MySQL數據同步方式：
Synchronous Replication 同步複製
Asynchronous Replication 異步複製
Semisynchronous Replication 半同步複製
同步複製：指的是客戶端連接到MySQL主服務器寫入一段數據,MySQL主服務器同步給MySQL從服務器需要等待從服務器發出同步完成的響應才返回客戶端OK, 這其中等待同步的過程是阻塞的, 如果有N臺從服務器, 效率極低
異步複製: 指的是客戶端連接到MySQL主服務器寫入一段數據,MySQL主服務器將寫入的數據發送給MySQL從服務器, 然後直接返回客戶端OK, 可能從服務器的數據會和主服務不一致
半同步複製:指的是客戶端連接到MySQL主服務器寫入一段數據, MySQL主服務器只將數據同步複製給其中一臺從服務器, 半同步複製給其他的從服務器, 來達到其中一臺從服務器完全同步的效果
MySQL複製原理
建立主從關係後, 主服務器如果有數據修改之後, BINLOG會更新, 從服務通過IO-Thread讀取主服務器的BINLOG到本地的Relay Log, 再通過SQL-Thread對其進行重放(replay), 從而同步到本地
MySQL簡單複製
拓撲：
Master配置文件
[mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock symbolic-links=0 skip_name_resolve = ON innodb_file_per_table = ON server_id=1 #主服務器ID log_bin=master-bin #開啓二進制日誌 [mysqld_safe] log-error=/var/log/mariadb/mariadb.log pid-file=/var/run/mariadb/mariadb.pid !includedir /etc/my.cnf.d
Slave配置文件
[mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock symbolic-links=0 skip_name_resolve = ON innodb_file_per_table = ON server_id=2 #從服務器ID relay_log=relay-log #開啓中繼日誌 [mysqld_safe] log-error=/var/log/mariadb/mariadb.log pid-file=/var/run/mariadb/mariadb.pid !includedir /etc/my.cnf.d
在主Master上面查看當前正在使用的二進制日誌，並記錄下position
MariaDB [(none)]> SHOW MASTER STATUS; +-------------------+----------+--------------+------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | +-------------------+----------+--------------+------------------+ | master-bin.000003 | 245 | | | +-------------------+----------+--------------+------------------+ 1 row in set (0.00 sec)
主Master上創建用戶並賦予權限
MariaDB [(none)]> GRANT REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'cpuser'@'10.1.%.%' IDENTIFIED BY ' userpass'; Query OK, 0 rows affected (0.00 sec) MariaDB [(none)]> FLUSH PRIVILEGES; Query OK, 0 rows affected (0.00 sec)
配置Slave
MariaDB [(none)]> CHANGE MASTER TO MASTER_HOST='10.1.72.100',MASTER_USER='cpuser',MASTER_PASSWORD='userpass',MASTER_LOG_FILE='master-bin.000001',MASTER_LOG_POS=245; Query OK, 0 rows affected (0.03 sec) MariaDB [(none)]> SLAVE START; #啓動IO和SQL Thread Query OK, 0 rows affected (0.02 sec) MariaDB [(none)]> SHOW SLAVE STATUS\G #查看相應信息 *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 10.1.72.100 Master_User: cpuser Master_Port: 3306 Connect_Retry: 60 Master_Log_File: master-bin.000001 Read_Master_Log_Pos: 245 Relay_Log_File: relay-log.000002 Relay_Log_Pos: 530 Relay_Master_Log_File: master-bin.000001 Slave_IO_Running: Yes #IO Thread已啓動 Slave_SQL_Running: Yes #SQL Thread已啓動 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: 245 Relay_Log_Space: 818 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 1 row in set (0.00 sec)
測試：
在Master上創建一個數據庫
Slave驗證
主主複製配置
拓撲
互爲主從：兩個節點各自都要開啓binlog和relay log
配置文件
[mysqld] datadir=/var/lib/mysql socket=/var/lib/mysql/mysql.sock symbolic-links=0 skip_name_resolve = ON innodb_file_per_table = ON server_id=1 #服務器ID log_bin=mysql-bin #開啓二進制日誌 relay_log=relay-log #開啓中繼日誌 auto_increment_offset=1 auto_increment_increment=2 [mysqld_safe] log-error=/var/log/mariadb/mariadb.log pid-file=/var/run/mariadb/mariadb.pid !includedir /etc/my.cnf.d
都授權有複製全的用戶賬號，並把對方指定爲主節點
Master1的配置
MariaDB [(none)]> GRANT REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'cpuser'@'10.1.72.200' IDENTIFIED BY 'userpass'; Query OK, 0 rows affected (0.00 sec) MariaDB [(none)]> FLUSH PRIVILEGES; Query OK, 0 rows affected (0.00 sec) MariaDB [(none)]> SHOW MASTER STATUS; +------------------+----------+--------------+------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | +------------------+----------+--------------+------------------+ | mysql-bin.000003 | 506 | | | +------------------+----------+--------------+------------------+ 1 row in set (0.01 sec) MariaDB [(none)]> CHANGE MASTER TO MASTER_HOST='10.1.72.200',MASTER_USER='cpuser',MASTER_PASSWORD='userpass',MASTER_LOG_FILE='mysql-bin.000003',MASTER_LOG_POS=506; Query OK, 0 rows affected (0.03 sec)
Master2的配置
MariaDB [(none)]> GRANT REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'cpuser'@'10.1.72.100' IDENTIFIED BY 'userpass'; Query OK, 0 rows affected (0.00 sec) MariaDB [(none)]> FLUSH PRIVILEGES; Query OK, 0 rows affected (0.00 sec) MariaDB [(none)]> CHANGE MASTER TO MASTER_HOST='10.1.72.100',MASTER_USER='cpuser',MASTER_PASSWORD='userpass',MASTER_LOG_FILE='mysql-bin.000003',MASTER_LOG_POS=506; Query OK, 0 rows affected (0.04 sec) MariaDB [(none)]> show master status; +------------------+----------+--------------+------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | +------------------+----------+--------------+------------------+ | mysql-bin.000003 | 506 | | | +------------------+----------+--------------+------------------+ 1 row in set (0.01 sec)
在兩個節點上同時啓動IO和SQL Thread
MariaDB [(none)]> START SLAVE; Query OK, 0 rows affected (0.00 sec) MariaDB [(none)]> SHOW SLAVE STATUS\G *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 10.1.72.100 Master_User: cpuser Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000003 Read_Master_Log_Pos: 506 Relay_Log_File: relay-log.000002 Relay_Log_Pos: 529 Relay_Master_Log_File: mysql-bin.000003 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: 506 Relay_Log_Space: 817 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 1 row in set (0.00 sec)
驗證
在Master1上創建數據庫test1，可同步至Master2上，相反在Master2上創建test2也可同步至Master1
半同步複製配置
拓撲
半同步的插件在/usr/lib64/mysql/plugin下, master用的semisync_master.so，slave用的semisync_slave.so
配置Master
MariaDB [(none)]> INSTALL PLUGIN rpl_semi_sync_master SONAME 'semisync_master.so'; Query OK, 0 rows affected (0.01 sec) MariaDB [(none)]> SET GLOBAL rpl_semi_sync_master_enabled=1; Query OK, 0 rows affected (0.00 sec) MariaDB [(none)]> SET GLOBAL rpl_semi_sync_master_timeout=2000; Query OK, 0 rows affected (0.00 sec)
配置Slave
MariaDB [(none)]> INSTALL PLUGIN rpl_semi_sync_slave SONAME 'semisync_slave.so'; Query OK, 0 rows affected (0.03 sec) MariaDB [(none)]> SET GLOBAL rpl_semi_sync_slave_enabled=1; Query OK, 0 rows affected (0.00 sec) MariaDB [(none)]> STOP SLAVE; Query OK, 0 rows affected (0.02 sec) MariaDB [(none)]> START SLAVE; Query OK, 0 rows affected (0.00 sec)
驗證
