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centos7 mysql5.6 配置主从同步

来源：SegmentFault

时间：2023-02-24 16:54:37 363浏览收藏

知识点掌握了，还需要不断练习才能熟练运用。下面golang学习网给大家带来一个数据库开发实战，手把手教大家学习《centos7 mysql5.6 配置主从同步》，在实现功能的过程中也带大家重新温习相关知识点，温故而知新，回头看看说不定又有不一样的感悟！

一、安装环境

数据库地址：

*　　192.168.0.212（主）

*　　192.168.0.221（从）

二、Master的配置

1.修改MySQL配置文件

[root@localhost ~]# vim /etc/my.cnf
 
[mysqld]
#开启二进制日志
log-bin=mysql-bin
#标识唯一id（必须），一般使用ip最后位
server-id=212
#不同步的数据库，可设置多个
binlog-ignore-db=mysql
#指定需要同步的数据库（和slave是相互匹配的），可以设置多个
binlog-do-db = xxxx_dt_business
binlog-do-db = xxxx_dt_home
 
 
 
binlog_format=MIXED
#日志清理时间
expire_logs_days=7
#日志大小
max_binlog_size=200m
#缓存大小
binlog_cache_size=4m
#最大缓存大小
max_binlog_cache_size=521m

2.重启MySQL

[root@localhost ~]# mysql -u root -p
 
 
#给从库放权限  
mysql> GRANT FILE ON _._ TO 'xxxxrep'@'192.168.0.221' IDENTIFIED BY 'xxxxrep123.';  
Query OK, 0 rows affected (0.00 sec)
 
mysql> GRANT REPLICATION SLAVE ON _._ TO 'xxxxrep'@'192.168.0.221' IDENTIFIED BY 'xxxxrep123.';  
Query OK, 0 rows affected (0.00 sec)
 
mysql> FLUSH PRIVILEGES;  
Query OK, 0 rows affected (0.00 sec)
 
注：如果数据库有数据需要进行数据迁移保证数据的一致性　　数据迁移
 
创建数据库： 在从库中创建一个和主库相同的数据库，不然两个数据库不能同步（进行过数据迁移就跳过）
 
CREATE DATABASE xxxx_dt_home CHARACTER SET utf8 COLLATE utf8_general_ci;  
CREATE DATABASE xxxx_dt_business CHARACTER SET utf8 COLLATE utf8_general_ci;

4.重启MySQL，登录MySQL，查看主库信息

mysql> show master status;  
+------------------+----------+---------------------------------+------------------+-------------------+  
| File             | Position | Binlog_Do_DB                    | Binlog_Ignore_DB | Executed_Gtid_Set |  
+------------------+----------+---------------------------------+------------------+-------------------+  
| mysql-bin.000149 |  1670048 | xxxx_dt_business,xxxx_dt_home |                  |                   |  
+------------------+----------+---------------------------------+------------------+-------------------+  
1 row in set (0.00 sec)
 
mysql>  
　注：如果执行这个步骤始终为Empty set(0.00 sec)，那说明前面的my.cnf没配置对
 
#开启二进制日志（可以不配置）log-bin=mysql-bin  
server-id=221 
replicate-do-db= xxxx_dt_business  
replicate-do-db = xxxx_dt_home  
replicate-ignore-db = mysql  
log-slave-updates  
slave-skip-errors = all  
slave-net-timeout = 60
 
#关闭Slave  
mysql> change master to master_host='192.168.0.212',master_user='xxxxrep',master_password='xxxxrep123.',master_log_file='mysql-bin.000149', master_log_pos=33345737;  
Query OK, 0 rows affected, 2 warnings (0.01 sec)
 
mysql> start slave;  
Query OK, 0 rows affected (0.00 sec)
 
　　注：上面的master_log_file是在配置Master的时候的File字段， master_log_pos是在配置Master的Position 字段。一定要一一对应

5.查看信息

mysql> show slave status \G;  
*************************** 1. row ***************************  
Slave_IO_State: Waiting for master to send event  
Master_Host: 192.168.0.212 
Master_User: xxxxrep  
Master_Port: 3306 
Connect_Retry: 60 
Master_Log_File: mysql-bin.000149 
Read_Master_Log_Pos: 44484424 
Relay_Log_File: mysql-relay-bin.000002 
Relay_Log_Pos: 11138970 
Relay_Master_Log_File: mysql-bin.000149 
Slave_IO_Running: Yes  
Slave_SQL_Running: Yes  
Replicate_Do_DB: xxxx_dt_business,xxxx_dt_home  
Replicate_Ignore_DB: mysql  
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: 44484424 
Relay_Log_Space: 11139143 
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: 212 
Master_UUID: 7e1414e2-8dd5-11e9-a10f-000c29f686d6  
Master_Info_File: /data/mysql/data/master.info  
SQL_Delay: 0 
SQL_Remaining_Delay: NULL  
Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it  
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 
1 row in set (0.00 sec)
 
ERROR:  
No query specified  
　　注：如果Slave_IO_Running: No　　出现下面的错误
 
Last_IO_Error: Fatal error: The slave I/O thread stops because master and slave have equal MySQL server UUIDs; these UUIDs must be different for replication to work.  
　　说明主服务器的UUID和从服务器的UUID重复，更改方式
 
[root@localhost ~]# vim /usr/local/mysql/data/auto.cnf　　#这是我的安装路径修改auto.cnf的server-uuid  
　　注：如果Slave_IO_Running: Connecting 并出现下面错误　　
 
error connecting to master ['root@192.168.3.28]('root@192.168.3.28):3306' - retry-time: 60  retries: 1 
　　解决方法，查看主库是否授权，查看change master to... 是否有用户密码ip填写错误
 
　　注：如果Slave_IO_Running: No 出现下面错误
 
Got fatal error 1236 from master when reading data from binary log: 'Could not find first log file name in binary log index file' 
　　解决方法：复位
 
mysql>stop slave;　　//停止  
mysql>reset slave;　　//清空  
mysql>start slave;　　//开启

扩展

当只针对某些库的某张表进行同步时，如下，只同步home库的hello表和other库的biao表：  
replicate-do-db = home  
replicate-wild-do-table = home.hello       //当只同步几个或少数表时，可以这样设置。注意这要跟上面的库指定配合使用；  
replicate-do-db = other  
replicate-wild-do-table = other.biao      //如果同步的库的表比较多时，就不能这样一一指定了，就把这个选项配置去掉，直接根据指定的库进行同步。
 
查询binlog主从日志的方法
 
#查看binlog全部文件  
mysql>show binary logs;
 
#查看binlog是否开启NO为开启  
mysql> show variables like 'log_bin%';
 
#详细信息  
mysql>  show variables like 'binlog%';
 
#查看binlog日志  
mysql> show binlog events in'mysql-bin.000017';
 
#或者使用mysqlbinlog，如果报错使用--no-defaults（使用全路径）  
[root@localhost ~]# /usr/local/mysql/bin/mysqlbinlog --no-defaults /usr/local/mysql/data/mysql-bin.000017 
　　
 
手动清理master日志，最好关闭日志，在/etc/my.cnf
 
#手动刷新日志  
mysql> show master status;  
#删除全部mysql> reset slave;或 rest master;#删除MySQL-bin.011mysql> PURGE MASTER LOGS TO 'MySQL-bin.011';
 
mysql> show status like  'Innodb_buffer_pool_%';  
+---------------------------------------+--------------------------------------------------+  
| Variable_name                         | Value                                            |  
+---------------------------------------+--------------------------------------------------+  
| Innodb_buffer_pool_dump_status        | not started                                      |  
| Innodb_buffer_pool_load_status        | Buffer pool(s) load completed at 200320 16:18:07 |  
| Innodb_buffer_pool_pages_data         | 93721                                            |  
| Innodb_buffer_pool_bytes_data         | 1535524864                                       |  
| Innodb_buffer_pool_pages_dirty        | 0                                                |  
| Innodb_buffer_pool_bytes_dirty        | 0                                                |  
| Innodb_buffer_pool_pages_flushed      | 328774                                           |  
| Innodb_buffer_pool_pages_free         | 37327                                            |  
| Innodb_buffer_pool_pages_misc         | 16                                               |  
| Innodb_buffer_pool_pages_total        | 131064                                           |  
| Innodb_buffer_pool_read_ahead_rnd     | 0                                                |  
| Innodb_buffer_pool_read_ahead         | 28                                               |  
| Innodb_buffer_pool_read_ahead_evicted | 0                                                |  
| Innodb_buffer_pool_read_requests      | 27973283                                         |  
| Innodb_buffer_pool_reads              | 90917                                            |  
| Innodb_buffer_pool_wait_free          | 0                                                |  
| Innodb_buffer_pool_write_requests     | 1205702                                          |  
+---------------------------------------+--------------------------------------------------+  
17 rows in set

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