MySQL主从复制

主服务器配置 my.cnf

# binary logging is required for replication
log-bin=mysql-bin
binary logging format - mixed recommended
binlog_format=mixed
required unique id between 1 and 2^32 - 1
defaults to 1 if master-host is not set
but will not function as a master if omitted
server-id       = 65

从服务器配置 my.cnf

server-id       = 75
relay-log=mysql-relay

log_salve_update = on [可选  从服务器将其SQL线程执行的更新记入到从服务器自己的二进制日志,当从服务器作为其他服务器的主服务器]
bin_log = mysql-bin
read_only = 1 [可选 只读]

在主服务器建立授权账号

mysql> grant replication slave on *.* to 'slave75'@'10.16.134.75' identified by '123'; 
Query OK, 0 rows affected (0.00 sec)
mysql> FLUSH PRIVILEGES;

Query OK, 0 rows affected (0.00 sec)
mysql> show master status;

+------------------+----------+--------------+------------------+

| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |

+------------------+----------+--------------+------------------+

| mysql-bin.000014 |      354 |              |                  |

+------------------+----------+--------------+------------------+

1 row in set (0.00 sec)

从服务器设置

mysql> change master to  master_host='10.16.134.65',  master_user='slave75',  master_password='123', master_port=3306, master_log_file='mysql-bin.000014', master_log_pos=354;
Query OK, 0 rows affected (0.15 sec)

Slave_SQL_Running: Yes

1.程序可能在slave上进行了写操作
2.也可能是slave机器重起后，事务回滚造成的.
一般是事务回滚造成的：
解决办法：
mysql> slave stop;
mysql> set GLOBAL SQL_SLAVE_SKIP_COUNTER=1;
mysql> slave start;
解决办法二、
首先停掉Slave服务：slave stop
到主服务器上查看主机状态：
记录File和Position对应的值
进入master
mysql> show master status;
+----------------------+----------+--------------+------------------+
| File                | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+----------------------+----------+--------------+------------------+
| localhost-bin.000094 | 33622483 |              |                  | 
+----------------------+----------+--------------+------------------+
1 row in set (0.00 sec)
然后到slave服务器上执行手动同步：
mysql> change master to 
> master_host='master_ip',
> master_user='user', 
> master_password='pwd', 
> master_port=3306, 
> master_log_file=localhost-bin.000094', 
> master_log_pos=33622483 ;
1 row in set (0.00 sec)
mysql> slave start;

mysql> show slave statusG
*************************** 1. row ***************************
               Slave_IO_State: 
                  Master_Host: 10.16.134.65
                  Master_User: slave75
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000014
          Read_Master_Log_Pos: 354
               Relay_Log_File: mysql-relay.000001
                Relay_Log_Pos: 4
        Relay_Master_Log_File: mysql-bin.000014
             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: 354
              Relay_Log_Space: 107
              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: 65
1 row in set (0.00 sec)
mysql> start slave;

Query OK, 0 rows affected (0.00 sec)
mysql> show slave statusG

 1. row 

Slave_IO_State: Waiting for master to send event

Master_Host: 10.16.134.65

Master_User: slave75

Master_Port: 3306

Connect_Retry: 60

Master_Log_File: mysql-bin.000014

Read_Master_Log_Pos: 354

Relay_Log_File: mysql-relay.000002

Relay_Log_Pos: 253

Relay_Master_Log_File: mysql-bin.000014

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: 354

Relay_Log_Space: 405

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: 65

1 row in set (0.00 sec)

MySQL5.7之前,一个从库只能有一个主库,MySQL5.7之后支持一从多主架构

主从延迟的因素

主库写入二进制日志的时间 [ 控制主库的事务大小,分割大事务 ]

二进制日志传输时间 [ 使用MIXED日志格式, set binlog_row_image = minimal ]

MySQL57.配置多线程复制

stop slave;
set global slave_parallel_type = 'logical_clock';
set global slave_parallel_workers = 4;
start slave;