Chapter 1. Introduction to the circuit breaker add-on for Red Hat build of Node.js

The circuit breaker add-on helps to reduce the impact of failures on service architectures, where services asynchronously invoke other services.

A failure can occur in either of the following situations:

In these situations, other services might exhaust critical resources by attempting to contact a service that is too slow or unable to respond. These other services can then become unusable, which causes a cascading failure that affects the entire microservice architecture. By using the circuit breaker add-on in your Node.js application code, you can make your applications more fault tolerant and resilient.

The circuit breaker pattern is designed to handle failures in service architectures and to prevent cascading failures across multiple systems. A circuit breaker can act as a proxy for a client function that is sending requests to a remote service endpoint that might fail. You can wrap any requests sent to the remote service endpoint in a circuit breaker object. The circuit breaker then calls the remote service and monitors its status. If the number of failures reaches a specified percentage threshold, the circuit breaker is triggered. The circuit breaker then ensures that any further requests to the remote service are automatically blocked with an error message or fallback response for a specified time period.

Based on the circuit breaker design pattern, the circuit breaker has one of the following states at any specific time: