Don't shoot the messenger. Dashboard is just displaying the alert that Prometheus/AlertManager is reporting. The alert definition is here <https://github.com/ceph/ceph/blob/3993779cde9d10512f4a26f87487d11103ac1bd0/monitoring/ceph-mixin/prometheus_alerts.yml#L342-L351>. As you may see, it's based on the status of the Prometheus "ceph" scrape job. This alert is vital, because if the "ceph" job is not scraping metrics from the "mgr/prometheus" module, no other Ceph alert condition will be detected, therefore creating a false sense of confidence.
You may start having a look at Prometheus and/or Alertmanager web UIs, or checking their logs. Kind Regards, Ernesto On Tue, Apr 15, 2025 at 7:28 PM Tim Holloway <t...@mousetech.com> wrote: > Although I've had this problem since at least Pacific, I'm still seeing > it on Reef. > > After much pain and suffering (covered elsewhere), I got my Prometheus > services deployed as intended, Ceph health OK, green across the board. > > However, over the weekend, the dreaded > "CephMgrPrometheusModuleInactive" alert has returned to the Dashboard. > "The mgr/prometheus module at dell02.mousetech.com:9283 is > unreachable." > > It's a blatant lie. > > I still get "Ceph HEALTH_OK". All monitor status command show > everything running. Checking ports on the host says it's listening. > > More to the point, I can send my desktop browser to > http://dell02.mousetech.com:9283 and get a page that will allow me to > see the metrics. So everyone can see it but the Dashboard! > > I did have some issues when the other prometheus host couldn't resolve > the hostname, but I fixed that for all ceph hosts and it was green for > days. Now the error is back. Restarting Prometheus didn't help. > > How is the Dashboard hallucinating this??? > > Tim > _______________________________________________ > ceph-users mailing list -- ceph-users@ceph.io > To unsubscribe send an email to ceph-users-le...@ceph.io > > _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-le...@ceph.io
