What Are Microservices? Definition, Examples And Architecture
What Are Microservices?
Microservice architecture, also known as ‘microservices,’ is a development method that breaks down software into modules with specialized functions and detailed interfaces.
Microservices have grown increasingly popular in the last few years as organizations adopt DevOps and continuous testing processes to become more agile. Leading online companies such as Amazon, eBay, Netflix, PayPal, Twitter, and Uber have dropped monolithic architectures and moved to microservices.
The monolithic architecture consists of applications built as large, autonomous units. Such applications cannot be changed easily because the entire system is heavily interconnected. Even a tiny modification to the code is likely to require creating and deploying a completely new version of the software. Monolithic applications are also difficult to scale, as scaling a specific function would require scaling the complete application.
Microservices address these problems of monolithic architecture by taking a modular approach to software development. In simple terms, microservices reimagine applications as a combination of multiple individual, interconnected services. Each service runs a specialized process and is deployed independently. If needed, the services can store and process data using different techniques and can be written in other programming languages.
Understanding the Architecture of Microservices
In a monolithic application, all processes rely heavily on each other and operate as a single service. In such an architecture, an increase in the demand for the bandwidth of any one process would mean that the complete architecture needs to be scaled up.
Since all the code in a monolithic application is deployed together on the same base, adding or enhancing features becomes a complicated process, especially as the code base expands in size and complexity. Additionally, monolithic applications might be susceptible to failure. This is because tightly coupled, essentially interdependent processes are easily affected if a single process goes down.
All this puts constraints on experimentation and can make it difficult for enterprises to stay fluid and responsive; this potentially puts them at a disadvantage in a highly dynamic, customer-centric market.
Microservices allow large applications to be split into smaller pieces that operate independently. Each ‘piece’ has its responsibilities and can carry them out regardless of what the other components are doing. A microservices-based application summons the collective services of these pieces to fulfill user requests.
The services in a microservices architecture ‘talk’ to each other using lightweight application programming interfaces (APIs) that connect to detailed interfaces. These services are created to perform specific business functions, such as monetary transactions, invoice creation, and data processing. Each service carries out a single operation. As they run independently, the services can be deployed, updated, and scaled according to the demand for their specific functions.
The implementation of a microservices architecture results in the creation of business systems that are flexible and scalable. However, shifting from monolith to microservices requires a dynamic renovation of IT infrastructure.
This isn’t necessarily bad, as microservices use many of the same solutions typically deployed in RESTful and web service environments. This means that they should be reasonably straightforward to work with for an adequately experienced IT team. For instance, API testing–a relatively common process–can be used to validate data flow throughout the microservices deployment.
Microservices architecture is ideal for modern digital businesses that cannot always account for all the different types of devices that will access their infrastructure. Numerous applications that started as a monolith were slowly revamped to use microservices as unforeseen requirements surfaced in the post-pandemic world. Revamping larger enterprise environments can be achieved using APIs to allow microservices to communicate with an older monolithic architecture.
Containers are an excellent example of microservices architecture as they allow businesses to focus on developing services without worrying about dependencies. Cloud-native applications are commonly built as microservices by leveraging containers.
Characteristics of a microservices architecture
Listed below are five primary characteristics of a microservices architecture.
1. Split into numerous components
Software built using a microservices architecture is, by definition, broken down into numerous component services. Each service can be created, deployed, and updated independently without compromising application integrity. The entire application can be scaled up by tweaking a few specific services instead of taking it down and redeploying it.
2. Robust and resistant to failure
It is not easy for an application built using a microservices architecture to fail. Of course, individual services can fail, undoubtedly affecting operations. After all, numerous diverse and unique services communicate with each other to carry out operations in a microservices environment, and failure is bound to occur at some point.
However, in a correctly configured microservices-based application, a function facing downtime should be able to reroute traffic away from itself while allowing its connected services to continue operating. It is also easy to reduce the risk of disruption by monitoring microservices and bringing them back up as soon as possible in case of failure.
3. Simple routing process
Microservices consist of intelligent components capable of processing data and applying logic. These components are connected by ‘dumb wires’ that transmit information from one element to another.
This simple routing process is the opposite of the architecture used by some other enterprise applications. For example, an enterprise service bus utilizes complex systems for message routing, choreography, and the application of business rules. Microservices, however, simply receive requests, process them, and produce an appropriate output to be transferred to the requesting component.
4. Decentralized operations
Microservices leverage numerous platforms and technologies. This makes traditional centralized governance methods inefficient for operating a microservices architecture.
Decentralized governance is better suited for microservices as developers worldwide create valuable tools to solve operational challenges. These tools can even be shared and used by other developers facing the same problems.
Similarly, a microservices architecture favors decentralized data management, as every microservice application manages its unique database. Conversely, monolithic systems typically operate using a centralized logical database for all applications.
5. Built for modern businesses
Microservices architecture is created to focus on fulfilling the requirements of modern, digital businesses. Traditional monolithic architectures have teams work on developing functions such as UI, technology layers, databases, and server-side logic. Microservices, on the other hand, rely on cross-functional teams. Each team takes responsibility for creating specific products based on individual services transmitting and receiving data through a message bus.
Example of Microservices
Leading tech companies use microservices for numerous reasons, such as to reduce the complexity of their architecture, speed up development, and make applications more responsive and easier to update.
Listed below are three real-life examples of market leaders adopting microservices to enhance their operations.
Amazon
At the turn of the millennium, Amazon’s retail website was a monolith with tightly knit connections between and within its multi-tiered services. This meant that developers had to work carefully to make sure nothing broke every time an upgrade or upscaling activity had to be undertaken.
This was not an exception, as many tech startups at the time adopted this methodology when building their applications. Even large-scale tech projects undertaken by big companies were created using monolithic architecture.
However, as the demand for the project or product increased, Amazon added more developers to work on it, and the codebase became bigger. This made the architecture more complex to modify, adding overheads to the process and slowing down the software development lifecycle.
Amazon’s customer base was growing rapidly in the early 2000s, and its development team was not always able to keep up. Delays, service interdependencies, and coding challenges put constraints on Amazon’s ability to fulfill its scaling requirements and keep up with the rapid expansion of its customer base.
Amazon divided its monolithic applications into small, independent, specialized applications to address these issues. The process began with developers analyzing the source code and isolating units of code that fulfilled a single function. Once this was done, the units were wrapped in a web service interface. A single service was developed for the ‘Buy’ button on the product page. Another was created for the tax calculator. Finally, each independent service was assigned to a team of developers, allowing a more granular view of development bottlenecks for swift and efficient resolutions.