Serverless lessons learned #4 circuit breaker

The document discusses circuit breakers and their importance for distributed systems. It notes that failures are difficult to detect in distributed systems and that retrying calls against an unresponsive subsystem can lead to resource shortages or cascading failures. It then introduces the circuit breaker pattern, which detects failures and prevents retrying the same failing action until the service recovers, in order to avoid cascading failures. The circuit breaker can be in an open, closed, or half-open state depending on success or failure detection.