Configure the data layer

Access the configuration page

1. Log on to the Multi-active Service for High Availability (MSHA) console.

2. In the left-side navigation pane, click Multi-active Instance to go to the Multi-active Instance list page.

3. On the Multi-active Instance list page, find the target multi-active instance and click its ID to go to the Instance Overview page.

4. In the left-side navigation pane, click Data Layer Configuration to open the data layer configuration page.

Step 1: Create a data source

1. On the Data Layer Configuration page, click Manage Data Sources.

2. On the Data Source List page, click Add Data Source, configure the parameters, and then click Submit.

   Parameter	Description	Example
   Data Source Name	The name of the database that your multi-active application connects to. This must be specific to the database level.	Hangzhou-Merchant-Trade-DB
   Data Source Unit	Select the unit where the data source is located. The region of this unit must match the region of the database instance.	Hangzhou Central Unit
   Data Source Type	The type of database that your multi-active application connects to. Supported types include PolarDB for MySQL, DRDS, MySQL, PostgreSQL, PolarDB for Oracle, and PolarDB-X 2.0.	MySQL
   Instance Type	The available instance types vary based on the selected Data Source Type. Different instance types require different configurations. Follow the instructions on the console to configure the parameters.	RDS
   Push Type	A unique identifier for the database used by your application when using the MSHA data plane SDK or Agent. The following two methods are available: Instance and Database Configuration: Add the following suffix to the database connection configuration in your application code. jdbc:mysql://host:port/dbName?mshaInstanceId=${instanceId}&mshaDbName=${dbName} Note Replace ${instanceId} and ${dbName} with the actual instance ID and database name from the management console. Instance and Database URL: No modifications to your application code are required. Note If the data source has multiple JDBC URLs, separate them with a comma (,).	Instance and Database URL
   Push Identifier	Required when the push type is Instance and Database URL. When the data protection rule takes effect after being pushed, this value serves as a unique identifier to distinguish between different data sources used by your application.	jdbc:mysql://host_01:port/dbName,jdbc:mysql://host_02:port/dbName

   After the data source is created, you can view it on the Data Source List page.

3. Optional: You can also perform the following operations on the Data Source List page:

   • View data source status: The status of the most recent task to update table metadata. A metadata update task runs by default after you create a data source.

     Possible statuses include:

     • Creating: The initial status of a data source before its metadata update task runs.

     • Normal: The most recent metadata update task was successful.

     • Loading table data: The metadata update task is in progress.

     • Load failed: The most recent metadata update task failed.

   • View data source details: In the Actions column, click Details to view detailed information about the data source.

   • View tables: In the Actions column, click View Tables to view table information, update the data source, and check the latest update status.

   • Update data source: In the Actions column, click Update to fetch the latest table metadata.

   • Delete data source: In the Actions column, click Delete, and then click OK in the confirmation dialog box.

(Optional) Step 2: Add a synchronization task

A bidirectional synchronization task includes both a forward and a reverse synchronization link, while a unidirectional synchronization task includes only a forward link.

Before adding a synchronization task, you must add another data source named Beijing-Merchant-Trade-DB to serve as the destination data source, using the method described in Step 1.

1. On the Data Layer Configuration page, click Manage Synchronization Link.

2. On the Synchronization Link List page, click Add Synchronization Task, configure the parameters, and then click Submit.

   Parameter	Description	Example
   Synchronization Task Name	Set a name for the synchronization task.	test-rds-forward
   Source Data Source Type	The type of database that your multi-active application connects to. Supported types include: DRDS MySQL PolarDB for MySQL PolarDB for Oracle PostgreSQL PolarDB-X 2.0	MySQL
   Source Data Source Unit	Select the unit where the source data source is located. This corresponds to the region of the source data source.	Hangzhou Central Unit
   Source Data Source	Select the data source name you added in Step 1.	Hangzhou-Merchant-Trade-DB
   Destination Data Source Type	The type of destination database that your multi-active application connects to. Supported types include: DRDS MySQL PolarDB for MySQL PolarDB for Oracle PostgreSQL PolarDB-X 2.0	MySQL
   Destination Data Source Unit	Select the unit of the destination data source.	Beijing Unit
   Destination Data Source	Select the name of the destination data source.	Beijing-Merchant-Trade-DB
   Synchronization Task Type	Data Transmission Service (DTS) is supported.	DTS
   Synchronization Topology	Specifies the synchronization topology, which can be unidirectional or bidirectional: Unidirectional synchronization: To ensure data consistency, the synchronization objects in the destination instance are read-only. Bidirectional synchronization: DTS currently supports bidirectional synchronization only between two MySQL databases. Note For more information about synchronization topologies, see Introduction to data synchronization topologies.	Bidirectional synchronization
   Synchronization Task Unit	The unit to which the synchronization task belongs. The task is created by default in the region where the destination instance is located.	Hangzhou Central Unit
   Synchronization Task Creation Method	You can choose from the following creation methods: Direct Entry: If you have already created a synchronization task in the Data Transmission Service (DTS) console whose status is Synchronizing (and the reverse link status is also Synchronizing for bidirectional tasks), you can select it directly. Manual Creation: If you have created a synchronization task in the DTS console whose status is Not Configured (and the reverse link status is also Not Configured for bidirectional tasks), you can enter the task and then configure it later in the MSHA console. Note For information about creating a synchronization task in the DTS console, see Overview of DTS data synchronization solutions.	Direct Entry
   Synchronization Task	The synchronization task ID (name). Select a task that has already been created in the DTS console.	dtsp6s12ghvv74xb7m (test-forward)

   After the synchronization link is created, you can view it on the Synchronization Link List page.

3. Optional: You can also perform the following operations on the Synchronization Link List page:

   • View synchronization link information: In the Actions column, click View to see the details of the synchronization link.

   • Modify synchronization object: In the Actions column, click Modify Synchronization Object to go to the Edit Synchronization Link page and modify the synchronization object.

   • Release task: Select a synchronization link, click Release Synchronization Task in the lower-left corner, and then click OK.

     Note

     • A task cannot be released if it is being used by an active data protection rule.

     • For a bidirectional synchronization task, selecting either the forward or reverse link will release both links.

   • Pause task: Select the target synchronization link, click Pause Synchronization Task in the lower-left corner, and then click OK.

   • Start task: Select the target synchronization link, click Start Synchronization Task in the lower-left corner, and then click OK.

   • Update synchronization status: Asynchronously updates the synchronization status on the current synchronization link list page.

Step 3: Create a data protection rule

Next steps

You can also perform the following operations on the Data Layer Configuration page:

View basic data

Data protection rule status

Push operations

• Push Canary Rule: Select a rule and click Push Canary Rule at the bottom of the page. This applies the data protection rule to the data plane SDK and Agent for a limited scope. The scope is controlled by the canary IP addresses specified when creating the rule, which are the private IP addresses of the ECS instances hosting your application.

  Note

  You can only perform a canary push on rules that are in the Draft status.

• Push Full Rule: Select a rule and click Push Full Rule at the bottom of the page. This applies the data protection rule fully to the data plane SDK and Agent.

• Delete Canary Rule: Select a rule and click Delete Canary Rule at the bottom of the page. This deactivates a data protection rule that has the Canary effective status.

• Delete Full Rule: Select a rule and click Delete Full Rule at the bottom of the page. This deactivates a data protection rule that has the Effective status.

• Degrade: Select a rule and click Degrade at the bottom of the page. This bypasses the multi-active logic for the application instances controlled by this data protection rule.

• Cancel Degradation: Click Cancel Degradation at the bottom of the page to restore the multi-active logic for the application instances controlled by this data protection rule.

Other operations

In the Actions column of the data protection rule list, you can perform the following operations:

• View or edit details: Click Details in the Actions column to view the details of a data protection rule. You can also edit certain details and then click Submit.

• Push history: Click Push History in the Actions column. On the Push History page, click View in the Actions column to see the content of a historical push.

• Delete rule: Click Delete in the Actions column to delete the rule.