Hadoop：
广义：以apache hadoop软件为主的生态圈（hive,zookeeper,spark,hbase）
狭义：apache hadoop软件
查询组件的官网：
hadoop.apache
hive.apache.org
spark.apache.org
hadoop软件有哪些组件：
hdfs:存储，分布式文件系统
mapreduce：计算
yarn：资源（cpu，memory）和作业调度
我所用的版本为 hadoop2.6.0-cdh5.7.0
cdh hadoop：http://archive.cloudera.com/cdh5/cdh/5/
可以通过wget上传：http://archive.cloudera.com/cdh5/cdh/5/hadoop-2.6.0-cdh5.7.0.tar.gz
1.创建用户和上传hadoop软件：
useradd hadoop
su - hadoop 切换用户
[hadoop@hadoop002 ~]$ mkdir app （需创建一个 app 文件夹 下存放hadoop软件）
[hadoop@hadoop002 ~]$ cd app/
[hadoop@hadoop002 ~]$ wget http://archive.cloudera.com/cdh5/cdh/5/hadoop-2.6.0-cdh5.7.0.tar.gz或
[hadoop@hadoop002 ~]$ rz 上传
2.部署jdk：
由于CDH环境的要求：jdk必须要部署在 /usr/java 目录下，否则会出现一些坑。
以后需要在/usr/shara/java 下部署CDH 需要的 mysql jdbc 的jar包
rz上传 jdk-8u45-linux-x64.gz
解压：
[root@hadoop002 java]# tar -xzvf jdk-8u45-linux-x64.gz
[root@hadoop002 java]# ll
total 319156
drwxr-xr-x 8 uucp 143 4096 Apr 11 2015 jdk1.8.0_45
-rw-r--r-- 1 root root 173271626 Sep 19 11:49 jdk-8u45-linux-x64.gz
注意：（解压之后会出现 jdk中的用户和用户组不对的情况，需要修改用户和用户组，这是查看 cat /etc/passwd，会发现有这两种形式：/bin/bash和/sbin/nologin，将用户的bash修改成nologin，用户就会无法登陆，
su - zookeeper切不了：This account is currently not available.
生产怎么做：/sbin/nologin --》 /bin/bash）
权限修正
[root@hadoop002 java]# chown -R root:root jdk1.8.0_45
[root@hadoop002 java]# ll
total 319156
drwxr-xr-x 8 root root 4096 Apr 11 2015 jdk1.8.0_45
-rw-r--r-- 1 root root 173271626 Sep 19 11:49 jdk-8u45-linux-x64.gz
配置环境变量：
[root@hadoop002 java]# vi /etc/profile
#env
export JAVA_HOME=/usr/java/jdk1.8.0_45
export JRE_HOME=$JAVA_HOME/jre
export CLASSPATH=.:$JAVA_HOME/lib:$JER_HOME/lib:$CLASSPATH
export PATH=$JAVA_HOME/bin:$JER_HOME/bin:$PATH
配置完成后 source /etc/peofile
3.解压hadoop：
3.解压hadoop
[hadoop@hadoop002 app]$ tar -xzvf hadoop-2.6.0-cdh5.7.0.tar.gz
[hadoop@hadoop002 app]$ cd hadoop-2.6.0-cdh5.7.0
[hadoop@hadoop002 hadoop-2.6.0-cdh5.7.0]$ ll
total 76
drwxr-xr-x 2 hadoop hadoop 4096 Mar 24 2016 bin 可执行脚本
drwxr-xr-x 2 hadoop hadoop 4096 Mar 24 2016 bin-mapreduce1
drwxr-xr-x 3 hadoop hadoop 4096 Mar 24 2016 cloudera
drwxr-xr-x 6 hadoop hadoop 4096 Mar 24 2016 etc 配置目录(conf)
drwxr-xr-x 5 hadoop hadoop 4096 Mar 24 2016 examples
drwxr-xr-x 3 hadoop hadoop 4096 Mar 24 2016 examples-mapreduce1
drwxr-xr-x 2 hadoop hadoop 4096 Mar 24 2016 include
drwxr-xr-x 3 hadoop hadoop 4096 Mar 24 2016 lib jar包目录
drwxr-xr-x 2 hadoop hadoop 4096 Mar 24 2016 libexec
drwxr-xr-x 3 hadoop hadoop 4096 Mar 24 2016 sbin hadoop组件的启动 停止脚本
drwxr-xr-x 4 hadoop hadoop 4096 Mar 24 2016 share
drwxr-xr-x 17 hadoop hadoop 4096 Mar 24 2016 src
4.修改配置文件信息Configuration：
Use the following:
etc/hadoop/core-site.xml:
<configuration>
<property>
<name>fs.defaultFS</name>
<value>hdfs://localhost:9000</value>
</property>
</configuration>
etc/hadoop/hdfs-site.xml:
<configuration>
<property>
<name>dfs.replication</name>
<value>1</value>
</property>
</configuration>
5.配置ssh localhost无密码信任关系：
> 这里要注意 我用的和官方的方法不一样
[hadoop@hadoop002 ~]$ ssh-keygen（密钥生成）
Generating public/private rsa key pair.（三下回车）
Enter file in which to save the key (/home/hadoop/.ssh/id_rsa):
Created directory '/home/hadoop/.ssh'.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/hadoop/.ssh/id_rsa.
Your public key has been saved in /home/hadoop/.ssh/id_rsa.pub.
The key fingerprint is:
ba:48:3d:ff:af:4d:da:74:67:31:d6:98:ad:a0:b3:76 hadoop@hadoop002
The key's randomart image is:
+--[ RSA 2048]----+
| |
| |
| |
| +.|
| S . o+o|
| . . . ...o|
| . + o o o o|
| . . + .OE. o |
| . . .o=++ |
+-----------------+
[hadoop@hadoop002 ~]$ cd .ssh
[hadoop@hadoop002 .ssh]$ ll
total 8
-rw------- 1 hadoop hadoop 1675 Feb 13 22:36 id_rsa 私钥
-rw-r--r-- 1 hadoop hadoop 398 Feb 13 22:36 id_rsa.pub 公钥
[hadoop@hadoop002 .ssh]$ cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys（将公钥放到认证文件中，来提供访问）
[hadoop@hadoop002 .ssh]$ ll
total 12
-rw-rw-r-- 1 hadoop hadoop 398 Feb 13 22:37 authorized_keys
-rw------- 1 hadoop hadoop 1675 Feb 13 22:36 id_rsa
-rw-r--r-- 1 hadoop hadoop 398 Feb 13 22:36 id_rsa.pub
-rw-r--r-- 1 hadoop hadoop 0 Feb 13 22:39 known_hosts
ssh localhost date 是需要输入密码，但是这个用户是没有配置密码。
我们应该在没有配置密码情况下去完成无密码信任呢？
将authorized_keys 权限修改成 640
[hadoop@hadoop002 .ssh]$ chmod 600 authorized_keys
[hadoop@hadoop002 .ssh]$ ssh localhost date
The authenticity of host 'localhost (127.0.0.1)' can't be established.
RSA key fingerprint is b1:94:33:ec:95:89:bf:06:3b:ef:30:2f:d7:8e:d2:4c.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'localhost' (RSA) to the list of known hosts.
Wed Feb 13 22:41:17 CST 2019
6.格式化：
[hadoop@hadoop002 hadoop-2.6.0-cdh5.7.0]$ bin/hdfs namenode -format
7.启动：
[hadoop@hadoop002 hadoop-2.6.0-cdh5.7.0]$ sbin/start-dfs.sh（启动）
19/02/13 22:57:23 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Starting namenodes on [localhost]
localhost: starting namenode, logging to /home/hadoop/app/hadoop-2.6.0-cdh5.7.0/logs/hadoop-hadoop-namenode-hadoop002.out
localhost: starting datanode, logging to /home/hadoop/app/hadoop-2.6.0-cdh5.7.0/logs/hadoop-hadoop-datanode-hadoop002.out
> ssh 信任关系 是配置localhost
Starting secondary namenodes [0.0.0.0]
0.0.0.0: starting secondarynamenode, logging to /home/hadoop/app/hadoop-2.6.0-cdh5.7.0/logs/hadoop-hadoop-secondarynamenode-hadoop002.out
19/02/13 22:57:38 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
[hadoop@hadoop002 hadoop-2.6.0-cdh5.7.0]$
[hadoop@hadoop002 hadoop-2.6.0-cdh5.7.0]$ jps
15059 Jps
14948 SecondaryNameNode 第二名称节点 老二
14783 DataNode 数据节点 小弟
14655 NameNode 名称节点 老大 读写
（必须保证这三个进程都有）
[hadoop@hadoop002 hadoop-2.6.0-cdh5.7.0]$
open http://ip:50070
8.配置环境变量：
[hadoop@hadoop002 hadoop-2.6.0-cdh5.7.0]$ vi ~/.bash_profile
# .bash_profile
# Get the aliases and functions
if [ -f ~/.bashrc ]; then
. ~/.bashrc
fi
# User specific environment and startup programs
export HADOOP_PREFIX=/home/hadoop/app/hadoop-2.6.0-cdh5.7.0
export PATH=$HADOOP_PREFIX/bin:$PATH
[hadoop@hadoop002 hadoop-2.6.0-cdh5.7.0]$
9.命令：
hdfs dfs -mkdir /ruozedate(在根目录下创建一个ruozedate文件夹)
hdfs dfs -ls /（查看根目录下文件或者文件夹）
10.如何查看命令帮助：
hdfs dfs