To handle the partial failure, the API Gateway uses a technique called circuit breaker pattern. A service failure in one service can cause the cascading failure in the flow to all the service calls in stack. The API Gateway can keep an eye on the threshold for any microservice. If any service passes that threshold, it marks that API as open circuit and decides not to make the call for a configured time. Hystrix (by Netflix) served this purpose efficiently. The default value in this is a failing of 20 requests in 5 seconds. Developers can also mention the fall back for this open circuit. This fall back can be of dummy service. Once API starts giving results as expected, then gateway marks it as a closed service again.