Hadoop中的数据复制错误，怎么办？
Hadoop中的数据复制错误，怎么办？
提问于 2018-02-24 00:17:01
我在我的机器上实现Hadoop单节点集群，遇到了数据复制错误：
以下是完整的错误消息：
> hadoop@laptop:~/hadoop$ bin/hadoop dfs -copyFromLocal
> tmp/testfiles testfiles
>
> 12/05/04 16:18:41 WARN hdfs.DFSClient: DataStreamer Exception:
> org.apache.hadoop.ipc.RemoteException: java.io.IOException: File
> /user/hadoop/testfiles/testfiles/file1.txt could only be replicated to
> 0 nodes, instead of 1 at
> org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getAdditionalBlock(FSNamesystem.java:1271)
> at
> org.apache.hadoop.hdfs.server.namenode.NameNode.addBlock(NameNode.java:422)
> at sun.reflect.GeneratedMethodAccessor7.invoke(Unknown Source) at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
> at java.lang.reflect.Method.invoke(Method.java:597) at
> org.apache.hadoop.ipc.RPC$Server.call(RPC.java:508) at
> org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:959) at
> org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:955) at
> java.security.AccessController.doPrivileged(Native Method) at
> javax.security.auth.Subject.doAs(Subject.java:396) at
> org.apache.hadoop.ipc.Server$Handler.run(Server.java:953)
>
> at org.apache.hadoop.ipc.Client.call(Client.java:740) at
> org.apache.hadoop.ipc.RPC$Invoker.invoke(RPC.java:220) at
> $Proxy0.addBlock(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:82)
> at
> org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:59)
> at $Proxy0.addBlock(Unknown Source) at
> org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.locateFollowingBlock(DFSClient.java:2937)
> at
> org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.nextBlockOutputStream(DFSClient.java:2819)
> at
> org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.access$2000(DFSClient.java:2102)
> at
> org.apache.hadoop.hdfs.DFSClient$DFSOutputStream$DataStreamer.run(DFSClient.java:2288)
>
> 12/05/04 16:18:41 WARN hdfs.DFSClient: Error Recovery for block null
> bad datanode[0] nodes == null 12/05/04 16:18:41 WARN hdfs.DFSClient:
> Could not get block locations. Source file
> "/user/hadoop/testfiles/testfiles/file1.txt" - Aborting...
> copyFromLocal: java.io.IOException: File
> /user/hadoop/testfiles/testfiles/file1.txt could only be replicated to
> 0 nodes, instead of 1 12/05/04 16:18:41 ERROR hdfs.DFSClient:
> Exception closing file /user/hadoop/testfiles/testfiles/file1.txt :
> org.apache.hadoop.ipc.RemoteException: java.io.IOException: File
> /user/hadoop/testfiles/testfiles/file1.txt could only be replicated to
> 0 nodes, instead of 1 at
> org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getAdditionalBlock(FSNamesystem.java:1271)
> at
> org.apache.hadoop.hdfs.server.namenode.NameNode.addBlock(NameNode.java:422)
> at sun.reflect.GeneratedMethodAccessor7.invoke(Unknown Source) at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
> at java.lang.reflect.Method.invoke(Method.java:597) at
> org.apache.hadoop.ipc.RPC$Server.call(RPC.java:508) at
> org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:959) at
> org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:955) at
> java.security.AccessController.doPrivileged(Native Method) at
> javax.security.auth.Subject.doAs(Subject.java:396) at
> org.apache.hadoop.ipc.Server$Handler.run(Server.java:953)
>
> org.apache.hadoop.ipc.RemoteException: java.io.IOException: File
> /user/hadoop/testfiles/testfiles/file1.txt could only be replicated to
> 0 nodes, instead of 1 at
> org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getAdditionalBlock(FSNamesystem.java:1271)
> at
> org.apache.hadoop.hdfs.server.namenode.NameNode.addBlock(NameNode.java:422)
> at sun.reflect.GeneratedMethodAccessor7.invoke(Unknown Source) at
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
> at java.lang.reflect.Method.invoke(Method.java:597) at
> org.apache.hadoop.ipc.RPC$Server.call(RPC.java:508) at
> org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:959) at
> org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:955) at
> java.security.AccessController.doPrivileged(Native Method) at
> javax.security.auth.Subject.doAs(Subject.java:396) at
> org.apache.hadoop.ipc.Server$Handler.run(Server.java:953)
>
> at org.apache.hadoop.ipc.Client.call(Client.java:740) at
> org.apache.hadoop.ipc.RPC$Invoker.invoke(RPC.java:220) at
> $Proxy0.addBlock(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:82)
> at
> org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:59)
> at $Proxy0.addBlock(Unknown Source) at
> org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.locateFollowingBlock(DFSClient.java:2937)
> at
> org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.nextBlockOutputStream(DFSClient.java:2819)
> at
> org.apache.hadoop.hdfs.DFSClient$DFSOutputStream.access$2000(DFSClient.java:2102)
> at
> org.apache.hadoop.hdfs.DFSClient$DFSOutputStream$DataStreamer.run(DFSClient.java:2288)同样，当我执行：
bin/stop-all.sh报错：
datanode has not been started and thus cannot be stopped. Though, the output ofjpssays the datanode being present
我试过格式化NameNode，更改所有者权限，但它似乎不起作用。
回答 2
Stack Overflow用户
发布于 2018-02-24 09:09:41
对我有效的解决方案是一个接一个地运行NameNode和DataNode，而不是使用bin/start-all.sh。使用这种方法所发生的情况是，如果您在网络上设置数据阳极有一些问题，那么错误是明显可见的，而且堆栈溢出上的许多帖子也表明，NameNode需要一些时间来启动，因此，应该在启动数据阳极之前给它一些时间来启动。此外，在本例中，我遇到了NameNode和datanodes的不同ID的问题，为此我必须用与NameNode相同的ID来更改DataNode的ID。
一步一步的程序将是：
- 启动NameNode
bin/hadoop namenode。检查错误，如果有。 - 启动数据阳极
bin/hadoop datanode。检查错误，如果有。 - 现在使用bin/start-mapred.sh启动任务跟踪器、作业跟踪器。
Stack Overflow用户
发布于 2018-02-24 09:41:06
看看你的NameNode(可能)http：//localhost：50070)，看看它说你有多少个数据结点。
如果它是0，那么要么您的DataNode没有运行，要么它没有配置为连接到NameNode。
如果是1，请检查DFS中有多少空闲空间。可能是数据节点没有可以写入数据的地方(数据dir不存在，或者没有写权限)。
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原文链接：
https://stackoverflow.com/questions/-100004161
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