The metrics structure passed to volume stat calculator
can contain real stats on subset of metrics fields. For example,
the metrics structure filled by a CSI driver can have
either INODES or BYTES filled, IOW it a valid return.
In such cases the volume stat calculator panic with below
trace:
0516 21:36:19.013143 14452 runtime.go:69] Observed a panic: "invalid memory address or nil pointer dereference" (runtime error: invalid memory address or nil pointer dereference)
/home/hchiramm/gopath/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/vendor/k8s.io/apimachinery/pkg/util/runtime/runtime.go:76
/home/hchiramm/gopath/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/vendor/k8s.io/apimachinery/pkg/util/runtime/runtime.go:65
/home/hchiramm/gopath/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/vendor/k8s.io/apimachinery/pkg/util/runtime/runtime.go:51
/usr/local/go/src/runtime/panic.go:522
/usr/local/go/src/runtime/panic.go:82
/usr/local/go/src/runtime/signal_unix.go:390
/home/hchiramm/gopath/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/vendor/k8s.io/apimachinery/pkg/api/resource/quantity.go:697
/home/hchiramm/gopath/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/vendor/k8s.io/apimachinery/pkg/api/resource/quantity.go:685
/home/hchiramm/gopath/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/pkg/kubelet/server/stats/volume_stat_calculator.go:144
/home/hchiramm/gopath/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/pkg/kubelet/server/stats/volume_stat_calculator.go:125
/home/hchiramm/gopath/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/pkg/kubelet/server/stats/volume_stat_calculator.go:65
/home/hchiramm/gopath/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go:152
/home/hchiramm/gopath/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go:153
/usr/local/go/src/runtime/asm_amd64.s:1337
Signed-off-by: Humble Chirammal <hchiramm@redhat.com>
CRI runtimes do not supply cpu nano core usage as it is not part of CRI
stats. However, there are upstream components that still rely on such
stats to function. The previous fix was faulty because the multiple
callers could compete and update the stats, causing
inconsistent/incoherent metrics. This change, instead, creates a
separate call for updating the usage, and rely on eviction manager,
which runs periodically, to trigger the updates. The caveat is that if
eviction manager is completley turned off, no one would compute the
usage.
For the next release, we include both sets of labels for pods and
containers: "container_name" and "container", "pod_name" and "pod".
In future releases, the "*_name" metrics will be deprecated.
