ApsaraDB RDS:Migrate data from a self-managed Db2 database to an ApsaraDB RDS for MySQL instance

Prerequisites

• The version of the Db2 database ranges from 9.7 to 11.5.
  Note DTS supports data migration from a Db2 for i database of version 7.3 or 7.4 to an RDS instance. You can follow the procedure described in this topic to migrate data from a Db2 for i database to an RDS instance.
• The storage space of the RDS instance must be larger than the storage space occupied by the Db2 database.

Precautions

• DTS cannot synchronize data definition language (DDL) operations.
• If the name of the source database is invalid, you must create a database in ApsaraDB RDS for MySQL before you configure a data migration task.
  Note For more information about the naming conventions of databases in ApsaraDB RDS for MySQL and how to create a database, see Create a database on an ApsaraDB RDS for MySQL instance.
• DTS uses read and write resources of the source and destination databases during full data migration. This may increase the loads of the database servers. 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 impact of data migration on 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 utilization of the source and destination databases is less than 30%.
• If a data migration task fails, DTS automatically resumes the 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.
• DTS synchronizes incremental updates from a Db2 database to the destination database based on the Change Data Capture (CDC) replication technology of Db2. However, the CDC replication technology has its own limits. For more information, see General data restrictions for SQL Replication.

Billing

Migration types

• Schema migration

  DTS migrates the schemas of the required objects to the destination instance. DTS supports schema migration for the following types of objects: table, index, and foreign key.

• Full data migration

  DTS migrates historical data of the required objects from the Db2 database to the destination database in ApsaraDB RDS for MySQL.

• Incremental data migration

  After full data migration is complete, DTS synchronizes incremental data from the Db2 database to the destination database in ApsaraDB RDS for MySQL. Incremental data migration helps ensure service continuity when you migrate data from a Db2 database.

Permissions required for database accounts

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

• Db2 database: Creating group and user IDs for a Db2 database installation (Linux and UNIX) and Authorities overview
• RDS instance: Create an account on an ApsaraDB RDS for MySQL instance and Modify the permissions of a standard account on an ApsaraDB RDS for MySQL instance

Data migration process

Before you begin

Before you configure an incremental data migration task, enable the archive log feature for the Db2 database. For more information, see Primary log archive method and Secondary log archive method.

Procedure

1. Log on to the DTS console.
   Note If you are redirected to the Data Management (DMS) console, you can click the icon in the lower-right corner to go to the previous version of the DTS console.
2. In the left-side navigation pane, click Data Migration.
3. In the upper part of the Migration Tasks page, select the region in which the ApsaraDB RDS for MySQL instance resides.
4. In the upper-right corner of the page, click Create Migration Task.
5. Configure the source and destination databases.

   Section	Parameter	Description
   N/A	Task Name	DTS automatically generates a task name. We recommend that you specify a name that can help you identify the task. You do not need to specify a unique task name.
   Source Database	Instance Type	Select an instance type of the source database. In this example, select User-Created Database with Public IP Address. Note If you select other instance types, you must deploy the network environment for the self-managed database. For more information, see Preparation overview.
   	Instance Region	If you select User-Created Database with Public IP Address as the instance type, you do not need to specify the Instance Region parameter. Note If a whitelist is configured for the Db2 database, you must add the CIDR blocks of DTS servers to the whitelist of the database. You can click Get IP Address Segment of DTS next to Instance Region to obtain the CIDR blocks of DTS servers.
   	Database Type	Select DB2.
   	Hostname or IP Address	Enter the endpoint that is used to connect to the Db2 database. In this example, enter the public IP address.
   	Port Number	Enter the service port number of the Db2 database. The default port number is 50000. Note The service port of the self-managed database must be accessible over the Internet.
   	Database Name	Enter the name of the Db2 database.
   	Database Account	Enter the account of the Db2 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 preceding 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 where the RDS instance resides.
   	RDS Instance ID	Select the ID of the RDS instance.
   	Database Account	Enter the database account of the destination ApsaraDB RDS for MySQL instance. For information about the permissions that are required for the account, see Permissions required for database accounts.
   	Database Password	Enter the password of the database account. Note After you specify the destination 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 destination database parameters based on the check results.
   	Encryption	Select Non-encrypted or SSL-encrypted. If you want to select SSL-encrypted, you must enable SSL encryption for the RDS instance before you configure the data synchronization task. For more information, see Configure SSL encryption on an ApsaraDB RDS for MySQL instance. Note The Encryption parameter is available only for regions in the Chinese mainland and the China (Hong Kong) region.

6. In the lower-right corner of the page, click Set Whitelist and Next.
   Note DTS adds the CIDR blocks of DTS servers 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 the objects to be migrated.

   Setting	Description
   Select the migration types	To perform only full data migration, select Schema Migration and Full Data Migration. To ensure service continuity during data migration, select Schema Migration, Full Data Migration, and Incremental Data Migration. Note If Incremental Data Migration is not selected, we recommend that you do not write data to the Db2 database during data migration. This ensures data consistency between the source and destination databases.
   Select the objects to be migrated	Select one or more objects from the Available section and click the icon to add the objects to the Selected section. Note You can select columns, tables, or databases. By default, after an object is migrated to the destination RDS instance, the name of the object remains the same as that in the Db2 database. You can use the object name mapping feature to rename the objects that are migrated to the RDS instance. For more information, see Object name mapping. If you use the object name mapping feature to rename an object, other objects that are dependent on the object may fail to be migrated.
   Specify whether to rename objects	You can use the object name mapping feature to rename the objects that are migrated to the destination instance. For more information, see Object name mapping.
   Specify the retry time range for failed connections to the self-managed Oracle database or RDS instance	By default, if DTS fails to connect to the self-managed Oracle database or RDS instance, DTS retries within the following 12 hours. You can specify the retry time range based on your business requirements. If DTS is reconnected to the self-managed Oracle database and RDS instance within the specified time range, DTS resumes the data migration task. Otherwise, the data migration task fails. Note Within the time range in which DTS attempts to reconnect to the self-managed Oracle database and RDS instance, you are charged for the DTS instance. We recommend that you specify the retry time range based on your business requirements. You can also release the DTS instance at the earliest opportunity after the self-managed Oracle database and RDS instance are released.

8. Click Precheck.
   Note

   • A precheck is performed before the migration task starts. The migration task only starts after the precheck succeeds.
   • If the precheck fails, click the icon next to each failed check item to view the related details. Fix the issues as instructed and run the precheck again.
9. After the task passes the precheck, click Next.
10. In the Confirm Settings dialog box, specify the Instance Class parameter and select the check box to agree to Data Transmission Service (Pay-As-You-Go) Service Terms.
11. Click Buy and Start to start the data migration task.
    • Full data migration

      Do not manually stop a full data migration task. If you manually stop a full data migration task, the data that is migrated to the ApsaraDB RDS for MySQL instance may be incomplete. You can wait until the data migration task automatically stops.

    • Incremental data migration

      An incremental data migration task does not automatically stop. You must manually stop the task.

      Note We recommend that you manually stop an incremental data migration task at an appropriate point in time. For example, you can stop the task during off-peak hours or before you switch your workloads over to the ApsaraDB RDS for MySQL instance.
      1. Wait until Incremental Data Migration and The data migration task is not delayed are displayed in the progress bar of the data migration task. Then, stop writing data to the source database for a few minutes. The latency of incremental data migration may be displayed in the progress bar.
      2. Wait until the status of incremental data migration changes to The data migration task is not delayed again. Then, manually stop the migration task.
12. Switch your workloads to the RDS instance.