‍How API Gateways Enable Microservices Architecture

Mansi Shah

January 22, 2025

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‍‍The introduction of microservices architecture solved the problems posed by rigid and unscalable traditional monolithic applications. However, managing the communication channels and functionality between the loosely coupled services in the microservices architecture needed to be managed. This is precisely where the API gateways play a vital role - by simplifying the complexities of client and microservices interactions.

‍What is an API Gateway?

‍An API gateway is basically a software layer that acts as a single entry point for client applications to access microservices. In layperson's terms, it simplifies interactions between clients and systems .An API gateway acts as a central hub for managing API requests, which are routed to the appropriate microservices while ensuring secure and efficient communication between the microservices. Let’s explore how API gateways facilitate and enhance microservices architectures.

‍How Do API Gateways Work?

‍The basic tasks of an API gateway are to receive API requests by acting as an API front-end, enforcing throttling and security policies, passing requests to the back-end service, and then returning the response to the client who had sent the initial request. The core functions of an API gateway are:

1. Request Routing

Request routing in API gateway is the process of receiving an incoming API request from a client and then directing it to the appropriate backend service based on the endpoint, parameters, or request type. It is essentially acting as a central point to distribute requests to different microservices within a system.Key Benefits:

Decoupling clients from backend services: Clients only need to know the API Gateway endpoint, not the specific backend services
Load balancing: Distributing requests across multiple instances of a backend service
Security and authorization: Implementing security checks at the API Gateway level before forwarding requests to backend services

2. Protocol Translation

Protocol translation refers to an API gateway’s capability to convert the different communication protocols into another in order to allow client applications and backend services to interact with each other. This process involves converting requests to protocols such as HTTP, HTTPS, gRPC, or WebSockets. For example an API gateway translating a client’s HTTP request into a gRPC request in order for the backend microservice that only speaks gRPC to process the request. Key Benefits:

Flexibility: The process allows clients to use their preferred protocol and access backend microservices that may use a different protocol
Simplified development: Allows developers to choose the most suitable protocol for each backend service without worrying about client compatibility as the API Gateway handles the translation

3. Aggregation

Aggregation is the process of combining the responses from multiple microservices into a single response to be returned to the client. This process allows the API gateway to act as a central point that the client can use to avail different microservices and get a consolidated single output. Key Benefits:

Simplified client interaction: Having a single endpoint on the API gateway to retrieve the aggregated data simplifies interaction for clients
Improved performance: The ability of an API gateway to combine multiple requests into one optimizes network calls and reduces latency

Let’s take the example of a gRPC request to understand the step-by-step process of its working. The image below showcases the API gateway architecture diagram to help you understand how it works.

Step 1: The client sends a gRPC request to the API Gateway
Step 2: The API Gateway will determine which request is coming, parses and validates the attributes of the request
Step 3: The API Gateway performs security checks to authenticate and authorize for safe access
Step 4: An SSL is used to establish an encrypted link between a server and a client
Step 5: The API gateway determines the appropriate microservice provider(s) to route the request(s) to
Step 6: The process of protocol translation from gRPC to the appropriate protocol depending on the backend microservice(s) availed is completed, if required
Step 7: After the microservices complete the requests, the responses are cached and aggregated by the API gateway, translated to the required protocol, and returned to the client as a single cohesive response

Now that the process of how an API gateway enables microservices architecture is clear, let’s take a look at why it is important.

‍The Necessity of API Gateways in Microservices Architecture

‍Microservices architecture faces a few prominent challenges, such as:

Managing numerous service endpoints
Ensuring consistent security and authentication across services
Handling cross-cutting concerns such as logging, monitoring, and rate limiting

API gateways become necessary for microservices architecture by eliminating these challenges through:

Unified Entry Point: Providing a single endpoint for client interactions, thereby removing the complexity of multiple requests for multiple services
Simplified Communication: Managing protocol translation and request aggregation, making client interactions seamless
Centralized Management: Consolidating security, logging, and performance policies in one place
Performance Optimization: API gateways cache responses to minimize the need for redundant calls between services, thereby enhancing performance and reducing latency

Key Functions of API Gateways in Microservices Architecture

‍In a microservices architecture, API gateways play a key role by serving as a reverse proxy that routes requests from clients to the appropriate microservices. Here are some key functions of an API gateway in a microservices architecture:

Service Aggregation: Reducing the number of requests the client needs to make by aggregating multiple microservices into a single API endpoint
Protocol Translation: Facilitate seamless communication between client and microservices by translation of protocols such as HTTP, WebSocket, and gRPC
Request Routing: Incoming requests are routed to the appropriate microservice based on different criteria
Load Balancing: Making the system scalable and responsible by distributing incoming requests equally across multiple instances of a service
Caching: In order to reduce latency and improve the overall performance of the system, API gateways can store frequently accessed responses
Authorization and Authentication: API gateways can manage security policies and access controls in a unified manner, reducing the burden on individual services
Rate Limiting: Controlling the number of requests a client can make to prevent abuse and ensure fair usage
Logging and Monitoring: Tracking the performance and the health of the system by collecting and monitoring metrics
Fault Tolerance: API gateways can implement circuit breaking, retry mechanisms, fallback responses, or redirect requests to alternate services in case of failure
Security: API gateways can provide an additional layer of security by hiding the internal structure of microservices from clients

‍Potential Challenges and Considerations

‍Despite its wide array of benefits and functionalities, there are certain considerations that need to be taken care of with API gateways.

Single Point of Failure: While a single endpoint provides tremendous benefits, it could also become a bottleneck if not managed properly
Increased Complexity: An API Gateway is an additional layer on top of the API, which may complicate the overall microservices architecture
Latency Concerns: Improper configuration may introduce delays in request processing

These challenges can be overcome by deploying a state-of-the-art such as Nexus Gateway by Arya.AI.

‍How Arya.ai’s API Gateway, Nexus, Enhances Microservices Architecture

‍Nexus API Gateway by Arya.ai empowers businesses to revolutionize their APIs with intelligent automation.Some key benefits of Nexus Gateway are:

Sub-Millisecond Latency: Nexus Gateway is optimized for high-speed API processing, ensuring fast response times and seamless performance, even under heavy traffic
Omni-Deployment Capability: Arya’s Nexus gateway can be seamlessly deployed across any environment, ensuring ultimate flexibility and scalability
Future-Ready Extensibility: Nexus Gateway’s built-in plugins enhance core features and easily create custom plugins to address unique use cases, offering unparalleled flexibility and customization 
Enterprise-Grade Security: Nexus Gateway protects APIs with its built-in static and dynamic authentication, encryption, and granular access control

Arya’s Nexus Gateway is a customized solution for enterprises to scale and streamline their APIs with unmatched flexibility, real-time insights, and advanced protocol support. It offers businesses a distinct advantage by providing them the ability to:

1. Revolutionize Apps and Services:

An intelligent multi-API orchestration layer enables automated workflow sequencing, self-healing mechanisms, and intelligent response-based routing

2. Build and Manage APIs‍

Transforming API management into a streamlined, intuitive experience by easing the app creation process, making API validation instant, and increasing performance through rate limiting

3. Safeguard APIs‍

Arya’s Nexus Gateway provides unmatched security for every API call by deploying advanced mechanisms such as flexible authentication, end-to-end encryption, and granular access control

4. Smarter Routing and Monitoring‍

Specially designed features such as reverse proxy optimization and comprehensive logging for intelligent traffic flow and an intuitive dashboard for real-time insights