Impact on the Source Database
When Data Transfer Service (DTS) is used to perform a full data migration, it occupies certain resources of the source instance, which may cause the source instance load to increase and add pressure to the database. If your database configuration is low, it is recommended to perform the migration during off-peak hours.
Migration Limitations and Instructions
1. The source instance can only be migrated when it is in normal operation. Migration cannot be performed when the password is uninitialized or when other tasks (such as scale-out) are in progress.
2. The maximum string length in TencentDB for KeeWiDB is 16 MB. This limit applies to both keys and values of the String type, as well as to each element in composite data structures such as Hash, Set, Zset, and List. If this limit is exceeded, an error will occur during migration. Make sure to perform a self-check before starting the migration.
3. DTS tasks shall not form a circular synchronization. The data written in circular synchronization will not be terminated and will keep running in the loop, which will lead to an infinite write loop.
4. Migration of modules is not supported.
5. Do not perform the following operations during migration. Otherwise, they will cause the migration task to fail.
Do not modify or delete user information (including usernames, passwords, and permissions) and port numbers in the source and target databases.
Do not delete the target database during the data migration phase.
Do not perform operations on the target database data during the data migration phase to avoid data inconsistency.