All terms
Glossary
Circuit breaker
A protective mechanism that stops calling a failed service for a while, instead of running into every timeout.
When a downstream service fails, without a breaker all requests wait for their timeout. Connections and memory fill up, and the outage travels upwards until your own system is down too.
The breaker watches the error rate, opens above a threshold, and after a waiting period lets single attempts through to check whether the other side is back.
How you notice it
- A failure in a third party system takes down your own application.
- Connection pools fill up during incidents.
- There are dependencies you do not control.
Frequently asked
What should happen while the breaker is open?
That is a business decision, not a technical one. A slightly stale cached value, a reduced view or an honest notice usually beats an error. Teams that do not decide this in advance simply pass the error through when it matters.