分步启动出现这个异常
java.net.SocketException: Call From master to null:0 failed on socket exception: java.net.SocketException: Unresolved address; For more details see: http://wiki.apache.org/hadoop/SocketException
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.apache.hadoop.net.NetUtils.wrapWithMessage(NetUtils.java:837)
at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:800)
at org.apache.hadoop.ipc.Server.bind(Server.java:640)
at org.apache.hadoop.ipc.Server$Listener.<init>(Server.java:1210)
at org.apache.hadoop.ipc.Server.<init>(Server.java:3103)
at org.apache.hadoop.ipc.RPC$Server.<init>(RPC.java:1039)
at org.apache.hadoop.ipc.ProtobufRpcEngine2$Server.<init>(ProtobufRpcEngine2.java:430)
at org.apache.hadoop.ipc.ProtobufRpcEngine2.getServer(ProtobufRpcEngine2.java:350)
at org.apache.hadoop.ipc.RPC$Builder.build(RPC.java:848)
at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.<init>(NameNodeRpcServer.java:475)
at org.apache.hadoop.hdfs.server.namenode.NameNode.createRpcServer(NameNode.java:857)
at org.apache.hadoop.hdfs.server.namenode.NameNode.initialize(NameNode.java:763)
at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:1014)
at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:987)
at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1756)
at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1821)
Caused by: java.net.SocketException: Unresolved address
at sun.nio.ch.Net.translateToSocketException(Net.java:134)
at sun.nio.ch.Net.translateException(Net.java:160)
at sun.nio.ch.Net.translateException(Net.java:166)
at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:87)
at org.apache.hadoop.ipc.Server.bind(Server.java:623)
... 13 more
Caused by: java.nio.channels.UnresolvedAddressException
at sun.nio.ch.Net.checkAddress(Net.java:104)
at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:217)
at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:85)
... 14 more

您好 请教一下这个问题是什么原因呢，我也遇到了