previously, the FQDN of a NameServer was generated using a globally
shared, monotonically increasing counter. that resulted in a
unpredictable FQDN in the presence other tests running concurrently /
in parallel
with this change, the presence of other test threads does not affect the
FQDN automatically chosen for a NameServer. the FQDN becomes only a
function of the order in which the NameServers are created *within a
thread*
