Circuit breakers and outlier detection

In this section, we will look at outlier detection and circuit breaker patterns. A circuit breaker is a design pattern in which you continuously monitor the response processing behavior of upstream systems and when the behavior is unacceptable, you stop sending any further requests upstream until the behavior has become acceptable again.

For example, you can monitor the average response time of the upstream system and when it crosses a certain threshold, you may decide to stop sending any further requests to the system; this is called tripping the circuit breaker. Once the circuit breaker has been tripped, you leave it that way for a certain duration so that the upstream service can heal. After the circuit breaker duration has elapsed, you can reset the circuit breaker to let the traffic pass through again.

While circuit breaking is the part that handles the flow of traffic, outlier detection is a set of policies to identify the conditions...