Is API gateway mandatory for microservices?
If you don’t have API Gateways, the client apps must send requests directly to the microservices and that raises problems, such as the following issues: Coupling: Without the API Gateway pattern, the client apps are coupled to the internal microservices.
Why do microservices need an API gateway?
An API gateway separates external public APIs From internal microservice APIs, allowing for microservices to be added and boundaries changed. The result is the ability to refactor and right-size microservices over time, without negatively impacting externally-bound clients.
How does the API gateway work in a microservice?
Therefore, the API gateway sits between the client apps and the microservices. It acts as a reverse proxy, routing requests from clients to services. It can also provide other cross-cutting features such as authentication, SSL termination, and cache.
How does a microservice communicate with a service?
There are two basic messaging patterns that microservices can use to communicate with other microservices. Synchronous communication. In this pattern, a service calls an API that another service exposes, using a protocol such as HTTP or gRPC.
Which is better direct client to microservice or direct gateway?
In any case, a load balancer and ADC are transparent from a logical application architecture point of view. A direct client-to-microservice communication architecture could be good enough for a small microservice-based application, especially if the client app is a server-side web application like an ASP.NET MVC app.
How are client apps coupled without API gateway pattern?
Coupling: Without the API Gateway pattern, the client apps are coupled to the internal microservices. The client apps need to know how the multiple areas of the application are decomposed in microservices.