This topic describes how to fix the issue if Data Transmission Service (DTS) fails to obtain the schemas of the source database when you configure a task.
When you select a database as the object to be migrated or synchronized, DTS fails to obtain the schemas of the source database. The following error message appears: Get source schemas failed, reason[null].
- Cause 1: No whitelists are configured or the whitelist settings are incomplete.
- Cause 2: The database accounts do not have the required permissions.
- Cause 3: The RAM user that you use to log on to the DTS console does not have the required permissions.
- Solution 1: Check the whitelist settings. Make sure that whitelists are configured and the whitelist settings are valid. For more information, see Add the CIDR blocks of DTS servers to the security settings of on-premises databases.
- Solution 2: Check the account permissions. Grant the required permissions to the accounts of the source and destination databases. For more information, see Prepare the database accounts for data migration.
- Solution 3: Check the permissions of the RAM user and grant the required permissions. For more information, see Authorize DTS to access Alibaba Cloud resources, Use a system policy to authorize a RAM user to manage DTS instances, and Use a custom policy to authorize a RAM user to manage DTS instances.