Datanode启动失败 java.net.BindException: Port in use: localhost:0

Hadoop启动集群后，发现datanode节点启动失败，查看datanode的日志，提示java.net.BindException: Port in use: localhost:0，如图所示：

java.net.BindException: Port in use: localhost:0
	at org.apache.hadoop.http.HttpServer2.openListeners(HttpServer2.java:919)
	at org.apache.hadoop.http.HttpServer2.start(HttpServer2.java:856)
	at org.apache.hadoop.hdfs.server.datanode.web.DatanodeHttpServer.(DatanodeHttpServer.java:104)
	at org.apache.hadoop.hdfs.server.datanode.DataNode.startInfoServer(DataNode.java:759)
	at org.apache.hadoop.hdfs.server.datanode.DataNode.startDataNode(DataNode.java:1108)
	at org.apache.hadoop.hdfs.server.datanode.DataNode.(DataNode.java:428)
	at org.apache.hadoop.hdfs.server.datanode.DataNode.makeInstance(DataNode.java:2373)
	at org.apache.hadoop.hdfs.server.datanode.DataNode.instantiateDataNode(DataNode.java:2260)
	at org.apache.hadoop.hdfs.server.datanode.DataNode.createDataNode(DataNode.java:2307)
	at org.apache.hadoop.hdfs.server.datanode.DataNode.secureMain(DataNode.java:2484)
	at org.apache.hadoop.hdfs.server.datanode.DataNode.main(DataNode.java:2508)
Caused by: java.net.BindException: Cannot assign requested address
	at sun.nio.ch.Net.bind0(Native Method)
	at sun.nio.ch.Net.bind(Net.java:444)
	at sun.nio.ch.Net.bind(Net.java:436)
	at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:214)
	at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
	at org.mortbay.jetty.nio.SelectChannelConnector.open(SelectChannelConnector.java:216)
	at org.apache.hadoop.http.HttpServer2.openListeners(HttpServer2.java:914)
	... 10 more

检查/etc/hosts文件的配置是否有问题，正确形式如下图所示，

• 不能删除默认的localhost 127.0.0.1
• IP 与 hostname形式是否正确

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
172.16.200.131 etc01
172.16.200.132 etc02
172.16.200.133 etc03

最后，重启HDFS：sbin/start-dsf.sh即可。