Win下Eclipse提交hadoop程序出错:org.apache.hadoop.security.AccessControlException: Permission denied: user=DrWho, access=WRITE

描述:在window下使用Eclipse进行hadoop的程序编写,然后Run on hadoop 后,出现如下错误:

11/10/28 16:05:53 INFO mapred.JobClient: Running job: job_201110281103_0003
11/10/28 16:05:54 INFO mapred.JobClient: map 0% reduce 0%
11/10/28 16:06:05 INFO mapred.JobClient: Task Id : attempt_201110281103_0003_m_000002_0, Status : FAILED
org.apache.hadoop.security.AccessControlException: org.apache.hadoop.security.AccessControlException: Permission denied: user=DrWho, access=WRITE, inode="hadoop":hadoop:supergroup:rwxr-xr-x
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)

 

解决方法:

  到服务器上修改hadoop的配置文件:conf/hdfs-core.xml, 找到 dfs.permissions 的配置项 , 将value值改为 false

<property>
<name>dfs.permissions</name>
<value>false</value>
<description>
If "true", enable permission checking in HDFS.
If "false", permission checking is turned off,
but all other behavior is unchanged.
Switching from one parameter value to the other does not change the mode,
owner or group of files or directories.
</description>
</property>

 

修改完貌似要重启下hadoop的进程才能生效

 

开发环境:win xp sp3 ,   Eclipse 3.3  ,   hadoop-0.20.2    

hadoop服务器部署环境: ubuntu 10.10  ,   hadoop-0.20.2  

小结:  接触Hadoop没多久,不知道这样修改对集群的安全性有啥影响。

 

//补充:

后来google到一篇文章,解释了错误出现的原因,原文地址如下:

http://hi.baidu.com/hontlong/blog/item/9ba50ddbd1e16270d0164ec4.html


因为Eclipse使用hadoop插件提交作业时,会默认以 DrWho 身份去将作业写入hdfs文件系统中,对应的也就是 HDFS 上的/user/xxx , 我的为/user/hadoop ,   由于 DrWho 用户对hadoop目录并没有写入权限,所以导致异常的发生。他提供的解决方法为:放开 hadoop 目录的权限 , 命令如下 :$ hadoop fs -chmod 777 /user/hadoop  


posted @ 2011-10-28 16:37 十年一贱 阅读(...) 评论(...) 编辑 收藏