Spring Cloud Gateway

SCG is a non-blocking API. When using non-blocking API, a thread is always available to process the incoming request. These incoming requests are then processed asynchronously in the background & once completed the response is returned. So no incoming request ever gets blocked when using SCG.

An API Gateway is a single entry point for a collection of microservices. External clients cannot access the microservices directly, but only via the application gateway.

Building Blocks

• Route - most basic unit of SCG. Consists of ID, destination URI, and collection of predicates/filters.

• Predicates - used to match HTTP request, such as headers, url, cookies or parameters

• Filter - to modify the request/response as per requirement.