"microk8s.kubectl" failed: cannot create transient scope: DBus error "System.Error.E2BIG"

Problem description

When trying to execute any of the microk8s commands I get:

internal error, please report: running "microk8s.kubectl" failed: cannot create transient scope: DBus error "System.Error.E2BIG": [Argument list too long]

After some time of cluster activity the microk8s fails with the above error. This error effectively prevents from doing any operations with microk8s command, including the microk8s inspect, microk8s.start/stop or microk8s.kubectl. It seems that the only solution is to restart the system and the cluster comes back to a healthy state again. However, after couple of hours it goes back to the failed state again.

Interestingly enough, it seems that the services inside the cluster ARE working and responding – I can query them and so on, they are working as expected, but I cannot check their state or logs.

System data

microk8s: 1.15/1.17 stable (both had the same problem occuring) System: Ubuntu 18.04.1

Comments

• Three of the services that run in the cluster mounts on the disk
• Other commands on that server are working fine, it’s just the microk8s that crashes with this error.
• I tried to increase the ulimit size but it didn’t help and I’m not too keen on doing that indefinitely.

Is there a way to at least recover the system permanently from that state? I tried restarting each of the services from here: https://microk8s.io/docs/configuring-services Only one did help: systemctl restart snap.microk8s.daemon-containerd, but the cluster falls back into the same failed state (DBus error) couple of seconds after restarting the containerd service – so eventually it didn’t help.

[LemurPwned]

@robotrapta yes, you linked the issue here 😃

[bboozzoo]

I’ve provided some info in https://forum.snapcraft.io/t/dbus-error-system-error-e2big-error/29227/2, if possible please capture the session bus traffic, as well as the journal.