This topic describes how to migrate data from a self-managed Oracle database to an ApsaraMQ for Kafka instance by using Data Transmission Service (DTS).
Prerequisites
The source self-managed Oracle database and the destination ApsaraMQ for Kafka instance are created.
NoteFor more information about the supported versions of the source database and the destination instance, see Overview of data migration scenarios.
The self-managed Oracle database is running in ARCHIVELOG mode. Archived log files are accessible, and an appropriate retention period is set for archived log files. For more information, see Managing Archived Redo Log Files.
The supplemental logging feature is enabled for the self-managed Oracle database, and the SUPPLEMENTAL_LOG_DATA_PK and SUPPLEMENTAL_LOG_DATA_UI parameters are set to Yes. For more information, see Supplemental Logging.
The available storage space of the destination ApsaraMQ for Kafka instance is larger than the storage space occupied by the self-managed Oracle database.
In the destination ApsaraMQ for Kafka instance, a topic is created to receive the migrated data. For more information, see the Step 1: Create a topic section of the Step 3: Create resources topic.
You are familiar with the capabilities and limits that DTS has if DTS is used to migrate data from an Oracle database. Advanced Database & Application Migration (ADAM) is used for database evaluation. This helps you smoothly migrate data to the cloud. For more information, see Prepare an Oracle database and Overview.
Limits
DTS does not migrate foreign keys in the source database to the destination database. Therefore, the cascade and delete operations of the source database are not migrated to the destination database.
Category | Description |
Limits on the source database |
|
Other limits |
|
Billing
Migration type | Instance configuration fee | Internet traffic fee |
Schema migration and full data migration | Free of charge. | Charged only when data is migrated from Alibaba Cloud over the Internet. For more information, see Billing overview. |
Incremental data migration | Charged. For more information, see Billing overview. |
Migration types
Migration type | Description |
Schema migration | DTS migrates the schemas of the selected objects from the source Oracle database to the destination ApsaraMQ for Kafka instance. Note In this scenario, DTS does not support schema migration for triggers. We recommend that you delete the triggers of the source database to prevent data inconsistency caused by the triggers. For more information, see Configure a data synchronization task for a source database that contains a trigger. |
Full data migration | DTS migrates the historical data of the selected objects from the source Oracle database to the destination ApsaraMQ for Kafka instance. Note During schema migration and full data migration, do not perform DDL operations on the objects to be migrated. Otherwise, the objects may fail to be migrated. |
Incremental data migration | DTS retrieves redo log files from the source Oracle database. Then, DTS migrates incremental data from the source Oracle database to the destination ApsaraMQ for Kafka instance. Incremental data migration ensures service continuity when you migrate data from a self-managed Oracle database. |
SQL operations that can be incrementally migrated
Operation type | SQL statement |
DML | INSERT, UPDATE, and DELETE |
DDL |
|
Preparations
Log on to the self-managed Oracle database, create an account that you want to use to collect data, and then grant permissions to the account.
If you have created an account that is granted the permissions described in the following table, you can skip this step.
Database | Schema migration | Full data migration | Incremental data migration |
Source Oracle database | Permissions of the schema owner | Permissions of the schema owner | Fine-grained permissions |
For more information about how to create a database account and grant permissions to the database account, see the following topics:
Self-managed Oracle database: Prepare a database account, CREATE USER, and GRANT
If you need to migrate incremental data from an Oracle database, you must enable archive logging and supplemental logging for the Oracle database to obtain incremental data. For more information, see the Configure an Oracle database section of the "Prepare an Oracle database" topic.
Procedure
Go to the Data Migration Tasks page.
Log on to the Data Management (DMS) console.
In the top navigation bar, click DTS.
In the left-side navigation pane, choose .
NoteOperations may vary based on the mode and layout of the DMS console. For more information, see Simple mode and Customize the layout and style of the DMS console.
You can also go to the Data Migration Tasks page of the new DTS console.
From the drop-down list next to Data Migration Tasks, select the region in which the data migration instance resides.
NoteIf you use the new DTS console, you must select the region in which the data migration instance resides in the upper-left corner.
Click Create Task. On the Create Task page, configure the source and destination databases. The following table describes the parameters.
WarningAfter you configure the source and destination databases, we recommend that you read the limits that are displayed in the upper part of the page. Otherwise, the task may fail or data inconsistency may occur.
Section
Parameter
Description
N/A
Task Name
The name of the task. DTS automatically assigns a name to the task. We recommend that you specify a descriptive name that makes it easy to identify the task. You do not need to specify a unique task name.
Source Database
Select a DMS database instance
The database instance that you want to use. You can choose whether to use an existing instance based on your business requirements.
If you select an existing instance, DTS automatically populates the parameters for the database.
If you do not select an existing instance, you must configure parameters for the source database.
Database Type
The type of the source database. Select Oracle.
Access Method
The access method of the source database. Select the access method based on the location in which the source database is deployed. In this example, Self-managed Database on ECS is selected.
NoteIf your source database is a self-managed database, you must deploy the network environment for the database. For more information, see Preparation overview.
Instance Region
The region where the source Oracle database resides.
ECS Instance ID
The ID of the Elastic Compute Service (ECS) instance that hosts the self-managed Oracle database.
Port Number
The service port number of the self-managed Oracle database. Default value: 1521.
Oracle Type
The architecture of the source database. If you select Non-RAC Instance, you must configure the SID parameter.
If you select RAC or PDB Instance, you must configure the Service Name parameter.
In this example, Non-RAC Instance is selected.
Database Account
The account of the source Oracle database. For more information about the permissions that are required for the account, see the Preparations section of this topic.
Database Password
The password of the database account.
Destination Database
Select a DMS database instance
The database instance that you want to use. You can choose whether to use an existing instance based on your business requirements.
If you select an existing instance, DTS automatically populates the parameters for the instance.
If you do not select an existing instance, you must configure parameters for the destination database.
Database Type
The type of the destination database. Select Kafka.
Access Method
The access method of destination database. Select Express Connect, VPN Gateway, or Smart Access Gateway.
NoteYou cannot select ApsaraMQ for Kafka as the access method. You can use the ApsaraMQ for Kafka instance as a self-managed Kafka database to configure data migration.
Instance Region
The region in which the destination ApsaraMQ for Kafka instance resides.
Connected VPC
The ID of the virtual private cloud (VPC) to which the destination ApsaraMQ for Kafka instance belongs. To obtain the VPC ID, perform the following operations: Log on to the ApsaraMQ for Kafka console and go to the Instance Details page of the ApsaraMQ for Kafka instance. In the Configuration Information section of the Instance Information tab, view the VPC ID.
IP Address or Domain Name
An IP address of the default endpoint of the destination ApsaraMQ for Kafka instance.
NoteTo obtain an IP address, perform the following operations: Log on to the ApsaraMQ for Kafka console and go to the Instance Details page of the ApsaraMQ for Kafka instance. In the Endpoint Information section of the Instance Information tab, obtain an IP address from the Default Endpoint parameter.
Port Number
The service port number of the ApsaraMQ for Kafka instance. Default value: 9092.
Database Account
The database account of the ApsaraMQ for Kafka instance.
NoteIf the instance type of the ApsaraMQ for Kafka instance is VPC Type, you do not need to specify the Database Account and Database Password parameters.
Database Password
The password of the database account.
Kafka Version
The version of the destination ApsaraMQ for Kafka instance.
Encryption
Specifies whether to encrypt the connection to the destination instance. Select Non-encrypted or SCRAM-SHA-256 based on your business and security requirements.
Topic
The topic that is used to receive the migrated data. Select a topic from the drop-down list.
Topic That Stores DDL Information
The topic that is used to store the DDL information. Select a topic from the drop-down list. If you do not configure this parameter, the DDL information is stored in the topic that is specified by the Topic parameter.
Use Kafka Schema Registry
Specifies whether to use Kafka Schema Registry. Kafka Schema Registry provides a serving layer for your metadata. It provides a RESTful API to store and retrieve your Avro schemas. Valid values:
No
Yes If you select Yes for this parameter, you must enter the URL or IP address that is registered in Kafka Schema Registry for your Avro schemas.
If an IP address whitelist is configured for your self-managed database, add the CIDR blocks of DTS servers to the IP address whitelist. Then, click Test Connectivity and Proceed.
WarningIf the public CIDR blocks of DTS servers are automatically or manually added to the whitelist of a database instance or to the security group rules of an ECS instance, security risks may arise. Therefore, before you use DTS to migrate data, you must understand and acknowledge the potential risks and take preventive measures, including but not limited to the following measures: enhancing the security of your username and password, limiting the ports that are exposed, authenticating API calls, regularly checking the whitelist or security group rules and forbidding unauthorized CIDR blocks, or connecting the database instance to DTS by using Express Connect, VPN Gateway, or Smart Access Gateway.
Configure the objects to be migrated and advanced settings.
Parameter
Description
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.
NoteIf you do not select Incremental Data Migration, we recommend that you do not write data to the source database during data migration. This ensures data consistency between the source and destination databases.
Processing Mode of Conflicting Tables
Precheck and Report Errors: checks whether the destination database contains tables that use the same names as tables in the source database. If the source and destination databases do not contain tables that have identical table names, the precheck is passed. Otherwise, an error is returned during the precheck and the data migration task cannot be started.
NoteIf the source and destination databases contain identical table names and the tables in the destination database cannot be deleted or renamed, you can use the object name mapping feature to rename the tables that are migrated to the destination database. For more information, see Map object names.
Ignore Errors and Proceed: skips the precheck for identical table names in the source and destination databases.
WarningIf you select Ignore Errors and Proceed, data inconsistency may occur and your business may be exposed to the following potential risks:
If the source and destination databases have the same schema, DTS does not migrate data records that have the same primary keys as data records in the destination database.
If the source and destination databases have different schemas, only specific columns are migrated or the data migration task fails. Proceed with caution.
Data Format in Kafka
The format in which data is stored in the destination ApsaraMQ for Kafka instance.
If you select DTS Avro, data is parsed based on the schema definition of DTS Avro. For more information, visit GitHub.
If you select SharePlex JSON, data is stored in the SharePlex JSON format. For more information, see the Shareplex Json section of the Data formats of a Kafka cluster topic.
Policy for Shipping Data to Kafka Partitions
The policy for migrating data to Kafka partitions. Select a policy based on your business requirements. For more information, see Specify the policy for migrating data to Kafka partitions.
Source Objects
Select one or more objects from the Source Objects section and click the icon to add the objects to the Selected Objects section.
Selected Objects
- To rename an object that you want to migrate to the destination instance, right-click the object in the Selected Objects section. For more information, see Map the name of a single object.
- To rename multiple objects at a time, click Batch Edit in the upper-right corner of the Selected Objects section. For more information, see Map multiple object names at a time.
NoteIf you use the object name mapping feature to rename an object, other objects that are dependent on the object may fail to be migrated.
To specify WHERE conditions to filter data, right-click a table in the Selected Objects section. In the dialog box that appears, specify the conditions. For more information, see Set filter conditions.
To select the SQL operations that are performed on a specific database or table, right-click the object in the Selected Objects section. In the dialog box that appears, select the SQL operations that you want to incrementally migrate. For more information, see the SQL operations that can be incrementally migrated section of this topic.
Click Next: Advanced Settings to configure advanced settings. The following table describes the parameters.
Parameter
Description
Select the dedicated cluster used to schedule the task
By default, DTS schedules the task to a shared cluster. You do not need to configure this parameter. You can also purchase and specify a dedicated cluster of the required specifications to run the data migration task. For more information, see What is a DTS dedicated cluster.
Retry Time for Failed Connections
The retry time range for failed connections. If the source or destination database fails to be connected after the data migration task is started, DTS immediately retries a connection within the retry time range. Valid values: 10 to 1440. Unit: minutes. Default value: 720. We recommend that you set the parameter to a value greater than 30. If DTS is reconnected to the source and destination databases within the specified retry time range, DTS resumes the data migration task. Otherwise, the data migration task fails.
NoteIf you specify different retry time ranges for multiple data migration tasks that share the same source or destination database, the value that is specified later takes precedence.
When DTS retries a connection, 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 source database and destination instance are released.
The wait time before a retry when other issues occur in the source and destination databases.
The retry time range for other issues. For example, if DDL or DML operations fail to be performed after the data migration task is started, DTS immediately retries the operations within the retry time range. Valid values: 1 to 1440. Unit: minutes. Default value: 10. We recommend that you set the parameter to a value greater than 10. If the failed operations are successfully performed within the specified retry time range, DTS resumes the data migration task. Otherwise, the data migration task fails.
ImportantThe value of the The wait time before a retry when other issues occur in the source and destination databases parameter must be smaller than the value of the Retry Time for Failed Connections parameter.
Enable Throttling for Full Data Migration
Specifies whether to enable throttling for full data migration. During full data migration, DTS uses the read and write resources of the source and destination databases. This may increase the loads of the database servers. You can enable throttling for full data migration based on your business requirements. To configure throttling, you must configure the Queries per second (QPS) to the source database, RPS of Full Data Migration, and Data migration speed for full migration (MB/s) parameters. This reduces the loads of the destination database server.
NoteYou can configure this parameter only when you select Full Data Migration for the Migration Types parameter.
Enable Throttling for Incremental Data Migration
Specifies whether to enable throttling for incremental data migration. To configure throttling, you must configure the RPS of Incremental Data Migration and Data migration speed for incremental migration (MB/s) parameters. This reduces the loads of the destination database server.
NoteYou can configure this parameter only when you select Incremental Data Migration for the Migration Types parameter.
Environment Tag
The environment tag that is used to identify the DTS instance. You can select an environment tag based on your business requirements. In this example, no environment tag is selected.
Actual Write Code
The encoding format in which data is written to the destination database. Select a format based on your business requirements.
Configure ETL
Specifies whether to enable the extract, transform, and load (ETL) feature. For more information, see What is ETL? Valid values:
Yes: configures the ETL feature. You can enter data processing statements in the code editor. For more information, see Configure ETL in a data migration or data synchronization task.
No: does not configure the ETL feature.
Monitoring and Alerting
Specifies whether to configure alerting for the data migration task. If the task fails or the migration latency exceeds the specified threshold, the alert contacts receive notifications. Valid values:
No: does not configure alerting.
Yes: configures alerting. If you select Yes, you must also specify the alert threshold and alert contacts. For more information, see the Configure monitoring and alerting for a new DTS task section of the "Configure monitoring and alerting" topic.
In the lower part of the page, click Next: Save Task Settings and Precheck.
You can move the pointer over Next: Save Task Settings and Precheck and click Preview API Call to view the parameter settings of the API operation that is called to configure the instance.
NoteBefore you can start the data migration task, DTS performs a precheck. You can start the data migration task only after the task passes the precheck.
If the task fails to pass the precheck, click View Details next to each failed item. After you troubleshoot the issues based on the causes, run a precheck again.
If an alert is generated for an item during the precheck, perform the following operations based on the scenario:
If the alert item cannot be ignored, click View Details next to the failed item and troubleshoot the issues. Then, run a precheck again.
If the alert item can be ignored, click Confirm Alert Details. In the View Details dialog box, click Ignore. In the message that appears, click OK. Then, click Precheck Again to run a precheck again. If you ignore the alert item, data inconsistency may occur and your business may be exposed to potential risks.
Wait until the success rate becomes 100%. Then, click Next: Purchase Instance.
On the Purchase Instance page, configure the Instance Class parameter for the data migration instance. The following table describes the parameters.
Section
Parameter
Description
New Instance Class
Resource Group
The resource group to which the data migration instance belongs. Default value: default resource group. For more information, see What is Resource Management?
Instance Class
DTS provides instance classes that vary in the migration speed. You can select an instance class based on your business scenario. For more information, see Specifications of data migration instances.
Read and agree to Data Transmission Service (Pay-as-you-go) Service Terms by selecting the check box.
Click Buy and Start to start the data migration task. You can view the progress of the task on the Task Management page of the data migration task.