一、简介：
为方便节点之间通过hostname访问，我们可以在hosts文件中配置各个节点hostname与IP的映射关系
二、举例：准备了三个集群节点
注：如果在192.168.24.60里面输入ping hadoop61和ping hadoop62，是没办法访问的，
步骤：
（1）hadoop60配置映射关系
[root@hadoop60 ~]# vi /etc/hosts 127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 192.168.24.60 hadoop60 192.168.24.61 hadoop61 192.168.24.62 hadoop62
（2）同样的，hadoop61和ping hadoop62里面也要配置
[root@hadoop61 ~]# vi /etc/hosts 127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 192.168.24.60 hadoop60 192.168.24.61 hadoop61 192.168.24.62 hadoop62
[root@hadoop62 ~]# vi /etc/hosts 127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 192.168.24.60 hadoop60 192.168.24.61 hadoop61 192.168.24.62 hadoop62
（3）此时，在192.168.24.60里面输入ping hadoop61和ping hadoop62，是可以访问的
[root@hadoop60 ~]# ping hadoop61 PING hadoop61 (192.168.24.61) 56(84) bytes of data. 64 bytes from hadoop61 (192.168.24.61): icmp_seq=1 ttl=64 time=0.290 ms 64 bytes from hadoop61 (192.168.24.61): icmp_seq=2 ttl=64 time=0.526 ms
