Hey Gerd,

The reason you can't get to the NameNode UI is because you have to have a kerberos ticket now to bring it up.  As for the failed canary, did you restart the MGMT services?  Once you enable kerberos, you have to restart the MGMT services so they can get a proper keytab.  That way they can run the canary tests.

Can you try restarting the MGMT services and let me know if that helps?

Thanks!

Chris