Returns true if given host is local host
Finds the DCs of the contact points and returns hosts in those DC(s) from allHosts.
Finds the DCs of the contact points and returns hosts in those DC(s) from allHosts.
It guarantees to return at least the hosts pointed by contactPoints, even if their
DC information is missing. Other hosts with missing DC information are not considered.
Sorts nodes in the following order: 1.
Sorts nodes in the following order:
1. live nodes in the same DC as contactPoints starting with localhost if up
2. down nodes in the same DC as contactPoints
Nodes within a group are ordered randomly. Nodes from other DCs are not included.