Impact on the Source Database
During full data migration, DTS will consume some resources from the source instance, which may lead to an increase in the load on the source instance and add pressure to the database. If your database has a low configuration, it is recommended to perform the migration during off-peak hours.
Migration Restrictions and Notes
1. DTS migration requires the source instance to support the PSYNC command.
2. The source instance should be in a normal operating status to support migration. Migration is not possible if the password has not been initialized or if other tasks (such as scaling) are in progress.
3. If the source database is AWS ElasticCache for Redis, it requires submitting a ticket for application. The corresponding constraints and limitations are as follows: 3.1 Only ElasticCache for Redis is supported for migration; other AWS Redis products are currently not supported.
3.2 TLS connections are currently not supported. If TLS is enabled on the source database, it should be disabled before migration. However, since disabling TLS on AWS ElasticCache for Redis also disables Auth user authentication, this may expose your data to risks. Therefore, it is recommended to first create a security group, then disable TLS, and add the DTS Service IP to the source database's security group allowlist. 3.3 Since AWS ElasticCache for Redis replica nodes does not support the PSYNC command, migration can only be performed using the primary node.
4. DTS tasks cannot form circular synchronization. Data written during circular synchronization will not be terminated and will continuously loop, leading to a write storm.
5. DTS does not support resumable transmission. Since there are no Binlog files, all incremental data is synchronized in memory. If the connection is lost, the incremental data is lost from memory. Therefore, once a task is initiated, it cannot be interrupted or paused.
6. Migration of Modules is not supported.
7. If global replication is enabled for Tencent Cloud Redis, DTS only supports selecting a primary instance when connecting to the source database. Selection of a read-only instance only facilitates the migration of full data, as migration of incremental data is not supported currently.
8. Do not perform the following operations during migration, as they may result in migration task failure.
Do not modify or delete user information (including usernames, passwords, permissions) and port numbers in the source and target databases.
Do not delete the target database during the data migration phase.
Do not make changes to the target database during the data migration phase to prevent inconsistencies in the final data.