Data Transmission Service:Synchronize RDS for MySQL to Function Compute

Prerequisites

• You have a source ApsaraDB RDS for MySQL instance.

• You have created the destination service and function, and set its Handler Type to Event Handler. To create a function, see Quickly create a function.

  Note

  Only Function Compute (FC) 2.0 is supported.

Usage notes

Billing

Supported SQL operations

Database account permissions

Procedure

1. Go to the data synchronization task list page in the destination region. You can do this in one of two ways.

   DTS console

   1. Log on to the DTS console.

   2. In the navigation pane on the left, click Data Synchronization.

   3. In the upper-left corner of the page, select the region where the synchronization instance is located.

   DMS console

   Note

   The actual steps may vary depending on the mode and layout of the DMS console. For more information, see Simple mode console and Customize DMS console layout and style.

   1. Log on to the DMS console.

   2. In the top menu bar, choose Data + AI > DTS (DTS) > Data Synchronization.

   3. To the right of Data Synchronization Tasks, select the region of the synchronization instance.

2. Click Create Task to open the task configuration page.

3. 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 descriptive name for easy identification. The name does not need to be unique.
   Source Database	Select Existing Connection	Select the registered database instance with DTS from the drop-down list. The database information below is automatically configured. Note In the DMS console, this configuration item is Select a DMS database instance. If you have not registered the database instance or do not need to use a registered instance, manually configure the database information below.
   	Database Type	Select MySQL.
   	Access Method	Select Alibaba Cloud Instance.
   	Instance Region	Select the region where the source ApsaraDB RDS for MySQL instance resides.
   	Replicate Data Across Alibaba Cloud Accounts	In this example, data is synchronized within the same Alibaba Cloud account. Select No.
   	RDS Instance ID	Select the instance ID of the source ApsaraDB RDS for MySQL instance.
   	Database Account	Enter the database account of the source ApsaraDB RDS for MySQL instance. For permission requirements, see Permissions required for database accounts.
   	Database Password	Enter the password for the specified database account.
   	Encryption	Select Non-encrypted or SSL-encrypted as needed. If you set this to SSL-encrypted, you must enable SSL encryption for the RDS for MySQL instance beforehand. For more information, see Use a cloud certificate to quickly enable SSL link encryption.
   Destination Database	Select Existing Connection	Select the registered database instance with DTS from the drop-down list. The database information below is automatically configured. Note In the DMS console, this configuration item is Select a DMS database instance. If you have not registered the database instance or do not need to use a registered instance, manually configure the database information below.
   	Database Type	Select Function Compute.
   	Access Method	Select Alibaba Cloud Instance.
   	Instance Region	By default, this parameter is set to the same value as the Instance Region of the source database and cannot be changed.
   	Service	Select the name of the destination Function Compute (FC) service.
   	Function	Select the destination Function Compute (FC) function that receives data.
   	Service Version and Alias	Select an option based on your business requirements. Default Version: The Service Version is fixed to LATEST. Specified Version: You must also select a Service Version. Specified Alias: You must also select a Service Alias. Note For more information about terms related to Function Compute, see Key concepts.

4. After completing the configuration, click Test Connectivity and Proceed at the bottom of the page.

   Note

   • Ensure that you add the CIDR blocks of the DTS servers (either automatically or manually) to the security settings of both the source and destination databases to allow access. For more information, see Add the IP address whitelist of DTS servers.

   • If the source or destination is a self-managed database (i.e., the Access Method is not Alibaba Cloud Instance), you must also click Test Connectivity in the CIDR Blocks of DTS Servers dialog box.

5. Configure the task objects.

   1. On the Configure Objects page, specify the objects to synchronize.

      Parameter	Description
      Synchronization Types	Incremental Data Synchronization is selected by default. If you need to synchronize existing data, you must also select Full Data Synchronization.
      Data Format	Specifies the format for data synchronized to the Function Compute (FC) function. Only Canal JSON is supported. Note For more information about the parameters and examples of the Canal JSON format, see Canal JSON format.
      Source Objects	In the Source Objects box, click the objects, and then click to move them to the Selected Objects box. Note You can select databases or tables as synchronization objects.
      Selected Objects	In the Selected Objects box, confirm the data to be synchronized. Note To remove an object, select the object in the Selected Objects box and click the icon.

   2. Click Next: Advanced Settings.

      Parameter	Description
      Dedicated Cluster for Task Scheduling	By default, DTS uses a shared cluster for tasks, so you do not need to make a selection. For greater task stability, you can purchase a dedicated cluster to run the DTS synchronization task. For more information, see What is a DTS dedicated cluster?.
      Retry Time for Failed Connections	If the connection to the source or destination database fails after the synchronization task starts, DTS reports an error and immediately begins to retry the connection. The default retry duration is 720 minutes. You can customize the retry time to a value from 10 to 1,440 minutes. We recommend a duration of 30 minutes or more. If the connection is restored within this period, the task resumes automatically. Otherwise, the task fails. Note If multiple DTS instances (e.g., Instance A and B) share a source or destination, DTS uses the shortest configured retry duration (e.g., 30 minutes for A, 60 for B, so 30 minutes is used) for all instances. DTS charges for task runtime during connection retries. Set a custom duration based on your business needs, or release the DTS instance promptly after you release the source/destination instances.
      Retry Time for Other Issues	If a non-connection issue (e.g., a DDL or DML execution error) occurs, DTS reports an error and immediately retries the operation. The default retry duration is 10 minutes. You can also customize the retry time to a value from 1 to 1,440 minutes. We recommend a duration of 10 minutes or more. If the related operations succeed within the set retry time, the synchronization task automatically resumes. Otherwise, the task fails. Important The value of Retry Time for Other Issues must be less than that of Retry Time for Failed Connections.
      Enable Throttling for Full Data Synchronization	During full data synchronization, DTS consumes read and write resources from the source and destination databases, which can increase their load. To mitigate pressure on the destination database, you can limit the migration rate by setting Queries per second (QPS) to the source database, RPS of Full Data Migration, and Data migration speed for full migration (MB/s). Note This parameter is available only if Synchronization Types is set to Full Data Synchronization. You can also adjust the rate of full data synchronization when the synchronization instance is running.
      Enable Throttling for Incremental Data Synchronization	You can also limit the incremental synchronization rate to reduce pressure on the destination database by setting RPS of Incremental Data Synchronization and Data synchronization speed for incremental synchronization (MB/s).
      Whether to delete SQL operations on heartbeat tables of forward and reverse tasks	Choose whether DTS writes heartbeat SQL information to the source database while the instance is running. Yes: Does not write heartbeat SQL information to the source database. The DTS instance may display latency. No: Writes heartbeat SQL information to the source database. This may interfere with source database operations like physical backups and cloning.
      Environment Tag	You can select an environment tag to identify the instance based on your business requirements. In this example, you do not need to select a tag.
      Configure ETL	Choose whether to enable the extract, transform, and load (ETL) feature. For more information, see What is ETL? Valid values: Yes: Enables the ETL feature. Enter data processing statements in the code editor. For more information, see Configure ETL in a data migration or data synchronization task. No: Disables the ETL feature.
      Monitoring and Alerting	Choose whether to set up alerts. If the synchronization fails or the latency exceeds the specified threshold, DTS sends a notification to the alert contacts. No: No alerts are configured. Yes: Configures alerts. You must also set the alert threshold and alert notifications. For more information, see Configure monitoring and alerting during task configuration.

6. Save the task and perform a precheck.

   • To view the parameters for configuring this instance via an API operation, hover over the Next: Save Task Settings and Precheck button and click Preview OpenAPI parameters in the tooltip.

   • If you have finished viewing the API parameters, click Next: Save Task Settings and Precheck at the bottom of the page.

   Note

   • Before a synchronization task starts, DTS performs a precheck. You can start the task only if the precheck passes.

   • If the precheck fails, click View Details next to the failed item, fix the issue as prompted, and then rerun the precheck.

   • If the precheck generates warnings:

     • For non-ignorable warning, click View Details next to the item, fix the issue as prompted, and run the precheck again.

     • For ignorable warnings, you can bypass them by clicking Confirm Alert Details, then Ignore, and then OK. Finally, click Precheck Again to skip the warning and run the precheck again. Ignoring precheck warnings may lead to data inconsistencies and other business risks. Proceed with caution.

7. Purchase the instance.

   1. When the Success Rate reaches 100%, click Next: Purchase Instance.

   2. On the Purchase page, select the billing method and link specifications for the data synchronization instance. For more information, see the following table.

      Category	Parameter	Description
      New Instance Class	Billing Method	Subscription: You pay upfront for a specific duration. This is cost-effective for long-term, continuous tasks. Pay-as-you-go: You are billed hourly for actual usage. This is ideal for short-term or test tasks, as you can release the instance at any time to save costs.
      	Resource Group Settings	The resource group to which the instance belongs. The default is default resource group. For more information, see What is Resource Management?.
      	Instance Class	DTS offers synchronization specifications at different performance levels that affect the synchronization rate. Select a specification based on your business requirements. For more information, see Data synchronization link specifications.
      	Subscription Duration	In subscription mode, select the duration and quantity of the instance. Monthly options range from 1 to 9 months. Yearly options include 1, 2, 3, or 5 years. Note This option appears only when the billing method is Subscription.

   3. Read and select the checkbox for Data Transmission Service (Pay-as-you-go) Service Terms.

   4. Click Buy and Start, and then click OK in the OK dialog box.

      You can monitor the task progress on the data synchronization page.

Next steps

• If a single record to be synchronized exceeds 16 MB, the DTS task reports an error. You can modify the synchronization objects or use the ETL feature to filter out large fields. For instructions, see Modify a sync task's ETL configuration and Modify synchronization objects.

• Write function code based on your business requirements. For more information, see Code development overview.

Destination data format

Function Compute (FC) receives data as an Object. The incremental data from the source is stored in the Records field, an array of records. Each record is an Object containing the fields described in the following table.

ALTER TABLE `demoTable` 
	ADD COLUMN `address` varchar(20) NULL AFTER `sex`
;

{
	'Records': [{
		'type': 'DDL',
		'serverId': '27142679',
		'es': 1690000000000,
		'sql': '/* Query from DMS-WEBSQL-0-Eid_15682857722282385K by user 14xxxxxxxx */ ALTER TABLE `demoDatabase`.`DDL` \n\tADD COLUMN `address` varchar(20) NULL AFTER `sex`',
		'database': 'demoDatabase',
		'id': 63151,
		'isDdl': True,
		'table': 'demoTable',
		'ts': 1690000000000
	}]
}

INSERT INTO demoTable VALUES("xiaoming", 10, "man");

{
	'Records': [{
		'data': [{
			'sex': 'man',
			'name': 'xiaoming',
			'age': '10'
		}],
		'pkNames': ['name'],
		'type': 'INSERT',
		'serverId': '27142678',
		'es': 1690000000000,
		'sql': '',
		'database': 'demoDatabase',
		'sqlType': {
			'sex': 253,
			'name': 253,
			'age': 3
		},
		'mysqlType': {
			'sex': 'varchar',
			'name': 'varchar',
			'age': 'int'
		},
		'id': 62051,
		'isDdl': False,
		'table': 'demoTable',
		'ts': 1690000000000
	}]
}

UPDATE `demoDatabase`.`demoTable` SET `age`=11 WHERE `name`='xiaoming';

{
	'Records': [{
		'data': [{
			'sex': 'man',
			'name': 'xiaoming',
			'age': '11'
		}],
		'pkNames': ['name'],
		'old': [{
			'sex': 'man',
			'name': 'xiaoming',
			'age': '10'
		}],
		'type': 'UPDATE',
		'serverId': '27142679',
		'es': 1690000000000,
		'sql': '',
		'database': 'demoDatabase',
		'sqlType': {
			'sex': 253,
			'name': 253,
			'age': 3
		},
		'mysqlType': {
			'sex': 'varchar',
			'name': 'varchar',
			'age': 'int'
		},
		'id': 62373,
		'isDdl': False,
		'table': 'demoTable',
		'ts': 1690000000000
	}]
}

DELETE FROM `demoDatabase`.`demoTable` WHERE `name`='xiaoming';

{
	'Records': [{
		'data': [{
			'sex': 'man',
			'name': 'xiaoming',
			'age': '11'
		}],
		'pkNames': ['name'],
		'type': 'DELETE',
		'serverId': '27142679',
		'es': 1690000000000,
		'sql': '',
		'database': 'demoDatabase',
		'sqlType': {
			'sex': 253,
			'name': 253,
			'age': 3
		},
		'mysqlType': {
			'sex': 'varchar',
			'name': 'varchar',
			'age': 'int'
		},
		'id': 62635,
		'isDdl': False,
		'table': 'demoTable',
		'ts': 1690000000000
	}]
}