CentOS8配置MySQL双主互备（安装centos8及MySQL）

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1安装操作系统centos8及配置

启用SSH

1. 首先，要确保CentOS8安装了openssh-server，在终端中输入yum list installed | grep openssh-server
2. 如果又没任何输出显示表示没有安装openssh-server，输入 yum install openssh-server
3. 找到了/etc/ssh/目录下的sshd服务配置文件sshd_config，将#Port 22去掉注释
4. 开启 sshd 服务，输入 sudo service sshd start
5. 检查 sshd 服务是否已经开启，输入ps -e | grep sshd

2安装MySQL及配置

2.1下载镜像

wget https://dev.mysql.com/get/mysql80-community-release-el7-3.noarch.rpm

2.2安装镜像

rpm -ivh mysql80-community-release-el7-3.noarch.rpm

2.3升级系统上的MySQL软件包

通过以下命令升级MySQL及其相关组件：
方案一.指定更新MySQL服务器（推荐使用）：

yum update mysql-server

方案二.通过更新系统上的所有内容来更新MySQL（谨慎使用）：
注意，这个方法需要谨慎使用，一般是在空白服务器的时候可以使用，因为有可能会把你系统中的其他软件都给升级了

yum update

2.4安装MySQL服务

yum install mysql-server

2.5初始化数据库

mysqld --initialize

2.6启动服务

service mysqld start

Job for mysqld.service failed because the control process exited with error code.
See “systemctl status mysqld.service” and “journalctl -xe” for details.

如果出现异常，执行以下语句：

chown mysql:mysql -R /var/lib/mysql
service mysqld start
systemctl status mysqld

● mysqld.service - MySQL 8.0 database server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; disabled; vendor preset: disabled)
   Active: active (running) since Thu 2019-09-26 17:42:23 CST; 6s ago
  Process: 30399 ExecStopPost=/usr/libexec/mysql-wait-stop (code=exited, status=0/SUCCESS)
  Process: 30550 ExecStartPost=/usr/libexec/mysql-check-upgrade (code=exited, status=0/SUCCESS)
  Process: 30464 ExecStartPre=/usr/libexec/mysql-prepare-db-dir mysqld.service (code=exited, status=0/SUCCESS)
  Process: 30439 ExecStartPre=/usr/libexec/mysql-check-socket (code=exited, status=0/SUCCESS)
 Main PID: 30501 (mysqld)
   Status: "SERVER_OPERATING"
    Tasks: 38 (limit: 101224)
   Memory: 379.8M
   CGroup: /system.slice/mysqld.service
           └─30501 /usr/libexec/mysqld --basedir=/usr

9月 26 17:42:22 hx-mysql-01 systemd[1]: Starting MySQL 8.0 database server...
9月 26 17:42:23 hx-mysql-01 systemd[1]: Started MySQL 8.0 database server.

2.7修改初始密码

获取密码

grep "password" /var/log/mysql/mysqld.log

2019-09-26T09:41:56.912605Z 5 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: ju7Ic#aQwyIJ

登陆

mysql -u root -p
ALTER USER 'root'@'%' IDENTIFIED BY '-你的密码-';
flush privileges;
exit;

2.8重启MySQL服务

service mysqld restart;

2.9设置MySQL开机自启动

systemctl enable mysqld

---

3配置双主互备

• 主机1：172.29.60.145
• 主机2：172.29.60.146

在安装172.29.60.145和172.29.60.146完成MySQL的安装，切勿直接复制虚拟主机。

3.1 配置主从文件

在172.29.60.145主机上操作

修改/etc/my.cnf

[client-server]

#
# include all files from the config directory
#
!includedir /etc/my.cnf.d
binlog-ignore-db=mysql,test,infromation_schema,sys,performance_schema
binlog-do-db=test1
master-host=172.29.60.146
master-port=3306
master-user=root
master-pass=KONGKONG
master-retry-count=999
master-connect-retry=60
[mysqld]
log-bin=bin-log
server-id=145

在172.29.60.146主机上操作

修改/etc/my.cnf

[client-server]

#
# include all files from the config directory
#
!includedir /etc/my.cnf.d
binlog-ignore-db=mysql,test,infromation_schema,sys,performance_schema
binlog-do-db=test1
master-host=172.29.60.145
master-port=3306
master-user=root
master-pass=KONGKONG
master-retry-count=999
master-connect-retry=60
[mysqld]
log-bin=bin-log
server-id=146

3.2创建互备专用用户（repl）

在172.29.60.145主机上操作

mysql -u root -p

mysql> CREATE USER 'repl'@'172.29.60.146' IDENTIFIED WITH mysql_native_password BY 'KONGKONG';
mysql> GRANT REPLICATION SLAVE ON *.* TO 'repl'@'172.29.60.146';
mysql> flush privileges;

在172.29.60.146主机上操作

mysql -u root -p

mysql> CREATE USER 'repl'@'172.29.60.145' IDENTIFIED WITH mysql_native_password BY 'KONGKONG';
mysql> GRANT REPLICATION SLAVE ON *.* TO 'repl'@'172.29.60.145';
mysql> flush privileges;

3.3修改日志文件标记

在172.29.60.145主机上操作

mysql> SHOW MASTER STATUS;
+----------------+----------+--------------+------------------+-------------------+
| File           | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+----------------+----------+--------------+------------------+-------------------+
| bin-log.000002 |     3864 |              |                  |                   |
+----------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

在172.29.60.146主机上操作

mysql> SHOW MASTER STATUS;
+----------------+----------+--------------+------------------+-------------------+
| File           | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+----------------+----------+--------------+------------------+-------------------+
| bin-log.000003 |     2443 |              |                  |                   |
+----------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

---

在172.29.60.145主机上操作

STOP SLAVE;
CHANGE MASTER TO MASTER_HOST='172.29.60.146',MASTER_USER='repl',MASTER_PASSWORD='KONGKONG',MASTER_LOG_FILE='bin-log.000003',MASTER_LOG_POS=2443;
START SLAVE;

在172.29.60.146主机上操作

STOP SLAVE;
CHANGE MASTER TO MASTER_HOST='172.29.60.145',MASTER_USER='repl',MASTER_PASSWORD='KONGKONG',MASTER_LOG_FILE='bin-log.000002',MASTER_LOG_POS=3864;
START SLAVE;

3.4校验是否设置成功

• Slave_IO_Running：Yes
• Slave_SQL_Running: Yes
  若以上两个参数均为Yes则表示同步成功。

在172.29.60.145主机上操作

mysql> SHOW SLAVE STATUS;
+----------------------------------+---------------+-------------+-------------+---------------+-----------------+---------------------+------------------------------+---------------+-----------------------+------------------+-------------------+-----------------+---------------------+--------------------+------------------------+-------------------------+-----------------------------+------------+------------+--------------+---------------------+-----------------+-----------------+----------------+---------------+--------------------+--------------------+--------------------+-----------------+-------------------+----------------+-----------------------+-------------------------------+---------------+---------------+----------------+----------------+-----------------------------+------------------+--------------------------------------+-------------------------+-----------+---------------------+--------------------------------------------------------+--------------------+-------------+-------------------------+--------------------------+----------------+--------------------+--------------------+-------------------+---------------+----------------------+--------------+--------------------+------------------------+-----------------------+
| Slave_IO_State                   | Master_Host   | Master_User | Master_Port | Connect_Retry | Master_Log_File | Read_Master_Log_Pos | Relay_Log_File               | Relay_Log_Pos | Relay_Master_Log_File | Slave_IO_Running | Slave_SQL_Running | Replicate_Do_DB | Replicate_Ignore_DB | Replicate_Do_Table | Replicate_Ignore_Table | Replicate_Wild_Do_Table | Replicate_Wild_Ignore_Table | Last_Errno | Last_Error | Skip_Counter | Exec_Master_Log_Pos | Relay_Log_Space | Until_Condition | Until_Log_File | Until_Log_Pos | Master_SSL_Allowed | Master_SSL_CA_File | Master_SSL_CA_Path | Master_SSL_Cert | Master_SSL_Cipher | Master_SSL_Key | Seconds_Behind_Master | Master_SSL_Verify_Server_Cert | Last_IO_Errno | Last_IO_Error | Last_SQL_Errno | Last_SQL_Error | Replicate_Ignore_Server_Ids | Master_Server_Id | Master_UUID                          | Master_Info_File        | SQL_Delay | SQL_Remaining_Delay | Slave_SQL_Running_State                                | Master_Retry_Count | Master_Bind | Last_IO_Error_Timestamp | Last_SQL_Error_Timestamp | Master_SSL_Crl | Master_SSL_Crlpath | Retrieved_Gtid_Set | Executed_Gtid_Set | Auto_Position | Replicate_Rewrite_DB | Channel_Name | Master_TLS_Version | Master_public_key_path | Get_master_public_key |
+----------------------------------+---------------+-------------+-------------+---------------+-----------------+---------------------+------------------------------+---------------+-----------------------+------------------+-------------------+-----------------+---------------------+--------------------+------------------------+-------------------------+-----------------------------+------------+------------+--------------+---------------------+-----------------+-----------------+----------------+---------------+--------------------+--------------------+--------------------+-----------------+-------------------+----------------+-----------------------+-------------------------------+---------------+---------------+----------------+----------------+-----------------------------+------------------+--------------------------------------+-------------------------+-----------+---------------------+--------------------------------------------------------+--------------------+-------------+-------------------------+--------------------------+----------------+--------------------+--------------------+-------------------+---------------+----------------------+--------------+--------------------+------------------------+-----------------------+
| Waiting for master to send event | 172.29.60.146 | repl        |        3306 |            60 | bin-log.000004  |                 155 | hx-mysql-01-relay-bin.000002 |           320 | bin-log.000004        | Yes              | Yes               |                 |                     |                    |                        |                         |                             |          0 |            |            0 |                 155 |             534 | None            |                |             0 | No                 |                    |                    |                 |                   |                |                     0 | No                            |             0 |               |              0 |                |                             |              146 | 668ce869-f082-11e9-b456-ae0d77cbedee | mysql.slave_master_info |         0 |                NULL | Slave has read all relay log; waiting for more updates |              86400 |             |                         |                          |                |                    |                    |                   |             0 |                      |              |                    |                        |                     0 |
+----------------------------------+---------------+-------------+-------------+---------------+-----------------+---------------------+------------------------------+---------------+-----------------------+------------------+-------------------+-----------------+---------------------+--------------------+------------------------+-------------------------+-----------------------------+------------+------------+--------------+---------------------+-----------------+-----------------+----------------+---------------+--------------------+--------------------+--------------------+-----------------+-------------------+----------------+-----------------------+-------------------------------+---------------+---------------+----------------+----------------+-----------------------------+------------------+--------------------------------------+-------------------------+-----------+---------------------+--------------------------------------------------------+--------------------+-------------+-------------------------+--------------------------+----------------+--------------------+--------------------+-------------------+---------------+----------------------+--------------+--------------------+------------------------+-----------------------+
1 row in set (0.00 sec)

操作：172.29.60.146

mysql> SHOW SLAVE STATUS;
+----------------------------------+---------------+-------------+-------------+---------------+-----------------+---------------------+------------------------------+---------------+-----------------------+------------------+-------------------+-----------------+---------------------+--------------------+------------------------+-------------------------+-----------------------------+------------+------------+--------------+---------------------+-----------------+-----------------+----------------+---------------+--------------------+--------------------+--------------------+-----------------+-------------------+----------------+-----------------------+-------------------------------+---------------+---------------+----------------+----------------+-----------------------------+------------------+--------------------------------------+-------------------------+-----------+---------------------+--------------------------------------------------------+--------------------+-------------+-------------------------+--------------------------+----------------+--------------------+--------------------+-------------------+---------------+----------------------+--------------+--------------------+------------------------+-----------------------+
| Slave_IO_State                   | Master_Host   | Master_User | Master_Port | Connect_Retry | Master_Log_File | Read_Master_Log_Pos | Relay_Log_File               | Relay_Log_Pos | Relay_Master_Log_File | Slave_IO_Running | Slave_SQL_Running | Replicate_Do_DB | Replicate_Ignore_DB | Replicate_Do_Table | Replicate_Ignore_Table | Replicate_Wild_Do_Table | Replicate_Wild_Ignore_Table | Last_Errno | Last_Error | Skip_Counter | Exec_Master_Log_Pos | Relay_Log_Space | Until_Condition | Until_Log_File | Until_Log_Pos | Master_SSL_Allowed | Master_SSL_CA_File | Master_SSL_CA_Path | Master_SSL_Cert | Master_SSL_Cipher | Master_SSL_Key | Seconds_Behind_Master | Master_SSL_Verify_Server_Cert | Last_IO_Errno | Last_IO_Error | Last_SQL_Errno | Last_SQL_Error | Replicate_Ignore_Server_Ids | Master_Server_Id | Master_UUID                          | Master_Info_File        | SQL_Delay | SQL_Remaining_Delay | Slave_SQL_Running_State                                | Master_Retry_Count | Master_Bind | Last_IO_Error_Timestamp | Last_SQL_Error_Timestamp | Master_SSL_Crl | Master_SSL_Crlpath | Retrieved_Gtid_Set | Executed_Gtid_Set | Auto_Position | Replicate_Rewrite_DB | Channel_Name | Master_TLS_Version | Master_public_key_path | Get_master_public_key |
+----------------------------------+---------------+-------------+-------------+---------------+-----------------+---------------------+------------------------------+---------------+-----------------------+------------------+-------------------+-----------------+---------------------+--------------------+------------------------+-------------------------+-----------------------------+------------+------------+--------------+---------------------+-----------------+-----------------+----------------+---------------+--------------------+--------------------+--------------------+-----------------+-------------------+----------------+-----------------------+-------------------------------+---------------+---------------+----------------+----------------+-----------------------------+------------------+--------------------------------------+-------------------------+-----------+---------------------+--------------------------------------------------------+--------------------+-------------+-------------------------+--------------------------+----------------+--------------------+--------------------+-------------------+---------------+----------------------+--------------+--------------------+------------------------+-----------------------+
| Waiting for master to send event | 172.29.60.145 | repl        |        3306 |            60 | bin-log.000003  |                 155 | hx-mysql-02-relay-bin.000002 |           320 | bin-log.000003        | Yes              | Yes               |                 |                     |                    |                        |                         |                             |          0 |            |            0 |                 155 |             534 | None            |                |             0 | No                 |                    |                    |                 |                   |                |                     0 | No                            |             0 |               |              0 |                |                             |              145 | 323720bf-f083-11e9-bc77-4e1da18bea09 | mysql.slave_master_info |         0 |                NULL | Slave has read all relay log; waiting for more updates |              86400 |             |                         |                          |                |                    |                    |                   |             0 |                      |              |                    |                        |                     0 |
+----------------------------------+---------------+-------------+-------------+---------------+-----------------+---------------------+------------------------------+---------------+-----------------------+------------------+-------------------+-----------------+---------------------+--------------------+------------------------+-------------------------+-----------------------------+------------+------------+--------------+---------------------+-----------------+-----------------+----------------+---------------+--------------------+--------------------+--------------------+-----------------+-------------------+----------------+-----------------------+-------------------------------+---------------+---------------+----------------+----------------+-----------------------------+------------------+--------------------------------------+-------------------------+-----------+---------------------+--------------------------------------------------------+--------------------+-------------+-------------------------+--------------------------+----------------+--------------------+--------------------+-------------------+---------------+----------------------+--------------+--------------------+------------------------+-----------------------+

---

4异常情况

4.1log file不同步

Got fatal error 1236 from master when reading data from binary log: ‘Could not find first log file name in binary log index file’

• log file不同步，重新执行步骤三

---

This operation cannot be performed with a running slave io thread; run STOP SLAVE IO_THREAD FOR CHANNEL ‘’ first.

• 执行：stop slave;

---

The slave I/O thread stops because master and slave have equal MySQL server ids

修改/etc/my.cnf

[client-server]
!includedir /etc/my.cnf.d
binlog-ignore-db=mysql,test,infromation_schema,sys,performance_schema
binlog-do-db=test1
master-host=172.29.60.146
master-port=3306
master-user=root
master-pass=***
master-retry-count=999
master-connect-retry=60
[mysqld]
log-bin=bin-log
server-id=145

---

Could not execute Write_rows event on table test1.user; Duplicate entry ‘12’

由于master要删除一条记录，而slave上找不到故报错，这种情况主上都将其删除了，那么从机可以直接跳过。可用命令：

stop slave;
set global sql_slave_skip_counter=1;
start slave;