Linux下配置Mysql主从复制（一主一从）
注：CentOS7 Mysql5.7
1. 主从服务器概况
-
主：IP:192.168.31.7 PORT:3306
-
从：IP:192.168.31.99 PORT:3306
2. 修改主服务器master
# vi /etc/my.cnf
[mysqld]
server-id = 1 # 节点ID,确保唯一
# log config
log-bin = mysql-bin # 开启mysql的binlog日志功能
sync_binlog = 1 # 控制数据数据库的binlog刷到磁盘上去 , 0 不控制，性能最好，1每次事物提交都会刷到日志文件中，性能最差，最安全
binlog_format = mixed #binlog日志格式，mysql默认采用statement，建议使用mixed
expire_logs_days = 7 #binlog过期清理时间
max_binlog_size = 100m #binlog每个日志文件大小
binlog_cache_size = 4m #binlog缓存大小
max_binlog_cache_size= 512m #最大binlog缓存大
binlog-ignore-db=mysql #不生成日志文件的数据库，多个忽略数据库可以用逗号拼接，或者 复制这句话，写多行
auto-increment-offset = 1 # 自增值的偏移量
auto-increment-increment = 1 # 自增值的自增量
slave-skip-errors = all #跳过从库错误3. 修改从服务器slave
server-id = 2
log-bin=mysql-bin
relay-log = mysql-relay-bin
#以下参数为过滤掉某些表以不记录到从服务器
#replicate-wild-ignore-table=mysql.%
#replicate-wild-ignore-table=test.%
#replicate-wild-ignore-table=information_schema.%4. master数据库，创建复制用户并授权
- root进入master数据库，为master创建复制用户
CREATE USER repl_user IDENTIFIED BY 'repl_passwd';- 授权
grant replication slave on *.* to 'repl_user'@'192.168.31.99' identified by 'repl_passwd';
FLUSH PRIVILEGES;- 查看master状态
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 | 1928 | | mysql | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)注意：注意结果中File和Position
5. slave数据库
- root进入slave数据库
mysql> CHANGE MASTER TO
-> MASTER_HOST = '192.168.31.7', #这里填master的IP
-> MASTER_USER = 'repl_user',
-> MASTER_PASSWORD = 'repl_passwd',
-> MASTER_PORT = 3306, #这里填master的PORT
-> MASTER_LOG_FILE='mysql-bin.000001', #这里填第4步中的File
-> MASTER_LOG_POS=1928, #这里填第4步中的Position
-> MASTER_RETRY_COUNT = 60,
-> MASTER_HEARTBEAT_PERIOD = 10000;
Query OK, 0 rows affected, 3 warnings (0.02 sec)- 启动slave
mysql> START SLAVE;
Query OK, 0 rows affected (0.01 sec)- 检查slave服务器复制功能状态
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.31.7
Master_User: repl_user
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 1928
Relay_Log_File: mysql-relay-bin.000144
Relay_Log_Pos: 320
Relay_Master_Log_File: mysql-bin.000001
#************************下面必须是两个YES**********
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
#*************************************************测试
master
[root@localhost ~]# mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 14
Server version: 5.7.37-log MySQL Community Server (GPL)
Copyright (c) 2000, 2022, Oracle and/or its affiliates.
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> create database test1;
Query OK, 1 row affected (0.00 sec)
mysql> use test1;
Database changed
mysql> create table test(id int(3),name char(10));
Query OK, 0 rows affected (0.03 sec)
mysql> insert into test values(001,'aaa');
Query OK, 1 row affected (0.04 sec)
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| test1 |
+--------------------+
5 rows in set (0.01 sec)
mysql> exit
Byeslave
[root@localhost src]# mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 20
Server version: 5.7.37-log MySQL Community Server (GPL)
Copyright (c) 2000, 2022, Oracle and/or its affiliates.
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> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| test1 |
+--------------------+
5 rows in set (0.00 sec)
mysql> use test1;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> show tables;
+-----------------+
| Tables_in_test1 |
+-----------------+
| test |
+-----------------+
1 row in set (0.00 sec)
mysql> select * from test;
+------+------+
| id | name |
+------+------+
| 1 | aaa |
+------+------+
1 row in set (0.00 sec)
mysql> exit
Bye问题处理
如果slave状态检查不是两个YES，则按照如下步骤排查
-
网络问题
两服务器是否互相ping通，3306端口是否telnet通
-
账户密码问题
检查master服务器是否可以登录repl_user用户
-
防火墙
# 开放端口
firewall-cmd --zone=public --add-port=3306/tcp --permanent
# 重新载入
firewall-cmd --reload
# 检查是否生效
ssh -v -p 3306 [email protected] # 看到debug1: Connection established.即为生效。-
mysql配置文件问题
-
根据第3 、4步检查配置文件是否正确
-
-
配置文件中注释掉bind-address
-
修改skip-networking参数为1
-
连接master时参数
-
根据5.1步骤检查参数是否正确
-
-
权限
尝试检查master中用户权限
# 首次检查结果如下，如果前面都没问题，可按照下面修改权限
mysql> show grants for repl_user;
+---------------------------------------+
| Grants for repl_user@% |
+---------------------------------------+
| GRANT USAGE ON *.* TO 'repl_user'@'%' |
+---------------------------------------+
1 row in set (0.00 sec)
# 授权
mysql> GRANT REPLICATION SLAVE ON *.* TO 'repl_user'@'%' identified by 'repl_passwd';
Query OK, 0 rows affected, 1 warning (0.01 sec)
# 再次检查结果如下
mysql> show grants for repl_user;
+---------------------------------------------------+
| Grants for repl_user@% |
+---------------------------------------------------+
| GRANT REPLICATION SLAVE ON *.* TO 'repl_user'@'%' |
+---------------------------------------------------+
1 row in set (0.00 sec)