Alert rule: CephOSDTimeoutsClusterNetwork

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Overview

OSD heartbeats on the cluster’s cluster network (backend) are slow. Investigate the network for latency issues on this subnet.

Steps for debugging

$ ceph_cluster_ns=syn-rook-ceph-cluster
$ kubectl -n ${ceph_cluster_ns} exec -it deploy/rook-ceph-tools -- ceph status
  cluster:
    id:     92716509-0f84-4739-8d04-541d2e7c3e66
    health: HEALTH_WARN (1)
            [ ... detailed information ... ] (2)
            [ ... detailed information ... ] (2)
            [ ... detailed information ... ] (2)

[ ... remaining output omitted ... ]

1	General cluster health status
2	One or more lines of information giving details why the cluster state is degraded. Only available if the cluster health isn’t `HEALTH_OK`.

Check Ceph crash logs

$ ceph_cluster_ns=syn-rook-ceph-cluster
$ kubectl -n "${ceph_cluster_ns}" exec -it deploy/rook-ceph-tools -- ceph crash ls (1)
[ ... list of crash logs ... ]
$ kubectl -n "${ceph_cluster_ns}" exec -it deploy/rook-ceph-tools -- \
      ceph crash info <CRASH_ID> (2)
[ ... detailed crash info ... ]

1	List currently not archived crash logs
2	Show detailed information of crash log with id `<CRASH_ID>`

Archive Ceph crash logs

$ ceph_cluster_ns=syn-rook-ceph-cluster
$ kubectl -n "${ceph_cluster_ns}" exec -it deploy/rook-ceph-tools -- \
      ceph crash archive-all (1)
$ kubectl -n "${ceph_cluster_ns}" exec -it deploy/rook-ceph-tools -- \
      ceph crash archive <CRASH_ID> (2)

1	Archive all currently not archived crash logs
2	Archive crash log with id `<CRASH_ID>`