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 machine-config-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.
any update? what's the current status?
I'll look into this in the next sprint.
Hi, do we have any update on that? Is someone working on it?
Hi, You need to update client-go library, the minimum version is 1.18.6. Let me know once you have a PR. I can review it. Thanks.
Verified on registry.ci.openshift.org/ocp/release:4.5.0-0.nightly-2021-02-04-091104 by checking that the commit contains the k8s.io/client-go to 0.18.6 bump Name: quay.io/openshift-release-dev/ocp-v4.0-art-dev@sha256:5e5fb6e221abf5d92f927f7d03b09921cf2567244b3880700960afd95b362dff Media Type: application/vnd.docker.distribution.manifest.v2+json Created: 1d ago Image Size: 144.5MB in 5 layers Layers: 76.42MB sha256:eae19a56e9c600eb0a59816d9d0ad7065824a34a13be60469084304fc7170334 1.811kB sha256:be73321c79565b4e2fdf9f55ba6333e5d50a1bcf583db3b41be45a9be7d82431 4.28MB sha256:c06d2750af3cc462e5f8e34eccb0fdd350b28d8cd3b72b86bbf4d28e4a40e6ea 9.609MB sha256:457122c845c27bd616c9f80748f1fa19f3d69783957448b3eca30cea7ed9a0a0 54.23MB sha256:f449e60719bbee9515266e93c2b145011916784268a6e11f1f30cd22defe6c1e OS: linux Arch: amd64 Entrypoint: /usr/bin/machine-config-operator User: 0 Environment: __doozer=merge BUILD_RELEASE=202102031005.p0 BUILD_VERSION=v4.5.0 OS_GIT_MAJOR=4 OS_GIT_MINOR=5 OS_GIT_PATCH=0 OS_GIT_TREE_STATE=clean OS_GIT_VERSION=4.5.0-202102031005.p0-fb06373 SOURCE_GIT_TREE_STATE=clean OS_GIT_COMMIT=fb06373 SOURCE_DATE_EPOCH=1611794431 SOURCE_GIT_COMMIT=fb06373b84578ddf16fe4848bd58fc6dd99af461 SOURCE_GIT_TAG=machine-config-daemon-4.5.0-202006231303.p0-69-gfb06373b SOURCE_GIT_URL=https://github.com/openshift/machine-config-operator PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin container=oci Labels: License=GPLv2+ architecture=x86_64 build-date=2021-02-03T11:45:48.108920 com.redhat.build-host=cpt-1008.osbs.prod.upshift.rdu2.redhat.com com.redhat.component=ose-machine-config-operator-container com.redhat.license_terms=https://www.redhat.com/agreements description=This is the base image from which all OpenShift Container Platform images inherit. distribution-scope=public io.k8s.description=This is the base image from which all OpenShift Container Platform images inherit. io.k8s.display-name=OpenShift Container Platform RHEL 7 Base io.openshift.build.commit.id=fb06373b84578ddf16fe4848bd58fc6dd99af461 io.openshift.build.commit.url=https://github.com/openshift/machine-config-operator/commit/fb06373b84578ddf16fe4848bd58fc6dd99af461 io.openshift.build.source-location=https://github.com/openshift/machine-config-operator io.openshift.maintainer.component=Machine Config Operator io.openshift.maintainer.product=OpenShift Container Platform io.openshift.release.operator=true io.openshift.tags=openshift,base name=openshift/ose-machine-config-operator release=202102031005.p0 summary=Provides the latest release of the Red Hat Universal Base Image 7. url=https://access.redhat.com/containers/#/registry.access.redhat.com/openshift/ose-machine-config-operator/images/v4.5.0-202102031005.p0 vcs-ref=593ad7e4f5a2d8a6e3d9c59eb1cff742af104dba vcs-type=git vendor=Red Hat, Inc. version=v4.5.0
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 (Important: OpenShift Container Platform 4.5.31 bug fix and security 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/RHSA-2021:0313