etcdHighNumberOfFailedGRPCRequests #

Meaning #

This alert fires when at least 5% of etcd gRPC requests failed in the past 10 minutes.

Impact #

First establish which gRPC method is failing, this will be visible in the alert. If it’s not part of the alert, the following query will display method and etcd instance that has failing requests:

100 * sum without(grpc_type, grpc_code)
(rate(grpc_server_handled_total{grpc_code=~"Unknown|FailedPrecondition|ResourceExhausted|Internal|Unavailable|DataLoss|DeadlineExceeded",job="etcd"}[5m]))
/ sum without(grpc_type, grpc_code)
(rate(grpc_server_handled_total{job="etcd"}[5m])) > 5 and on()
(sum(cluster_infrastructure_provider{type!~"ipi|BareMetal"} == bool 1))

Diagnosis #

All the gRPC errors should also be logged in each respective etcd instance logs. You can get the instance name from the alert that is firing or by running the query detailed above. Those etcd instance logs should serve as further insight into what is wrong.

To get logs of etcd containers either check the instance from the alert and check logs directly or run the following:

NAMESPACE="kube-etcd"
kubectl logs -n $NAMESPACE -lapp=etcd etcd

Mitigation #

Depending on the above diagnosis, the issue will most likely be described in the error log line of either etcd or openshift-etcd-operator. Most likely causes tend to be networking issues.