What is Circuit Breaker in Microservices?

Hello everyone. Let's learn about Circuit Breaker Design Patterns today. This pattern is very much used in the context of Microservices and distributed systems.

Circuit Breaker

In microservices, an application or service makes a lot of remote calls to applications running in different services, usually on different machines across a network. If there are many callers to an unresponsive service, you can run out of critical resources leading to cascading failures across multiple systems.

Consider an example that multiple users log in to a banking application and the account service is down. The authentication service will wait on the account service and now a lot of user threads are waiting for a response thereby exhausting the CPU on the authentication service as well as the account service. As a result, the system cannot serve any of the users.

Circuit breakers are a design pattern to create resilient microservices by limiting the impact of service failures and latencies. The major aim of the Circuit Breaker pattern is to prevent any cascading failure in the system. In a microservice system, failing fast is critical.

If there are failures in the Microservice ecosystem, then you need to fail fast by opening the circuit. This ensures that no additional calls are…