如屏幕截图所示，在数据节点日志中出现以下错误。
尝试格式化 namenode 和 stop-all.sh -- start-all.sh。没运气。
清除 /app/hadoop/tmp 文件夹两次以上。
2018-07-10 19:02:12,715 ERROR org.apache.hadoop.hdfs.server.datanode.DataNode: Exception in secureMain
java.net.BindException: Port in use: localhost:0
at org.apache.hadoop.http.HttpServer2.constructBindException(HttpServer2.java:1014)
at org.apache.hadoop.http.HttpServer2.bindForSinglePort(HttpServer2.java:1037)
at org.apache.hadoop.http.HttpServer2.openListeners(HttpServer2.java:1094)
at org.apache.hadoop.http.HttpServer2.start(HttpServer2.java:951)
at org.apache.hadoop.hdfs.server.datanode.web.DatanodeHttpServer.<init>(DatanodeHttpServer.java:135)
at org.apache.hadoop.hdfs.server.datanode.DataNode.startInfoServer(DataNode.java:962)
at org.apache.hadoop.hdfs.server.datanode.DataNode.startDataNode(DataNode.java:1370)
at org.apache.hadoop.hdfs.server.datanode.DataNode.<init>(DataNode.java:495)
at org.apache.hadoop.hdfs.server.datanode.DataNode.makeInstance(DataNode.java:2695)
at org.apache.hadoop.hdfs.server.datanode.DataNode.instantiateDataNode(DataNode.java:2598)
at org.apache.hadoop.hdfs.server.datanode.DataNode.createDataNode(DataNode.java:2645)
at org.apache.hadoop.hdfs.server.datanode.DataNode.secureMain(DataNode.java:2789)
at org.apache.hadoop.hdfs.server.datanode.DataNode.main(DataNode.java:2813)
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:433)
at sun.nio.ch.Net.bind(Net.java:425)
at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)
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.bindListener(HttpServer2.java:1002)
at org.apache.hadoop.http.HttpServer2.bindForSinglePort(HttpServer2.java:1033)
... 11 more
2018-07-10 19:02:12,726 INFO org.apache.hadoop.util.ExitUtil: Exiting with status 1: java.net.BindException: Port in use: localhost:0
2018-07-10 19:02:12,736 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: SHUTDOWN_MSG: