Circuit Breakers—Theory

What is a circuit breaker?

Circuit breakers are a pattern used in software development to improve the stability and resilience of systems. The basic idea is to create a connector between two systems, which can be opened or closed depending on the status of the downstream system, i.e., the system we are calling in our API. If the downstream system is experiencing problems or is down, the circuit breaker is opened and requests are redirected to a fallback mechanism. This fallback mechanism could vary wildly depending on the desired outcome. Because it essentially is an error handling mechanism, depending on usage and purpose, we could return a simple error message, or, if the original operation was fetching data from the source, we could return a stale version from the cache. This approach helps to reduce ...