Editing a Migration Task

Prerequisites

• You have logged in to the DRS console.
• A migration task has been created.

Method 1

1. In the task list on the Online Migration Management page, locate the target task and click Edit in the Operation column.
2. On the Configure Source and Destination Databases page, enter information about the source and destination databases and click Next.
3. On the Set Task page, select the accounts and objects to be migrated, and click Next.
   Figure 1 Migration type
   

   Table 1 Migration types and objects

   Parameter	Description
   Flow Control	You can choose whether to control the flow. Yes You can customize the maximum migration speed. In addition, you can set the time range based on your service requirements. The traffic rate setting usually includes setting of a rate limiting time period and a traffic rate value. Flow can be controlled all day or during specific time ranges. The default value is All day. A maximum of three time ranges can be set, and they cannot overlap. The flow rate must be set based on the service scenario and cannot exceed 9,999 MB/s. Figure 2 Flow control No The migration speed is not limited and the outbound bandwidth of the source database is maximally used, which will increase the read burden on the source database. For example, if the outbound bandwidth of the source database is 100 MB/s and 80% bandwidth is used, the I/O consumption on the source database is 80 MB/s. NOTE: Flow control mode takes effect only during a full migration. You can also change the flow control mode after creating a task. For details, see Modifying the Flow Control Mode.
   Take Snapshot	If you perform a full migration, you can take a snapshot for your databases. No This option applies to exports for which no data is written to the source database. If data is modified during a full migration, the exported data is point in time inconsistent. The stability and performance of a migration without a snapshot taken is better than that of a migration with a snapshot taken. Yes A snapshot with consistent data at the point in time is generated during service running. Data changes during migration are not shown in the exported data. NOTE: Snapshot reads use MySQL backup lock to lock global tables and automatically unlock them within 3s after consistent reads are enabled. To prevent full migration failures, take a snapshot when the source database is idle and does not perform DML or DDL operations during snapshot migration. Only MySQL full migration tasks support the snapshot mode. To use this function, you can submit a whitelist application. Do not perform DDL operations during migration in snapshot mode. Otherwise, full migration will fail.
   Migrate Account	During a database migration, accounts need to be migrated separately. There are accounts that can be migrated completely, accounts whose permissions need to be reduced, and accounts that cannot be migrated. You can choose whether to migrate the accounts based on service requirements. If you select Yes, you can select the accounts to be migrated as required. Yes If you need to migrate accounts, see Migrating Accounts. No During migration, accounts, permissions, and passwords are not migrated.
   Filter DROP DATABASE	To reduce the risks involved in data migration, DDL operations can be filtered out. You can choose not to synchronize certain DDL operations. If you select Yes, any database deletion operations performed on the source database are not migrated during data migration. If you select No, related operations are migrated to the destination database during data migration.
   Migrate Object	You can choose to migrate all objects, tables, or databases based on your service requirements. All: All objects in the source database are migrated to the destination database. After the migration, the object names will remain the same as those in the source database and cannot be modified. Tables: The selected table-level objects will be migrated. Databases: The selected database-level objects will be migrated. If the source database is changed, click in the upper right corner before selecting migration objects to ensure that the objects to be selected are from the changed source database. NOTE: If you choose not to migrate all of the databases, the migration may fail because the objects, such as stored procedures and views, in the databases to be migrated may have dependencies on other objects that are not migrated. To prevent migration failure, migrate all of the databases. When you select an object, the spaces before and after the object name are not displayed. If there are two or more consecutive spaces in the middle of the object name, only one space is displayed. The search function can help you quickly select the required database objects.

4. On the Check Task page, check the migration task.
   • If any check fails, review the cause and rectify the fault. After the fault is rectified, click Check Again.

     For details about how to handle check failures, see Checking Whether the Source Database Is Connected in Data Replication Service User Guide.

     Figure 3 Pre-check
     
   • If the check is complete and the check success rate is 100%, click Next.
     

     You can proceed to the next step only when all checks are successful. If there are any items that require confirmation, view and confirm the details first before proceeding to the next step.

5. On the Confirm Task page, specify Start Time, confirm that the configured information is correct, and click Submit to submit the task.
   

   • Set Start Time to Start upon task creation or Start at a specified time based on site requirements.
   • After a migration task is started, the performance of the source and destination databases may be affected. You are advised to start a migration task during off-peak hours.
   • Under specific conditions, the destination database needs to be restarted once during the task startup, which may interrupt database services.

6. After the task is submitted, view and manage it on the Online Migration Management page.
   • You can view the task status. For more information about task status, see Task Statuses.
   • You can click in the upper-right corner to view the latest task status.

Method 2

1. On the Online Migration Management page, click the target migration task name in the Task Name/ID column.
2. On the displayed page, click edit this task to go to the Configure Source and Destination Databases page.
3. Perform steps 2 to 6.