How do I monitor a REST health endpoint?

Add a monitor of type REST Health Check on a verified endpoint, enter the path of the health endpoint and describe the values for OK and Critical. A Representational State Transfer (REST) health endpoint returns a JavaScript Object Notation (JSON) document such as {"status": "UP"}. For that, use $.status == 'UP' for OK when.

Before you start

• You are an OPERATIONS or ADMIN member.
• The endpoint is verified. See how to verify an endpoint.

Steps

1. Open the service, select Monitoring, then Add Monitoring.
2. Choose REST Health Check as Type and pick the Endpoint.
3. Enter the Path, for example /health.
4. Under Check Configuration, set:
   • OK when: $.status == 'UP'
   • Critical when: $.status == 'DOWN'
   • Degraded when: optional, for example $.status == 'SLOW'
5. Set the interval, timeout and thresholds. See thresholds and timing.
6. Select Verify to run one test check.
7. Select Add Monitor.

Questions

What if my endpoint returns no JSON?

Leave the expressions empty. Then any 2xx reply is Operational, and a reply that takes more than 80 percent of the timeout is Degraded. A 5xx reply is Critical.

What happens when no expression matches?

The check counts as an execution failure. See how to choose what happens when a target is unreachable.