在python pydoop程序中找不到HADOOP_CONF_DIR错误

Question

我正在使用Pydoop连接到python程序内的hdfs文件系统。 这个python程序尝试在hdfs中读/写文件。 当我尝试执行时，我收到错误。

用于执行的命令：命令：

hadoop jar /usr/share/bigdata/hadoop-1.2.0/contrib/streaming/hadoop-streaming-1.2.0.jar -file ./Methratio.py -mapper './Methratio.py  -d /user/hadoop/gnome.fa -r -g  -o hdfs://ai-ole6-main.ole6.com:54311/user/hadoop/bsmapout.txt hdfs://ai-ole6-main.ole6.com:54311/user/hadoop/Example.bam ' -input sampleinput.txt -output outfile

错误 ：

Traceback（最近一次调用最后一次）：

  File "/tmp/hadoop-hadoop/mapred/local/taskTracker/hadoop/jobcache/job_201501251859_0001/attempt_201501251859_0001_m_000000_1/work/./Methratio.py", line 2, in <module>
    import sys, time, os, array, optparse,pydoop.hdfs as hdfs
  File "/usr/local/lib/python2.7/site-packages/pydoop-1.0.0_rc1-py2.7.egg/pydoop/hdfs/__init__.py", line 98, in <module>
    init()
  File "/usr/local/lib/python2.7/site-packages/pydoop-1.0.0_rc1-py2.7.egg/pydoop/hdfs/__init__.py", line 92, in init
    pydoop.hadoop_classpath(), _ORIG_CLASSPATH, pydoop.hadoop_conf()
  File "/usr/local/lib/python2.7/site-packages/pydoop-1.0.0_rc1-py2.7.egg/pydoop/__init__.py", line 103, in hadoop_classpath
    return _PATH_FINDER.hadoop_classpath(hadoop_home)
  File "/usr/local/lib/python2.7/site-packages/pydoop-1.0.0_rc1-py2.7.egg/pydoop/hadoop_utils.py", line 551, in hadoop_classpath
    jars.extend([self.hadoop_native(), self.hadoop_conf()])
  File "/usr/local/lib/python2.7/site-packages/pydoop-1.0.0_rc1-py2.7.egg/pydoop/hadoop_utils.py", line 493, in hadoop_conf
    PathFinder.__error("hadoop conf dir", "HADOOP_CONF_DIR")
  File "/usr/local/lib/python2.7/site-packages/pydoop-1.0.0_rc1-py2.7.egg/pydoop/hadoop_utils.py", line 385, in __error
    raise ValueError("%s not found, try setting %s" % (what, env_var))
ValueError: hadoop conf dir not found, try setting HADOOP_CONF_DIR
java.lang.RuntimeException: PipeMapRed.waitOutputThreads(): subprocess failed with code 1
    at org.apache.hadoop.streaming.PipeMapRed.waitOutputThreads(PipeMapRed.java:362)
    at org.apache.hadoop.streaming.PipeMapRed.mapRedFinished(PipeMapRed.java:576)
    at org.apache.hadoop.streaming.PipeMapper.close(PipeMapper.java:135)
    at org.apache.hadoop.mapred.MapRunner.run(MapRunner.java:57)
    at org.apache.hadoop.streaming.PipeMapRunner.run(PipeMapRunner.java:36)
    at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:430)
    at org.apache.hadoop.mapred.MapTask.run(MapTask.java:366)
    at org.apache.hadoop.mapred.Child$4.run(Child.java:255)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.security.auth.Subject.doAs(Subject.java:415)
    at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1190)
    at org.apache.hadoop.mapred.Child.main(Child.java:249)

编码 ：

with hdfs.open(options.reffile) as hdfsfile:
    for line in hdfsfile.open(options.reffile):
        if line[0] == '>': 
        #some processing

Answer 1

必须将HADOOP_CONF_DIR环境变量设置为适当的位置，即包含core-site.xml，mapred-site.xml，hdfs-site.xml等文件的文件夹的路径。通常这些文件可以在hadoop / etc /文件夹中找到。
在我的例子中，我从tarball安装了Hadoop 2.6并将解压缩的文件夹放在/ usr / local中。
我在〜/ .bashrc中添加了以下行
export HADOOP_CONF_DIR=/usr/local/hadoop/etc/hadoop
然后从终端给出命令source ~/.bashrc 。