最近我开始使用 hadoop 。现在我想从远程主机访问 hdfs，它没有安装 hadoop-client，只是依赖 hadoop-client-2.0.4-alpha.jar 。
但是当我尝试访问 hdfs 时，出现以下异常：
java.io.IOException: Failed on local exception: com.google.protobuf.InvalidProtocolBufferException: Message missing required fields: callId, status; Host Details : local host is: "webserver/127.0.0.1"; destination host is: "222.333.111.77":8020;
at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:761)
at org.apache.hadoop.ipc.Client.call(Client.java:1239)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:202)
at $Proxy25.getFileInfo(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:164)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:83)
at $Proxy25.getFileInfo(Unknown Source)
at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.getFileInfo(ClientNamenodeProtocolTranslatorPB.java:630)
at org.apache.hadoop.hdfs.DFSClient.getFileInfo(DFSClient.java:1559)
at org.apache.hadoop.hdfs.DistributedFileSystem.getFileStatus(DistributedFileSystem.java:811)
at org.apache.hadoop.fs.FileSystem.exists(FileSystem.java:1345)
at com.kongming.kmdata.service.ExportService.copyToLocalFileFromHdfs(ExportService.java:60)
at com.kongming.kmdata.service.KMReportManager.run(KMReportManager.java:105)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
Caused by: com.google.protobuf.InvalidProtocolBufferException: Message missing required fields: callId, status
at com.google.protobuf.UninitializedMessageException.asInvalidProtocolBufferException(UninitializedMessageException.java:81)
at org.apache.hadoop.ipc.protobuf.RpcPayloadHeaderProtos$RpcResponseHeaderProto$Builder.buildParsed(RpcPayloadHeaderProtos.java:1094)
at org.apache.hadoop.ipc.protobuf.RpcPayloadHeaderProtos$RpcResponseHeaderProto$Builder.access$1300(RpcPayloadHeaderProtos.java:1028)
at org.apache.hadoop.ipc.protobuf.RpcPayloadHeaderProtos$RpcResponseHeaderProto.parseDelimitedFrom(RpcPayloadHeaderProtos.java:986)
at org.apache.hadoop.ipc.Client$Connection.receiveResponse(Client.java:946)
at org.apache.hadoop.ipc.Client$Connection.run(Client.java:844)
它看起来像一个 rpc 异常，如何修复它？这是我的代码：
package com.xxx.xxx.service;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.log4j.Logger;
import com.xxx.xxx.fileSystem.IFilePath;
import com.xxx.xxx.inject.GuiceDependency;
public class ExportService {
private static Logger log = Logger.getLogger(ExportService.class);
private static Configuration configuration = new Configuration();
private static String dir = "./";
private static String hadoopConf = "hadoop-conf/";
static {
configuration.addResource(new Path(hadoopConf + "core-site.xml"));
configuration.addResource(new Path(hadoopConf + "hdfs-site.xml"));
configuration.addResource(new Path(hadoopConf + "mapred-site.xml"));
configuration.addResource(new Path(hadoopConf + "yarn-site.xml"));
}
public static boolean copyToLocalFileFromHdfs(String reportID) {
IFilePath filePath = GuiceDependency.getInstance(IFilePath.class);
String resultPath = filePath.getFinalResult(reportID) + "/part-r-00000";
Path src = new Path(resultPath);
String exportPath = dir + reportID + ".csv";
Path dst = new Path(exportPath);
System.out.println(configuration.get("fs.defaultFS"));
System.out.println("zxz copyToLocalFileFromHdfs scr: "
+ src.toString() + " , dst: " + dst.toString());
try {
System.out.println("zxz get fileSystem start ");
FileSystem fs = FileSystem.get(configuration);
System.out.println("zxz get fileSystem end "
+ fs.getHomeDirectory().toString());
System.out.println("zxz ~~~~~~~~~~~~~~~~~~~~~~~~~"
+ fs.exists(src));
;
fs.copyToLocalFile(false, src, dst);
fs.copyToLocalFile(false, src, dst, true);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
log.error("copyFromHDFSFile error : ", e);
return false;
}
System.out.println("zxz end copyToLocalFileFromHdfs for report: "
+ reportID);
return true;
}
}
和 core-site.xml ：
<?xml version="1.0" encoding="UTF-8"?>
<!--Autogenerated by Cloudera CM on 2013-07-19T00:57:49.581Z-->
<configuration>
<property>
<name>fs.defaultFS</name>
<value>hdfs://222.333.111.77:8020</value>
</property>
<property>
<name>fs.trash.interval</name>
<value>1</value>
</property>
<property>
<name>io.file.buffer.size</name>
<value>65536</value>
</property>
<property>
<name>hadoop.security.authentication</name>
<value>simple</value>
</property>
<property>
<name>hadoop.rpc.protection</name>
<value>authentication</value>
</property>
<property>
<name>hadoop.security.auth_to_local</name>
<value>DEFAULT</value>
</property>
<property>
<name>hadoop.native.lib</name>
<value>false</value>
<description>Should native hadoop libraries, if present, be used.</description>
</property>
</configuration>
有人知道这个问题吗？非常感谢您的帮助~