配置Hadoop集群：java.net.NoRouteToHostException: No route to host问题的解决

datanode连接不上namenode，导致datanode无法启动。 

[root@slave bin]# ./hdfs dfsadmin -report
report: No Route to Host from  slave/10.14.44.211 to master:9000 failed on socket timeout exception: java.net.NoRouteToHostException: No route to host; For more details see:  http://wiki.apache.org/hadoop/NoRouteToHost

关闭防火墙

 

[root@master bin]# service iptables stop
Flushing firewall rules:                                   [  OK  ]
Setting chains to policy ACCEPT: filter                    [  OK  ]
Unloading iptables modules:                                [  OK  ]

 

机器重启后，防火墙还会开启。 so，you must do it again the next time。