hadoop@master:/usr/lib/jvm/java/bin$ jps
The program 'jps' can be found in the following packages:
* openjdk-7-jdk
* openjdk-6-jdk
Ask your administrator to install one of them
明明都安装了jdk，而且环境变量也没有出现路径错误，为什么就是找不到jps命令呢？结果还是要用update-alternative命令来解决这个问题
hadoop@master:/usr/lib/jvm/java/bin$ sudo update-alternatives --install /usr/bin/jps jps /usr/lib/jvm/java/bin/jps 1
update-alternatives: using /usr/lib/jvm/java/bin/jps to provide /usr/bin/jps (jps) in auto mode
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