A recent fix in the reflector/informer https://github.com/kubernetes/kubernetes/pull/92688 prevents components/operators from entering a hotloop and stuck. There are already reported cases that have run into that issue and were stuck for hours or even days. For example https://bugzilla.redhat.com/show_bug.cgi?id=1877346. The root cause of the issue is the fact that a watch cache is initialized from the global revision (etcd) and might stay on it for an undefined period (if no changes were (add, modify) made). That means that the watch cache across server instances may be out of sync. That might lead to a situation in which a client gets a resource version from a server that has observed a newer rv, disconnect (due to a network error) from it, and reconnect to a server that is behind, resulting in “Too large resource version“ errors. More details in https://github.com/kubernetes/kubernetes/issues/91073 and https://github.com/kubernetes/enhancements/tree/master/keps/sig-api-machinery/1904-efficient-watch-resumption It looks like the issue only affects 1.18. According to https://github.com/kubernetes/kubernetes/issues/91073#issuecomment-652251669 the issue was first introduced in that version by changes done to the reflector. The fix is already present in 1.19. Please make sure that cluster-kube-scheduler-operator is using a client-go that includes https://github.com/kubernetes/kubernetes/pull/92688 if not please use this BZ and file a PR. In case you are using a framework to build your operator make sure it uses the right version of the client-go library.
PR in the queue.
Verified with payload below and i see that fix is present 4.5.0-0.nightly-2020-11-07-002125 [knarra@knarra cluster-kube-scheduler-operator]$ oc adm release info --commits registry.svc.ci.openshift.org/ocp/release:4.5.0-0.nightly-2020-11-07-002125 | grep cluster-kube-scheduler-operator cluster-kube-scheduler-operator https://github.com/openshift/cluster-kube-scheduler-operator a8218a72d631f93990c46f1337873954b2e66d88 [knarra@knarra cluster-kube-scheduler-operator]$ grep 'k8s.io/client-go ' go.mod k8s.io/client-go v0.18.9 [knarra@knarra cluster-kube-scheduler-operator]$ git log --date local --pretty="%h %an %cd - %s" a8218a7 | grep "#287" c419f3bd OpenShift Merge Robot Thu Oct 15 07:09:40 2020 - Merge pull request #287 from soltysh/bug1880326 Based on the above moving bug to verified state.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (OpenShift Container Platform 4.5.19 bug fix update), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2020:5051
Setting qe_test_coverage flag to '+' as i see that regression test coverage would be sufficient to test this bug.