The ZK documentation says:
New in 3.2: Enables a ZooKeeper ensemble administrator to access the znode
hierarchy as a "super" user. In particular no ACL checking occurs for a user
authenticated as super.
However, in some testing today I created a digest user, logged in as this user,
set the ACLs for "/" to Ids.READ_ACL_UNSAFE, and now even when I am logged in
as the superuser, I cannot actually change this ACL or write nodes below it on
the tree. So it does not actually seem to be the case that "super" skips ACL
checks. Is this a bug or a feature?