Hi,
I don't know how solr authentication from the viewpoint of ZooKeeper.
ACL makes sense to restrict the content solr cretes in ZooKeeper.
I'm not sure what you mean by enabling authentication for the whole
ZooKeeper?
ZK has server-to-server (quorum auth) and client-to-server mutual
authentication.
Looks like solr has org.apache.solr.common.cloud.SaslZkACLProvider, that's
basically the client authentication part in ZooKeeper, and you can use ACL.
Quorum authentication won't help you to protect your data from fraudulent
clients. That's just against fraudulent servers.
So my short answer is that ACL is the way to go when securing client data
is the question.
Regards,
Norbert