What is an API Gateway in Microservices?

In microservices architectures, an API gateway provides an entry point to your system that hides the network of services beneath it

Microservices work by splitting applications into task-specific services that connect, but can be programmed, maintained and upgraded independently. In this way, when you need to change the functionality of an application, you can do so by deploying a new microservice or updating only the microservice that is required for that function, rather than needing to update the application code as a whole.

For IT teams working to tight schedules and heavy workloads, this makes it easier to customize the functionality of applications faster, with fewer programming errors that may occur when working on much larger volumes of code.

End users already expect organizations of all sizes to operate dynamically, creating brand risks for companies with older monolithic structures that are less scalable and more costly to upgrade, with the additional risk of business interruption if applications need to be taken offline to implement upgrades.

How do microservices work?

Microservices are individual and autonomous services, but they do not work in total isolation. Instead, they are loosely coupled to create a cohesive experience akin to that achieved by a single larger volume of application code.

With a microservices architecture, each individual service can be deployed independently of the rest of the system. This makes it possible to scale up particular services for better performance and resiliency.

For larger development teams, this is an even more significant capability, as it means development workflows can be divided up between individuals and groups with each working on a different microservice, contributing towards the overall application without redundant and overlapping program code.

This unlocks the option of parallel development — multiple teams working on components at the same time — while giving each team a greater sense of ownership over the modules they create.

When it comes to compiling internal API documentation to describe how each module or microservice operates, this makes it much more likely that there will be one individual or a smaller group of people within your organization capable of outlining its functionality comprehensively and without missing anything important.

More benefits of microservices

We have already touched on the ability of microservices to improve agility by enabling parallel development of new applications, but this is not only an advantage during the initial programming stage.

Microservices deliver powerful benefits at every stage of development:

  • As mentioned above, development teams can divide larger applications into individual microservices that can then be programmed independently, allowing them to be developed simultaneously by individuals and groups working in isolation.
  • Newly developed and newly updated microservices can be tested more easily independently from the application as a whole, and before they are deployed into the real world. Errors are easier to locate within the microservice’s much smaller volume of code.
  • Updates can be deployed much more agilely, as there may only be one or few microservices that need to be upgraded, allowing the rest of the application to remain in its existing form. Depending on how core the functionality of the microservice is, it may be possible to update it without taking the application as a whole offline.

In addition to all of this, microservices improve resiliency as they disperse functionality, allowing individual components to be replaced rapidly in the event of a failure, without the application as a whole ceasing to function.

This reduction in downtime is arguably one of the most critical capabilities of microservices architecture in the modern era, when data-driven enterprises are expected to provide always-on access for customers, especially via the web and mobile apps.

How is a microservices API Gateway different?

As the entry point to your system, an API gateway proxies requests to the individual services that make up your application. By providing a client-facing front to your system, you can hide the complexity of the individual services and how they interact from the outside world, while keeping the benefits of developing and deploying in smaller chunks.

But an API gateway is more than just a façade. It can provide additional system functionality, such as authentication and authorization to control access to your system, load balancing, rate limiting and throttling to manage performance, and monitoring and tracing to help debug issues.

When choosing an API gateway for your microservices, consider not just your current needs but how your system will evolve in future. Bare metal, VMs and containers all have their advantages, and many organizations transition between them as their products evolve. A growing user base increases demand and puts pressure on services for better performance and maximum uptime. And as complexity grows, good visibility and ease of management become essential.

Kong Gateway is built on a strong open-source core, with a flexible, lightweight design that means it can grow with your application. Suitable for both monolithic and microservice architectures, you can use Kong to provide a consistent interface for your application when transitioning from a single codebase to multiple services.

Being platform-agnostic, Kong is compatible with any platform, including hybrid solutions and Kubernetes, while its ultra-low latency design ensures it keeps up as you scale to hundreds or thousands of services. The extensive range of plugins allow you to add functionality when you need it, while keeping your API gateway tailored to your organization’s needs. 

Want to learn more?

Request a demo to talk to our experts to answer your questions and explore your needs.