Hive整合MySQL

安装MySQL

1）上传MySQL安装包以及MySQL驱动jar包

2）解压MySQL安装包

3）卸载系统自带的mariadb

1）用刚刚查到的密码进入MySQL（如果报错，给密码加单引号）

2）设置复杂密码（由于MySQL密码策略，此密码必须足够复杂）

7）修改user表，把Host表内容修改为%

Hive整合MySQL

安装MySQL

1）上传MySQL安装包以及MySQL驱动jar包

mysql-5.7.28-1.el7.x86_64.rpm-bundle.tar
mysql-connector-java-5.1.37.jar

2）解压MySQL安装包

[lzl@hadoop12software]$ mkdir mysql_lib
[lzl@hadoop12software]$ tar -xf mysql-5.7.28-1.el7.x86_64.rpm-bundle.tar -C mysql_lib/

3）卸载系统自带的mariadb

[lzl@hadoop12~]$ sudo rpm -qa | grep mariadb | xargs sudo rpm -e --nodeps

4）安装MySQL依赖

[lzl@hadoop12software]$ cd mysql_lib
[lzl@hadoop12mysql_lib]$ sudo rpm -ivh mysql-community-common-5.7.28-1.el7.x86_64.rpm
[lzl@hadoop12mysql_lib]$ sudo rpm -ivh mysql-community-libs-5.7.28-1.el7.x86_64.rpm
[lzl@hadoop12mysql_lib]$ sudo rpm -ivh mysql-community-libs-compat-5.7.28-1.el7.x86_64.rpm

5）安装mysql-client

[lzl@hadoop12mysql_lib]$ sudo rpm -ivh mysql-community-client-5.7.28-1.el7.x86_64.rpm

6）安装mysql-server

[lzl@hadoop12mysql_lib]$ sudo rpm -ivh mysql-community-server-5.7.28-1.el7.x86_64.rpm

注意：若出现以下错误

warning: 05_mysql-community-server-5.7.16-1.el7.x86_64.rpm: Header V3 DSA/SHA1 Signature, key ID 5072e1f5: NOKEY
error: Failed dependencies:
libaio.so.1()(64bit) is needed by mysql-community-server-5.7.16-1.el7.x86_64

解决办法：

[lzl@hadoop12software]$ sudo yum -y install libaio

7）启动MySQL

[lzl@hadoop12software]$ sudo systemctl start mysqld

8）查看MySQL密码

[lzl@hadoop12software]$ sudo cat /var/log/mysqld.log | grep password

配置MySQL

配置主要是root用户 + 密码，在任何主机上都能登录MySQL数据库。

1）用刚刚查到的密码进入MySQL（如果报错，给密码加单引号）

[lzl@hadoop12software]$ mysql -uroot -p'password'

2）设置复杂密码（由于MySQL密码策略，此密码必须足够复杂）

mysql> set password=password("Qs23=zs32");

3）更改MySQL密码策略

mysql> set global validate_password_policy=0;
mysql> set global validate_password_length=4;

4）设置简单好记的密码

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mysql> set password=password("123456");

5）进入MySQL库

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mysql> use mysql

6）查询user表

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mysql> select user, host from user;

7）修改user表，把Host表内容修改为%

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mysql> update user set host="%" where user="root";

8）刷新

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mysql> flush privileges;

9）退出

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mysql> quit;

卸载MySQL说明

若因为安装失败或者其他原因，MySQL需要卸载重装，可参考以下内容。

清空原有数据

通过/etc/my.cnf查看MySQL数据的存储位置

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[lzl@hadoop12software]$ sudo cat /etc/my.cnf

[mysqld]
datadir=/var/lib/mysql

去往/var/lib/mysql路径需要root权限

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[lzl@hadoop12mysql]$ su - root
[root@hadoop12~]# cd /var/lib/mysql
[root@hadoop12mysql]# rm -rf *

卸载MySQL相关包

查看安装过的MySQL相关包

1[lzl@hadoop12software]$ sudo rpm -qa | grep -i -E mysql

输出示例：

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mysql-community-libs-5.7.16-1.el7.x86_64
mysql-community-client-5.7.16-1.el7.x86_64
mysql-community-common-5.7.16-1.el7.x86_64
mysql-community-libs-compat-5.7.16-1.el7.x86_64
mysql-community-server-5.7.16-1.el7.x86_64

一键卸载命令

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[lzl@hadoop12software]$ rpm -qa | grep -i -E mysql\|mariadb | xargs -n1 sudo rpm -e --nodeps

配置Hive元数据存储到MySQL

配置元数据到MySQL

新建Hive元数据库

登录MySQL

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[lzl@hadoop12software]$ mysql -uroot -p123456

创建Hive元数据库

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mysql> create database metastore;
mysql> quit;

将MySQL的JDBC驱动拷贝到Hive的lib目录下

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[lzl@hadoop12software]$ cp /opt/software/mysql-connector-java-5.1.37.jar $HIVE_HOME/lib

在$HIVE_HOME/conf目录下新建hive-site.xml文件

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[lzl@hadoop12software]$ vim $HIVE_HOME/conf/hive-site.xml

添加如下内容：

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<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>

<configuration>
  
  <!-- jdbc连接的URL -->
  <property>
    <name>javax.jdo.option.ConnectionURL</name>
    <value>jdbc:mysql://hadoop12:3306/metastore?useSSL=false</value>
  </property>
  
  <!-- jdbc连接的Driver -->
  <property>
    <name>javax.jdo.option.ConnectionDriverName</name>
    <value>com.mysql.jdbc.Driver</value>
  </property>
  
  <!-- jdbc连接的username -->
  <property>
    <name>javax.jdo.option.ConnectionUserName</name>
    <value>root</value>
  </property>
  
  <!-- jdbc连接的password -->
  <property>
    <name>javax.jdo.option.ConnectionPassword</name>
    <value>123456</value>
  </property>
  
  <!-- Hive默认在HDFS的工作目录 -->
  <property>
    <name>hive.metastore.warehouse.dir</name>
    <value>/user/hive/warehouse</value>
  </property>
</configuration>

初始化Hive元数据库（修改为采用MySQL存储元数据）
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```
[lzl@hadoop12hive]$ bin/schematool -dbType mysql -initSchema -verbose
```

验证元数据是否配置成功

再次启动Hive
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```
[lzl@hadoop12hive]$ bin/hive
```

使用Hive

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hive> show databases;
hive> show tables;
hive> create table stu(id int, name string);
hive> insert into stu values(1,"ss");
hive> select * from stu;

在Xshell窗口中开启另一个窗口开启Hive（两个窗口都可以操作Hive，没有出现异常）
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```
hive> show databases;
hive> show tables;
hive> select * from stu;
```

查看MySQL中的元数据

登录MySQL

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[lzl@hadoop12hive]$ mysql -uroot -p123456

查看元数据库metastore

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mysql> show databases;
mysql> use metastore;
mysql> show tables;

查看元数据库中存储的库信息

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mysql> select * from DBS;
+-------+-----------------------+-------------------------------------------+---------+------------+------------+-----------+
| DB_ID | DESC          | DB_LOCATION_URI              | NAME   | OWNER_NAME | OWNER_TYPE | CTLG_NAME |
+-------+-----------------------+-------------------------------------------+---------+------------+------------+-----------+
|   1 | Default Hive database | hdfs://hadoop12:8020/user/hive/warehouse | default | public   | ROLE    | hive    |
+-------+-----------------------+-------------------------------------------+---------+------------+------------+-----------+

查看元数据库中存储的表信息

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mysql> select * from TBLS;
+--------+-------------+-------+------------------+---------+------------+-----------+-------+----------+---------------+
| TBL_ID | CREATE_TIME | DB_ID | LAST_ACCESS_TIME | OWNER  | OWNER_TYPE | RETENTION | SD_ID | TBL_NAME | TBL_TYPE    | 
+--------+-------------+-------+------------------+---------+------------+-----------+-------+----------+---------------+
|    1 |  1656318303 |   1 |         0 | lzl | USER    |     0 |   1 | stu    | MANAGED_TABLE |
+--------+-------------+-------+------------------+---------+------------+-----------+-------+----------+---------------+

查看元数据库中存储的表中列相关信息

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mysql> select * from COLUMNS_V2;
+-------+----------+---------+------------+-------------+-------------+--------+
| CS_ID | CAT_NAME | DB_NAME | TABLE_NAME | COLUMN_NAME | COLUMN_TYPE | TBL_ID |
+-------+----------+---------+------------+-------------+-------------+--------+
|   1 | hive   | default | stu     | id      | int     |    1 |
|   2 | hive   | default | stu     | name     | string    |    1 |
+-------+----------+---------+------------+-------------+-------------+--------+