“ hadoop namenode -format”返回java.net.UnknownHostException

Question

我目前正在学习hadoop，并且尝试设置http://hadoop.apache.org/common/docs/current/single_node_setup.html中定义的单节点测试

我已经配置了ssh（我可以不用密码登录）。

我的服务器在我们的Intranet上，位于代理后面。

当我试图跑步时

bin / hadoop namenode-格式

我收到以下java.net.UnknownHostException异常：

$ bin/hadoop namenode -format
11/06/10 15:36:47 INFO namenode.NameNode: STARTUP_MSG: 
/************************************************************
STARTUP_MSG: Starting NameNode
STARTUP_MSG:   host = java.net.UnknownHostException: srv-clc-04.univ-nantes.prive3: srv-clc-04.univ-nantes.prive3
STARTUP_MSG:   args = [-format]
STARTUP_MSG:   version = 0.20.203.0
STARTUP_MSG:   build = http://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.20-security-203 -r 1099333; compiled by 'oom' on Wed May  4 07:57:50 PDT 2011
************************************************************/
Re-format filesystem in /home/lindenb/tmp/HADOOP/dfs/name ? (Y or N) Y
11/06/10 15:36:50 INFO util.GSet: VM type       = 64-bit
11/06/10 15:36:50 INFO util.GSet: 2% max memory = 19.1675 MB
11/06/10 15:36:50 INFO util.GSet: capacity      = 2^21 = 2097152 entries
11/06/10 15:36:50 INFO util.GSet: recommended=2097152, actual=2097152
11/06/10 15:36:50 INFO namenode.FSNamesystem: fsOwner=lindenb
11/06/10 15:36:50 INFO namenode.FSNamesystem: supergroup=supergroup
11/06/10 15:36:50 INFO namenode.FSNamesystem: isPermissionEnabled=true
11/06/10 15:36:50 INFO namenode.FSNamesystem: dfs.block.invalidate.limit=100
11/06/10 15:36:50 INFO namenode.FSNamesystem: isAccessTokenEnabled=false accessKeyUpdateInterval=0 min(s), accessTokenLifetime=0 min(s)
11/06/10 15:36:50 INFO namenode.NameNode: Caching file names occuring more than 10 times 
11/06/10 15:36:50 INFO common.Storage: Image file of size 113 saved in 0 seconds.
11/06/10 15:36:50 INFO common.Storage: Storage directory /home/lindenb/tmp/HADOOP/dfs/name has been successfully formatted.
11/06/10 15:36:50 INFO namenode.NameNode: SHUTDOWN_MSG: 
/************************************************************
SHUTDOWN_MSG: Shutting down NameNode at java.net.UnknownHostException: srv-clc-04.univ-nantes.prive3: srv-clc-04.univ-nantes.prive3
************************************************************/

之后，Hadoop开始了

./bin/start-all.sh

但是当我尝试复制本地文件时，又出现了另一个新异常：

 bin/hadoop fs  -copyFromLocal ~/file.txt  file.txt

DataStreamer Exception: org.apache.hadoop.ipc.RemoteException: java.io.IOException: File /user/lindenb/file.txt could only be replicated to 0 nodes, instead of 1
    at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getAdditionalBlock(FSNamesystem.java:1417)

请问该如何解决？

谢谢

Answer 1

当hadoop尝试将DNS名称（srv-
clc-04.univ-
nantes.prive3）解析为IP地址时，抛出UnknownHostException。这失败了。

在配置文件中查找域名，然后将其替换为“ localhost”。（或者更新DNS向上将名称解析为IP地址）