Customer disaster recovery case - a MySQL database migration scheme

During the construction of customer disaster recovery plan , The customer migrates the database instance to the cloud MySQL Is a very common need . At present, the most commonly used general migration scheme is a more mature one , This scheme can be adopted in the general migration process ; But there is an inconvenient point in the general scheme ： Business switching in the migration process is a difficult point , Adjust the business database connection configuration , Switch the read / write data source to CDB Example of IP. The step of adjusting the connection configuration of the business database is likely to store the missing information , The front-end business has been developing for a long time , There are multiple sources that connect to the database , It is difficult to adjust the access source to the target at one time .

General switching scheme ：

In the figure, No 3 Step , The business side is required to modify the direction MySQL Of IP.

This scheme provides a migration scheme ： By directly modifying the database connection IP, Realize fast business switching , Avoid business front-end redirection IP.

This plan ：

HHA yes MySQL Relatively mature solutions for high availability , This article illustrates with examples , Create a database on behalf of the customer .

Switch preconditions ：

at present MySQL The console provides modification " Connect VIP" The function of ：

This address is MySQL Connection provided VIP, this VIP It can be modified to any unoccupied in the subnet of this instance IP Address . Based on this principle , Require previous source data VIP In the same subnet as the target instance . This is guaranteed by resource planning .

Switching steps ：

1. Pre check . Check that the data synchronization is complete and as expected .
2. Close target MySQL read-only , Open source MySQL read-only .
3. Put the source library's MHA Of VIP Release .
4. The target MySQL Of VIP Change to source VIP.

1. Log in to the source library ,kill The process of deleting non system accounts .
2. Observe the business situation , To complete the migration .

matters needing attention ： A fallback strategy should be made during the switching process ,3,4 There are certain risks in the process , Careful evaluation is required before operation .