Hello Community!
If your Checkmk site is running a version between 2.5.0p9 and 2.5.0p12, a bug in these versions can stop the Checkmk Relay’s certificate from renewing. Once that happens, the Relay stops sending data for every host it monitors.
As the Relay certificate auto-renews every three months, you are likely only affected if you have been using the Relay for more than three months.
How to know if you are affected:
- You need to be using the Checkmk relay
- Services on Relay-monitored hosts have gone stale
If you are affected, please follow this article to resolve the issue: https://checkmk.atlassian.net/wiki/spaces/KB/pages/1420427266/How-to+renew+an+expired+Checkmk+Relay+certificate