Help Center> Distributed Database Middleware> FAQ> RDS-related Questions> What Risky Operations on RDS for MySQL Will Affect DDM?
View PDF

What Risky Operations on RDS for MySQL Will Affect DDM?

Table 1 lists risky operations on RDS for MySQL.

Table 1 Risky operations on RDS for MySQL

Operation Type

Operation

Impact of the Operation

Operations on the RDS console

Deleting an RDS MySQL DB instance

After an RDS MySQL DB instance is deleted, all schemas and logical tables of the DDM instance associated with the DB instance unavailable.

Performing the primary/standby switchover of an RDS MySQL DB instance

RDS may be intermittently interrupted during the primary/standby switchover. In addition, a small amount of data may be lost in case of long delay in primary/standby synchronization.

  • Creating schemas or logical tables or scaling out schemas is not allowed on DDM during the primary/standby switchover of the RDS MySQL DB instance.
  • After a primary/standby switchover of an RDS MySQL instance, the RDS MySQL instance ID in DDM remains unchanged.

Restarting an RDS MySQL DB instance

An RDS MySQL DB instance being restarted is unavailable, and the DDM service will be affected.

Resetting a password

After the RDS DB instance password is reset, enter the changed password on DDM when creating a schema.

Modifying a parameter template

The following parameters are set to fixed values. If their values are changed, DDM will not function properly.

  • lower_case_table_names: Set this parameter to 1, indicating that data table names and sequence names are case-insensitive.
  • local_infile: Set this parameter to ON in scale-out scenarios.

Modifying a security group

The DDM instance cannot connect to the RDS MySQL DB instance.

Modifying a VPC

The DDM instance and RDS MySQL DB instance cannot communicate with each other if they are in different VPCs.

Restoring data

Restoring data may damage data integrity.

Operations through an RDS MySQL client

Deleting a physical database created on DDM

After a physical database is deleted, the original data will be lost and new data cannot be written into the database.

Deleting a physical account created on DDM

After a physical account is deleted, logical tables cannot be created on DDM.

Deleting a physical table created on DDM

After a logical table is deleted, data will be lost on DDM, and the table cannot be used on DDM.

Modifying the name of a logical table created on DDM

After the name of a logical table is modified, DDM cannot obtain the table data, and the table cannot be used on DDM.

Changing a record

Changing a record in a broadcast table will affect the data consistency of shards.

Modifying a whitelist

The DDM instance cannot access the RDS MySQL DB instance if the DDM instance is not in the DB instance whitelist.
Parent topic: RDS-related Questions