{TAIL ~ Machine manager} 610 knows a location of each rack within {HEAD ~ the networks} and each machine and the database that is/are located within the rack 
{ TAIL ~ Machine manager } 610 knows a location of each rack within { HEAD ~ the networks } and each machine and the database that is / are located within the rack
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH