Microservices architecture has come out as a viable solution for problems associated with software development’s monolithic architecture. The monolithic architecture of building software components focuses on all deployable parts of the application contained within the single application. So, imagine if the application will be a large one, implementing new features becomes an overhead. The traditional concept of service-oriented architecture or SOA segregates applications into smaller parts. With the more complex applications, if we consider scalability and the new breed of development techniques, the microservices architecture is an effective solution. Microservices vs. SOA – here, the organizational and architectural approach of Microservices solves the inherent problems associated with monolithic or SOA architecture.
Now, what is microservices? Well, in the Microservices approach, the entire software development is divided into a collection of small autonomous services. Like SOA, The services implement a single business capability while communicating over well-defined APIs. Additionally, this architecture is a perfect fit for DevOps as self-contained teams own the services. Besides, this multi-platforms supportive architecture covers a wide range of technical areas like cloud, mobile, Internet of Things (IoT), etc., along with wearable devices.
Microservice architecture, an evolution from Service Oriented Architecture, leverages the design of complex and web-based applications. Each microservices represent a specific business requirement through a user story, which it implements through different protocols like http/REST and JSON.
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Microservices architecture Components
Services are the first component in a microservices architecture. Besides it hold below components:
Service Discovery. This component maintains the list of nodes and services they are located on. Also, service discovery enables service lookup to find the service endpoint.
Management. This component is used to place services on nodes and rebalances services to identify failures, and so forth.
API Gateway. Clients call services through the API gateway, and the API gateway forwards it to the back end. Again, the API gateway aggregates the responses from services and returns the response to the client.
Microservices vs Monolithic architecture
A monolithic architecture tightly couples all the services which run as a single service. So, in scaling up one service, the entire architecture needs to scale accordingly, resulting in an increased code base and complex features. Consequently, it narrows down the implementation scope of the new features in the long run. Additionally, it creates a lot of interdependencies as services remain tightly coupled.
For example, you want to build a web application using Java. If you follow the monolithic architecture design, you need a presentation layer, an integration layer, and a database layer. Once the development of all the layers is done, we need to create an EAR or WAR package. Then it is deployed on an application server. So, as we advance, if any change is required at any layer, you need to rebuild the EAR or WAR.
Whereas in a microservice architecture, functional decomposition means various functions work as independent services. Thus we can deploy each service independently instead of deploying all the services, which offers greater flexibility.
Steps to get started with Microservice architecture
A Microservice architecture necessarily follows below-mentioned steps:
Decomposition of services – the first step is to identify the use cases and required services which require a high-level understanding of the business.
Design – Once the services are identified, those must be designed appropriately. For example, which protocols to be used, how services will be exposed, etc. The design should be simple with detailed implementation. Furthermore, the design should not involve unnecessary ones and will expose only the important ones.
Build and deploy – Usually, individual services are developed by individual teams once the design is completed. Post-development, they set up CI/CD pipelines with the available CI servers and run automated test cases with microservices independently.
Decentralization –Decentralization is an essential aspect of microservices, which can be performed in different ways. For example, you can assign the development teams entire tasks like development, deployment, maintenance, and support related to the service. In another way, using an internal open-source model, a dedicated developer can change the service, check out the code, fix a feature, and find out the workaround on necessary changes.
Deployment – Whiledeploying, microservice API must contain project-specific or customer-specific contracts, which need to share with the provider. This ensures that in case of any new changes, API doesn't break your service. Also, it assures if any obligations must be fulfilled for the client.
Benefits of Microservices
Loosely coupled and fault-tolerant
Since microservice architecture loosely couple service, if anyone module fails, the application remains unaffected. This means the overall architecture becomes fault-tolerant and resilient, resulting in reduced downtime.
No vendor lock-in
In a microservice architecture, one can deploy services individually and need-based. Furthermore, since there is no vendor lock-in implementing a new technology stack is no big task.
Reusable services
Each microservice represents a unique business case so that we can reuse it for other project purposes. Reusability, in other terms, reduces the overall cost.
Scalability
With microservices, we can do granular scaling as it is componentized. This significantly utilizes VM resources like memory, CPU, etc. As a result, services can naturally integrate with other services or applications. For this purpose, industry-standard interfaces like REST is used.
Developer freedom
As Microservices architecture provides the team the freedom to choose the best option to solve a specific problem, developers can remain focused. It also leverages the possibility of continuous innovation with faster release cycles.
Expedite delivery timeline
Microservices offers a broader range of developer pools and the use of multiple programming languages. So, it reduced the delivery timeline significantly.
What is microservices challenges
Complex architecture
Though Microservices architecture gives more flexibility, the entire architecture becomes more complicated than a monolithic architecture. Here every service works as an independent service, so handling requests between the modules becomes essential. It increases codebase, as well.
Governance Issue
When you use multiple programming languages and frameworks, that causes additional governance headache, the decentralization approach creates a maintenance issue and makes deployments cumbersome.
Latency Issue
Granular services in a microservices architecture perform inter-service communication. If such communication gets too long, it generates additional latency issues. So, it is advised to design APIs accordingly. Some of the techniques to be adopted here are Serialization formats and asynchronous communication patterns.
Testing issue
Since microservices are granular, multiple servers may be used for development purposes. Hence, during integration testing, it makes the tester's life troublesome to integrate them. It eats up a lot of time as well.
When should you adopt Microservices Architecture?
Does Microservices architecture fit in all scenarios? Though microservices architecture has many advantages itself, it is a complex architecture. So, while designing, extra care must be taken. Microservices architecture is an ideal scenario if your existing system and scenario demand the following:
- It is a monolithic application and difficult to maintain.
- It deals with high volumes of traffic.
- It has priority on modularisation
- If the code needs reusability.
- If it needs multiple connectivities on various device types such as mobile, web, and IoT.
- If specific areas of it need to be able to scale -on demand.
Final words:
No doubt, Microservice architecture is a potent idea for enterprise applications. This is a preferred choice in recent days, where even if you don't know anything that is service-oriented architecture, you can design and implement APIs as microservices. We are not sure whether or not microservice architecture will become the preferred style of enterprises in the future. However, it has severe benefits for designing and implementing enterprise applications. Finally, it is advisable that if you start to develop microservices, it should be modestly and with a minimal number of services. Once you experiment with the architecture, then add experiencing more.