This topic describes how to migrate full data from an Amazon Aurora PostgreSQL database to an ApsaraDB RDS for PostgreSQL database by using Data Transmission Service (DTS).

Prerequisites

  • The version of the Amazon Aurora PostgreSQL database is 9.4, 9.5, 9.6, or 10.0.
  • The Public accessibility option of Amazon Aurora PostgreSQL is set to Yes. This ensures that DTS can access Amazon Aurora PostgreSQL over the Internet.
  • An ApsaraDB RDS for PostgreSQL instance is created. For more information, see Create an RDS for PostgreSQL instance.
    Note The version of the ApsaraDB RDS for PostgreSQL database is 9.4 or 10.0.
  • The available storage space of the ApsaraDB RDS for PostgreSQL instance is larger than the total space of the data in the Amazon Aurora PostgreSQL instance.

Notes

  • You cannot use DTS to migrate incremental data from an Amazon Aurora PostgreSQL database to an ApsaraDB RDS for PostgreSQL database. Before you start the data migration task, you must stop your business that runs on the Amazon Aurora PostgreSQL database. To ensure data consistency, do not write new data into the Amazon Aurora PostgreSQL database during data migration.
  • DTS does not support incremental data migration. When using DTS for full data migration, you need to stop business operations that are related to the Amazon Aurora PostgreSQL database before migration. To ensure data consistency, do not write new data to the Amazon Aurora PostgreSQL database during migration.
  • A single data migration task can migrate data from only one database. To migrate data from multiple databases, you must create a data migration task for each database.
  • Functions that are written in the C programming language cannot be migrated.
  • 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 resumes a failed data migration task. Before switching your workloads to the destination instance, you must stop or release the data migration task. Otherwise, the data from the source database will overwrite the data in the destination instance after the task is resumed.

Billing

Migration type Instance configurations Internet traffic
Schema migration or full data migration Free of charge Migrating data from Alibaba Cloud over the Internet incurs fees. For more information, see Pricing.

Migration types

  • Schema migration

    DTS migrates the schemas of the required objects to the ApsaraDB RDS for PostgreSQL database. DTS supports schema migration for the following types of objects: table, trigger, view, sequence, function, user-defined type, rule, domain, operation, and aggregate.

  • Full data migration

    DTS migrates historical data of the required objects from the Amazon RDS for PostgreSQL database to the ApsaraDB RDS for PostgreSQL database.

Permissions required for database accounts

Database Schema migration Full data migration
Amazon Aurora PostgreSQL The usage permission for pg_catalog The permission to perform SELECT operations on the objects to be migrated
ApsaraDB RDS for PostgreSQL database The create and usage permissions on the objects to be migrated The owner permission for schemas

Full data migration

To avoid data migration failures caused by dependencies between objects, DTS migrates the schemas and data of the source PostgreSQL database in the following order:

  1. Migrate the schemas of tables, views, sequences, functions, user-defined types, rules, domains, operations, and aggregates.
  2. Perform full data migration.
  3. Migrate the schemas of triggers and foreign keys.

Preparation 1: Modify Amazon inbound rules

  1. Log on to the Amazon Aurora console.
  2. Go to the Basic Information page of the source Amazon Aurora PostgreSQL instance.
  3. Select the node that is set to the role of Writer.
  4. In the Connectivity & security section, click the name of the VPC security group that corresponds to the Writer node.
    Security group rules
  5. On the Security Groups page, click the Inbound tab in the Security Group section. On the Inbound tab, click Edit, and add CIDR blocks of DTS servers to the Edit inbound rules dialog box that appears. The CIDR blocks of DTS servers vary with the region where the destination database resides. For more information about the CIDR blocks of DTS servers, see Add the CIDR blocks of DTS servers to the security settings of on-premises databases.
    AWS postgresql入站规则
    Note
    • You only need to add the CIDR blocks of DTS servers that are located in the same region as the destination database. For example, the source database is located in Singapore and the destination database is located in Hangzhou. You only need to add the CIDR blocks of DTS servers that are located in the China (Hangzhou) region.
    • You can add all the required CIDR blocks to the inbound rule at one time.

Preparation 2: Create a database and schema in the destination RDS instance

Create a database and schema in the destination RDS instance based on the database and schema information of the objects to be migrated. The schema name of the destination database must be the same as that of the source database. For more information, see Create a database and Schema management.

Procedure

  1. Log on to the DTS console.
  2. In the left-side navigation pane, click Data Migration.
  3. At the top of Migration Tasks the page, select the region where the destination cluster resides.
    Select a region
  4. In the upper-right corner of the page, click Create Migration Task.
  5. Configure the information about the source and destination databases for the data migration task.
    Configure the source and destination databases
    Section Parameter Description
    N/A Task Name DTS automatically generates a task name. We recommend that you use an informative name for easy identification. You do not need to use a unique task name.
    Source Database Instance Type Select User-Created Database with Public IP Address.
    Instance Region Select the region where the source instance resides. If the instance type is set to User-Created Database with Public IP Address, you do not need to specify the instance region.
    Database Type Select PostgreSQL.
    Hostname or IP Address Enter the endpoint that is used to connect to the Amazon Aurora PostgreSQL database.
    Note You can obtain the endpoint on the Basic information page of the source Amazon Aurora PostgreSQL instance.
    View the endpoint
    Port Number Enter the service port number of the Amazon Aurora PostgreSQL database. The default port number is 5432.
    Database Name Enter the name of the source Amazon Aurora PostgreSQL database.
    Database Account Enter the account for the Amazon Aurora PostgreSQL database. For more information about permissions required for the account, see Permissions required for database accounts.
    Database Password Enter the password for the database account.
    Note After the source database information is specified, click Test Connectivity next to Database Password to verify whether the specified information is valid. If the specified information is valid, the Passed message appears. If the Failed message appears, click Check in the Failed message. Modify the source database information as prompted.
    Destination Database Instance Type Select RDS Instance.
    Instance Region Select the region where the destination ApsaraDB RDS for PostgreSQL instance resides.
    RDS Instance ID Select the ID of the destination ApsaraDB RDS for PostgreSQL instance.
    Database Name Enter the name of the destination ApsaraDB RDS for PostgreSQL database. The name can be different from the name of the source Amazon Aurora PostgreSQL database.
    Note Before you configure the data migration task, you must create a database and schema in the ApsaraDB RDS for PostgreSQL instance. For more information, see Preparation 2: Create a database and schema in the destination RDS instance.
    Database Account Enter the database account of the destination ApsaraDB RDS for PostgreSQL instance. For more information about permissions required for the account, see Permissions required for database accounts.
    Database Password Enter the password for the database account.
    Note After the destination database information is specified, click Test Connectivity next to Database Password to verify whether the specified information is valid. If the specified information is valid, the Passed message appears. If the Failed message appears, click Check in the Failed message. Modify the destination database information as prompted.
  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 ApsaraDB for RDS instance. This ensures that DTS servers can connect to the ApsaraDB for 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 Select Schema Migration and Full Data Migration. In this data migration task, incremental data migration is not supported.
    Note To ensure data consistency, do not write new data into the Amazon Aurora PostgreSQL database during data migration.
    Objects to be migrated

    In the Available section, select the objects to be migrated and click the Right arrow icon to add the objects to the Selected section.

    Note
    • You can select databases, tables, or columns as the objects to be migrated.
    • After an object is migrated to the destination database, the name of the object remains unchanged. If you want an object to have a different name after the object is migrated to the ApsaraDB RDS for PostgreSQL instance, you can use the object name mapping feature provided by DTS. For more information about how to use this feature, see Object name mapping.
    • If you use the object name mapping feature on an object, other objects that are dependent on the object may fail to be migrated.
  8. Click Precheck on the lower right of the page.
    Note
    • A precheck is performed for a data migration task. A data migration task can be started only if it passes the precheck.
    • If the precheck fails, click Note icon corresponding to each failed item to view the details. Fix the problems as instructed and run the precheck again.
  9. After the precheck is passed, click Next.
  10. On the Confirm Settings dialog box that appears, specify 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 migration task. Otherwise, data migrated to the destination database will be incomplete. Wait until the data migration task stops when it is complete.
    Full data migration
  12. Switch your workloads to the ApsaraDB RDS for PostgreSQL instance.