Using both an API gateway and a service mesh allows you to manage and secure both external and internal traffic effectively. The API gateway controls and secures the external requests, while the service mesh manages the internal microservice-to-microservice communication, improving scalability and reliability.
The Difference Between API Gateway and Service Mesh
In modern IT environments, API gateways and service meshes play distinct but complementary roles in managing and securing APIs and microservices. While an API gateway primarily handles external traffic, managing API requests and responses, a service mesh focuses on internal communication between microservices, ensuring reliability, security, and observability. Both technologies can coexist, providing robust solutions for traffic management, scalability, and security in cloud native applications.
If you work in the IT field long enough, you will see a new technology debut with functionality that looks like something you already have. You wonder, “Do I need this? Don’t I already have this? Why is everyone so excited about this new idea when it overlaps with an existing solution?” Vendor noisemaking can amplify the confusion, unfortunately.
The current dialogue comparing API gateways to service meshes falls into this category. The two technologies are distinct, but they are starting to converge. People are asking if they need a service mesh if they have an API gateway, among other questions. This article explores how API gateways and service meshes are similar, how they differ, and why you might want to use both.
APIs vs. microservices
To discuss API gateways vs. service meshes, it’s a good idea to start by differentiating the underlying technologies of APIs and microservices. Microservices, for which a service mesh handles communications, are analogous to APIs, up to a point. They’re not the same, however. To further complicate matters, microservices often get paired with an API to handle interactions with other software applications.
Briefly, then, an API is part of an application that interacts with other applications. Using an API, an app can invoke functionality, request and receive data, modify data, and more. A microservice, in contrast, is a software architectural style that serves to break up a larger application into components, referred to as “services.” An application built using services in this fashion is said to comprise a “microservices architecture.”
Thus, API and microservices have certain superficial similarities, but they are quite different from one another. As a result, the technologies that handle their management and communications — the API gateway and the service mesh, respectively — are also different.
What is an API gateway?
An API gateway is software that sits in front of a group of application programming interfaces (APIs). It routes API calls (also known as API requests) to the appropriate API and manages the delivery of data and services from the API back to API consumers (also known as API clients).
The API gateway functions as a single point of entry for API calls. Think of it like a control center for API call/response traffic. It does not matter if the APIs are hosted on-premises, in the cloud, or at a separate corporate entity. API calls can similarly come to the API gateway from pretty much anywhere. API gateways are usually part of a broader API management and security solution that handles API discovery, API security, policy enforcement, and the like. It can also balance traffic between API instances and handle load balancing, failover, and other issues related to API reliability and availability.
What is a service mesh?
A service mesh is a technology pattern that takes the form of an infrastructure layer, or layers, that ride atop microservices. A service mesh handles communications between microservices. It routes messages back and forth, securing the data in the process. Working this way, a service mesh facilitates observability, reliability, and security for the microservices in the architecture. A microservices architecture needs a service mesh. Without one, it can be unwieldy to manage multiple microservices and ensure the kind of reliability and availability the microservices application needs.
Authentication and traffic management in API gateways and service meshes
Both API gateways and service meshes play crucial roles in traffic management and authentication. While an API gateway often includes authentication mechanisms to ensure that only authorized users can access specific APIs, a service mesh handles internal traffic between microservices, ensuring that requests are routed correctly and securely. Traffic management in a service mesh often involves more granular control, such as load balancing across microservices and rerouting traffic in response to service failures. These mechanisms are essential in cloud native environments, where scalability and reliability are key.
Key differences between an API gateway and a service mesh
You might be starting to see how an API gateway and a service mesh are similar. They both handle requests and responses, routing data across networks. They can both take care of service discovery and policy enforcement for rate limiting, access controls, and the like. The differences emerge when comparing the details. A service mesh is meant to manage microservice-to-microservice interactions. An API gateway mostly manages traffic to and from API clients and APIs.
There’s a simplistic way to think about it, derided as wrong by some in the industry, but useful nevertheless: An API gateway handles “north-south” traffic, which comes from outside entities and into the network, and back. A service mesh handles “east-west” traffic, i.e., internal network traffic between internal microservices. It’s true some of the time, but not always. However, this comparison does capture an essential difference between API gateways and service meshes. Some key points of differentiation:
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What is service discovery?
API gateways and service meshes both usually offer service discovery, which is the automatic detection of services — including APIs, microservices, devices, and data sources — on a network. Service discovery is an essential element of API management and service mesh operation. Without service discovery, it would be a cumbersome, manual task to figure out where all the APIs and microservices were located prior to using them. And service discovery performs a vital function in identifying API and microservices that are no longer in use. Old APIs and microservices can be a source of risk exposure. Also, in a microservices architecture, resources change constantly (like containers spinning up/down), and the service mesh simplifies the continued connectivity.
Should you use both?
The answer to the question “Should I use both an API gateway and a service mesh?” may change in the future. It’s likely that combined solutions will come on the market soon, offering API gateways with service mesh functionality. For now, though, it’s worth considering deploying both technologies.
The reason to go in this direction is that you will likely have APIs and microservices to manage in a modern enterprise. And you probably have APIs exposing your microservices already, so you’ll need an API gateway to make them work securely and effectively.
Scalability is another reason to use both an API gateway and a service mesh. A service mesh improves connectivity between services, which enables greater scalability of microservices. API gateways, as a central point of contact for APIs and API clients, similarly facilitate scalability for APIs. If you’re anticipating growth in microservices and APIs, you’ll do well with both solutions.
Having both API gateways and service meshes at work in your enterprise can also make it easier for developers and architects to innovate. Being able to deploy APIs and API clients alongside microservices-based applications is a good formula for success. The two technologies working together make possible the kind of loosely coupled, flexible applications that drive digital transformation.
Integration with cloud native and DevOps practices
As enterprises increasingly adopt cloud native architectures and DevOps practices, the integration of API gateways and service meshes becomes even more critical. In Kubernetes environments, for example, a service mesh can manage the internal communication between containers, while an API gateway manages external requests to the application. This dual-layer approach aligns with DevOps practices, where continuous integration and continuous deployment (CI/CD) pipelines require robust traffic management and security measures. Metrics gathered from both the API gateway and service mesh can also provide valuable insights into application performance and security, helping teams to optimize their cloud native applications.
FAQs
An API gateway primarily handles external traffic, managing API requests and responses between API clients and APIs. In contrast, a service mesh manages internal traffic between microservices within a microservices architecture, ensuring secure and reliable communication.
An API gateway often includes built-in authentication mechanisms to validate and authorize external API requests. A service mesh manages authentication internally between microservices, ensuring that only authenticated services can communicate with each other.
An API gateway manages traffic coming into and out of your APIs, handling tasks such as load balancing and rate limiting. A service mesh manages traffic within a microservices architecture, handling load balancing between microservices and rerouting traffic in the event of service failures.
Yes, a service mesh is highly compatible with Kubernetes and other cloud native environments. It manages the dynamic nature of microservices in these environments by handling communication, traffic management, and security, making it easier to scale and manage applications.
Metrics are crucial in both API gateway and service mesh implementations for monitoring performance, security, and reliability. In an API gateway, metrics help track API usage and detect potential issues. In a service mesh, metrics provide insights into the health and performance of microservices, helping optimize traffic and manage resources effectively.
Yes, there are several open source options available for both API gateways and service meshes. For example, Kong and Ambassador are popular open source API gateways, while Istio and Linkerd are widely used open source service meshes.
Why customers choose Akamai
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