What happens when Envoy reaches its circuit breaking threshold?

When Envoy reaches its circuit breaking threshold, it triggers a fail-fast mechanism, which is a crucial aspect of maintaining system reliability and availability under stress. This process helps to prevent overwhelming a service that is already struggling by not allowing more requests to continue to it, thereby reducing the risk of cascading failures throughout the system.

Instead, Envoy directs traffic away from the failing service to alternative services that are still healthy and capable of handling requests. This intelligent traffic management is essential for maintaining an optimal user experience and system performance, especially in distributed architectures where microservices interact with each other.

This design helps to gracefully handle failures and can contribute to the stability of the entire ecosystem, allowing businesses to mitigate downtime and maintain service continuity. By proactively redirecting requests, Envoy can effectively balance the load and ensure that overall service resilience is maintained even when certain components are unable to perform optimally.