Shulou(Shulou.com)05/31 Report--

The main content of this article is to explain "how to configure Mysql from the library delay application", interested friends may wish to take a look. The method introduced in this paper is simple, fast and practical. Let's let the editor take you to learn "how to configure the delayed application from the library by Mysql".

Delayed application is mainly used to prevent logic errors, such as mismodification and deletion of the master library. If the slave database has not applied these incorrect SQL within the set time, the data before misoperation can be obtained from the slave library.

Mysql implements deferred application by specifying the master_delay option of the slave library.

1. Install Mysql and configure master and slave

Refer to http://blog.itpub.net/28536251/viewspace-2138854/ to install Mysql on both nodes.

Refer to http://blog.itpub.net/28536251/viewspace-2138928/ or http://blog.itpub.net/28536251/viewspace-2139007/ to configure master and slave.

2. Configure delayed applications from the library

(root@localhost) [(none)] stop slave sql_thread

Query OK, 0 rows affected (0.15 sec)

(root@localhost) [(none)] change master to master_delay=60

Query OK, 0 rows affected (0.02 sec)

# the delay from the library is 60 seconds.

(root@localhost) [(none)] start slave sql_thread

Query OK, 0 rows affected (0.04 sec)

3. Testing

Main library:

(root@localhost) [test] insert into tb1 values (3)

Query OK, 1 row affected (0.33 sec)

From the library:

(root@localhost) [(none)] show slave status\ G

* * 1. Row *

Slave_IO_State: Waiting for master to send event

Master_Host: 10.163.84.16

Master_User: repl

Master_Port: 3306

Connect_Retry: 60

Master_Log_File: mysql-bin.000002

Read_Master_Log_Pos: 1298

Relay_Log_File: dbrac17-relay-bin.000003

Relay_Log_Pos: 594

Relay_Master_Log_File: mysql-bin.000002

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: 1024

Relay_Log_Space: 1839

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: 4

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: 8416

Master_UUID: 3de828ce-354c-11e7-9f0b-0050568a4cf6

Master_Info_File: / usr/local/mysql/data/master.info

SQL_Delay: 60

SQL_Remaining_Delay: 56

Slave_SQL_Running_State: Waiting until MASTER_DELAY seconds after master executed event

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)

# SQL_Delay: 60 indicates a delay of 60 seconds.

# SQL_Remaining_Delay: 56 means it will take 56 seconds to apply the log.

Check it in 1 minute:

(root@localhost) [test] select * from tb1

+-+

| | id |

+-+

| | 1 |

| | 2 |

| | 3 |

+-+

3 rows in set (0.00 sec)

At this point, I believe that everyone has a deeper understanding of "how to configure the delayed application from the library". You might as well do it in practice. Here is the website, more related content can enter the relevant channels to inquire, follow us, continue to learn!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.