improved resilience. However, the monolith architectural style is still in use, and for reasons abound.
For an application that isn’t that complex, a monolithic architecture is a good option. A microservices architecture is well suited for complex business applications. However, you need a more pragmatic approach that would help you to reap the maximum benefits. An excellent strategy is to adopt a mix approach, or a hybrid microservices approach to be more precise.
This tutorial discusses this approach, the business benefits, and when we should consider a hybrid architectural approach for microservices.
Put simply, a hybrid microservices architecture comprises a mix of the two different architectural approaches. It comprises some components that adhere to the microservices architectural style and some other components that follow the monolithic architectural style.
A hybrid microservices architecture is usually comprised of a collection of scalable, platform-agnostic components. It should take advantage of open-source tools, technologies, and resources and adopt a business-first approach with several reusable components. Hybrid microservices architectures are well-suited for cloud-native, containerized applications.
A hybrid microservices-based application is a conglomeration of monolithic and microservices architectures – one in which some parts of the application are built as a microservice and the remaining parts continue to remain as a monolith. In other words, a hybrid microservice architecture is one in which you can have a mix of both worlds.
Why do we need a hybrid approach anyway? When using microservices architecture in your application the usual approach is to refactor the application and then implement the microservices architecture in the application. If microservices architecture is not well suited, you might want to continue to use the monolithic style. Hence, the choice here is an either-or-proposition, i.e., either use microservices architecture or continue to use a monolithic style of architecture. However, you can use a hybrid approach – use a mix of both. This approach can have better yields since it combines the best of both worlds – i.e., microservices architecture and monolithic architecture.
You can hybridize microservices architecture to reap the benefits of microservices architecture without the need of having to refactor a monolith in its entirety – a monolithic architecture can co-exist with microservices in the same application. The objective is to reap the maximum benefits of microservices architecture (flexibility, scalability, and security, etc.) by having a mix of both monolithic and microservices architectures in an application.
You should start by splitting a monolith into logical components. When splitting the monolith, you should be able to decipher the common or reusable components. After that, you should consider the business benefits of combining the two architectural styles in the same application and deciphering the components that can be built and deployed as a single monolithic solution.
The most important thing to consider is refactoring those parts of the application that will yield the best results when converted to microservices. You should be able to find out those parts of the application that can scale better (if not seamlessly) than the other parts of the application.
You should be able to find out the resource consumption of each module and then based on this you can decide which parts of the application can scale better. You might consider making security a separate microservice that scales based on load if your application is intended for multiple concurrent users. Another reason for isolating the security module as a microservice is to be able to handle or mitigate security risks in your application.
Microservices architecture allows for the application to be updated seamlessly. One significant advantage of microservices architecture is that it allows you to change portions of an application without affecting other components. As an example, the backend of your application might not change often while the front-end would need to be updated.
You can update certain components of your app without affecting the other components. To facilitate seamless updates to your application, you might want to make those parts of the application that might change frequently, a microservice.
For example, assuming that the data access components of your application might not be updated often, you might want it to be a monolithic codebase while the other components of the application can be converted to one or more microservices.
You might think of migrating your monolithic application to microservices for better scalability and performance. However, you wouldn’t be able to convert your monolith to a microservice at the drop of a hat – there are challenges galore. There can be several constraints such as, availability of the right technologies and tools, availability of the necessary developer resources, etc. You should not leverage microservices architecture just for the sake of using it. Rather, you should leverage it when your application needs it.
A recommended practice is to adopt a hybrid approach as discussed here. Like a hybrid cloud that comprises of public, private and/or on-premises infrastructure, you can hybridize microservice architecture for improved flexibility, scalability, and security of your application.
For large business systems, neither a completely monolithic nor a microservices architecture is sufficient. An entirely monolithic approach is not suitable for systems that need to scale, such IoT. Furthermore, a complete microservices architecture isn’t ideal – the next logical step is a hybrid strategy, which combines a blend of monolithic and microservices architectural styles.