This topic describes how to migrate full data from a user-created SQL Server database to an ApsaraDB RDS for SQL Server instance by using Data Transmission Service (DTS). DTS supports schema migration, full data migration, and incremental data migration. To migrate full data from a user-created SQL Server database, you can select schema migration and full data migration.

Note For more information about how to migrate data without service disruptions, see Migrate incremental data from a user-created SQL Server database to an ApsaraDB RDS for SQL Server database.

Prerequisites

  • The version of the user-created SQL Server database is 2005, 2008, 2008 R2, 2012, 2014, 2016, or 2017.
    Note
    • SQL Server clusters and SQL Server Always On high availability group are not supported.
    • To perform full migration between databases of different versions, make sure that the two versions are compatible.
  • The available storage space of the ApsaraDB RDS for SQL Server instance is larger than the total size of the data in the user-created SQL Server database.

Background information

  • DTS uses read and write resources of the source and destination databases during full data migration. This may increase the database load. If the database performance is unfavorable, the specification is low, or the data volume is large, database services may become unavailable. For example, DTS occupies a large amount of read and write resources in the following cases: a large number of slow SQL queries are performed on the source database, the tables have no primary keys, or a deadlock occurs in the destination database. Before you migrate data, evaluate the performance of the source and destination databases. We recommend that you migrate data during off-peak hours. For example, you can migrate data when the CPU usage of the source and destination databases is less than 30%.
  • The source database must have PRIMARY KEY or UNIQUE constraints and all fields must be unique. Otherwise, duplicate data may exist in the destination database.
  • DTS automatically creates a destination database in the ApsaraDB RDS for SQL Server instance. However, if the name of the source database is invalid, you must manually create a database in the ApsaraDB RDS for SQL Server instance before you configure the data migration task.
    Note For more information about how to create a database and the database naming conventions, see Create a database.
  • DTS automatically resumes a failed data migration task. Before you switch your workloads to the destination instance, stop or release the data migration task. Otherwise, the data in the source database will overwrite the data in the destination instance after the task is resumed.

Limits

  • DTS cannot migrate data of the sql_variant type.
  • DTS does not support the schema migration for assemblies, service brokers, full-text indexes, full-text catalogs, distributed schemas, distributed functions, CLR stored procedures, CLR scalar-valued functions, CLR table-valued functions, internal tables, systems, and aggregate functions.

Migration types

  • Schema migration

    DTS migrates the schemas of objects to the destination instance. DTS can migrate the schemas of the following objects: tables, views, triggers, synonyms, SQL stored procedures, SQL functions, plan guides, user-defined types, rules, and defaults.

  • Full data migration

    DTS migrates full data of the source objects from the user-created SQL Server database to the ApsaraDB RDS for SQL Server instance.

Billing

Migration type Instance configurations Internet traffic
Full data migration Free of charge Charged only when data is migrated from Alibaba Cloud over the Internet. For more information, see Pricing.

Permissions required for database accounts

Database Schema migration Full data migration
User-created SQL Server database SELECT privilege SELECT privilege
ApsaraDB RDS for SQL Server database Read and write permissions Read and write permissions

For more information about how to create and authorize a database account, see the following topics:

Full data migration

To avoid data migration failures caused by dependencies among objects, DTS migrates the schemas and data from the source SQL Server database in the following order:

  1. Migrate the schemas of tables, views, synonyms, user-defined types, rules, defaults, and plan guides.
  2. Migrate full data.
  3. Migrate the schemas of SQL stored procedures, SQL functions, triggers, and foreign keys.

Procedure

  1. Log on to the DTS console.
  2. In the left-side navigation pane, click Data Migration.
  3. At the top of the Migration Tasks page, select the region where the destination RDS instance resides.Select a region
  4. In the upper-right corner of the page, click Create Migration Task.
  5. Configure the source and destination databases. Configure the source and destination databases
    Section Parameter Description
    N/A Task Name DTS automatically generates a task name. We recommend that you specify an informative name for easy identification. You do not need to use a unique task name.
    Source Database Instance Type Select an instance type based on the location where the database is deployed. In this topic, a User-Created Database with Public IP Address is used as an example.
    Note If you select other instance types, you must prepare the environments that are required for the source database. For more information, see Preparation overview.
    Instance Region If Instance Type is set to User-Created Database with Public IP Address, you do not need to specify the Instance Region.
    Note If you have configured a whitelist for the user-created SQL Server database, you must add the CIDR blocks of DTS servers to the whitelist. You can click Get IP Address Segment of DTS next to Instance Region to obtain the CIDR blocks of DTS servers.
    Database Type Select SQL Server.
    Hostname or IP Address Enter the endpoint that is used to connect to the user-created SQL Server database. In this example, enter the public IP address.
    Port Number Enter the service port number of the user-created SQL Server database. The default port number is 1433.
    Note In this example, the service port of the user-created MongoDB database must be open to the public network.
    Database Account Enter the account that is used to log on to the user-created SQL Server database. For more information about the permissions that are required for the account, see Permissions required for database accounts.
    Database Password Enter the password of the source database account.
    Note After you specify the source database parameters, click Test Connectivity next to Database Password to verify whether the specified parameters are valid. If the specified parameters are valid, the Passed message appears. If the Failed message appears, click Check next to Failed. Modify the source database parameters based on the check results.
    Destination Database Instance Type Select RDS Instance.
    Instance Region Select the region in which the destination RDS instance resides.
    RDS Instance ID Select the ID of the destination RDS instance.
    Database Account Enter the account that is used to log on to the destination RDS instance. For more information about the permissions that are required for the account, see Permissions required for database accounts.
    Database Password Enter the password of the destination database account.
    Note After you specify the destination database parameters, click Test Connectivity next to Database Password to verify whether the parameters are valid. If the specified parameters are valid, the Passed message appears. If the Failed message appears, click Check next to Failed. Modify the destination database parameters based on the check results.
  6. In the lower-right corner of the page, click Set Whitelist and Next.
    Note The CIDR blocks of DTS servers are automatically added to the whitelist of the destination RDS instance. This ensures that DTS servers can connect to the destination RDS instance.
  7. Select the migration types and objects to be migrated. Select the migration types and objects to be migrated
    Parameter Description
    Migration Types
    • To perform only full data migration, select Schema Migration and Full Data Migration.
    • To migrate data with minimal downtime, select Schema Migration, Full Data Migration, and Incremental Data Migration.

    In this example, select Schema Migration and Full Data Migration.

    Note To ensure data consistency, we recommend that you do not write new data into the user-created SQL Server database during full data migration.
    Migration objects

    Select objects from the Available section and click the Right arrow icon to move the objects to the Selected section.

    Note
    • The selected objects can be databases, tables, or columns.
    • By default, the name of an object remains unchanged after migration. You can change the names of the objects in the destination RDS instance by using the object name mapping feature. For more information about how to use this feature, see Object name mapping.
    • If you use the object name mapping feature for an object, objects that depend on the object may fail to be migrated.
  8. In the lower-right corner of the page, click Precheck.
    Note
    • Before you can start the data migration task, a precheck is performed. You can start the data migration task only after the task passes the precheck.
    • If the task fails to pass the precheck, click the Info icon icon next to each failed item to view details. Troubleshoot the issues based on the causes and run the precheck again.
  9. After the task passes the precheck, click Next.
  10. In the Confirm Settings dialog box, specify the Channel Specification and select the Data Transmission Service (Pay-As-You-Go) Service Terms.
  11. Click Buy and Start to start the data migration task.
    Note Do not manually stop a data migration task. Otherwise, data migrated to the destination database will be incomplete. Wait until the data migration task succeeds.
  12. Switch your workloads to the destination RDS instance.

What to do next

The database accounts used for data migration have the read/write permissions. After the data migration is complete, you must delete the accounts of both the user-created SQL Server database and the ApsaraDB RDS for SQL Server instance to ensure database security.