code: public static Map<InetAddress, Map<String,String>> loadDcRackInfo()
      {
          Map<InetAddress, Map<String, String>> result = new HashMap<InetAddress, Map<String, String>>();
          for (UntypedResultSet.Row row : executeInternal("SELECT peer, data_center, rack from system." + PEERS_CF))
          {
              InetAddress peer = row.getInetAddress("peer");
              if (row.has("data_center") && row.has("rack"))
              {
                  Map<String, String> dcRack = new HashMap<String, String>();
                  dcRack.put("data_center", row.getString("data_center"));
                  dcRack.put("rack", row.getString("rack"));
                  result.put(peer, dcRack);
              }
          }
          return result;
      }
docs: Return a map of IP addresses containing a map of dc and rack info