　　Previously installed Hadoop is followed by a detailed tutorial Xiamen woods filled with rain, so much the problems encountered, he did not how to think, lead to follow Hbase official website a lot of problems when the stand-alone configuration, remember now down to avoid future recidivism.

First, install the software first Tell me what network tutorial. However, the official website of the tutorial is very simple, such as Hadoop installation. Hadoop user is created by default; to hadoop rights; all are operating (or be wrong) at hadoop user; will update apt; will extract; will be equipped JAVA_HOME, will configure SSH-free secret landing. But I'm a white ah, do not understand, so check a lot of information. But these are Linux-based, I have to remember this.

First, create a user hadoop

1.1 hadoop user can create landing, and automatically create the user's login directory

sudo useradd -m hadoop

　　-m is automatically set up the user's login directory, log in as the new user will lose if you do not go wrong.

　　After user login shell specified -s used. The default is / bin / bash. (So you can not specify)

　　Other See Detailed useradd command:

https://www.cnblogs.com/irisrain/p/4324593.html

1.2 Set password, you can simply set hadoop, follow the prompts to enter the password twice

sudo passwd hadoop

　　sudo that allows ordinary users to have root privileges command, if the root is not necessary to lose

1.3 can increase hadoop administrator privileges to users, easy to deploy

sudo adduser hadoop sudo

Second, update apt

sudo apt-get update

Third, install SSH, configuration-free landing close

　　Xiamen cf official website tutorial tutorials, Xiamen University, said download ssh-server (first make sure your linux system has been installed ssh, only for ubuntu system is generally installed by default ssh client, so we also need to manually install ssh server)

The official website says install ssh (why? I do not know, but I believe the official website hhh)

So the installation process is:

sudo apt-get install ssh
sudo apt-get install pdsh

Configuration -free secret landing is:

First check what can you avoid secret:

ssh localhost

If not, using ssh-keygen generated key and the authorization key is added (refer to the official website)

ssh-keygen -t rsa -P '' -f ~/.ssh/id_rsa
cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys #加入授权
chmod 0600 ~/.ssh/authorized_keys               #啥意思？

Fourth, install the Java environment

4.1 apt fool install java

　　Press Options teacher seems to be the first to see the Java -version , no, the system prompts apt-install headlessjava getting better, and then install openjdk-8-jdk

apt install openjdk-8-jdk

11 seems to be disturbed because this is not wrong on hadoop3, stable

4.2 edit the current logged in user environment variable configuration file

vim ~/.bashrc

export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64

JAVA_HOME指明JDK安装路径，此路径下包括lib，bin，jre等文件夹
如果你不记得自己的JAVA在哪里，可以输 whereis java ，再翻文件夹到第一个不是快捷键的就是你java的位置啦！

4.3 Let environment variables to take effect immediately

　　Perform the following code:

source ~/.bashrc

4.4 Inspection

　　After executing the above command, you can check to see if settings are correct:

　　Etc. with a view java -version test it, so far, successfully installed the Java environment. Here you can enter the Hadoop installation.

echo $ JAVA_HOME      # test variable value 
the Java - Version
 $ JAVA_HOME / bin / java -version   # and directly execute the same java -version

Recently installed Hadoop experiences

First, create a user hadoop

Second, update apt

Third, install SSH, configuration-free landing close

Fourth, install the Java environment

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