Circuit Breaker Microservice

You will build a microservice application that uses the circuit breaker pattern to gracefully degrade functionality when a method call fails.

Circuit breaker microservice.

It will be a rest based service. An application can combine these two patterns. The circuit breaker pattern is the solution to this problem. Circuit breaker does a great job in protecting the service from a heavy load.

Fortunately if the supplier microservice responds the circuit breaker goes back to the closed state. You have applied the microservice architecture services sometimes collaborate when handling requests. When one service synchronously invokes another there is always the possibility that the other service is unavailable or is exhibiting such high latency it is essentially unusable. In a microservice landscape failing fast is critical.

The circuit breaker uses a monitoring and feedback mechanism called the half open state to know if and when the supplier microservice has recovered. Hystrix library provides an implementation of the circuit breaker pattern using which you can apply circuit breakers to potentially failing method calls. Use of the circuit breaker pattern can let a microservice continue operating when a related service fails preventing the failure from cascading and giving the failing service time to recover. It uses this mechanism to make a trial call to the supplier microservice periodically to check if it has recovered.

If the supplier microservice doesn t reply within a specific threshold the circuit breaker will switch back to the open state from the half open state. If the call to the supplier microservice. To demo circuit breaker we will create following two microservices where first is dependent on another. Circuit breaker sequence of invocation.

This microservices tutorial shows how to set up a netflix hystrix circuit breaker to fix potential cascading failures from microservice dependencies. So when the circuit breaker is in the open state it usually jumps to the half open state. The circuit breaker pattern prevents an application from performing an operation that s likely to fail. Hystrix circuit breaker example.

The basic idea behind the circuit breaker is very simple. You wrap a protected function call in a circuit breaker object which. One of the primary goals of the circuit breaker pattern is to handle failures gracefully so that no cascading failures occur. Student microservice which will give some basic functionality on student entity.

However the retry logic should be sensitive to any exception returned by the circuit breaker and it should abandon retry attempts if the circuit breaker indicates that a fault is not transient.