Access denied for user 'root'@'localhost'

I get this error in the logs, just after installing Percona XtraDB cluster:

[Note] Access denied for user ‘root’@‘localhost’ (using password: NO)

I followed these steps to install it (Debian jessie):

The message will go away after I add the root password in the client config, but I reckon this is not appropriate. :slight_smile:

The service starts normally

Is it something to worry about?