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.
Components/Operators using client-go in 1.18 version must update to a version that includes https://github.com/kubernetes/kubernetes/pull/92688
I'm creating this BZ as a central place that will allow us to track the progress.
This bug is actively worked on.
This bug hasn't had any activity in the last 30 days. Maybe the problem got resolved, was a duplicate of something else, or became less pressing for some reason - or maybe it's still relevant but just hasn't been looked at yet. As such, we're marking this bug as "LifecycleStale" and decreasing the severity/priority. If you have further information on the current state of the bug, please update it, otherwise this bug can be closed in about 7 days. The information can be, for example, that the problem still occurs, that you still want the feature, that more information is needed, or that the bug is (for whatever reason) no longer relevant. Additionally, you can add LifecycleFrozen into Keywords if you think this bug should never be marked as stale. Please consult with bug assignee before you do that.
This bug is just a common tracker for many other bugs so I understand it must be kept open until all of the dependent bugs are closed.
Removing LifecycleStale. Please don't re-add it unless this bug is to be closed for a valid reason.
Hi, wondering if we have an update on this. Thanks.
I'm closing this BZ since all dependent BZs have been closed.
Isn't https://bugzilla.redhat.com/show_bug.cgi?id=1880333 still pending? I see it in verified state
The last related bug 1877346 was verified, all dependent BZs have been verified, so the Top-level bug can be verified now.
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 4.5.33 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.