（1）在使用eclipse远程调用hadoop时，抛出的异常，eclipse默认使用的是8020端口，而我的nameNode使用的9000,所以我将nameNode的端口设置为8020，问题解决
java.net.ConnectException: Call From LAPTOP-FD4J94H3/192.168.177.111 to hadoop-node1.com:8020 failed on connection exception: java.net.ConnectException: Connection refused: no further information; For more details see: http://wiki.apache.org/hadoop/ConnectionRefused at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) at java.lang.reflect.Constructor.newInstance(Unknown Source) at org.apache.hadoop.net.NetUtils.wrapWithMessage(NetUtils.java:792) at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:732) at org.apache.hadoop.ipc.Client.call(Client.java:1479) at org.apache.hadoop.ipc.Client.call(Client.java:1412) at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:229)