詳解MySQL主從復制實戰 - 基于日志點的復制

2024-07-24 13:12:33

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基于日志點的復制

1、在主庫與從庫上建立專用的復制賬號

MariaDB [employees]> create user 'repl'@'172.%' identified by '123456';

注意在生產上的密碼必須依照相關規范以達到一定的密碼強度, 并且規定在從庫上的特定網段上才能訪問主庫

2、在主庫與從庫上授予復制權限

MariaDB [employees]> grant replication slave on *.* to 'repl'@'172.%';

3、配置主庫

注意啟用二進制日志需要重啟服務, 而server_id是一個動態參數, 可以結合命令行與配置文件以達到免重啟的持久化配置. 注意server_id在集群中是唯一的.

[mysqld]log_bin = /var/log/mysql/mariadb-binlog_bin_index = /var/log/mysql/mariadb-bin.indexbinlog_format = rowserver_id = 101

NOTE: 把日志與數據分開是個好習慣, 最好能放到不同的數據分區

4、配置從庫

選項log_slave_update決定是否把中繼日志relay_log存放到本機的binlog中, 如果是配置鏈路復制, 那么該選項必填. 注意server_id在集群中是唯一的.

[mysqld]# replicationlog_bin = /var/log/mysql/mariadb-binlog_bin_index = /var/log/mysql/mariadb-bin.indexserver_id = 102# slavesrelay_log    = /var/log/mysql/relay-binrelay_log_index  = /var/log/mysql/relay-bin.indexrelay_log_info_file  = /var/log/mysql/relay-bin.infolog_slave_updates = ONread_only

5、初始化從庫的數據

此處使用mysqldump在主庫上進行備份, 在生產上建議大家用xtrabackup進行無鎖的熱備(基于innodb引擎).

備份主庫上的employees數據庫的數據

復制代碼代碼如下:

	
	mysqldump --single-transaction --master-data=1 --triggers --routines --databases employees -u root -p >> backup.sql

將備份文件backup.sql通過scp或者docker volume卷掛載到從服務器上, 并且導入至從庫中

mysql -u root -p < backup.sql

6、啟動復制鏈路

現有master@172.20.0.2和slave@172.20.0.3, 并且已經通過mysqldump將數據同步至從庫slave中. 現在在從服務器slave上配置復制鏈路

MariaDB [(none)]> CHANGE MASTER TO MASTER_HOST='master', MASTER_USER='repl', MASTER_PASSWORD='123456', MASTER_LOG_FILE='mariadb-bin.000029', MASTER_LOG_POS=516;Query OK, 0 rows affected (0.02 sec)

在從庫上啟動復制鏈路

MariaDB [(none)]> start slave;Query OK, 0 rows affected (0.01 sec)

7、在從庫上檢查slave狀態

Slave_IO_Running與Slave_SQL_Running必須為YES, 如果出現錯誤須詳細閱讀Last_IO_Error或Last_SQL_Error的提示信息

MariaDB [(none)]> show slave status/G*************************** 1. row ***************************        Slave_IO_State: Waiting for master to send event         Master_Host: master         Master_User: repl         Master_Port: 3306        Connect_Retry: 60       Master_Log_File: mariadb-bin.000029     Read_Master_Log_Pos: 516        Relay_Log_File: relay-bin.000002        Relay_Log_Pos: 539    Relay_Master_Log_File: mariadb-bin.000029       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: 516       Relay_Log_Space: 831       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: 101        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)

8、在主庫檢查dump線程

檢測是否已經正確啟動binlog dump線程

MariaDB [(none)]> show processlist /G*************************** 1. row ***************************   Id: 7  User: root  Host: 172.20.0.1:41868   db: employees Command: Sleep  Time: 56  State:  Info: NULLProgress: 0.000*************************** 2. row ***************************   Id: 10  User: repl  Host: 172.20.0.3:45974   db: NULL Command: Binlog Dump  Time: 246  State: Master has sent all binlog to slave; waiting for binlog to be updated  Info: NULLProgress: 0.000

可以看到row 2上有Command為Binlog Dump的命令被啟動, 證明復制線程已經被成功啟動

9、總結

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