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 idserver-id = 1#事务安全sync_master_info = 1sync_binlog = 1 innodb_support_xa = ON

2.2.Master配置文件全文

[client]port  = 3306socket = /tmp/mysql.sock[mysqld]port = 3306socket = /tmp/mysql.sockskip-external-lockingkey_buffer_size = 256Mmax_allowed_packet = 1Mtable_open_cache = 256sort_buffer_size = 1Mread_buffer_size = 1Mread_rnd_buffer_size = 4Mmyisam_sort_buffer_size = 64Mthread_cache_size = 8query_cache_size= 16Mthread_concurrency = 8log-bin=mysql-binbinlog_format=mixedserver-id = 1sync_master_info = 1sync_binlog = 1 innodb_support_xa = ONdatadir = /data/mysql/3306/datainnodb_data_home_dir = /data/mysql/3306/datainnodb_data_file_path = ibdata1:10M:autoextendinnodb_log_group_home_dir = /data/mysql/3306/datainnodb_buffer_pool_size = 256Minnodb_additional_mem_pool_size = 20Minnodb_log_file_size = 64Minnodb_log_buffer_size = 8Minnodb_flush_log_at_trx_commit = 2innodb_lock_wait_timeout = 50innodb_file_per_table = ONskip_name_resolve = ON[mysqldump]quickmax_allowed_packet = 16M[mysql]no-auto-rehash[myisamchk]key_buffer_size = 128Msort_buffer_size = 128Mread_buffer = 2Mwrite_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IDserver-id = 3 #启用relay logrelay_log= relay-logrelay_log_index=relay-log.index#事务安全skip_slave_start = ONsync_relay_log = 1sync_relay_log_info = 1

3.3.slave配置文件全文

[client]port            = 3306socket          = /tmp/mysql.sock[mysqld]port            = 3306socket          = /tmp/mysql.sockskip-external-lockingkey_buffer_size = 256Mmax_allowed_packet = 1Mtable_open_cache = 256sort_buffer_size = 1Mread_buffer_size = 1Mread_rnd_buffer_size = 4Mmyisam_sort_buffer_size = 64Mthread_cache_size = 8query_cache_size= 16Mthread_concurrency = 8server-id = 3relay_log= relay-logrelay_log_index=relay-log.indexskip_slave_start = ONsync_relay_log = 1sync_relay_log_info = 1innodb_data_home_dir = /data/mysql/3306/datainnodb_data_file_path = ibdata1:10M:autoextendinnodb_log_group_home_dir = /data/mysql/3306/datainnodb_buffer_pool_size = 256Minnodb_additional_mem_pool_size = 20Minnodb_log_file_size = 64Minnodb_log_buffer_size = 8Minnodb_flush_log_at_trx_commit = 2innodb_lock_wait_timeout = 50innodb_file_per_table = ONskip_name_resolve = ON[mysqldump]quickmax_allowed_packet = 16M[mysql]no-auto-rehash[myisamchk]key_buffer_size = 128Msort_buffer_size = 128Mread_buffer = 2Mwrite_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: 0Master_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: conservative1 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 changedMariaDB [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: 0MariaDB [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 changedMariaDB [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。