Everything You Need to Know About Microservices in Simple Terms

While the great white shark may be the ocean’s greatest dread, there are numerous cases in which a school of fish is more likely to survive and thrive than the one individual. Success in working together is a winning strategy for the entire animal kingdom: ant colonies, bee hives, and wolf packs all benefit from working in systems to distribute control and achieve common goals. And if a member of the colony, hive, or pack dies, the rest of the group can continue to live and compensate for the loss.

Microservices take this approach and apply it to software development and system architecture. The idea is that it’s often faster, easier, safer, and more efficient to create a set of features or services separately than it’s to install the same features in a standalone, fully interconnected system. Let’s take a look at the features of microservice architecture, its pros, cons, available tools, best practices, and how it has helped many companies, including Uber, Netflix, and even Amazon. Today, we will make sure that it’s time for businesses to turn to software development services for the transition to microservice architecture.

Disadvantages of Monolithic Development

Before addressing the question of what microservices are, it’s worth remembering another type of application that is opposed to them — monoliths. These are applications built as a whole. Of course, monoliths can have a modular structure—containing separate classes, functions, and namespaces (depending on the chosen programming language). But links between these modules are so strong that changing any one of them inevitably affects the operation of the entire application.

Imagine a brick wall. It’s built from separate blocks. During construction, the bricks are still separable from each other, but over time, when the cement hardens, they become inextricably linked. You can continue the wall in one of the directions, but to fundamentally change the previously built wall, you will most likely have to use a sledgehammer.

Take a regular online retailer as an example. A three-tier architecture will be used by a monolithic application for it, consisting of a user interface, the server part is responsible for the business logic of the application, data access, and database.

We see that business functions of the application are very diverse: working with a product catalog and shopping cart, processing orders, payment transactions, tracking their status, etc. But at the application level, they are all combined into one monolithic block. When deployed, the code for the various functions resides on the same server. Running an application in several instances on various physical servers is necessary to scale it. The disadvantages of such a monolithic architecture scheme are obvious:

• The need to build and deploy a new version of the complete program arises from even the smallest modification to one of the business operations
• You have to scale the entire application, even if it’s necessary for a single component with the lowest performance. In our example, we can assume that calls to the product catalog will occur much more often than placing orders—that is, it would be worth allocating additional resources for this function, but this is impossible in a monolithic architecture
• Due to the interdependencies within the program, the failure of one module typically has an impact on the overall job. Therefore, the cost of solving this issue will be higher
• Developers are limited to a technology stack chosen for the application, although for some components it might be effective to use other technologies
• It demands a sizable, challenging-to-manage staff, with a structure that is likely to correspond to the selected architecture: distinct experts in the user interface, business logic, and database. And each of these groups will need to have expertise in all business functions, which will become increasingly difficult over time
• Since changes affect the entire application, the time to debug and test them increases, which leads to infrequent releases of updates and an increase in the number of changes released in one release, which, in turn, increases the risks
• Any database update will have an impact on the entire application and necessitate substantial code modifications

For small, infrequently updated applications, this architecture can work just fine. But as the functionality increases, the inter-module connections in the monolith will inevitably increase and become more complex, and changes in some modules will increasingly affect others; as a result, the further development of such systems becomes extremely difficult. This would be the right time to consider microservices.

What Exactly are Microservices?

Let’s now be more clear about what a microservices architecture is. Unlike monoliths, this application is built as a set of small, loosely coupled components (microservices) that can be developed, deployed, and maintained independently of each other.

If a monolithic application is most easily compared to brickwork, then microservices are like Legos. You have a lot of parts with clear standard boundaries to connect. You can always replace or remove some of the components without compromising the remaining ones. And this is the most important among all the advantages of microservices architecture.

Each of the services is responsible for a specific business task, has its data store, and communicates with other services through APIs to solve more complex tasks. In our scenario, we may distinguish between microservices for managing a product catalog, using a basket, placing orders, making payments, and other tasks.

This provides flexibility for both the engineering teams and the business itself. For example, applications based on microservices are easier to scale. Individual services are often faster to develop and deploy than monolithic applications. And here, the list of microservices architecture benefits is just beginning.

Benefits of Microservices Architecture

Microservices address a number of issues that arise for developing businesses; below are the main microservices architecture benefits.

Easy Scalability

Projects built from individual components are easier to scale. Each component serves a specific purpose, so when an application needs to be extended to perform new or more complex functionality, developers can focus on microservices as a starting point. Scalable software is better able to respond to changes in functionality or client needs.

Possibility of Independent Deployment

Each microservice in an application is deployed independently. This means that the development team can selectively deploy and test individual services for troubleshooting, instead of testing the entire application. As a result, it’s less expensive to test, debug, and update an application, and you may increase the flexibility of it.

Small Teams

Due to the separation and structuring of microservices, development teams can work in small groups. Compared to large teams with hundreds of participants, small teams can achieve better communication, organization, and quality of results. Instead of tackling the entire program at once, small teams can assign more specialized tasks, concentrate on a particular product or service, and debug.

Programming Options

With a monolithic approach, all system components would need to be written in the same language that the development team started with. There is no other choice except to refactor the entire code if this is not the best industry practice. On the other hand, using microservices allows developers to choose the most convenient and practical technologies (programming languages, frameworks, etc.) for each feature or process, and the resulting product will work perfectly.

Increased Stability

Since microservices are deployed separately from each other, the application becomes more resilient to changes or issues. The development team keeps an eye on each microservice separately to make sure it continues to operate without interfering with other parts. This helps save time and money by reducing the need to update the entire application when one service scales or needs to be modified.

Drawbacks of Microservices

Despite the trend and a large number of advantages of microservice architecture, it also has disadvantages, which include the following:

The Complexity of Development Process

Microservices add complexity compared to monolithic architectures, as there are more and more services created by multiple teams in different places. If sprawl is not properly controlled, it slows down development and reduces operational efficiency.

Rising Spending on Infrastructure

Each new microservice may require its own set of tests, deployment guidelines, hosting resources, monitoring tools, etc.

Additional Organizational Costs

To plan upgrades and interfaces, teams require an additional level of coordination and cooperation.

Debugging Issues

Each microservice has its own set of logs, which complicates debugging. Other issues may arise when a single business process is executed across multiple machines.

Lack of Standardization

In the absence of a single platform, the number of languages, logging standards, and monitoring systems may rise.

Lack of Clarity About Ownership

The number of teams working on new services increases as they emerge. Over time, it becomes more difficult to determine which services a team can use and who to contact for support.

Microservice Tools

Creating a microservice architecture requires a combination of tools and processes to perform the basic tasks of building and maintaining a shared infrastructure. Some of these tools are listed below.

Operating System

One of the most basic tools needed to create an application is the operating system (OS). Let’s start with an example. Imagine that on your web development team, one person is using MacOS, another is working in Windows, and a third member of your team has decided he’s better off working in Debian. Each developer looks through 20 pages of installation instructions for various libraries and programming languages and then begins work. All three people use different environments to develop the same application, and each environment requires a unique setup. However, the microservice architecture ensures that libraries and languages do not conflict in these three different development environments.

Programming Languages

One of the benefits of using a microservices architecture is that you can use different programming languages in applications for different services. Depending on the nature of the microservice, different programming languages have different utilities deployed. 

API Management and Testing Tools

Various services must interact when building an application using a microservices architecture. This is achieved through Application Programming Interfaces (APIs). API management and testing solutions are necessary for this because in order for APIs to operate as efficiently and as desired, they must be continuously monitored, maintained, and tested.

Messaging Tools

Messaging tools allow microservices to communicate both internally and externally. A microservices system may use communication tools like RabbitMQ and Apache Kafka.

Tool Kits

Developers have access to various toolkits, each of which has specialized functions and is used to build and develop programs. The microservices toolkits Fabric8 and Seneca are two examples.

Architectural Frameworks

Frameworks for developing microservices-based applications provide practical solutions and frequently come with a library of code and other resources that can be used to create and deploy applications.

Orchestration Tools

A container is a collection of executables, codes, libraries, and files needed to run a microservice. Tools for container orchestration like Kubernetes or Openshift give microservice architecture systems a framework for managing and optimizing containers.

Monitoring Tools

Once a microservice application is up and running, you should constantly monitor it to make sure everything runs smoothly and as intended. Monitoring tools help developers monitor application performance and avoid potential bugs or crashes.

Serverless Tools

Serverless tools further increase the flexibility and portability of the various microservices in an application by removing the dependency on a server. This helps to simplify the rationalization and separation of application tasks.

When Can Microservices be Beneficial?

If you are working with a monolithic application or launching a new application and at least one item from this list suits you or your project, consider using microservices:

Big groups.Different microservice development teams don’t have to synchronize all of their decisions regarding tools, steps, and other specifics up to a certain point. Parallel development and immediate release of new features are also possible.

Massively complex architectural projects. It’s considerably simpler to update and maintain individual modules than it’s to manage how changes impact the system as a whole.

Аpplications that work in dynamic situations. Microservices will enable you to grow quickly and lower the possibility of a system failure if your product is utilized more frequently during special occasions or sales. Additionally, you are not required to pay for extra equipment that is only required during times of peak consumption.

Applications that demand frequent updates. Only the module you want to update needs to be changed and debugged. This drastically cuts down on development time and expedites the release.

Microservices Best Practices 

Understanding the best practices for using microservices can help your application get the most out of the advantages of microservices architecture. Here are some best practices to consider:

Use a Сircuit Breaker for Fast Failover

When microservices depend on responses from other services to move forward, response times can be affected. To prevent slowness and increase application robustness, set a call timeout using a circuit breaker.

Use an API gateway

The API gateway might expose several APIs for each client rather than offering a universal API. For instance, the Netflix API gateway runs client-specific adaptor code to deliver an API that is best suited to the needs of each client. The API gateway may also include security measures, such as confirming the client’s authorisation to make the request.

Use a Separate Database for Your Microservices

The goal of a microservice is to prevent or reduce centralization. Microservices are kept independent and send requests through different API gateways by using a separate database to store them.

Reduce the Number of Updates

Each microservice is updated to a new version over time, but minimizing the number of versions helps reduce coding issues for developers. You can also remove old versions or redirect traffic to new versions.

Focus on Decentralization

Decentralization helps the team split projects into multiple components for better data management and security. It also helps provide more autonomy in the design process and move projects more efficiently through the design pipeline.

Microservices Examples

There are many companies today that have moved to the cloud by adopting a modern microservices architecture, including Amazon, Google, IBM, LinkedIn, Nike, Nordstrom, Orbitz, PayPal, Spotify, Target, and Twitter, and the list with examples of microservices architecture goes on and on—some of which were using modular systems before the term was even coined.

Netflix

Netflix was one of the first companies to move to the cloud and implement microservices. This is why almost every article that mentions microservices these days also mentions Netflix.

Like most companies, Netflix had a monolithic system when it wasn’t an online streaming service and just mailed DVDs. In 2008, a database error caused the entire service to be down for several days. Then it was decided to break the old system into microservices. Because of this, the business was able to adopt improvements and address bugs much more quickly. Since the Netflix system is so big, a new application called Conductor was created to arrange many microservices among themselves.

Netflix completed its transition to a microservice architecture in December 2011. This transition to a microservices architecture has allowed Netflix to overcome scalability issues and offer its services to millions of people around the world. File Explorer gives Netflix the ability to centrally manage (pause or restart) and scale microservices. The program is based on a service called Decider. Mantis (streaming processing), Dynomite (data storage), and Vizceral (traffic intuition) are further Netflix products designed to operate well with microservices.

Netflix currently has 210 million users globally and is expanding without experiencing any significant operational problems, in large part because microservices are used.

Spotify

Another microservices architecture example is the streaming service Spotify. The problem that Spotify has to face in its daily development is strong competition. The audio streaming market features some of the world’s largest IT companies, including Amazon, Apple, and Google. At the same time, due to the increase in the number of users, developers have to constantly meet the growing demand and comply with certain business rules (for example, licensing rights). For Spotify to be able to react swiftly to new advances from rivals and publish their innovations more quickly, microservices are the ideal option.

For example, a feature that allows users to receive suggestions as soon as they enter a search term is a self-contained microservice that is taken care of by a dedicated team. In addition, Spotify benefits from the robustness of a microservice architecture: if one microservice fails, the entire product does not become unusable. In total, over 800 microservices are actively running on Spotify. By the way, the streaming service uses Java for most of the microservices. However, this does not mean microservices cannot be written in different programming languages. This is related to workflows: developers are constantly moving from one team to another, and it’s easier if everyone uses the same language.

Amazon

Next on our list of microservices architecture examples is Amazon. At the turn of the millennium, Amazon’s retail website was a monolith with tightly coupled links between and within tiered services. This meant that the developers had to work carefully to make sure nothing broke every time an update or scaling needed to be done. However, as its popularity grew, Amazon hired more developers, and the code base got bigger. This made the architecture more difficult to change, increased process overhead, and slowed down the software development lifecycle. 

Amazon’s customer base grew rapidly in the early 2000s, and its development team couldn’t always keep up. Latency, service interdependencies, and coding issues placed limits on Amazon’s ability to meet its scaling requirements and keep up with the rapid growth of its customer base.

Amazon has broken down its monolithic applications into small, independent, specialized applications. The process began with the developers analyzing the source code and highlighting blocks of code that perform the same function. A single service has been developed for the Buy button on the product page. Another was created for the tax calculator. Once this was done, the blocks were wrapped in a web service interface. Finally, each independent service was assigned to a development team, allowing for a more detailed understanding of development bottlenecks and a quick and efficient solution.

Uber

Like Amazon, Uber has also decided to abandon its monolithic structure due to growth impediments. Problems faced by the sharing platform included inefficient development and launch of new features, an inability to quickly fix bugs, and problems integrating its rapidly growing global operations. It got to the point where the complex architecture of the application needed experienced developers to make minor changes and updates to the system.

To solve the problems associated with a monolithic application, Uber broke it up into cloud microservices. Soon, separate microservices were developed for business functions such as ride and passenger management. These services communicate with each other through an API gateway.

eBay

And the last but not least among the examples of microservices architectures:eBay. Like most systems, this selling platform started as a monolith—it had 3.4 million lines of code in a single file. eBay decided to break the monolith and develop microservices in Java. On eBay, individual services also communicate with each other via REST.

The fact that eBay and many other companies have successfully transitioned from a monolithic to a microservice architecture proves the value of this approach. A monolith is perfect enough in the early stages of an online project with a small number of active users and a manageable range of services, but as requirements grow, it transforms into a suffocating monster.

Final Thoughts

Recently, microservices have had an immeasurable impact on software development. Teams now have a more straightforward way to create, manage, deploy, and scale a variety of apps over the cloud, thanks to this substitute for the monolithic architectural model that has long dominated software development.

Microservices may not be for everyone. While there are benefits of microservices architecture for proper use cases, the transition can be tricky. If a legacy monolithic application works flawlessly, it may not be necessary to break it into pieces. A microservices architecture, however, can be beneficial as a company develops and its application requirements increase.

If you’re looking for ways to scale your organization’s technical capabilities and overcome downtime, slow performance, and geographic challenges, then it’s best to hire experienced developers who can create an exceptional product with a microservices architecture.