What Are Microservices? Definition, Examples, Architecture, and Best Practices for 2022

Microservice architecture, also known as ‘microservices,’ is defined as a development method that breaks down software into modules with specialized functions and detailed interfaces. This article covers the definition, examples, and architecture of microservices and lays down a few best practices for implementing them in 2022.

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.

See More: What Is DevOps? Definition, Goals, Methodology, and Best Practices

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.

See More: Why Agile DevOps Is Now the Default Standard for Software Development

Examples 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.

1. 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.

The adoption of such a service-oriented architecture by Amazon was a significant step toward what is now known as microservices. Today, Amazon is the developer and distributor of solutions that make it easier for other organizations to adopt microservices, including AWS and Apollo.

2. Netflix

Just like Amazon, Netflix is a pioneer in the microservices space. Its migration began in 2008 when the streaming platform faced numerous scaling issues and service outages.

When a primary database of the company was corrupted, causing a three-day blockage on DVD shipping to members, Netflix realized it was time to migrate to microservices. It began migrating away from vertically-scaled single points of failure, such as relational databases in its data centers. Instead, the platform adopted highly reliable cloud-based distributed systems that were horizontally scalable. Netflix chose Amazon Web Services as its cloud provider to achieve its migration goals.

In 2009, Netflix started gradually refactoring its monolithic architecture into microservices, one service at a time. It began by migrating its movie-coding platform–which was not user-facing – to operate on the AWS cloud through a standalone microservice architecture. Soon after, it began converting its user-facing systems to microservices, completing the process in 2012.

Adopting a microservices architecture enabled Netflix to overcome its challenges and considerably reduce costs. Today, Netflix caters to approximately 210 million subscribers worldwide and continues to grow without any significant operational challenges, thanks in no small part to its adoption of microservices.

3. Uber

Like Amazon and Netflix, Uber, too, decided to shift away from its monolithic structure due to growth hurdles. The challenges faced by the ride-sharing platform included inefficiency in the development and launch of new features, the inability to fix bugs quickly, and problems with integrating its fast-growing global operations. It reached a point where the complex application architecture needed extensively experienced developers to make minor changes and updates to the system.

To conquer the challenges presented by its monolithic application, Uber broke it down into cloud-powered microservices. Soon, individual microservices were developed for business functions such as trip management and passenger management. These services communicate with each other through an API gateway.

The adoption of this microservices architecture helped Uber overcome its technological challenges. Here’s how:

• Development teams took ownership of specific services, boosting development initiative quality, speed, and manageability.
• Teams focused on the services that needed to be scaled up, thus facilitating swift scaling up of the entire application as demand increased over time.
• Fault tolerance was improved, and Uber could update individual services without disrupting the rest of the application.

See More: DevOps vs. Agile Methodology: Key Differences and Similarities

Microservices Best Practices for 2022

Now that we’re familiar with how a microservices architecture works and its potential benefits for an organization, here are a few best practices that will allow you to get the most out of your microservices in 2022.

1. Ensure relevant use case and stakeholder support

Start by determining whether your organization has a relevant use case for a microservices architecture. Even if you’re working with a digital-first company aiming to compete with Big Tech, do not opt for microservices just because they have done so. Instead, analyze your business requirements and see whether your application can be segmented into services that provide value. You should be able to divide your application into microservices without losing its core operability and features.

Also, just because you believe your application is ready to be split into microservices does not mean everybody will agree with you. The transition from monolith to microservices can be a long, tedious process with implications for all stakeholders.

Work with all stakeholders to set a proper timeline and budget. Also, gauge your organization’s level of technical expertise and assess whether it is sufficient for such an exercise. Your engineering team should be prepared for extensive infrastructural changes and other disruptions throughout the process. If required, consider hiring the services of an expert consultant.

Microservices are independent and work best when owned by independent teams. Be prepared to split your teams according to the microservices they will be responsible for. Each team should have the required tools and skills to develop, deploy, and operate their assigned microservice.

2. Adopt functional and secure design

Do not categorize microservices solely around business functions and services, as this could create microservices that are either too small or too large. The former can lead to an unnecessary increase in operational costs, while the latter will minimize the benefit of using microservices that are not so ‘micro’ anymore.

Instead, design specialized services according to in-application functions. Some business functions would probably have more in-application tasks than others. This would require in-depth planning with all stakeholders, covered in the previous step.

Once you know how to categorize your microservices, it’s time to begin the designing process. Microservices need to cover a single specialized process, have high cohesion, and exhibit minimal dependencies on each other.

Design your microservices in such a way that they are domain-specific and contain internal information of the domain as well as domain-specific models. This helps each microservice fulfill a specialized function and achieve a domain-driven design.

APIs and events should be used for communication between services. Do not set up services to call each other directly. Instead, adopt an API gateway that handles requests, responses, authentication, and throttling for services. Such an API gateway allows you to redirect traffic to updated versions of microservices whenever required quickly.

Finally, account for security vulnerabilities while designing microservices. Their distributed structure means that microservices generally have a broader attack surface. The DevSecOps model can help you ensure a secured framework for your microservices.

3. Opt for virtualization, specialized repositories, and backward compatibility during the development

Arrange for consistent development environments across machines for maximum efficacy during development. Consider setting up the development environment of your microservices in the form of virtual machines. This can allow your development team to adapt the framework and speed up the process.

Having a specialized repository for each service helps make access provisioning easy while allowing you to maintain clean version control logs. This can also be helpful during the implementation of changes that might potentially impact the operations of other services.

All exposed service endpoints should include backward compatibility to prevent callers from breaking. Undertaking rigid contract testing can help you protect the system against breaking changes. This also allows for backward compatibility for API calls in response to all user queries. Following these steps will enable your enterprise to create production-ready applications swiftly.

4. Deploy and host microservices separately

Deploying microservices separately saves time during coordination with multiple teams while undertaking regular upgrade or maintenance efforts. Doing so also prevents specific services from using an unreasonably large amount of resources, which would otherwise impact the operations of other services.

Using dedicated infrastructure for hosting microservices separately helps isolate them from any errors in other services. This enhances fault tolerance and minimizes the likelihood of a complete outage.

Containerizing microservices will allow the deployment of individual components independently, without the risk of affecting the services hosted on other containers. Containers also enable platform interoperability without compromising on microservice independence.

Finally, arrange for separate builds for different microservices and ensure that the deployment process is automated. This helps leverage the potential of the DevOps model better. Automation tools such as Jenkins can help you automate DevOps workflows by allowing for continuous integration and continuous delivery (CI/CD).

5. Opt for service-specific data management and storage

Create different databases and data management provisions for other microservices. Choose a database capable of fulfilling the specific requirements of each microservice. Optimize the storage and infrastructure according to the stored data and use it exclusively for that microservice. Doing so will enable you to create a robust microservices architectural framework where every service is managed independently while working cohesively with other services via a service mesh.

6. Centralize operations and adopt cutting-edge security

Finally, implement a centralized monitoring and logging system that ensures all microservices create standardized logs. This can help ensure swift root cause analysis and exception handling.

Advanced monitoring solutions allow you to monitor the availability of resources efficiently. They also maintain security levels by highlighting compromised components before they have a chance to bring the entire system down.

See More: Top 10 Challenges of Using Microservices for Managing Distributed Systems

Takeaway

Microservices break down monolithic applications into smaller, more manageable components that are easier to handle. While a microservices architecture has numerous benefits for the proper use case, the transition can be complex. The end goal of migrating to microservices is to implement a distributed, loosely coupled, and independent framework. Leading technology companies like Amazon, Netflix, and Uber leverage microservices to operate efficiently while avoiding major operational challenges.

Did this article help you gain a better understanding of microservices? Let us know on LinkedInOpens a new window , TwitterOpens a new window , or FacebookOpens a new window . We’d love to hear what you have to say!

MORE ON DEVOPS

• Top 10 DevOps Automation Tools in 2021
• Top 8 DevOps Strategies to Test in 2021 
• DevOps Roadmap: 7-Step Complete Guide
• Top 10 Must-Have DevOps Tools in 2021
• What Is Serverless? Definition, Architecture, Examples, and Applications