hadoop /usr/bin/env: python: No such file or direc

Question

I am trying to run a hadoop streaming server with following command from a shell script

hadoop jar /usr/local/hadoop/contrib/streaming/hadoop-0.19.2-streaming.jar -input $1 -output Twitter/Net.pegasus -mapper 'mapper.py Reverse' -reducer NONE -file mapper.py
hadoop jar /usr/local/hadoop/contrib/streaming/hadoop-0.19.2-streaming.jar -input $1 -output Twitter/Net.exclude -mapper 'mapper.py Reverse' -reducer reducer.py -file mapper.py -file reducer.py -file ../twitter/exclude.txt
hadoop jar /usr/local/hadoop/contrib/streaming/hadoop-0.19.2-streaming.jar -input $1 -output Twitter/Net.complete -mapper 'mapper.py Reverse' -reducer reducer.py -file mapper.py -file reducer.py

I am getting following error

/usr/bin/env: python2.5: No such file or directory
java.lang.RuntimeException: PipeMapRed.waitOutputThreads(): subprocess failed with code 127
    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:436)
    at org.apache.hadoop.mapred.MapTask.run(MapTask.java:372)
    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:1136)
    at org.apache.hadoop.mapred.Child.main(Child.java:249)

However the higher version of python is already installed

$ which python
/usr/bin/python
$ python --version
Python 2.7.3

I read on some other post that by "apt-get install python2.5" it will work but that package isnt available and I also tried adding #!/usr/bin/env python to the top of my python script and it didnt work either

Hadoop Streaming Job failed error in python

Answer 1

$ which python
/usr/bin/python
$ python --version
Python 2.7.3

Indicate you have a higher version of Python installed than default. You have to make sure this is the same case for every node in the cluster. For example, I work with a cluster Redhat 6.4 version cluster and the default Python is Python 2.6 I think as default, but I have customized the master node a bit and it is different from the datanode. So you need to configure your mapper to call a python that exist on every node.

put

#!/usr/bin/python

at the beginning of the python script always work for me.