必须配置系统以指定如何确定机架信息。例如，这个cloudera链接告诉您如何在cloudera manager中为主机配置机架。
或者，这个apache链接解释了如何通过配置文件在java类的外部脚本中指定这些信息。
拓扑结构通常采用/myrack/myhost的形式，不过您可以使用更深层的层次结构。它们有下面的python示例，假设每个机架都有一个/24子网，因此提取ip地址的前三个字节用作机架号-如果可以相应地设置节点ip地址，则可以采用类似的方法，或者编写您自己的脚本，根据每个节点上的ip地址或其他可用信息确定机架（在您的示例中，即使是主机名和机架之间的简单硬编码Map也适用于相对较少的节点）。

# !/usr/bin/python

# this script makes assumptions about the physical environment.

# 1) each rack is its own layer 3 network with a /24 subnet, which

# could be typical where each rack has its own

# switch with uplinks to a central core router.

# 

# +-----------+

# |core router|

# +-----------+

# /             \

# +-----------+        +-----------+

# |rack switch|        |rack switch|

# +-----------+        +-----------+

# | data node |        | data node |

# +-----------+        +-----------+

# | data node |        | data node |

# +-----------+        +-----------+

# 

# 2) topology script gets list of IP's as input, calculates network address, and prints '/network_address/ip'.

import netaddr
import sys
sys.argv.pop(0)                                                  # discard name of topology script from argv list as we just want IP addresses

netmask = '255.255.255.0'                                        # set netmask to what's being used in your environment.  The example uses a /24

for ip in sys.argv:                                              # loop over list of datanode IP's
address = '{0}/{1}'.format(ip, netmask)                      # format address string so it looks like 'ip/netmask' to make netaddr work
try:
   network_address = netaddr.IPNetwork(address).network     # calculate and print network address
   print "/{0}".format(network_address)
except:
   print "/rack-unknown"                                    # print catch-all value if unable to calculate network address