MySQL主从配置
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mysql主从介绍
- MySQL主从又叫做Replication、AB复制。简单讲就是A和B两台机器做主从后，在A上写数据，另外一台B也会跟着写数据，两者数据实时同步的。
- MySQL主从是基于binlog的，主上须开启binlog才能进行主从。
- 主从过程大致有3个步骤:
- 主将更改操作记录到binlog里;
- 从将主的binlog事件(sql语句)同步到从本机上并记录在relaylog里;
- 从根据relaylog里面的sql语句按顺序执行;
- 主上有一个log dump线程，用来和从的I/O线程传递binlog;
- 从上有两个线程，其中I/O线程用来同步主的binlog并生成relaylog，另外一个SQL线程用来把relaylog里面的sql语句落地;
准备工作
1. 准备AB两台机器都安装好mysql，mysql安装详情请查看如下链接。
http://blog.51cto.com/taoxie/2050826
配置主 （A机器）
1.修改my.cnf配置文件
[[email protected] mysql]# vi /etc/my.cnf
增加配置内容：
server-id=100
log_bin=aminglinux1
[[email protected] mysql]# /etc/init.d/mysqld restart //更改完配置重启mysql
Shutting down MySQL.... SUCCESS!
Starting MySQL.. SUCCESS!
[[email protected] mysql]# cd /data/mysql/
[[email protected] mysql]# ls -lt //重启完成后目录下有生成新的文件
总用量 110648
-rw-rw---- 1 mysql mysql 50331648 1月 19 19:44 ib_logfile0
-rw-rw---- 1 mysql mysql 12582912 1月 19 19:44 ibdata1
-rw-rw---- 1 mysql mysql 24867 1月 19 19:44 gary-tao.err
-rw-rw---- 1 mysql mysql 6 1月 19 19:44 gary-tao.pid
-rw-rw---- 1 mysql mysql 120 1月 19 19:44 aminglinux1.000001
-rw-rw---- 1 mysql mysql 21 1月 19 19:44 aminglinux1.index
drwx------ 2 mysql mysql 324 1月 18 13:42 zrlog
drwx------ 2 mysql mysql 4096 1月 15 19:25 mysql2
-rw-rw---- 1 mysql mysql 56 12月 27 19:40 auto.cnf
drwx------ 2 mysql mysql 4096 12月 27 19:32 mysql
drwx------ 2 mysql mysql 4096 12月 27 19:32 performance_schema
-rw-rw---- 1 mysql mysql 50331648 12月 27 19:32 ib_logfile1
drwx------ 2 mysql mysql 6 12月 27 19:32 test
修改配置示例图
2.准备一个数据库做演示使用
[[email protected] mysql]# mysqldump -uroot -pszyino-123 zrlog > /tmp/zrlog.sql //备份之前旧的数据库zrlog
Warning: Using a password on the command line interface can be insecure.
[[email protected] mysql]# du -sh /tmp/zrlog.sql //查看数据库大小
12K /tmp/zrlog.sql
[[email protected] mysql]# mysql -uroot -pszyino-123 -e "create database aming" //创建一个新的数据库
Warning: Using a password on the command line interface can be insecure.
[[email protected] mysql]# mysql -uroot -pszyino-123 aming < /tmp/zrlog.sql //恢复之前备份的zrlog库
Warning: Using a password on the command line interface can be insecure.
[[email protected] mysql]# ls -lt
总用量 225344
-rw-rw---- 1 mysql mysql 50331648 1月 19 20:45 ib_logfile0
-rw-rw---- 1 mysql mysql 79691776 1月 19 20:45 ibdata1
-rw-rw---- 1 mysql mysql 12097 1月 19 20:45 aminglinux1.000001
drwx------ 2 mysql mysql 324 1月 19 20:45 aming
-rw-rw---- 1 mysql mysql 24867 1月 19 19:44 gary-tao.err
-rw-rw---- 1 mysql mysql 6 1月 19 19:44 gary-tao.pid
-rw-rw---- 1 mysql mysql 21 1月 19 19:44 aminglinux1.index
drwx------ 2 mysql mysql 324 1月 18 13:42 zrlog
drwx------ 2 mysql mysql 4096 1月 15 19:25 mysql2
-rw-rw---- 1 mysql mysql 56 12月 27 19:40 auto.cnf
drwx------ 2 mysql mysql 4096 12月 27 19:32 mysql
drwx------ 2 mysql mysql 4096 12月 27 19:32 performance_schema
-rw-rw---- 1 mysql mysql 50331648 12月 27 19:32 ib_logfile1
drwx------ 2 mysql mysql 6 12月 27 19:32 test
3.创建用作主从相互同步数据的用户
[[email protected] mysql]# mysql -uroot -pszyino-123
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1535
Server version: 5.6.35-log MySQL Community Server (GPL)
Copyright (c) 2000, 2016, 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> grant replication slave on *.* to ‘repl‘@‘172.16.111.110‘ identified by ‘szyino-123‘; //创建同步账户
#这里的repl是为从（slave）端设置的访问主（master）端的用户，也就是要完成主从复制的用户，密码为szyino-123，这里的127.16.111.110为slave（从）的ip。
Query OK, 0 rows affected (0.00 sec)
mysql> flush tables with read lock; //锁定数据库写操作
Query OK, 0 rows affected (0.02 sec)
mysql> show master status; //查看master的状态，这些数据是要记录的，一会在slave端用到。
+--------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+--------------------+----------+--------------+------------------+-------------------+
| aminglinux1.000001 | 12777 | | | |
+--------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
mysql> quit
Bye
[[email protected] mysql]# ls //为了更加与生产环境一样，把所有的库都做一个备份，包括aming\mysql2\zrlog,mysql库不需要同步。
aming aminglinux1.index gary-tao.err ibdata1 ib_logfile1 mysql2 test
aminglinux1.000001 auto.cnf gary-tao.pid ib_logfile0 mysql performance_schema zrlog
[[email protected] mysql]# ls /tmp/zrlog.sql
/tmp/zrlog.sql
[[email protected] mysql]# mysqldump -uroot -pszyino-123 mysql2 > /tmp/my2.sql
Warning: Using a password on the command line interface can be insecure.
[[email protected] mysql]# ls /tmp/*sql
/tmp/my2.sql /tmp/zrlog.sql
配置从（B机器）
1.修改slave的配置文件my.cnf
[[email protected] mysql]# vi /etc/my.cnf
增加配置如下内容：
server-id=110 //设置成和master（主）不一样的数字，若一样会导致后面的操作不成功
[[email protected] mysql]# /etc/init.d/mysqld restart //重启MysqL
Shutting down MySQL.. SUCCESS!
Starting MySQL.. SUCCESS!
修改配置示例图
2.把主上库同步到从上
[[email protected] mysql]# scp 172.16.111.100:/tmp/*.sql /tmp/
The authenticity of host ‘172.16.111.100 (172.16.111.100)‘ can‘t be established.
ECDSA key fingerprint is 89:19:99:8c:63:ff:d9:e6:19:0d:81:03:27:54:49:78.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added ‘172.16.111.100‘ (ECDSA) to the list of known hosts.
[email protected]‘s password:
Permission denied, please try again.
[email protected]‘s password:
my2.sql 100% 638KB 637.7KB/s 00:00
zrlog.sql
[[email protected] ~]# mysql -uroot
-bash: mysql: 未找到命令
[[email protected] ~]# alias ‘mysql=/usr/local/mysql/bin/mysql‘
[[email protected] ~]# alias ‘mysqldump=/usr/local/mysql/bin/mysqldump‘
[[email protected] ~]# mysql -uroot
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.6.35 MySQL Community Server (GPL)
Copyright (c) 2000, 2016, 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> create database aming;
Query OK, 1 row affected (0.00 sec)
mysql> create database zrlog;
Query OK, 1 row affected (0.00 sec)
mysql> create database mysql2;
Query OK, 1 row affected (0.00 sec)
mysql> quit
Bye
3.恢复数据
[[email protected] mysql]# mysql -uroot zrlog < /tmp/zrlog.sql
[[email protected] mysql]# mysql -uroot aming < /tmp/zrlog.sql
[[email protected] mysql]# mysql -uroot mysql2 < /tmp/my2.sql 4.实现主从
[[email protected] mysql]# mysql -uroot
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 5
Server version: 5.6.35 MySQL Community Server (GPL)
Copyright (c) 2000, 2016, 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> stop slave;
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql> change master to master_host=‘172.16.111.100‘, master_user=‘repl‘, master_password=‘szyino-123‘, master_log_file=‘aminglinux1.000001‘, master_log_pos=12777;
Query OK, 0 rows affected, 2 warnings (0.02 sec)
#解释说明：
change master这个命令是一条，打完逗号后可以按回车，直到你打分号才算结束，其中，master_log_file和master_log_pos是在前面使用show master status命令查到的数据。
mysql> start slave;
Query OK, 0 rows affected (0.00 sec)
mysql> show slave status\G //查看主从是否配置成功
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 172.16.111.100
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: aminglinux1.000001
Read_Master_Log_Pos: 12777
Relay_Log_File: gary-relay-bin.000002
Relay_Log_Pos: 285
Relay_Master_Log_File: aminglinux1.000001
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: 12777
Relay_Log_Space: 457
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: ccffc787-eafa-11e7-9474-000c2909e558
Master_Info_File: /data/mysql/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)
#解释说明：
看是否有,两个Yes说明配置成功。
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
还需关注
Seconds_Behind_Master: 0 //为主从延迟的时间
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
如果主从不正常了，需要看这里的error信息。
配置成功示例图：
5.到主上机器开启数据库写操作
[[email protected] mysql]# mysql -uroot -pszyino-123
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2407
Server version: 5.6.35-log MySQL Community Server (GPL)
Copyright (c) 2000, 2016, 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> unlock tables; //执行开启数据写操作命令
Query OK, 0 rows affected (0.00 sec)
测试主从同步
1.说明几个配置参数
主服务器上，这两个参数用一个就可以了。
binlog-do-db= //定义需要同步指定的库，多个库用英文的逗号分隔。
binlog-ignore-db= //定义不需要同步的库。
从服务器上
replicate_do_db= //定义需要同步指定的库，多个库用英文的逗号分隔
replicate_ignore_db= //定义不需要同步的库。
replicate_do_table= //定义需要同步的表
replicate_ignore_table= //定义不需要同步的表
replicate_wild_do_table= //如aming库.%, 支持通配符%（主要使用）
replicate_wild_ignore_table=
2.测试主从同步
[[email protected] mysql]# mysql -uroot -pszyino-123
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2407
Server version: 5.6.35-log MySQL Community Server (GPL)
Copyright (c) 2000, 2016, 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> unlock tables;
Query OK, 0 rows affected (0.00 sec)
mysql> use aming;
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_aming |
+-----------------+
| comment |
| link |
| log |
| lognav |
| plugin |
| tag |
| type |
| user |
| website |
+-----------------+
9 rows in set (0.00 sec)
//进入主上查看website表行数
mysql> select count(*) website;
+---------+
| website |
+---------+
| 1 |
+---------+
1 row in set (0.00 sec)
mysql> truncate table website;
Query OK, 0 rows affected (0.03 sec)
//进入从上查看user表行数
mysql> use aming;
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> select count(*) website;
+---------+
| website |
+---------+
| 1 |
+---------+
1 row in set (0.00 sec)
//清空主上的website表内容
mysql> truncate table website;
Query OK, 0 rows affected (0.03 sec)
//再次查看主上wedsite表虽然显示一行，但是内容已为空。
mysql> select count(*) website;
+---------+
| website |
+---------+
| 1 |
+---------+
1 row in set (0.00 sec)
mysql> select * from website;
Empty set (0.00 sec)
//查看从上的wedsite内容已为空。
mysql> select count(*) from website;
+----------+
| count(*) |
+----------+
| 0 |
+----------+
1 row in set (0.00 sec)
//在主上删除website这个表
mysql> drop table website;
Query OK, 0 rows affected (0.02 sec)
//在从上查看websitep这个表已被删除
mysql> select * from webiste;
ERROR 1146 (42S02): Table ‘aming.webiste‘ doesn‘t exist
注意：如果不小心在从上删除了表，你再次打开查看主从配置时，发现报错了，如下：
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 172.16.111.100
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: aminglinux1.000001
Read_Master_Log_Pos: 12997
Relay_Log_File: gary-relay-bin.000002
Relay_Log_Pos: 383
Relay_Master_Log_File: aminglinux1.000001
Slave_IO_Running: Yes
Slave_SQL_Running: No //这里变NO了
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 1051
Last_Error: Error ‘Unknown table ‘aming.website‘‘ on query. Default database: ‘aming‘. Query: ‘DROP TABLE `website` /* generated by server */‘
Skip_Counter: 0
Exec_Master_Log_Pos: 12875
Relay_Log_Space: 677
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: NULL
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 1051
Last_SQL_Error: Error ‘Unknown table ‘aming.website‘‘ on query. Default database: ‘aming‘. Query: ‘DROP TABLE `website` /* generated by server */‘
Replicate_Ignore_Server_Ids:
Master_Server_Id: 100
Master_UUID: ccffc787-eafa-11e7-9474-000c2909e558
Master_Info_File: /data/mysql/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State:
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp: 180123 15:28:37
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
1 row in set (0.00 sec)
如果出现了这个情况只能重新做主从：
主上操作查看master:
mysql> show master status;
+--------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+--------------------+----------+--------------+------------------+-------------------+
| aminglinux1.000001 | 12997 | | | |
+--------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
从上配置change master重做主从（为什么可以直接做主从，因为数据还是一致的，没有做其它的操作）
mysql> stop slave;
Query OK, 0 rows affected (0.01 sec)
//除了最后面数字需要更改，其它参数都一样。
mysql> change master to master_host=‘172.16.111.100‘, master_user=‘repl‘, master_password=‘szyino-123‘, master_log_file=‘aminglinux1.000001‘, master_log_pos=12997;
Query OK, 0 rows affected, 2 warnings (0.02 sec)
mysql> start slave;
Query OK, 0 rows affected (0.00 sec)
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 172.16.111.100
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: aminglinux1.000001
Read_Master_Log_Pos: 12997
Relay_Log_File: gary-relay-bin.000002
Relay_Log_Pos: 285
Relay_Master_Log_File: aminglinux1.000001
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: 12997
Relay_Log_Space: 457
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: ccffc787-eafa-11e7-9474-000c2909e558
Master_Info_File: /data/mysql/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)
备注：如果在数据不一致的情况下，需要重新同步数据，然后在做change master操作。
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