Your cloud application can include many services, with many interactions between the services. In case a service fails or is unavailable, you can provide an alternative response - a circuit breaker - that handles the error condition without increasing service load. A circuit breaker can quickly and easily determine that a service is not functioning properly and then can either return a default result or a quick and graceful fail notice with detailed information about the failure.
When you open this page, it invokes the Greeting Service (which is backed by Apache Camel). This Greeting Service invokes a name service. The invocations are protected by a circuit breaker that uses the camel-hystrix component.
To monitor the state of the circuit breaker, you can use the Hystrix Monitor dashboard.
You can stop, start, and clear the calls to the Greeting Service on this page.
To demonstrate the behavior of the circuit breaker when a service becomes unavailable:
For OpenShift deployments, in the web console, downscale the name service pod number to 0.
For a standalone deployment, press Ctrl+C while in the window of the shell prompt where the name service is running.