MySQL master-slave replication, detailed configuration, create unable to connect processing prompt

One 、 Implementation conditions ：

      Here is a demonstration of one-to-one master-slave replication , It is a master server , A slave server

      Readers are required to install two virtual machines

Two 、 Master slave replication principle ：

        As shown in the figure below

       1、 The data in the master server is added, deleted and modified , This operation will be saved in the log (Baniry log)

       2、 The slave server will utilize IOThread The thread reads the log of the master server

       3、IOThread Save the read information to the log in the slave server Relay log 

       4、SQLThread Read log SQL Statement to execute , This will change the data from the server

3、 ... and 、 The law of master-slave replication

 1、 Addition, deletion and modification of data by the master server , Can affect the slave server The data on the

2、 The addition, deletion and modification of data from the server , It will not affect the primary server

3、 Simply speaking , The slave server in the form of master-slave replication only performs the query function

Four 、 Server settings

    Master server setting

   1、 Create a database for master-slave replication

        create database  abb;

  2、 Open share permissions

grant replication slave on *.* to 'root'@'%' identified by 'ok';   / / Set the permissions

flush privileges;   // Refresh the permissions

3、 To configure my.cnf file

1、 stay dos Interface input     cd /etc/my.cnf

2、 Add configuration file  

（ Press a edit , Press ESC Exit the editor , Press : wq Exit the configuration file interface ）

       [mysqld]
        server-id = 1           // Indicates the server number , Each server has a unique number , Can't repeat
        log-bin = mysql-bin     // Log name
        binlog-do-db =abb     // Database for sharing , Not writing means that all databases are shared
        binlog-ignore-db = information_schema,mysql,performance_schema

                                          // Indicates that the synchronized database is not shared

3、 Restart the server

    service mysql restart

4、 Check the status

Up reading lock   flush tables with read lock;

Check the status    show master status\G

Unlock   unlock tables;   

  The view status is as follows （ remember Position Value , From the server ）

 Slaver Server configuration

1、 Create a database synchronized with the main service

        create database  abb;

2、 To configure my.cnf file

1、 stay dos Interface input     cd /etc/my.cnf

2、 Add configuration file  

（ Press a edit , Press ESC Exit the editor , Press : wq Exit the configuration file interface ）

       [mysqld]
        server-id = 2          // Cannot be the same as the main service
        log-bin =mysql-bin     // Log name
        binlog-do-db =abb     // Database for sharing , Not writing means that all databases are shared
        binlog-ignore-db = information_schema,mysql,performance_schema

                                          // Indicates that the synchronized database is not shared

3、 Restart the server

    service mysql restart

3、 Change the parameters of the primary server to which this server is connected

stop slave;
        change master to
        master_host='192.168.234.100',master_user='root',master_password='ok',
        master_log_file='mysql-bin.000007',master_log_pos=120;

       // The parameters in turn are ： Host number （ Of the main server IP）+ user name + password + The log of + Based on the same （position）
  start slave;

4、 Check the status

Up reading lock   flush tables with read lock;

Check the status    show slave status\G

Unlock   unlock tables;   

    The results of checking the status are as follows ：

   Slave_IO_Running    and Slave_SQL_Running Must indicate open status

  5、 ... and 、 How to handle the error report

   1、 Check Slave_IO_Running    and Slave_SQL_Running Is it in yes state

   2、 In the main server Read_Master_Log_Pos And from the server position The value must be the same

   3、 After the configuration file is changed , You have to restart the server    service mysql restart

   4、 Detect settings from the server Master Is the parameter correct