前言
级联复制就是master服务器，只给后端一台slave服务器同步数据，然后这个slave服务器在向后端的所有slave服务器同步数据，这样就可以降低master服务器的写压力，和复制数据的网络IO。
实现级联复制演示
准备
主服务器IP:10.220.5.137
从1服务器IP:10.220.5.138
从2服务器IP:10.220.5.139
配置主服务器
开启二进制日志
mysql> show global variables like '%log_bin%'; +---------------------------------+--------------------------------------------+ | Variable_name | Value | +---------------------------------+--------------------------------------------+ | log_bin | ON | | log_bin_basename | /data/mysql/mysql3306/logs/mysql-bin | | log_bin_index | /data/mysql/mysql3306/logs/mysql-bin.index | | log_bin_trust_function_creators | ON | | log_bin_use_v1_row_events | OFF | +---------------------------------+--------------------------------------------+ 5 rows in set (0.01 sec)
创建用于复制的用户
mysql> grant replication slave on *.* to 'ken'@'%' identified by 'xx';
查看主服务器端状态
需要查看现在主服务器端在哪个日志文件写入日志以及现在的位置
mysql> show master statusG *************************** 1. row *************************** File: mysql-bin.000012 Position: 2057 Binlog_Do_DB: Binlog_Ignore_DB: Executed_Gtid_Set: 987ac782-d7b8-11e8-a462-000c292218ec:1-13, c01b1811-d7b3-11e8-8698-000c29492f7b:3-7 1 row in set (0.00 sec)
配置从1服务器
与主服务器端建立连接
MySQL [(none)]> change master to master_host='10.220.5.137',master_user='ken',master_passowrd='xx',master_log_file='mysql-bin.000012',master_log_pos=2057;
启动slave
MySQL [(none)]> start slave;
查看连接状态
要确认IO以及SQL线程成功开启
ySQL [(none)]> show slave statusG *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 10.220.5.137 Master_User: ken Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000012 Read_Master_Log_Pos: 2057 Relay_Log_File: relay-bin.000012 Relay_Log_Pos: 1586 Relay_Master_Log_File: mysql-bin.000012 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: 2057 Relay_Log_Space: 1834 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: 1003306 Master_UUID: 987ac782-d7b8-11e8-a462-000c292218ec Master_Info_File: /data/mysql/mysql3306/data/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: 987ac782-d7b8-11e8-a462-000c292218ec:8-13 Executed_Gtid_Set: 987ac782-d7b8-11e8-a462-000c292218ec:1-13, c01b1811-d7b3-11e8-8698-000c29492f7b:1-7 Auto_Position: 0 Replicate_Rewrite_DB: Channel_Name: Master_TLS_Version: 1 row in set (0.00 sec)
查看从1服务器端状态
需要查看现在从1服务器端在哪个日志文件写入日志以及现在的位置
mysql> show master statusG
*************************** 1. row ***************************
File: mysql-bin.000007
Position: 2057
Binlog_Do_DB:
Binlog_Ignore_DB:
Executed_Gtid_Set: 987ac782-d7b8-11e8-a462-000c292218ec:1-13,
c01b1811-d7b3-11e8-8698-000c29492f7b:3-7
1 row in set (0.00 sec)
配置从2服务器端
与从1服务器端建立连接
MySQL [(none)]> change master to master_host='10.220.5.138',master_user='ken',master_passowrd='xx',master_log_file='mysql-bin.000007',master_log_pos=2057;
启动slave
MySQL [(none)]> start slave;
查看连接状态
要确认IO以及SQL线程成功开启
ySQL [(none)]> show slave statusG *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 10.220.5.138 Master_User: ken Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000007 Read_Master_Log_Pos: 2057 Relay_Log_File: relay-bin.000007 Relay_Log_Pos: 1586 Relay_Master_Log_File: mysql-bin.000007 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: 2057 Relay_Log_Space: 1834 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: 1003306 Master_UUID: 987ac782-d7b8-11e8-a462-000c292218ec Master_Info_File: /data/mysql/mysql3306/data/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: 987ac782-d7b8-11e8-a462-000c292218ec:8-13 Executed_Gtid_Set: 987ac782-d7b8-11e8-a462-000c292218ec:1-13, c01b1811-d7b3-11e8-8698-000c29492f7b:1-7 Auto_Position: 0 Replicate_Rewrite_DB: Channel_Name: Master_TLS_Version: 1 row in set (0.00 sec)
测试
现在从2服务器是从从1服务器端同步的数据，没有直接和主服务器端建立连接，而是通过从1间接的进行了连接。现在在主服务器端建库建表，查看从2服务器是否有主服务器端的库和表。
主服务器建库建表
mysql> create database ken6; <<建立数据库ken6 mysql> use ken6; <<切换至ken6 Database changed mysql> create table ken(id int); <<创建表ken Query OK, 0 rows affected (0.02 sec) mysql> insert into ken values (1),(2); <<插入数据 Query OK, 2 rows affected (0.01 sec) Records: 2 Duplicates: 0 Warnings: 0 mysql> select * from ken; <<查看刚才插入的数据 +------+ | id | +------+ | 1 | | 2 | +------+ 2 rows in set (0.00 sec)
在从1服务器端查看已经同步过来了主服务器端新建的库和表
MySQL [(none)]> select * from ken6.ken; +------+ | id | +------+ | 1 | | 2 | +------+
在从2检查发现也已经同步过来了主服务器端的库和表，这样就完后了级联复制的操作
MySQL [(none)]> select * from ken6.ken; +------+ | id | +------+ | 1 | | 2 | +------+ 2 rows in set (0.00 sec)