MySQL5.7主從從配置
阿新 • • 發佈：2018-11-25
主從配置可參考：【MySQL5.7主從同步配置】
主從從，也稱為級聯主從，資料流向：A(主)->B(從)->C(從從)，主從從級聯複製。
應用場景
- 在主從配置的基礎上，再增加一個從庫，進一步提高資料安全，容災備份。
- 讀寫分離，從庫只用於查詢，提高資料庫整體效能。
- 從從庫，用於備份，等同線上實時增量備份。
部署環境
注：使用docker部署mysql例項，方便快速搭建演示環境。但本文重點是講解主從配置，因此簡略描述docker環境構建mysql容器例項。
- 資料庫：MySQL 5.7.x （相比5.5，5.6而言，5.7同步效能更好，支援多源複製，可實現多主一從，主從庫版本應保證一致）
- 作業系統：CentOS 7.x
- 容器：Docker 17.09.0-ce
- 映象：mysql:5.7
- 主庫：IP=192.168.10.212; PORT=4200; server-id=200; database=test; table=user
- 從庫：IP=192.168.10.212; PORT=4211; server-id=210; database=test; table=user
- 從從庫：IP=192.168.10.212; PORT=4211; server-id=211; database=test; table=userk
配置約束
- 主從庫必須保證網路暢通可訪問
- 主庫必須開啟binlog日誌
- 主從庫的server-id必須不同
【主庫】操作及配置
配置my.cnf
[client] port = 3306 default-character-set = utf8mb4 [mysql] port = 3306 default-character-set = utf8mb4 [mysqld] ########################## # summary ########################## #bind-address = 0.0.0.0 #port = 3306 #datadir=/datavol/mysql/data #資料儲存目錄 ########################## # log bin ########################## server-id = 200 #必須唯一 log_bin = mysql-bin #開啟及設定二進位制日誌檔名稱 binlog_format = MIXED sync_binlog = 1 expire_logs_days =7 #二進位制日誌自動刪除/過期的天數。預設值為0，表示不自動刪除。 #binlog_cache_size = 128m #max_binlog_cache_size = 512m #max_binlog_size = 256M binlog-do-db = test #要同步的資料庫 binlog-ignore-db = mysql #不需要同步的資料庫 binlog_ignore_db = information_schema binlog_ignore_db = performation_schema binlog_ignore_db = sys ########################## # character set ########################## character-set-server = utf8mb4 collation-server = utf8mb4_unicode_ci
安裝啟動主庫
[[email protected] ~]# docker run -d -p 4200:3306 --name=mysql-200 -v /datavol/mysql-200/conf:/etc/mysql/conf.d -v /datavol/mysql-200:/datavol/mysql -e MYSQL_ROOT_PASSWORD=123456 mysql:5.7
5691bac538e646db00273e3cad5b350dbe6cce0bd176346b7eefd9a6f9e3a9ad
[[email protected] ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
5691bac538e6 mysql:5.7 "docker-entrypoint..." 44 seconds ago Up 43 seconds 33060/tcp, 0.0.0.0:4200->3306/tcp mysql-200
[[email protected] ~]# docker exec -it mysql-200 /bin/bash
[email protected]:/# mysql -u root -p
Enter password:
注：若不熟悉docker，可使用傳統方式安裝mysql，效果相同。
建立授權使用者
連線mysql主資料庫，鍵入命令mysql -u root -p，輸入密碼後登入資料庫。建立使用者用於從庫同步複製，授予複製、同步訪問的許可權
mysql> CREATE USER 'slave'@'%' IDENTIFIED BY '123456';
Query OK, 0 rows affected (0.01 sec)
mysql> GRANT REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'slave'@'%';
Query OK, 0 rows affected (0.00 sec)
log_bin是否開啟
mysql> show variables like 'log_bin';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| log_bin | ON |
+---------------+-------+
1 row in set檢視master狀態
mysql> show master status;
+------------------+----------+--------------+--------------------------------------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+--------------------------------------------------+-------------------+
| mysql-bin.000001 | 154 | test | mysql,information_schema,performation_schema,sys | |
+------------------+----------+--------------+--------------------------------------------------+-------------------+
1 row in set【從庫】配置及操作
配置my.cnf
[client]
port = 3306
default-character-set = utf8mb4
[mysql]
port = 3306
default-character-set = utf8mb4
[mysqld]
##########################
# summary
##########################
#bind-address = 0.0.0.0
#port = 3306
#datadir=/datavol/mysql/data #資料儲存目錄
##########################
# log bin
##########################
server-id = 210 #必須唯一
log_bin = mysql-bin #開啟及設定二進位制日誌檔名稱
binlog_format = MIXED
sync_binlog = 1
expire_logs_days =7 #二進位制日誌自動刪除/過期的天數。預設值為0，表示不自動刪除。
log_slave_updates = 1 #【關鍵點】從主伺服器接收到的更新同時要寫入二進位制日誌
#binlog_cache_size = 128m
#max_binlog_cache_size = 512m
#max_binlog_size = 256M
binlog-do-db = test #要同步的資料庫
binlog-ignore-db = mysql #不需要同步的資料庫
binlog_ignore_db = information_schema
binlog_ignore_db = performation_schema
binlog_ignore_db = sys
##########################
# character set
##########################
character-set-server = utf8mb4
collation-server = utf8mb4_unicode_ci
log_slave_updates = 1 #【關鍵點】從主伺服器接收到的更新同時要寫入二進位制日誌
安裝啟動從庫
[[email protected] ~]# docker run -d -p 4210:3306 --name=mysql-210 -v /datavol/mysql-210/conf:/etc/mysql/conf.d -v /datavol/mysql-210:/datavol/mysql -e MYSQL_ROOT_PASSWORD=123456 mysql:5.7
19e93b6d93ca4e6ca0d540e3f6c831b835cdbb35362733867c3977aee4d33bf7
[[email protected] ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
19e93b6d93ca mysql:5.7 "docker-entrypoint..." 4 seconds ago Up 3 seconds 33060/tcp, 0.0.0.0:4210->3306/tcp mysql-210
[[email protected] ~]# docker exec -it mysql-210 /bin/bash
[email protected]:/# mysql -u root -p
Enter password: 設定主庫200資訊
登入【從資料庫】，進入mysql命令列。
mysql> stop slave;
Query OK, 0 rows affected
mysql> CHANGE MASTER TO
MASTER_HOST='192.168.10.212',
MASTER_PORT=4200,
MASTER_USER='slave',
MASTER_PASSWORD='123456',
MASTER_LOG_FILE='mysql-bin.000003',
MASTER_LOG_POS=617;
Query OK, 0 rows affected
mysql> start slave;
Query OK, 0 rows affectedstop slave; //停止同步
start slave; //開始同步
//必須和【主資料庫】的資訊匹配。
CHANGE MASTER TO
MASTER_HOST='192.168.10.212', //主庫IP
MASTER_PORT=4200, //主庫埠
MASTER_USER='slave', //訪問主庫且有同步複製許可權的使用者
MASTER_PASSWORD='123456', //登入密碼
//【關鍵處】從主庫的該log_bin檔案開始讀取同步資訊，主庫show master status返回結果
MASTER_LOG_FILE='mysql-bin.000001',
//【關鍵處】從檔案中指定位置開始讀取，主庫show master status返回結果
MASTER_LOG_POS=154;
檢視同步狀態
mysql> show slave status \G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.10.212
Master_User: slave
Master_Port: 4200
Connect_Retry: 60
Master_Log_File: mysql-bin.000003
Read_Master_Log_Pos: 617
Relay_Log_File: 5f0d9861bcb1-relay-bin.000002
Relay_Log_Pos: 320
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: 617
Relay_Log_Space: 534
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: 200
Master_UUID: b6df98cf-e71f-11e8-9987-0242ac110007
Master_Info_File: /var/lib/mysql/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
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
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
1 row in set (0.00 sec)
只有【Slave_IO_Running】和【Slave_SQL_Running】都是Yes，則同步是正常的。
如果是No或者Connecting都不行，可檢視mysql-error.log，以排查問題。
mysql> show variables like 'log_error%';
+---------------------+--------+
| Variable_name | Value |
+---------------------+--------+
| log_error | stderr |
| log_error_verbosity | 3 |
+---------------------+--------+
2 rows in set配置完成，則主從資料庫開始自動同步。此外，【從庫】相當於【從從庫】的主庫，也需要設定賬號及同步許可權。
建立授權使用者
建立使用者用於從庫同步複製，授予複製、同步訪問的許可權
mysql> CREATE USER 'slave'@'%' IDENTIFIED BY '123456';
Query OK, 0 rows affected (0.01 sec)
mysql> GRANT REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'slave'@'%';
Query OK, 0 rows affected (0.00 sec)
log_bin是否開啟
mysql> show variables like 'log_bin';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| log_bin | ON |
+---------------+-------+
1 row in set檢視master狀態
mysql> show master status;
+------------------+----------+--------------+--------------------------------------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+--------------------------------------------------+-------------------+
| mysql-bin.000003 | 154 | test | mysql,information_schema,performation_schema,sys | |
+------------------+----------+--------------+--------------------------------------------------+-------------------+
1 row in set【從從庫】配置及操作
配置my.cnf
[client]
port = 3306
default-character-set = utf8mb4
[mysql]
port = 3306
default-character-set = utf8mb4
[mysqld]
##########################
# summary
##########################
#bind-address = 0.0.0.0
#port = 3306
#datadir=/datavol/mysql/data #資料儲存目錄
##########################
# log bin
##########################
server-id = 211
##########################
# character set
##########################
character-set-server = utf8mb4
collation-server = utf8mb4_unicode_ci安裝啟動從從庫
[[email protected] ~]# docker run -d -p 4211:3306 --name=mysql-211 -v /datavol/mysql-211/conf:/etc/mysql/conf.d -v /datavol/mysql-211:/datavol/mysql -e MYSQL_ROOT_PASSWORD=123456 mysql:5.7
19e93b6d93ca4e6ca0d540e3f6c831b835cdbb35362733867c3977aee4d33bf7
[[email protected] ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
19e93b6d93ca mysql:5.7 "docker-entrypoint..." 4 seconds ago Up 3 seconds 33060/tcp, 0.0.0.0:4211->3306/tcp mysql-211
[[email protected] ~]# docker exec -it mysql-211 /bin/bash
[email protected]:/# mysql -u root -p
Enter password: 設定從庫210資訊
登入【從資料庫】，進入mysql命令列。
mysql> stop slave;
Query OK, 0 rows affected
mysql> CHANGE MASTER TO MASTER_HOST='192.168.10.212',
MASTER_PORT=4210,
MASTER_USER='slave',
MASTER_PASSWORD='123456',
MASTER_LOG_FILE='mysql-bin.000003',
MASTER_LOG_POS=617;
Query OK, 0 rows affected
mysql> start slave;
Query OK, 0 rows affectedstop slave; //停止同步
start slave; //開始同步
//必須和【主資料庫】的資訊匹配。
CHANGE MASTER TO
MASTER_HOST='192.168.10.212', //主庫IP
MASTER_PORT=4210, //主庫埠
MASTER_USER='slave', //訪問主庫且有同步複製許可權的使用者
MASTER_PASSWORD='123456', //登入密碼
//【關鍵處】從主庫的該log_bin檔案開始讀取同步資訊，主庫show master status返回結果
MASTER_LOG_FILE='mysql-bin.000003',
//【關鍵處】從檔案中指定位置開始讀取，主庫show master status返回結果
MASTER_LOG_POS=617;
檢視同步狀態
mysql> show slave status \G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.10.212
Master_User: slave
Master_Port: 4210
Connect_Retry: 60
Master_Log_File: mysql-bin.000003
Read_Master_Log_Pos: 617
Relay_Log_File: a3d52e314640-relay-bin.000002
Relay_Log_Pos: 783
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: 617
Relay_Log_Space: 997
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: 210
Master_UUID: 088c2c93-e720-11e8-8e80-0242ac110009
Master_Info_File: /var/lib/mysql/master.info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
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
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
1 row in set (0.00 sec)
只有【Slave_IO_Running】和【Slave_SQL_Running】都是Yes，則同步是正常的。
如果是No或者Connecting都不行，可檢視mysql-error.log，以排查問題。
mysql> show variables like 'log_error%';
+---------------------+--------+
| Variable_name | Value |
+---------------------+--------+
| log_error | stderr |
| log_error_verbosity | 3 |
+---------------------+--------+
2 rows in set配置完成，則從從資料庫開始自動同步。
驗證資料同步
建庫
使用root賬號登入【主伺服器】，建立test資料庫
mysql> CREATE DATABASE test;
Query OK, 1 row affected (0.00 sec)
mysql> USE test;
Database changed
建表
在【主庫】中建立user表
CREATE TABLE `user` (
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`name` varchar(20) COLLATE utf8mb4_unicode_ci NOT NULL,
`age` tinyint(3) unsigned NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
新增
在【主庫】中向user表插入一條資料：
mysql> use test;
Database changed
mysql> INSERT INTO user (id, name, age) VALUES (1, '張三', 18);
Database changed
mysql> SELECT * FROM user;
+----+------+-----+
| id | name | age |
+----+------+-----+
| 1 | 張三 | 18 |
+----+------+-----+
1 row in set在【從庫】及【從從庫】中查詢user表資料：
mysql> use test;
Database changed
mysql> SELECT * FROM user;
+----+------+-----+
| id | name | age |
+----+------+-----+
| 1 | 張三 | 18 |
+----+------+-----+
1 row in set新增記錄同步成功。
更新
在【主庫】中修改剛才插入的資料：
mysql> UPDATE user SET name='李四' where id=1;
Database changed
Rows matched: 1 Changed: 1 Warnings: 0
mysql> SELECT * FROM user;
+----+------+-----+
| id | name | age |
+----+------+-----+
| 1 | 李四 | 18 |
+----+------+-----+
1 row in set在【從庫】及【從從庫】中查詢user表資料：
mysql> SELECT * FROM user;
+----+------+-----+
| id | name | age |
+----+------+-----+
| 1 | 李四 | 18 |
+----+------+-----+
1 row in set更新記錄同步成功。
刪除
在【主庫】中刪除剛才更新的資料：
mysql> DELETE FROM user WHERE id=1;
Database changed
mysql> SELECT * FROM user;
Empty set在【從庫】及【從從庫】中查詢user表資料：
mysql> SELECT * FROM user;
Empty set刪除記錄同步成功。
補充：
- 如果【主伺服器】重啟mysql服務，【從伺服器】會等待與【主伺服器】重連。當主伺服器恢復正常後，從伺服器會自動重新連線上主伺服器，並正常同步資料。
- 如果某段時間內，【從資料庫】伺服器異常導致同步中斷（可能是同步點位置不匹配），可以嘗試以下恢復方法：進入【主資料庫】伺服器（正常），在bin-log中找到【從資料庫】出錯前的position，然後在【從資料庫】上執行change master，將master_log_file和master_log_pos重新指定後，開始同步。