Readiness

Readiness is the idea of whether a service should accept new traffic right now.

A process may be running, but if it has not finished connecting to a dependent database, is still warming a cache, or should stop accepting new work because shutdown has begun, readiness is set to false. In other words, it does not ask whether the process is alive, but whether it is ready to accept work.

Typical use cases

• Kubernetes readiness probe
• Traffic control behind a load balancer
• Stopping new inflow before graceful shutdown

Notes

Readiness is not the same as liveness. A process can still be functioning normally even when readiness is false.