java架构之路（Sharding JDBC）mysql5.7yum安装和主从

安装mysql5.7单机

1.获取安装yum包

[root@iZm5e7sz135n16ua2rmbk6Z local]# wget http://dev.mysql.com/get/mysql57-community-release-el7-11.noarch.rpm

 你可以下载到你的本地，然后上传到linux某目录下

2.安装软件源，在其目录下输入

[root@iZm5e7sz135n16ua2rmbk6Z local]# rpm -Uvh mysql57-community-release-el7-11.noarch.rpm 

3.安装mysql服务端

[root@iZm5e7sz135n16ua2rmbk6Z local]# yum install -y mysql-community-server

4.启动mysql

[root@iZm5e7sz135n16ua2rmbk6Z local]# service mysqld start
Redirecting to /bin/systemctl start mysqld.service

5.查看mysql运行状态

[root@iZm5e7sz135n16ua2rmbk6Z local]# service mysqld status
Redirecting to /bin/systemctl status mysqld.service
● mysqld.service - MySQL Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
   Active: active (running) since Sun 2019-11-24 14:45:59 CST; 20s ago
     Docs: man:mysqld(8)
           http://dev.mysql.com/doc/refman/en/using-systemd.html
  Process: 14787 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid $MYSQLD_OPTS (code=exited, status=0/SUCCESS)
  Process: 14667 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
 Main PID: 14791 (mysqld)
   CGroup: /system.slice/mysqld.service
           └─14791 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid

Nov 24 14:45:55 iZm5e7sz135n16ua2rmbk6Z systemd[1]: Starting MySQL Server...
Nov 24 14:45:59 iZm5e7sz135n16ua2rmbk6Z systemd[1]: Started MySQL Server.

 6.初始化密码

[root@iZm5e7sz135n16ua2rmbk6Z local]# grep 'temporary password' /var/log/mysqld.log
2019-11-24T06:45:56.831037Z 1 [Note] A temporary password is generated for root@localhost: -cTy=VNwI7!H
[root@iZm5e7sz135n16ua2rmbk6Z local]# 

每个人都不一样，别复制我的。输入mysql -uroot -p，然后输入你的密码进入

[root@iZm5e7sz135n16ua2rmbk6Z local]# mysql -uroot -p
Enter password:  -cTy=VNwI7!H
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.28

Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> 

mysql> alter user 'root'@'localhost' identified by '%liX9-k';//由于5.7有策略限制，我们先随便改一个复杂的密码。
Query OK, 0 rows affected (0.00 sec)

mysql> SHOW VARIABLES LIKE 'validate_password%';//查看密码策略
+--------------------------------------+--------+
| Variable_name                        | Value  |
+--------------------------------------+--------+
| validate_password_check_user_name    | OFF    |
| validate_password_dictionary_file    |        |
| validate_password_length             | 8      |
| validate_password_mixed_case_count   | 1      |
| validate_password_number_count       | 1      |
| validate_password_policy             | MEDIUM |
| validate_password_special_char_count | 1      |
+--------------------------------------+--------+
7 rows in set (0.00 sec)

mysql> 

mysql> set global validate_password_policy=LOW;//修改限制策略
Query OK, 0 rows affected (0.00 sec)

mysql> set global validate_password_length=1;//修改密码长度
Query OK, 0 rows affected (0.00 sec)

mysql> alter user 'root'@'localhost' identified by '123456';//修改一个简单的密码(练习方便,实际不建议这样做)
Query OK, 0 rows affected (0.00 sec)

mysql> update mysql.user set host = '%' where user = 'root';//允许远程访问DB
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> FLUSH PRIVILEGES;//刷新权限
Query OK, 0 rows affected (0.00 sec)

到这里就可以了,反正我是按照上面的代码复制粘贴完全可以成功,不知道你们可以吗?

mysql的主从配置

 　　这里我给大家搭建一个简单的主从(从)配置,就是说一个主节点对应一个从节点,那个从节点下还有一个从节点.

 1.准备三台服务器,分别安装一下mysql,按照上面的按照就可以的.

 2.编辑master配置文件

[root@iZm5eitsswnra4j66dzb9nZ ~]# vim /etc/my.cnf

log-bin=/usr/local/mysql/data/binlog/mysql_bin #打开Mysql日志，日志格式为二进制 mysq_bin结尾是固定的别改，前面是路径
server-id=1 #[必须]服务器唯一ID，默认是1
sync-binlog=1 #每次执行写入就与硬盘同步
binlog-do-db=xiaocaijishu #需要同步的二进制数据库名 
expire-logs-days=7 #只保留7天的二进制日志，以防磁盘被日志占满
binlog-ignore-db=information_schema #不备份的数据库
binlog-ignore-db=performation_schema #不备份的数据库
binlog-ignore-db=sys #不备份的数据库

　　重启mysql-master，可能会启动失败，是由于mysql的binlog的用户组不对，再来改一下用户组，以我们的/usr/local/mysql/data/binlog为例

[root@iZbp1hvg9qhaf4c75o2k58Z binlog]# chown -R mysql /usr/local/mysql/data/binlog/

[root@iZbp1hvg9qhaf4c75o2k58Z binlog]# chgrp -R mysql /usr/local/mysql/data/binlog/

 3.设置一个同步账号

mysql> CREATE USER 'xiaocaijishu'@'47.105.%.%' IDENTIFIED BY '123456'; // 设置账号xiaocaijishu用于47.105等IP地址的mysql同步,你可以直接写%全匹配
Query OK, 0 rows affected (0.00 sec)

mysql> grant replication slave,replication client on *.* to xiaocaijishu@'47.105.%.%' identified by 'root';//赋予权限
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> FLUSH PRIVILEGES; //刷新权限
Query OK, 0 rows affected (0.00 sec)

4.设置slave节点配置文件

server-id=2 #[必须]服务器唯一ID，默认是1
relay_log = /usr/local/mysql/data/binlog/mysql_relay_bin # 开启中继日志
read_only = 1               #设置只读权限
log_bin=/usr/local/mysql/data/binlog/mysql_bin # 开启binlog，如果没有下级节点无须开启。
log_slave_updates = 1       #使得更新的数据写进二进制日志中 
replicate-rewrite-db = xiaocaijishu -> xiaocai # 从主节点的xiaocaijishu库写入到从节点的xiaocai库
# replicate-wild-do-table 指定需要同步的表。

 5.查找主节点日志

mysql>  show master status;
+------------------+----------+--------------+--------------------------------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB                           | Executed_Gtid_Set |
+------------------+----------+--------------+--------------------------------------------+-------------------+
| mysql_bin.000001 |     1349 | xiaocaijishu | information_schema,performation_schema,sys |                   |
+------------------+----------+--------------+--------------------------------------------+-------------------+
1 row in set (0.00 sec)

 6.创建主从连接

　　首先我们进入进入mysql客户端，然后输入

mysql> change master to master_host='121.41.60.188',master_user='xiaocaijishu',master_password='123456',master_log_file='mysql_bin.000001',master_log_pos=1349;
Query OK, 0 rows affected, 2 warnings (0.01 sec)

意思是master_host=“我们的主节点IP”，master_user=“刚才创建的主节点用户”，master_password=“账户密码”，master_log_file=“需要从哪个二进制binlog复制”，master_log_pos=“对应主节点的Position”

如遇报错请先输入

mysql> stop slave;
Query OK, 0 rows affected (0.00 sec)

然后输入start slave开启线程

mysql> start slave;
Query OK, 0 rows affected (0.00 sec)

输入SHOW SLAVE STATUS\G检查线程是否创建成功

 如果看到上面的那个Yes，就说明主从搭建完成了，如果下面还有搭建从节点，开启binlog，和上面一个道理。

 如果遇到

Last_Errno: 1051                    
Last_Error: Error 'Unknown table 'xiaocai.student'' on query. Default database: 'xiaocai'. Query: 'DROP TABLE `student` /* generated by server */'

　可以尝试下面的解决方式来处理。

mysql> stop slave;
Query OK, 0 rows affected (0.01 sec)
mysql> set GLOBAL SQL_SLAVE_SKIP_COUNTER=1;
Query OK, 0 rows affected (0.00 sec)
mysql> start slave;
Query OK, 0 rows affected (0.01 sec)