MySQL主从复制原理及其配置过程

一、MySQL复制原理。

二、MySQL复制配置。

一、MySQL复制原理

1.MySQL复制原理图

复制原理：

Slave启动IO Thread和SQL Thread

Master启动DumpThread

1.Slave通过IO Thread向Master的Dump Thread发送请求，Master的Dump Thread请求本地的binlog。

2.Master读取本地的binlog，并将读取内容发送给Slave的IO Thread线程。

3.Slave的IO Thread将收到的内容，写入到本地的relaylog中。

4.Slave的SQL Thread读取本地的relaylog文件内容。

5.Slave的SQL Thread将读取的内容写入到本地数据库。

二、MySQL复制配置

1.MySQL复制图

2.配置Master

2.1.修改Master配置文件

vim /etc/my.cnf [mysqld] #开启二进制日志文件 log-bin = mysql-bin #配置唯一server id server-id = 1 #事务安全 sync_master_info = 1 sync_binlog = 1  innodb_support_xa = ON

2.2.Master配置文件全文

[client] port  = 3306 socket = /tmp/mysql.sock [mysqld] port = 3306 socket = /tmp/mysql.sock skip-external-locking key_buffer_size = 256M max_allowed_packet = 1M table_open_cache = 256 sort_buffer_size = 1M read_buffer_size = 1M read_rnd_buffer_size = 4M myisam_sort_buffer_size = 64M thread_cache_size = 8 query_cache_size= 16M thread_concurrency = 8 log-bin=mysql-bin binlog_format=mixed server-id = 1 sync_master_info = 1 sync_binlog = 1  innodb_support_xa = ON datadir = /data/mysql/3306/data innodb_data_home_dir = /data/mysql/3306/data innodb_data_file_path = ibdata1:10M:autoextend innodb_log_group_home_dir = /data/mysql/3306/data innodb_buffer_pool_size = 256M innodb_additional_mem_pool_size = 20M innodb_log_file_size = 64M innodb_log_buffer_size = 8M innodb_flush_log_at_trx_commit = 2 innodb_lock_wait_timeout = 50 innodb_file_per_table = ON skip_name_resolve = ON [mysqldump] quick max_allowed_packet = 16M [mysql] no-auto-rehash [myisamchk] key_buffer_size = 128M sort_buffer_size = 128M read_buffer = 2M write_buffer = 2M [mysqlhotcopy] interactive-timeout

2.3.创建复制权限的用户

MariaDB [(none)]> grant replication slave,replication client on *.* to 'repl'@'192.168.1.5' identified by 'slavepass'; Query OK, 0 rows affected (0.39 sec) MariaDB [(none)]> flush privileges; Query OK, 0 rows affected (0.06 sec)

3.配置Slave

3.1.修改Slave配置文件

vim /etc/my.cnf [mysqld] #设置唯一ID server-id = 3  #启用relay log relay_log= relay-log relay_log_index=relay-log.index #事务安全 skip_slave_start = ON sync_relay_log = 1 sync_relay_log_info = 1

3.3.slave配置文件全文

[client] port            = 3306 socket          = /tmp/mysql.sock [mysqld] port            = 3306 socket          = /tmp/mysql.sock skip-external-locking key_buffer_size = 256M max_allowed_packet = 1M table_open_cache = 256 sort_buffer_size = 1M read_buffer_size = 1M read_rnd_buffer_size = 4M myisam_sort_buffer_size = 64M thread_cache_size = 8 query_cache_size= 16M thread_concurrency = 8 server-id = 3 relay_log= relay-log relay_log_index=relay-log.index skip_slave_start = ON sync_relay_log = 1 sync_relay_log_info = 1 innodb_data_home_dir = /data/mysql/3306/data innodb_data_file_path = ibdata1:10M:autoextend innodb_log_group_home_dir = /data/mysql/3306/data innodb_buffer_pool_size = 256M innodb_additional_mem_pool_size = 20M innodb_log_file_size = 64M innodb_log_buffer_size = 8M innodb_flush_log_at_trx_commit = 2 innodb_lock_wait_timeout = 50 innodb_file_per_table = ON skip_name_resolve = ON [mysqldump] quick max_allowed_packet = 16M [mysql] no-auto-rehash [myisamchk] key_buffer_size = 128M sort_buffer_size = 128M read_buffer = 2M write_buffer = 2M [mysqlhotcopy] interactive-timeout

4.开始复制

4.1.在Master上查看binlog Pos点

MariaDB [(none)]> show master status\G *************************** 1. row ***************************             File: mysql-bin.000008         Position: 652     Binlog_Do_DB:  Binlog_Ignore_DB:  1 row in set (0.00 sec)

4.2.在slave上执行同步操作

MariaDB [(none)]> change master to master_host='192.168.1.4',master_user='repl',master_password='slavepass',master_log_file='mysql-bin.000008',master_log_pos=652; Query OK, 0 rows affected (0.93 sec)

4.3.在slave上启动slave

MariaDB [(none)]> start slave; Query OK, 0 rows affected (0.02 sec)

4.3.在slave上查看slave状态

MariaDB [(none)]> show slave status\G *************************** 1. row ***************************                Slave_IO_State: Waiting for master to send event                   Master_Host: 192.168.1.4                   Master_User: repl                   Master_Port: 3306                 Connect_Retry: 60               Master_Log_File: mysql-bin.000008           Read_Master_Log_Pos: 652                Relay_Log_File: relay-log.000002                 Relay_Log_Pos: 537         Relay_Master_Log_File: mysql-bin.000008              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: 652               Relay_Log_Space: 829               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: 1                Master_SSL_Crl:             Master_SSL_Crlpath:                     Using_Gtid: No                   Gtid_IO_Pos:        Replicate_Do_Domain_Ids:    Replicate_Ignore_Domain_Ids:                  Parallel_Mode: conservative 1 row in set (0.00 sec)

5.测试同步

5.1.在master创建数据

MariaDB [(none)]> create database ckldb; Query OK, 1 row affected (0.37 sec) MariaDB [(none)]> use ckldb; Database changed MariaDB [ckldb]> create table jone(id int,name varchar(30)); Query OK, 0 rows affected (0.29 sec) MariaDB [ckldb]> insert into jone values(1,'wukaka');           Query OK, 1 row affected (0.49 sec) MariaDB [ckldb]> delete from jone; Query OK, 1 row affected (0.09 sec) MariaDB [ckldb]> insert into jone values(1,'wukaka'),(2,'side');           Query OK, 2 rows affected (0.06 sec) Records: 2  Duplicates: 0  Warnings: 0 MariaDB [ckldb]> select * from jone; +------+--------+ | id   | name   | +------+--------+ |    1 | wukaka | |    2 | side   | +------+--------+ 2 rows in set (0.00 sec)

5.2.在slave上查看

MariaDB [(none)]> show databases; +--------------------+ | Database           | +--------------------+ | ckldb              | | information_schema | | mysql              | | performance_schema | | test               | +--------------------+ 5 rows in set (0.34 sec) MariaDB [(none)]> use ckldb; Database changed MariaDB [ckldb]> show tables; +-----------------+ | Tables_in_ckldb | +-----------------+ | jone            | +-----------------+ 1 row in set (0.00 sec) MariaDB [ckldb]> select * from jone; +------+--------+ | id   | name   | +------+--------+ |    1 | wukaka | |    2 | side   | +------+--------+ 2 rows in set (0.00 sec)

注意，如果主库已经运行很久，同步之前最好，备份主库，记录binlog Pos点。将备份导入到slave库

，然后从binlog Pos开始恢复。