The simplest and most effective strategy we know today to automatically recover that gives the impacted service the ability to avoid entering a metastable state is for clients to implement retries with exponential backoff. No circuit breaker-type functionality is required. Unfortunately it requires that clients be well behaved.

Also, circuit breakers have issues of their own:

“Even with a single layer of retries, traffic still significantly increases when errors start. Circuit breakers, where calls to a downstream service are stopped entirely when an error threshold is exceeded, are widely promoted to solve this problem. Unfortunately, circuit breakers introduce modal behavior into systems that can be difficult to test, and can introduce significant addition time to recovery. We have found that we can mitigate this risk by limiting retries locally using a token bucket. This allows all calls to retry as long as there are tokens, and then retry at a fixed rate when the tokens are exhausted.” https://aws.amazon.com/builders-library/timeouts-retries-and...

Consider a situation in which all the clients have circuit breakers. All of them enter the open state once the trigger condition is met, which drops request load on the service to zero. Your autoscaler reduces capacity to the minimum level in response. Then, all the circuit breakers are reset to the closed state. Your service then experiences a sudden rush of normal- or above-normal traffic, causing it to immediately exhaust availabile capacity. It’s a special case of bimodal behavior, which we try to avoid as a matter of sound operational practice.