【发布时间】：2018-07-19 23:24:24
【问题描述】：
我只想通过 Java 代码访问 Hadoop 文件系统，但我似乎经常遇到异常
public class hdfsClient {
public hdfsClient() {}
public void addFile(String source, String dest) throws IOException{
Configuration conf = new Configuration();
conf.addResource(new Path("/usr/local/hadoop/etc/hadoop/core-site.xml"));
conf.addResource(new Path("/usr/local/hadoop/etc/hadoop/hdfs-site.xml"));
FileSystem fs = null;
try {
fs = FileSystem.get(conf);
} catch (Exception e) {
System.out.println("Error in getting the fileSystem");
e.printStackTrace();
}
}
现在主文件是这样的
public class testMain {
public static void main(String[] args) throws Exception{
// TODO Auto-generated method stub
hdfsClient client = new hdfsClient();
if (args[0].equals("add")) {
if (args.length < 3) {
System.out.println("Usage: hdfsclient add <local_path> " +
"<hdfs_path>");
System.exit(1);
}
client.addFile(args[1], args[2]);
}
}
}
我在 eclipse 中创建了这些文件并导出为 JAR，然后我使用了
java -jar <jarname> add <path in local system> <path in hadoop>
确切的命令是
java -jar add.jar add /home/aman/test.txt /
我收到以下错误
org.apache.hadoop.ipc.RemoteException: Server IPC version 9 cannot communicate with client version 4
at org.apache.hadoop.ipc.Client.call(Client.java:1113)
at org.apache.hadoop.ipc.RPC$Invoker.invoke(RPC.java:229)
at com.sun.proxy.$Proxy1.getProtocolVersion(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:85)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:62)
at com.sun.proxy.$Proxy1.getProtocolVersion(Unknown Source)
at org.apache.hadoop.ipc.RPC.checkVersion(RPC.java:422)
at org.apache.hadoop.hdfs.DFSClient.createNamenode(DFSClient.java:183)
at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:281)
at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:245)
at org.apache.hadoop.hdfs.DistributedFileSystem.initialize(DistributedFileSystem.java:100)
at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:1446)
at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:67)
at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:1464)
at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:263)
at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:124)
at crud.crud.hdfsClient.addFile(hdfsClient.java:28)
at crud.crud.testMain.main(testMain.java:16)
我尝试了整整两天但无法解决问题的任何帮助
PS：
来自mjps的输出
16341 Jps
14985 NameNode
20704 -- process information unavailable
15655 NodeManager
15146 DataNode
15349 SecondaryNameNode
15517 ResourceManager
【问题讨论】：
-
参见stackoverflow.com/questions/23634985/… 和hortonworks.com/community/forums/topic/server-ipc-version-9 中的第五个帖子。听起来您遇到了图书馆冲突。