Hadoop技术原理:
Hdfs主要模块:NameNode、DataNode
Yarn主要模块:ResourceManager、NodeManager
HDFS主要模块及运行原理:
1)NameNode:
功能:是整个文件系统的管理节点。维护整个文件系统的文件目录树,文件/目录的元数据和
每个文件对应的数据块列表。接收用户的请求。
2)DataNode:
功能:是HA(高可用性)的一个解决方案,是备用镜像,但不支持热备
一、hadoop单机版测试
1.创建用户并安装
[root@server1 ~]# ls
anaconda-ks.cfg hadoop-3.0.3.tar.gz jdk-8u181-linux-x64.tar.gz
[root@server1 ~]# useradd -u 1000 hadoop
[root@server1 ~]# passwd hadoop
Changing password for user hadoop.
New password:
BAD PASSWORD: The password is shorter than 8 characters
Retype new password:
passwd: all authentication tokens updated successfully.
[root@server1 ~]# mv hadoop-3.0.3.tar.gz jdk-8u181-linux-x64.tar.gz /home/hadoop/
[root@server1 ~]# su - hadoop
[hadoop@server1 ~]$ ls
hadoop-3.0.3.tar.gz jdk-8u181-linux-x64.tar.gz
[hadoop@server1 ~]$ tar zxf jdk-8u181-linux-x64.tar.gz
[hadoop@server1 ~]$ ls
hadoop-3.0.3.tar.gz jdk1.8.0_181 jdk-8u181-linux-x64.tar.gz
[hadoop@server1 ~]$ ln -s jdk1.8.0_181/ java
[hadoop@server1 ~]$ tar zxf hadoop-3.0.3.tar.gz
[hadoop@server1 ~]$ ls
hadoop-3.0.3 java jdk-8u181-linux-x64.tar.gz
hadoop-3.0.3.tar.gz jdk1.8.0_181
[hadoop@server1 ~]$ ln -s hadoop-3.0.3 hadoop
[hadoop@server1 ~]$ ls
hadoop hadoop-3.0.3.tar.gz jdk1.8.0_181
hadoop-3.0.3 java jdk-8u181-linux-x64.tar.gz
2、配置环境变量
[hadoop@server1 hadoop]$ cd /home/hadoop/hadoop/etc/hadoop/
[hadoop@server1 hadoop]$ pwd
/home/hadoop/hadoop/etc/hadoop
[hadoop@server1 hadoop]$ vim hadoop-env.sh
[hadoop@server1 hadoop]$ cd
[hadoop@server1 ~]$ vim .bash_profile
3、测试
[hadoop@server1 ~]$ source .bash_profile
[hadoop@server1 ~]$ jps
942 Jps
[hadoop@server1 ~]$ cd /home/hadoop/hadoop
[hadoop@server1 hadoop]$ pwd
/home/hadoop/hadoop
[hadoop@server1 hadoop]$ mkdir input
[hadoop@server1 hadoop]$ cp etc/hadoop/*.xml input/
[hadoop@server1 hadoop]$ bin/hadoop jar share/hadoop/mapreduce/hadoop-mapreduce-examples-3.0.3.jar grep input output 'dfs[a-z.]+'
[hadoop@server1 hadoop]$ cd output/
[hadoop@server1 output]$ ls
part-r-00000 _SUCCESS
[hadoop@server1 output]$ cat *
1 dfsadmin
二、伪分布式
1.编辑文件
[hadoop@server1 output]$ cd /home/hadoop/hadoop/etc/hadoop/
[hadoop@server1 hadoop]$ pwd
/home/hadoop/hadoop/etc/hadoop
[hadoop@server1 hadoop]$ vim core-site.xml
[hadoop@server1 hadoop]$ vim hdfs-site.xml
2.生成密钥做免密连接
[hadoop@server1 sbin]$ ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/home/hadoop/.ssh/id_rsa):
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:
8e:f1:1d:4e:29:e2:56:eb:42:4f:79:f2:f3:89:42:69 hadoop@server1
The key's randomart image is:
+--[ RSA 2048]----+
| |
| |
| |
| . |
| o So+ |
| ..BE*.. |
| .+=++o |
| ...o o. . |
| ....oo |
+-----------------+
[hadoop@server1 sbin]$ ssh-copy-id localhost
/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
hadoop@localhost's password:
Number of key(s) added: 1
Now try logging into the machine, with: "ssh 'localhost'"
and check to make sure that only the key(s) you wanted were added.
3.格式化并开启服务
[hadoop@server1 hadoop]$ bin/hdfs namenode -format
[hadoop@server1 hadoop]$ pwd
/home/hadoop/hadoop
[hadoop@server1 sbin]$ ./start-dfs.sh
Starting namenodes on [localhost]
Starting datanodes
Starting secondary namenodes [server1]
[hadoop@server1 sbin]$ jps
11060 NameNode
11159 DataNode
11341 SecondaryNameNode
11485 Jps
4.浏览器查看
5.测试,创建目录,并上传
[hadoop@server1 hadoop]$ bin/hdfs dfs -mkdir -p /user/hadoop
[hadoop@server1 hadoop]$ bin/hdfs dfs -ls
[hadoop@server1 hadoop]$ bin/hdfs dfs -put input
[hadoop@server1 hadoop]$ bin/hdfs dfs -ls
Found 1 items
drwxr-xr-x - hadoop supergroup 0 2019-05-19 01:47 input
6. 删除input和output文件,重新执行命令
[hadoop@server1 hadoop]$ rm -fr input/ output/
[hadoop@server1 hadoop]$ bin/hadoop jar share/hadoop/mapreduce/hadoop-mapreduce-examples-3.0.3.jar grep input output 'dfs[a-z.]+'
[hadoop@server1 hadoop]$ ls
bin etc include lib libexec LICENSE.txt logs NOTICE.txt README.txt sbin share
此时input和output不会出现在当前目录下,而是上传到了分布式文件系统中,网页上可以看到
[hadoop@server1 hadoop]$ bin/hdfs dfs -cat output/*
1 dfsadmin
[hadoop@server1 hadoop]$ bin/hdfs dfs -get output ##从分布式系统中get下来output目录
[hadoop@server1 hadoop]$ cd output/
[hadoop@server1 output]$ ls
part-r-00000 _SUCCESS
三、分布式
1.先停掉服务,清除原来的数据
[hadoop@server1 hadoop]$ sbin/stop-dfs.sh
Stopping namenodes on [localhost]
Stopping datanodes
Stopping secondary namenodes [server1]
[hadoop@server1 hadoop]$ cd /tmp/
[hadoop@server1 tmp]$ ls
hadoop hadoop-hadoop hsperfdata_hadoop
[hadoop@server1 tmp]$ rm -fr *
2.新开两个虚拟机,当做节点
创建用户
[root@server2 ~]# useradd -u 1000 hadoop
[root@server3 ~]# useradd -u 1000 hadoop
安装nfs-utils
[root@server1 ~]# yum install -y nfs-utils
[root@server2 ~]# yum install -y nfs-utils
[root@server3 ~]# yum install -y nfs-utils
[root@server1 ~]# systemctl start rpcbind
[root@server2 ~]# systemctl start rpcbind
[root@server3 ~]# systemctl start rpcbind
3.server1开启服务,配置
[root@server1 ~]# systemctl start nfs-server
[root@server1 ~]# vim /etc/exports
/home/hadoop *(rw,anonuid=1000,anongid=1000)
[root@server1 ~]# exportfs -rv
exporting *:/home/hadoop
[root@server1 ~]# showmount -e
Export list for server1:
/home/hadoop *
4.server2,3挂载
[root@server2 ~]# vim /etc/hosts
[root@server2 ~]# mount 172.25.11.1:/home/hadoop /home/hadoop
[root@server2 ~]# df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sda3 18351104 1092520 17258584 6% /
devtmpfs 498480 0 498480 0% /dev
tmpfs 508264 0 508264 0% /dev/shm
tmpfs 508264 6736 501528 2% /run
tmpfs 508264 0 508264 0% /sys/fs/cgroup
/dev/sda1 508580 110596 397984 22% /boot
tmpfs 101656 0 101656 0% /run/user/0
172.25.11.1:/home/hadoop 18351104 2790656 15560448 16% /home/hadoop
[root@server3 ~]# mount 172.25.11.1:/home/hadoop /home/hadoop
[root@server3 ~]# df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sda3 18351104 1092468 17258636 6% /
devtmpfs 498480 0 498480 0% /dev
tmpfs 508264 0 508264 0% /dev/shm
tmpfs 508264 6736 501528 2% /run
tmpfs 508264 0 508264 0% /sys/fs/cgroup
/dev/sda1 508580 110596 397984 22% /boot
tmpfs 101656 0 101656 0% /run/user/0
172.25.11.1:/home/hadoop 18351104 2790656 15560448 16% /home/hadoop
此时使用hadoop用户时可以直接从server1登陆到server2和server3的
5.重新编辑文件
[root@server1 hadoop]# pwd
/home/hadoop/hadoop/etc/hadoop
[root@server1 hadoop]# vim core-site.xml
<configuration>
<property>
<name>fs.defaultFS</name>
<value>hdfs://172.25.11.1:9000</value>
</property>
</configuration>
[root@server1 hadoop]# vim hdfs-site.xml
<configuration>
<property>
<name>dfs.replication</name>
<value>2</value> ##改为两个节点
</property>
</configuration>
[root@server1 hadoop]# vim workers
[root@server1 hadoop]# cat workers
172.25.11.2
172.25.11.3
在一个地方编辑,其他节点都有了
[hadoop@server2 hadoop]$ cat workers
172.25.11.2
172.25.11.3
[root@server3 ~]# cat /home/hadoop/hadoop/etc/hadoop/workers
172.25.11.2
172.25.11.3
6.格式化,并启动服务
[hadoop@server1 hadoop]$ pwd
/home/hadoop/hadoop
[hadoop@server1 hadoop]$ bin/hdfs namenode -format
[hadoop@server1 hadoop]$ sbin/start-dfs.sh
Starting namenodes on [server1]
Starting datanodes
172.25.11.2: Warning: Permanently added '172.25.11.2' (ECDSA) to the list of known hosts.
172.25.11.3: Warning: Permanently added '172.25.11.3' (ECDSA) to the list of known hosts.
Starting secondary namenodes [server1]
[hadoop@server1 hadoop]$ sbin/start-dfs.sh
Starting namenodes on [server1]
Starting datanodes
Starting secondary namenodes [server1]
[hadoop@server1 hadoop]$ vim /etc/hosts
[hadoop@server1 hadoop]$ vim /etc/hosts
[hadoop@server1 hadoop]$ jps
14000 SecondaryNameNode ##生成SecondaryNameNode
13814 NameNode
14153 Jps
从节点可以看到datanode信息
[hadoop@server2 ~]$ jps
10336 Jps
10273 DataNode
[hadoop@server3 ~]$ jps
1141 DataNode
1230 Jps
7.测试
[hadoop@server1 hadoop]$ bin/hdfs dfs -mkdir -p /user/hadoop
[hadoop@server1 hadoop]$ bin/hdfs dfs -mkdir input
[hadoop@server1 hadoop]$ bin/hdfs dfs -put etc/hadoop/*.xml input
[hadoop@server1 hadoop]$ bin/hadoop jar share/hadoop/mapreduce/hadoop-mapreduce-examples-3.0.3.jar grep input output 'dfs[a-z.]+'
8.网页上查看,有两个节点,且数据已经上传
9.server4模拟客户端
[root@server4 ~]# useradd -u 1000 hadoop
[root@server4 ~]# vim /etc/hosts
[root@server4 ~]# yum install -y nfs-utils
[root@server4 ~]# systemctl start rpcbind
[root@server4 ~]# mount 172.25.11.1:/home/hadoop /home/hadoop
[root@server4 ~]# su - hadoop
[hadoop@server4 ~]$ cd /home/hadoop/hadoop/etc/hadoop/
[hadoop@server4 hadoop]$ vim workers
[hadoop@server4 hadoop]$ cat workers
172.25.11.2
172.25.11.3
172.25.11.4
[hadoop@server4 hadoop]$ sbin/hadoop-daemon.sh start
[hadoop@server4 hadoop]$ jps
2609 Jps
2594 DataNode
浏览器查看,节点添加成功
[hadoop@server4 hadoop]$ dd if=/dev/zero of=bigfile bs=1M count=500
500+0 records in
500+0 records out
524288000 bytes (524 MB) copied, 25.8653 s, 20.3 MB/s
[hadoop@server4 hadoop]$ bin/hdfs dfs -put bigfile
- 显示bigfile已经上传成功