Exception in thread "main" java.io.IOException: Failed on local exception: org.apache.hadoop.ipc.RpcException: RPC response exceeds maximum data length; Host Details : local host is: "mzmuer/172.19.82.225"; destination host is: "localhost":9870;
at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:808)
at org.apache.hadoop.ipc.Client.getRpcResponse(Client.java:1495)
at org.apache.hadoop.ipc.Client.call(Client.java:1437)
at org.apache.hadoop.ipc.Client.call(Client.java:1347)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:228)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:116)
at com.sun.proxy.$Proxy11.getBlockLocations(Unknown Source)
at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.getBlockLocations(ClientNamenodeProtocolTranslatorPB.java:305)
解决方法：
1.通过 jps 查看namenode和datanode是否启动。未启动需要调用start-dfs启动。
2.查看core-site.xml配置文件中的fs.default.name属性。是否是请求的链接。请求到了错误的链接也可能是该错误.