Verifying the Consistency of Data Migrated from Alibaba Cloud ApsaraDB for ClickHouse to Huawei Cloud MRS ClickHouse

Preparations

Install Edge, an MgC tool used for data verification, in the source intranet environment and register an account for using Edge. For details, see Installing Edge for Linux.

Procedure

1. Sign in to the MgC console. On the Overview page, click Create Migration Project.

   

2. In the displayed dialog box, enter a project name, select a project type, and click Confirm.
   

   To review this migration project, choose Settings > Migration Projects in the navigation pane.

   

3. Connect Edge to MgC. For more information, see Connecting the Edge Device to MgC.
4. After the connection is successful, add the username/password pairs for accessing the source and target ClickHouse servers to Edge. For more information, see Adding Resource Credentials.
5. On the MgC console, in the navigation pane on the left, choose Research > Data Lineage. In the upper left corner of the page, choose the migration project created in step 2 from the drop-down list.

   

6. In the Metadata Collection area, click Create Connection.

   

7. On the Select Connection Type page, select ApsaraDB for ClickHouse and click Next.

   

8. Configure the parameters for creating a ClickHouse connection, and click Test. If the test is successful, the connection is set up.

   Table 1 Parameters for creating a ClickHouse connection

   Parameter	Configuration
   Connection To	Select Source.
   Connection Name	The default name is ApsaraDB for ClickHouse-4 random characters (including letters and numbers). You can also customize a name.
   Edge Device	Select the Edge device connected to MgC in step 3.
   ClickHouse Credential (Optional)	Select the credential used for accessing Alibaba Cloud ApsaraDB for ClickHouse you added to Edge in step 4.
   Database URL	Enter the public address of the source ClickHouse cluster. You can view the IP address in the cluster details.

9. In the Metadata Collection area, choose Create Task > Metadata Collection.

   

10. Configure the parameters for creating a metadata collection task and click Confirm.

    

    Table 2 Parameters for configuring a metadata collection task

    Parameter	Configuration
    Task Name	The default name is Metadata-Collection-4 random characters (including letters and numbers). You can also customize a name.
    Metadata Connection	Select the connection created in step 8.
    Databases (Optional)	Enter the names of the databases whose metadata needs to be collected. Use commas (,) to separate the database names. If no database name is specified, the metadata of all databases is collected.
    Concurrent Threads	Set the maximum number of threads for executing the collection. The default value is 3. The value ranges from 1 to 10. More concurrent threads means more efficient collection, but more connection and Edge device resources will be consumed.

11. In the Metadata Collection area, click Collection tasks.

    

12. Under Tasks, you can review the created metadata collection task and its settings. Click Execute Task in the Operation column to run the task. Each time the task is executed, a task execution is generated.

    

13. Click View Executions in the Operation column. Under Task Executions, you can view the execution records of the task and the status and collection results of each task execution. When a task execution enters a Completed status and the collection results are displayed, you can view the list of databases and tables extracted from collected metadata on the Tables tab.

    

14. In the navigation pane on the left, choose Migrate > Big Data Verification. If this is your first time to visit this page, select an Edge device to enable the verification feature. Click Select Edge Device. In the displayed dialog box, select the Edge device connected to MgC in step 3.

    

    

    Ensure that the selected Edge device is always Online and Enabled before your verification is complete.

15. In the Features area, click Table Management.

    

16. Under Table Groups, click Create. Configure the parameters for creating a table group and click Confirm.

    

    Table 3 Parameters for creating a table group

    Parameter	Description
    Table Group	User-defined
    Metadata Connection	Select the connection created in step 8. CAUTION: A table group can only contain tables coming from the same metadata source.
    Verification Rule	Select a rule that defines the method for verifying data consistency and the inconsistency tolerance. You can View More to see more information about the verification rules provided by MgC.
    Description (Optional)	Enter a description to identify the table group.

17. On the Table Management page, click the Tables tab, select the data tables to be added to the same table group, and choose Option > Add Tables to Group above the list. In the displayed dialog box, select the desired table group and click Confirm.

    

    

    You can manually import information of incremental data tables to MgC. For details, see Creating a Table Group and Adding Tables to the Group.

18. On the Big Data Verification page, in the Features area, click Connection Management.

    

19. Click Create Connection in the upper right corner of the page. On the Select Connection Type page, select ClickHouse and click Next.

    

20. Configure the parameters for creating a ClickHouse connection, and click Test. If the test is successful, the connection is set up.

    Table 4 Parameters for creating a ClickHouse connection

    Parameter	Configuration
    Connection To	Select Target.
    Connection Name	The default name is ClickHouse-4 random characters (including letters and numbers). You can also customize a name.
    ClickHouse Credential (Optional)	Select the credential used for accessing the target MRS ClickHouse cluster you added to Edge in step 4.
    Secured Cluster	Choose whether the cluster is secured.
    ClickHouse Server IP Address	Enter the IP address of the MRS ClickHouse server. Generally, the IP address refers to that of the server where ClickHouse is hosted.
    HTTP Port	If the MRS ClickHouse cluster is unsecured, enter the HTTP port for communicating with the ClickHouse server. To obtain the value, log in to the FusionInsight Manager of the target cluster, choose Cluster > Services > ClickHouse > Configurations > All Configurations, and search for the http_port parameter.
    HTTP SSL/TLS Port	If the MRS ClickHouse cluster is secured, enter the HTTPS port for communicating with the ClickHouse server. To obtain the value, log in to the FusionInsight Manager of the target cluster, choose Cluster > Services > ClickHouse > Configurations > All Configurations, and search for the https_port parameter.

21. Create a data verification task for the source Alibaba Cloud ApsaraDB for ClickHouse cluster, and execute the task. For more information, see Creating and Executing Verification Tasks. During the task creation, select the table group created in step 16.
    • On the Select Task Type page, choose ApsaraDB for ClickHouse.

      

    • Select Full Verification for Verification Method.

22. Create a data verification task for the MRS ClickHouse cluster, and execute the task. For more information, see Creating and Executing Verification Tasks. During the task creation, select the table group created in step 16.
    • On the Select Task Type page, choose ClickHouse.

      

    • Select Full Verification for Verification Method.

23. Wait until the task executions enter a Completed status. On the Verification Results page, you can view and export the task execution results. For details, see Viewing and Exporting Verification Results.