Hadoop : JPS can not find Java installed

Question

my configurations are

hduser@worker1:/usr/local/hadoop/conf$ jps
The program \'jps\' can be found in the following packages:
 * openjdk-6-jdk
 * openjdk-7-jd         


        

Answer 1

I have found the solution for the missing JPS command. I was installing Hadoop 1.x on ubuntu machine in a pseudo distributed mode. I used Java-7-openJDK to provide for the Java commands and tools. For some reason there was a java-1.6.0-openjdk-devel for version 6 but none for version 7 specifically debian and ubuntu distributions. I am not sure if the same is true for Fedora and Redhat. So the best answer as that time was using the linux command

ps -aux | grep java

I hated doing that because Hadoop daemons start with so many options that each result fills up more than a screen. Apart from seeing that java is running it is impossible to see what hadoop daemons are running. Hence i came up with a short soultion in the form of one line shell script

This is my JPS scirpt for open JDK

!#/bin/bash

ps -aux | grep java | awk '{print $12}'

END

I saved these two lines in a file named jps and stored it in the hadoop/bin directory with execute permissions

**Here is the result of the script hduser@localhsot# ./jps

-Dproc-namenode

-Dproc-datanode

-Dproc-JobTracker

-Dproc-TaskTracker**