背景：
目前MySQL依然只支持一个Slave从一个Master复制数据，虽然也可以做到一主多备(M->S)，双主复制(M<->M)等架构，但是局限性依然很大。由于项目的要求，需要各个主库的表整合到一个地方进行统计和分析，要是每次连不同的实例操作，是一件非常耗体力的操作。所以继续一种类似多主一从的实例。
安装：
sudo apt-get install software-properties-common sudo apt-key adv --recv-keys --keyserver hkp://keyserver.ubuntu.com:80 0xcbcb082a1bb943db sudo add-apt-repository 'deb http://mirrors.hustunique.com/mariadb/repo/10.0/ubuntu trusty main' sudo apt-get update sudo apt-get install mariadb-server
环境搭建：
Master 1：200.51(MySQL) Master 2：200.52(MySQL) Slave ：200.73(MariaDB) 修改好server-id
确认好Master的POS：
M1: rep@192.168.200.51 : (none) 10:26:11>show master status; +--------------------+----------+--------------+------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | +--------------------+----------+--------------+------------------+ | mysql-bin51.000013 | 107 | | test | +--------------------+----------+--------------+------------------+ 1 row in set (0.01 sec) M2： rep@192.168.200.52 : r2 10:26:23>show master status; +---------------------+----------+--------------+------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | +---------------------+----------+--------------+------------------+ | mysql-bin_52.000106 | 107 | | test | +---------------------+----------+--------------+------------------+ 1 row in set (0.00 sec)
Slave 操作：
MariaDB [(none)]> change master 'r1' to master_host='192.168.200.51',master_user='rep',master_password='rep123456',master_log_file='mysql-bin51.000013',master_log_pos=107; Query OK, 0 rows affected (0.23 sec) MariaDB [(none)]> change master 'r2' to master_host='192.168.200.52',master_user='rep',master_password='rep123456',master_log_file='mysql-bin_52.000106',master_log_pos=107; Query OK, 0 rows affected (0.25 sec)
MariaDB的change方法和MySQL有点不一样，多了一个 ['connection_name'] ，这个就是多主一从的关键。为每个主设置一个通道标识，这样就可以支持多主复制了。
如何保存复制的信息？单主复制会把复制信息保存在master.info中，在多主复制中的保存也类似，只是在最后加上通道标识名称。如：
-rw-rw---- 1 mysql mysql 113 11月 17 10:30 master-r1.info -rw-rw---- 1 mysql mysql 114 11月 17 10:31 master-r2.info -rw-rw---- 1 mysql mysql 248 11月 17 10:30 mysqld-relay-bin-r1.000001 -rw-rw---- 1 mysql mysql 29 11月 17 10:30 mysqld-relay-bin-r1.index -rw-rw---- 1 mysql mysql 248 11月 17 10:31 mysqld-relay-bin-r2.000001 -rw-rw---- 1 mysql mysql 29 11月 17 10:31 mysqld-relay-bin-r2.index -rw-rw---- 1 mysql mysql 54 11月 17 10:30 relay-log-r1.info -rw-rw---- 1 mysql mysql 55 11月 17 10:31 relay-log-r2.info
查看同步：
#查看所有通道
MariaDB [(none)]> show all slaves statusG; *************************** 1. row *************************** Connection_name: r1 Slave_SQL_State: Slave_IO_State: Master_Host: 192.168.200.51 Master_User: rep Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin51.000013 Read_Master_Log_Pos: 107 Relay_Log_File: mysqld-relay-bin-r1.000001 Relay_Log_Pos: 4 Relay_Master_Log_File: mysql-bin51.000013 Slave_IO_Running: No Slave_SQL_Running: No 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: 107 Relay_Log_Space: 248 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: NULL 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: 0 Master_SSL_Crl: Master_SSL_Crlpath: Using_Gtid: No Gtid_IO_Pos: Retried_transactions: 0 Max_relay_log_size: 104857600 Executed_log_entries: 0 Slave_received_heartbeats: 0 Slave_heartbeat_period: 1800.000 Gtid_Slave_Pos: *************************** 2. row *************************** Connection_name: r2 Slave_SQL_State: Slave_IO_State: Master_Host: 192.168.200.52 Master_User: rep Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin_52.000106 Read_Master_Log_Pos: 107 Relay_Log_File: mysqld-relay-bin-r2.000001 Relay_Log_Pos: 4 Relay_Master_Log_File: mysql-bin_52.000106 Slave_IO_Running: No Slave_SQL_Running: No 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: 107 Relay_Log_Space: 248 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: NULL 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: 0 Master_SSL_Crl: Master_SSL_Crlpath: Using_Gtid: No Gtid_IO_Pos: Retried_transactions: 0 Max_relay_log_size: 104857600 Executed_log_entries: 0 Slave_received_heartbeats: 0 Slave_heartbeat_period: 1800.000 Gtid_Slave_Pos: 2 rows in set (0.00 sec) ERROR: No query specified
#查看单个通道 MariaDB [(none)]> show slave 'r1' statusG; *************************** 1. row *************************** Slave_IO_State: Master_Host: 192.168.200.51 Master_User: rep Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin51.000013 Read_Master_Log_Pos: 107 Relay_Log_File: mysqld-relay-bin-r1.000001 Relay_Log_Pos: 4 Relay_Master_Log_File: mysql-bin51.000013 Slave_IO_Running: No Slave_SQL_Running: No 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: 107 Relay_Log_Space: 248 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: NULL 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: 0 Master_SSL_Crl: Master_SSL_Crlpath: Using_Gtid: No Gtid_IO_Pos: 1 row in set (0.00 sec) ERROR: No query specified MariaDB [(none)]> show slave 'r2' statusG; *************************** 1. row *************************** Slave_IO_State: Master_Host: 192.168.200.52 Master_User: rep Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin_52.000106 Read_Master_Log_Pos: 107 Relay_Log_File: mysqld-relay-bin-r2.000001 Relay_Log_Pos: 4 Relay_Master_Log_File: mysql-bin_52.000106 Slave_IO_Running: No Slave_SQL_Running: No 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: 107 Relay_Log_Space: 248 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: NULL 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: 0 Master_SSL_Crl: Master_SSL_Crlpath: Using_Gtid: No Gtid_IO_Pos: 1 row in set (0.00 sec) ERROR: No query specified
开启同步：
#开启单个通道
MariaDB [(none)]> start slave 'r1'; Query OK, 0 rows affected (0.00 sec) MariaDB [(none)]> start slave 'r2'; Query OK, 0 rows affected (0.00 sec) #开启所有通道 MariaDB [(none)]> start all slaves; Query OK, 0 rows affected, 2 warnings (0.01 sec) MariaDB [(none)]> show warnings; +-------+------+--------------------+ | Level | Code | Message | +-------+------+--------------------+ | Note | 1937 | SLAVE 'r2' started | | Note | 1937 | SLAVE 'r1' started | +-------+------+--------------------+ 2 rows in set (0.00 sec)
通过 show all slaves status 命令可知是否同步成功。
关闭同步：
#关闭单个通道
MariaDB [(none)]> stop slave 'r1'; Query OK, 0 rows affected (0.14 sec) MariaDB [(none)]> stop slave 'r2'; Query OK, 0 rows affected (0.03 sec) #关闭所有通道 MariaDB [(none)]> stop all slaves; Query OK, 0 rows affected, 2 warnings (0.08 sec) MariaDB [(none)]> show warnings; +-------+------+--------------------+ | Level | Code | Message | +-------+------+--------------------+ | Note | 1938 | SLAVE 'r2' stopped | | Note | 1938 | SLAVE 'r1' stopped | +-------+------+--------------------+ 2 rows in set (0.00 sec)
多源复制在原先复制的基础上多了几个变量，现在来说明下：
MariaDB [(none)]> show all slaves statusG;
*************************** 1. row ***************************
Connection_name: r1 #master的连接名，通道名，第一个参数。
Slave_SQL_State: Slave has read all relay log; waiting for the slave I/O thread to update it
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.200.51
Master_User: rep
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin51.000013
Read_Master_Log_Pos: 107
Relay_Log_File: mysqld-relay-bin-r1.000005
Relay_Log_Pos: 396
Relay_Master_Log_File: mysql-bin51.000013
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: 107
Relay_Log_Space: 845
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
Master_SSL_Crl:
Master_SSL_Crlpath:
Using_Gtid: No
Gtid_IO_Pos:
Retried_transactions: 0 #这个连接重试事务的次数
Max_relay_log_size: 104857600 #relay log的最大值. 如果是0的话，那么在启动的时候就会被设置成max_binlog_size 的大小
Executed_log_entries: 17 #slave已经指向了多少个日志条目
Slave_received_heartbeats: 0 #我们从master收到了多少个心跳包
Slave_heartbeat_period: 1800.000 #多久从master请求一个心跳包 (以秒计算)
Gtid_Slave_Pos:
测试复制
Master 1: rep@192.168.200.51 : (none) 01:52:34>show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mha_test | | mysql | | performance_schema | | xtra_test | +--------------------+ 5 rows in set (0.00 sec) rep@192.168.200.51 : (none) 01:52:37>create database r1 default charset utf8; Query OK, 1 row affected (0.01 sec) rep@192.168.200.51 : (none) 01:53:36>use r1; Database changed rep@192.168.200.51 : r1 01:53:44>create table r1(id int not null auto_increment primary key,name varchar(30))default charset utf8; Query OK, 0 rows affected (1.35 sec) rep@192.168.200.51 : r1 01:54:09>insert into r1(name) values('a'),('b'),('c'); Query OK, 3 rows affected (0.01 sec) Records: 3 Duplicates: 0 Warnings: 0 rep@192.168.200.51 : r1 01:54:56>select * from r1; +----+------+ | id | name | +----+------+ | 1 | a | | 2 | b | | 3 | c | +----+------+ 3 rows in set (0.00 sec) Master 2: rep@192.168.200.52 : (none) 01:52:13>create database r2 default charset utf8; Query OK, 1 row affected (0.01 sec) rep@192.168.200.52 : (none) 01:54:27>use r2 Database changed rep@192.168.200.52 : r2 01:54:30>create table r2(id int not null auto_increment primary key,name varchar(30))default charset utf8; Query OK, 0 rows affected (0.23 sec) rep@192.168.200.52 : r2 01:54:32>insert into r2(name) values('A'),('B'),('C'); Query OK, 3 rows affected (0.28 sec) Records: 3 Duplicates: 0 Warnings: 0 rep@192.168.200.52 : r2 01:55:18>select * from r2; +----+------+ | id | name | +----+------+ | 1 | A | | 2 | B | | 3 | C | +----+------+ 3 rows in set (0.01 sec) Slave: MariaDB [(none)]> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | r1 | | r2 | +--------------------+ 5 rows in set (0.00 sec) MariaDB [(none)]> use r1; Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Database changed MariaDB [r1]> select * from r1; +----+------+ | id | name | +----+------+ | 1 | a | | 2 | b | | 3 | c | +----+------+ 3 rows in set (0.00 sec) MariaDB [r1]> use r2; Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Database changed MariaDB [r2]> select * from r2; +----+------+ | id | name | +----+------+ | 1 | A | | 2 | B | | 3 | C | +----+------+ 3 rows in set (0.00 sec)
同步成功，那如何错误跳过呢（default_master_connection）？
在Master 1上创建r2数据库，因为Slave上存在，所以会报错： Master 1： rep@192.168.200.51 : r1 01:55:52>create database r2 default charset utf8; Query OK, 1 row affected (0.01 sec) rep@192.168.200.51 : r1 01:59:51>insert into r1(name) values('d'),('e'),('f'); Query OK, 3 rows affected (0.01 sec) Records: 3 Duplicates: 0 Warnings: 0 rep@192.168.200.51 : r1 02:04:22>select * from r1; +----+------+ | id | name | +----+------+ | 1 | a | | 2 | b | | 3 | c | | 4 | d | | 5 | e | | 6 | f | +----+------+ 6 rows in set (0.00 sec) Slave ： MariaDB [r2]> show slave 'r1' statusG; *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 192.168.200.51 Master_User: rep Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin51.000013 Read_Master_Log_Pos: 767 Relay_Log_File: mysqld-relay-bin-r1.000005 Relay_Log_Pos: 956 Relay_Master_Log_File: mysql-bin51.000013 Slave_IO_Running: Yes Slave_SQL_Running: No Replicate_Do_DB: Replicate_Ignore_DB: Replicate_Do_Table: Replicate_Ignore_Table: Replicate_Wild_Do_Table: Replicate_Wild_Ignore_Table: Last_Errno: 1007 Last_Error: Error 'Can't create database 'r2'; database exists' on query. Default database: 'r2'. Query: 'create database r2 default charset utf8' Skip_Counter: 0 Exec_Master_Log_Pos: 667 Relay_Log_Space: 1505 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: NULL Master_SSL_Verify_Server_Cert: No Last_IO_Errno: 0 Last_IO_Error: Last_SQL_Errno: 1007 Last_SQL_Error: Error 'Can't create database 'r2'; database exists' on query. Default database: 'r2'. Query: 'create database r2 default charset utf8' Replicate_Ignore_Server_Ids: Master_Server_Id: 1 Master_SSL_Crl: Master_SSL_Crlpath: Using_Gtid: No Gtid_IO_Pos: 1 row in set (0.00 sec) MariaDB [r1]> select * from r1; +----+------+ | id | name | +----+------+ | 1 | a | | 2 | b | | 3 | c | +----+------+ 3 rows in set (0.00 sec) r1的同步失败了，那r2可以继续同步吗？ Master 2: rep@192.168.200.52 : r2 01:55:59>insert into r2(name) values('D'),('E'),('F'); Query OK, 3 rows affected (0.01 sec) Records: 3 Duplicates: 0 Warnings: 0 rep@192.168.200.52 : r2 02:02:19>select * from r2; +----+------+ | id | name | +----+------+ | 1 | A | | 2 | B | | 3 | C | | 4 | D | | 5 | E | | 6 | F | +----+------+ 6 rows in set (0.01 sec) Slave： MariaDB [r2]> select * from r2; +----+------+ | id | name | +----+------+ | 1 | A | | 2 | B | | 3 | C | | 4 | D | | 5 | E | | 6 | F | +----+------+ 6 rows in set (0.00 sec) 上面可以得出：r1同步失败之后，不影响r2的同步。想要r1同步正常，则需要忽略即跳过该错误。如： MariaDB [r1]> stop slave 'r1'; Query OK, 0 rows affected (0.12 sec) MariaDB [r1]> set @@default_master_connection='r1'; #这里是重点：指定一个通道，然后用单通道的sql_slave_skip_counter。 Query OK, 0 rows affected (0.00 sec) MariaDB [r1]> select @@default_master_connection; +-----------------------------+ | @@default_master_connection | +-----------------------------+ | r1 | +-----------------------------+ 1 row in set (0.00 sec) MariaDB [r1]> SET GLOBAL sql_slave_skip_counter =1; Query OK, 0 rows affected (0.00 sec) MariaDB [r1]> start slave 'r1'; Query OK, 0 rows affected (0.00 sec) MariaDB [r1]> show slave 'r1' statusG; *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 192.168.200.51 Master_User: rep Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin51.000013 Read_Master_Log_Pos: 993 Relay_Log_File: mysqld-relay-bin-r1.000006 Relay_Log_Pos: 396 Relay_Master_Log_File: mysql-bin51.000013 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: 993 Relay_Log_Space: 1731 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 Master_SSL_Crl: Master_SSL_Crlpath: Using_Gtid: No Gtid_IO_Pos: 1 row in set (0.00 sec) MariaDB [r1]> select * from r1; +----+------+ | id | name | +----+------+ | 1 | a | | 2 | b | | 3 | c | | 4 | d | | 5 | e | | 6 | f | +----+------+ 6 rows in set (0.00 sec) 看到跳过/忽略错误之后，r1的复制就正常了。
从上面的测试上说明，在用多主一从的复制时，需要保证各个主的Master Schema 要唯一，不能有重复。
MariaDB [r1]> show all slaves statusG; *************************** 1. row *************************** Connection_name: r1 Slave_SQL_State: Slave has read all relay log; waiting for the slave I/O thread to update it Slave_IO_State: Waiting for master to send event Master_Host: 192.168.200.51 Master_User: rep Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin51.000013 Read_Master_Log_Pos: 1376 Relay_Log_File: mysqld-relay-bin-r1.000006 Relay_Log_Pos: 779 Relay_Master_Log_File: mysql-bin51.000013 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: 1376 Relay_Log_Space: 2114 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 Master_SSL_Crl: Master_SSL_Crlpath: Using_Gtid: No Gtid_IO_Pos: Retried_transactions: 0 Max_relay_log_size: 104857600 Executed_log_entries: 39 Slave_received_heartbeats: 4 Slave_heartbeat_period: 1800.000 Gtid_Slave_Pos: *************************** 2. row *************************** Connection_name: r2 Slave_SQL_State: Slave has read all relay log; waiting for the slave I/O thread to update it Slave_IO_State: Waiting for master to send event Master_Host: 192.168.200.52 Master_User: rep Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin_52.000106 Read_Master_Log_Pos: 893 Relay_Log_File: mysqld-relay-bin-r2.000005 Relay_Log_Pos: 1183 Relay_Master_Log_File: mysql-bin_52.000106 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: 893 Relay_Log_Space: 1633 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: 2 Master_SSL_Crl: Master_SSL_Crlpath: Using_Gtid: No Gtid_IO_Pos: Retried_transactions: 0 Max_relay_log_size: 104857600 Executed_log_entries: 28 Slave_received_heartbeats: 4 Slave_heartbeat_period: 1800.000 Gtid_Slave_Pos: 2 rows in set (0.00 sec) #单个通道初始化 MariaDB [r1]> reset slave 'r1' all; ERROR 1198 (HY000): This operation cannot be performed as you have a running slave 'r1'; run STOP SLAVE 'r1' first MariaDB [r1]> stop slave 'r1'; Query OK, 0 rows affected (0.03 sec) MariaDB [r1]> reset slave 'r1' all; Query OK, 0 rows affected (0.04 sec) MariaDB [r1]> stop slave 'r2'; Query OK, 0 rows affected (0.02 sec) MariaDB [r1]> reset slave 'r2' all; Query OK, 0 rows affected (0.02 sec) MariaDB [r1]> show all slaves statusG; Empty set (0.00 sec) #所有通道初始化 MariaDB [r1]> stop all slaves; Query OK, 0 rows affected, 2 warnings (0.05 sec) MariaDB [r1]> show warnings; +-------+------+--------------------+ | Level | Code | Message | +-------+------+--------------------+ | Note | 1938 | SLAVE 'r2' stopped | | Note | 1938 | SLAVE 'r1' stopped | +-------+------+--------------------+ 2 rows in set (0.00 sec) MariaDB [r1]> reset slave all; #执行时候发现只能让r1初始化，不能初始化r2。所以初始化还是要单通道执行。
总结：
经过上面的测试，实现了多个主实例的数据同步到一个从实例，这个就可以把集中做分析的数据表同步到一起进行分析处理，大大减少了数据的中间处理时间和安全，这里还有一点特别注意的是，在同步数据库的时候可以用过滤选项（Replicate_Do_Table、Replicate_Ignore_Table、Replicate_Wild_Do_Table、Replicate_Wild_Ignore_Table），看着需要同步自己需要的表，不需要把没必要的也同步过来。
传统复制模式 -> 多源复制的命令变化
reset slave -> reset slave 'conn_erp',多个连接源名字 start slave -> start slave 'connection_name' 或者start all slaves show slave status -> show slave 'conn_mall' status,或者 show all slaves status查看所有的slave连接状态 sql_slave_skip_couter -> stop slave 'connection_name'，先指定连接源名称 set @@default_master_connection='connection_name';然后再set global sql_slave_skip_counter=1;最后start slave 'connection_name' 多源复制环境下的replicate-... variables 变量问题 在my.cnf replicate_ignore_db 前添加conn连接串前缀，比如 r1.replicate_ignore_db=ignore_database若不加前缀，就是忽略所有同名的数据库，其他变量类推。
更多信息见：
http://www.penglixun.com/tech/database/diy_multi_master_replication.html