API Gateway vs Direct Service Exposure (PDF)

❗ 208 API Gateway vs Direct Service Exposure ** API Gateway and Direct Service Exposure are two approaches to exposing services and ** **...

❗ 208 API Gateway vs Direct Service Exposure ** API Gateway and Direct Service Exposure are two approaches to exposing services and ** ** ** * ** APIs in a microservices architecture or a distributed system. Each approach has its own ** * benefits and is suitable for different scenarios. API Gateway ** Definition: An API Gateway is a single entry point for all clients to access various services in ** *** ** a microservices architecture. It acts as a reverse proxy, routing requests from clients to the * *** *** * appropriate backend services. * ** Characteristics: ** ** Aggregation: The gateway aggregates requests and responses from various services. ** ** Cross-Cutting Concerns: Handles cross-cutting concerns like authentication, ** authorization, rate limiting, and logging. ** Simplifies Client Interaction: Clients interact with one endpoint, simplifying the client- ** side logic. ** Example: An e-commerce platform where the API Gateway routes user requests to ** *** *** *** ** appropriate services like product catalog, user accounts, or order processing. * *** *** *** *** *** *** A mobile app client makes a single request to the API Gateway to get a user’s profile * * * * * and order history, * and the gateway routes this request to the respective services. *** *** *** *** * * ** Pros: ** ** Centralized Management: Simplifies management of cross-cutting functionalities. ** * * * * * * ** Reduced Complexity for Clients: Clients need to know only the endpoint of the API ** * ** ** Gateway, not the individual services. * *** ** ~~ ~~ * ** Enhanced Security: Provides an additional layer of security by offering centralized ** * ** authentication and SSL termination. ** ** ** * ** Cons: ** ** Single Point of Failure: Can become a bottleneck if not properly managed. ** ** Increased Latency: Adding an extra network hop can increase response times. ** * * *** ***  ❗ * Direct Service Exposure (no API Gateway) * ~~ ~~ ** Definition: In direct service exposure, each microservice or service is directly exposed to ** * * *** clients. Clients interact with each service through its own endpoint. *** ** Characteristics: ** *** Direct Access: Clients access services directly using individual service endpoints. * ** *** Decentralized: Each service manages its own cross-cutting concerns. *** * * ** Example: In a cloud storage service, clients might directly interact with separate endpoints ** *** *** for file uploads, downloads, and metadata retrieval. The client application has to manage multiple endpoints * * and handle cross-service functionalities like authentication for each service separately. * * * * * * ** Pros: ** ** Eliminates Single Point of Failure: Avoids the bottleneck of a central gateway. ~~ ~~** ** Potentially Lower Latency: Can offer reduced latency as requests do not go through an * * ** * ~~ additional layer. ~~ * ** Cons: ** ** Increased Client Complexity: Clients must handle interactions with multiple services. * * ** *** Redundant Implementations: Cross-cutting concerns may need to be implemented * ** in each service. Key Differences ** Point of Contact: ** ** API Gateway provides a single point of contact for accessing multiple services, ** *** *** * *  * while direct service exposure requires clients to interact with multiple endpoints. * *** *** * * * * ** Cross-Cutting Concerns: ** ** API Gateway centralizes common functionalities like security and rate limiting, ** * * * * *** *** *** *** * whereas in direct service exposure, these concerns are handled by each service. * ** ** * * Conclusion The choice between using an API Gateway and direct service exposure depends on the ** ** ** ** * specific requirements of the architecture and the trade-offs in terms of complexity, ** ** ** ** ** ** ** latency, and single points of failure. ** ** ** * ** API Gateways are beneficial for unifying access to a distributed system and simplifying ** * * * client interactions, making them suitable for complex, large-scale microservices * * architectures. * ** Direct service exposure can be more efficient in terms of latency and is simpler ** * * * architecturally but places more burden on the client to manage interactions with multiple * *** *** * * * * services.