dea 远程操作 hdfs hadoop

• idea 远程操作 hdfs Hadoop、报错 Caused by: java.net.ConnectException: Connection refused: no further information

1 源代码

package com.github.td.hdfs;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.junit.Test;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
/**


@Description: TODO


@Author:


@DateTime: 2021/12/20 17:52
**/
public class HdfsClient {
@Test
public void testMkdirs() throws IOException, URISyntaxException, InterruptedException{
 <span class="hljs-comment">// 1 获取文件系统</span>
 <span class="hljs-type">Configuration</span> <span class="hljs-variable">configuration</span> <span class="hljs-operator">=</span> <span class="hljs-keyword">new</span> <span class="hljs-title class_">Configuration</span>();
 <span class="hljs-comment">// master == 192.168.xx.xx</span>
 <span class="hljs-comment">// cdh版本端口号为8020，普通版本Hadoop端口号为9000</span>
 <span class="hljs-type">FileSystem</span> <span class="hljs-variable">fs</span> <span class="hljs-operator">=</span> FileSystem.get(<span class="hljs-keyword">new</span> <span class="hljs-title class_">URI</span>(<span class="hljs-string">"hdfs://master:8020"</span>), configuration, <span class="hljs-string">"root"</span>);

 <span class="hljs-comment">// 2 创建目录</span>
 fs.mkdirs(<span class="hljs-keyword">new</span> <span class="hljs-title class_">Path</span>(<span class="hljs-string">"/hadoop/hdfs-api"</span>));

 <span class="hljs-comment">// 3 关闭资源</span>
 fs.close();

}
}

2 报错日志

java.net.ConnectException: Call From to master: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(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:831)
at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:755)
at org.apache.hadoop.ipc.Client.getRpcResponse(Client.java:1549)
at org.apache.hadoop.ipc.Client.call(Client.java:1491)
at org.apache.hadoop.ipc.Client.call(Client.java:1388)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:233)
at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:118)
at com.sun.proxy.$Proxy12.mkdirs(Unknown Source)
at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.mkdirs(ClientNamenodeProtocolTranslatorPB.java:657)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:422)
at org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invokeMethod(RetryInvocationHandler.java:165)
at org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invoke(RetryInvocationHandler.java:157)
at org.apache.hadoop.io.retry.RetryInvocationHandler$Call.invokeOnce(RetryInvocationHandler.java:95)
at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:359)
at com.sun.proxy.$Proxy13.mkdirs(Unknown Source)
at org.apache.hadoop.hdfs.DFSClient.primitiveMkdir(DFSClient.java:2420)
at org.apache.hadoop.hdfs.DFSClient.mkdirs(DFSClient.java:2396)
at org.apache.hadoop.hdfs.DistributedFileSystem$27.doCall(DistributedFileSystem.java:1319)
at org.apache.hadoop.hdfs.DistributedFileSystem$27.doCall(DistributedFileSystem.java:1316)
at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81)
at org.apache.hadoop.hdfs.DistributedFileSystem.mkdirsInternal(DistributedFileSystem.java:1333)
at org.apache.hadoop.hdfs.DistributedFileSystem.mkdirs(DistributedFileSystem.java:1308)
at org.apache.hadoop.fs.FileSystem.mkdirs(FileSystem.java:2275)
at com.github.td.hdfs.HdfsClient.testMkdirs(HdfsClient.java:29)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:230)
at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:58)

Caused by: java.net.ConnectException: Connection refused: no further information
at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:715)
at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206)
at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:531)
at org.apache.hadoop.ipc.Client$Connection.setupConnection(Client.java:700)
at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:804)
at org.apache.hadoop.ipc.Client$Connection.access$3800(Client.java:421)
at org.apache.hadoop.ipc.Client.getConnection(Client.java:1606)
at org.apache.hadoop.ipc.Client.call(Client.java:1435)
... 46 more

3 原因分析

• 端口问题
• cdh 的环境下，hdfs 是 8020 端口，conf.set(“fs.defaultFS”, “hdfs://192.168.0.4:8020”);
  普通 hadoop 环境，hdfs 是 9000 端口，conf.set(“fs.defaultFS”, “hdfs://192.168.0.121:9000”);

4 解决方案

• 修改端口号为 9000