After a sandbox instance is created for emergency disaster recovery, you can use Data Transmission Service (DTS) to migrate data from the sandbox instance to an ApsaraDB RDS for MySQL instance.
Background information
Database Backup (DBS) provides a sandbox solution based on copy data management (CDM). You can create independent DBS sandbox instances with ease. This way, it takes less time to make your backup data available. For more information, see Overview.
- Save the data that is written in a sandbox instance. Read and write operations performed within sandbox instances do not affect source databases. To save the data that is written to a sandbox instance, you can migrate the data from the sandbox instance to an ApsaraDB RDS for MySQL instance.
- Accelerate restoration. Compared with the regular restoration methods provided by DBS, the DBS sandbox feature accelerates the restoration of backup sets. You can use the DBS sandbox instance feature to create a sandbox instance for emergency disaster recovery and then migrate the tables or databases in the sandbox instance to an ApsaraDB RDS for MySQL instance.
Prerequisites
- A sandbox instance is created for emergency disaster recovery. For more information, see Use the emergency recovery feature for an ApsaraDB RDS for MySQL instance.
- The available storage space of the ApsaraDB RDS for MySQL instance is larger than the total size of the data to be migrated.
Usage notes
- Data migration does not affect the data in the sandbox instance. During data migration, DTS reads the data in the sandbox instance and copies the data to the ApsaraDB RDS for MySQL instance. DTS does not modify the data in the sandbox instance.
- To ensure data consistency, we recommend that you do not write data to the sandbox instance during full data migration.
Migration types and billing rules
Migration type | Task 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. |
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 .
Note- Operations 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. Note If 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. In the Create Task wizard, configure the source and destination databases.Warning
After 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 an existing DMS database instance The database instance that you want to use. You can determine whether to select 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 source database.
Database Type The type of the source database. Select MySQL. Access Method The service that is used to access the source database. Select User-Created Database Connected over Express Connect, VPN Gateway, or Smart Access Gateway. Instance Region The region in which the sandbox instance resides. Replicate Data Across Alibaba Cloud Accounts Specifies whether data is migrated across Alibaba Cloud accounts. In this example, No is selected. Alibaba Cloud Account for Migration The ID of the Alibaba Cloud account to which the source instance belongs. Note This parameter is displayed only after Yes is selected for Replicate Data Across Alibaba Cloud Accounts.RAM Role Name The name of the RAM user that is configured by the Alibaba Cloud account to which the source instance belongs. Note This parameter is displayed only after Yes is selected for Replicate Data Across Alibaba Cloud Accounts.Connected VPC The virtual private cloud (VPC) that is used to connect to the sandbox instance. You can view VPC information on the VPCs page. IP Address The IP address that is used to connect to the sandbox instance. You can view the IP address on the details page of the sandbox instance. Ports The port number that is used to connect to the sandbox instance. Default value: 3306. Database Account The username of the account that is used to connect to the sandbox instance. - To perform schema migration and full data migration, make sure that the account has the SELECT permission.
- To perform incremental data migration, make sure that the account has the REPLICATION CLIENT, REPLICATION SLAVE, SHOW VIEW, and SELECT permissions.
Note The username and password of the sandbox instance must be consistent with those of the database whose data was migrated to the sandbox instance.Database Password The password of the database account.
Destination Database Select an existing DMS database instance The database instance that you want to use. You can determine whether to select 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 MySQL. Access Method The access method of the destination database. Select Alibaba Cloud Instance. Instance Region The region in which the destination ApsaraDB RDS for MySQL instance resides. RDS Instance ID The ID of the destination ApsaraDB RDS for MySQL instance. Database Account The username of the account that is used to connect to the ApsaraDB RDS for MySQL instance. The account must have the read and write permissions on the ApsaraDB RDS for MySQL instance. Database Password The password of the database account.
Encryption Specifies whether to encrypt the connection to the source database. You can select Non-encrypted or SSL-encrypted based on your business requirements. If you select SSL-encrypted, you must enable SSL encryption for the ApsaraDB RDS for MySQL instance before you configure the data migration task. For more information, see Configure the SSL encryption feature.
- In the lower part of the page, click Test Connectivity and Proceed.
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 IP address 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 account and password, limiting the ports that are exposed, authenticating API calls, regularly checking the IP address whitelist or ECS security group rules and forbidding unauthorized CIDR blocks, and connecting the database 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 have 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.
NoteYou can use the object name mapping feature to rename the tables that are migrated to the destination database. You can use this feature if the source and destination databases contain tables that have identical table names and the tables in the destination database cannot be deleted or renamed. 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 schemas, DTS does not migrate data records that have the same primary key values 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.
Capitalization of Object Names in Destination Instance The capitalization of database names, table names, and column names in the destination instance. By default, DTS default policy is selected. You can select other options to make sure that the capitalization of object names is consistent with that in the source or destination database. For more information, see Specify the capitalization of object names in the destination instance.
Source Objects Select one or more objects from the Source Objects section. Click the icon and add the objects to the Selected Objects section.
NoteYou can select columns, tables, or schemas as the objects to be migrated. If you select tables or columns as the objects to be migrated, DTS does not migrate other objects, such as views, triggers, or stored procedures, to the destination database.
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.
Note- 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.
- To specify WHERE conditions to filter data, right-click an object in the Selected Objects section. In the dialog box that appears, specify the conditions. For more information, see Use SQL conditions to filter data.
- To select the SQL operations performed on a specific database or table, right-click an object in the Selected Objects section. In the dialog box that appears, select the SQL operations that you want to migrate. For more information about the SQL operations that can be migrated, see SQL operations that can be performed for incremental data migration.
- Click Next: Advanced Settings to configure advanced settings.
Parameter Description Set Alerts 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 will 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 Configure monitoring and alerting.
Copy the temporary table of the Online DDL tool that is generated in the source table to the destination database If you use DMS or the gh-ost tool to perform online DDL operations on the source database, you can specify whether to migrate the data of temporary tables generated by online DDL operations. Valid values:
ImportantYou cannot use tools such as pt-online-schema-change to perform online DDL operations on the source database. Otherwise, the DTS task fails.
Yes: DTS migrates the data of temporary tables generated by online DDL operations.
NoteIf online DDL operations generate a large amount of data, the data migration task may take an extended period of time to complete.
No, Adapt to DMS Online DDL: DTS does not migrate the data of temporary tables generated by online DDL operations. Only the original DDL operations that are performed by using DMS are migrated.
NoteIf you select No, Adapt to DMS Online DDL, the tables in the destination database may be locked.
No, Adapt to gh-ost: DTS does not migrate the data of temporary tables generated by online DDL operations. Only the original DDL operations that are performed by using the gh-ost tool are migrated. You can use the default or custom regular expressions to filter out the shadow tables of the gh-ost tool and tables that are not required.
NoteIf you select No, Adapt to gh-ost, the tables in the destination database may be locked.
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 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 reconnects to the source and destination databases within the specified time range, DTS resumes the data migration task. Otherwise, the data migration task fails.Note- If you set different retry time ranges for multiple data migration tasks that have the same source or destination database, the shortest retry time range that is set 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 your earliest opportunity after the source and destination instances are released.
Configure ETL Specifies whether to configure 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.
Whether to delete SQL operations on heartbeat tables of forward and reverse tasks Specifies whether to write SQL operations on heartbeat tables to the source database while the DTS instance is running.
Yes: does not write SQL operations on heartbeat tables. In this case, a latency of the DTS instance may be displayed.
No: writes SQL operations on heartbeat tables. In this case, specific features such as physical backup and cloning of the source database may be affected.
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 OpenAPI parameters to view the parameters to be specified when you call the relevant API operation to configure the DTS task.
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 error message, you can run a precheck again.
If an alert is triggered for an item during the precheck:
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 in the task list.