MySql搭建主从复制
MySql搭建主从复制✨
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主从复制（也称AB复制)允许将来自一个MySQL数据库服务器（主服务器）的数据复制到一个或多个MySQL数据库服务器(从服务器)。
复制是异步的从站不需要永久连接以接收来自主站的更新。
工作原理
- master将改变记录到二进制日志(binary log)中(这些记录叫做二进制日志事件，binary log events)；
- slave将master的binary log events拷贝到它的中继日志(relay log)；
- slave重做中继日志中的事件，将改变反映它自己的数据。
搭建主从复制
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数据库的安装，可以参考这篇博文，默认已经安装好MySQL，且有两台服务器
1、Master 节点配置
[root@localhost ~]# vim /etc/my.cnf
[mysqld]
## 同一局域网内注意要唯一
server-id=100
## 开启二进制日志功能，可以随意取(关键)
log-bin=mysql-bin
##设置 binlog_format 格式
binlog_format=MIXED
## 复制过滤：不需要备份的数据库，不输出(mysql库一般不同步)
binlog-ignore-db=mysql
## 为每个session分配的内存，在事务过程中用来存储二进制日志的缓存
binlog_cache_size=1M
## 主从复制的格式(mixed,statement,row，默认格式是statement)
binlog_format=mixed
2、slave节点配置
[root@localhost ~]# vim /etc/my.cnf
[mysqld]
## 同一局域网内注意要唯一
server-id=102
## 开启二进制日志功能，可以随意取(关键)
log-bin=mysql-slave-bin
## 设置 binlog_format 格式
binlog_format=MIXED
## relay_log 配置中继日志
relay_log=edu-mysql-relay-bin
## 复制过滤：不需要备份的数据库，不输出(mysql库一般不同步)
binlog-ignore-db=mysql
## 如果需要同步函数或者存储过程
log_bin_trust_function_creators=true
## 为每个session分配的内存，在事务过程中用来存储二进制日志的缓存
binlog_cache_size=1M
## 主从复制的格式(mixed,statement,row，默认格式是statement)
binlog_format=mixed
##跳过主从复制中遇到的所有错误或指定类型的错误，避免slave端复制中断。
##如:1062错误是指一些主键重复，1032错误是因为主从数据库数据不一致
slave_skip_errors=1062
3、重启MySQL
配置结束之后需要重启MySQL
systemctl restart mysqld
4、在master服务器授权slave服务器可以同步权限(master节点执行)
mysql > mysql -uroot -pmaster的密码
# 授予slave服务器可以同步master服务
mysql > grant replication slave,replication client on *.* to 'root'@'slave服务的ip' identified by 'slave服务器的密码';
mysql > flush privileges;
# 查看MySQL现在有哪些用户及对应的IP权限(可以不执行，只是一个查看)
mysql > select user,host from mysql.user;
# 5.7密码策略加强，可能会遇如下错误
mysql> grant replication slave,replication client on *.* to 'root'@'115.236.38.120' identified by 'admin123';
# ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
mysql> set global validate_password_policy=0;
Query OK, 0 rows affected (0.00 sec)
mysql> set global validate_password_mixed_case_count=0;
Query OK, 0 rows affected (0.00 sec)
mysql> set global validate_password_number_count=3;
Query OK, 0 rows affected (0.00 sec)
mysql> set global validate_password_special_char_count=0;
Query OK, 0 rows affected (0.00 sec)
mysql> set global validate_password_length=3;
Query OK, 0 rows affected (0.00 sec)
mysql> grant replication slave,replication client on *.* to 'root'@'115.236.38.120' identified by 'admin123';
Query OK, 0 rows affected, 1 warning (0.01 sec)
5、查看MySQL现在有哪些用户及对应的IP权限
[root@localhost ~]# mysql -uroot -padmin123
mysql> select user,host from mysql.user;
+---------------+----------------+
| user | host |
+---------------+----------------+
| root | % |
| root | 115.236.38.120 |
| mysql.session | localhost |
| mysql.sys | localhost |
| root | localhost |
+---------------+----------------+
5 rows in set (0.00 sec)
6、查询master服务的binlog文件名和位置(master节点执行)
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000003 | 622 | | mysql | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
7、slave进行关联master节点(slave节点执行)
这里注意一下 master_log_file和 master_log_pos 都是 master 服务器通过 show master status 获得。
> change master to master_host='master服务器ip', master_user=' root ', master_password='master密码', master_port=3306,master_log_file='mysql-bin.000003',master_log_pos=622
mysql> change master to master_host='115.236.38.101', master_user='root', master_password='admin123', master_port=3306,master_log_file='mysql-bin.000003',master_log_pos=622;
Query OK, 0 rows affected, 2 warnings (0.00 sec)
mysql> start slave;
Query OK, 0 rows affected (0.01 sec)
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 115.236.38.101
Master_User: root
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000005
Read_Master_Log_Pos: 154
Relay_Log_File: edu-mysql-relay-bin.000002
Relay_Log_Pos: 320
Relay_Master_Log_File: mysql-bin.000005
# 两个都为yes表示成功
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 154
Relay_Log_Space: 531
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 100
Master_UUID: 2b66e049-8ab0-11eb-8601-000c29e77dc3
Master_Info_File: /var/lib/mysql/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
1 row in set (0.00 sec)
ERROR:
No query specified
问题排查
主从复制Connecting 问题
- 网络不通
- 检测IP、端口
- 密码不对
- 检查是否创建用于同步的用户和密码是否正确
- pos不对
- 检查Master的 Postion
MYSQL镜像服务器因错误停止的恢复—Slave_SQL_Running: No
> stop slave;
> set global sql_slave_skip_counter=1;
> start slave;
> show slave status\G;
从MYSQL服务器Slave_lO_Runnng: No的解决
- master节点执行，获取日志文件和post
> show master status;
- slave节点重新绑定
> stop slave;
> change master to master_host='115.236.38.101', master_user='root', master_password='admin123', master_port=3306,master_log_file='mysql-bin.000003',master_log_pos=622;
> start slave;