From DB2 for LUW to GaussDB(DWS)

Supported Source and Destination Databases

Database Account Permission Requirements

To start a synchronization task, the source and destination database users must meet the requirements in the following table. Different types of synchronization tasks require different permissions. For details, see Table 2. DRS automatically checks the database account permissions in the pre-check phase and provides handling suggestions.

• You are advised to create an independent database account for DRS task connection to prevent task failures caused by database account password modification.
• After changing the account passwords for the source and destination databases, modify the connection information of the DRS task by referring to Modifying Connection Information to prevent automatic retry after a task failure. Automatic retry will lock the database accounts.

Supported Synchronization Objects

Table 3 lists the objects that can be synchronized in different scenarios. DRS will automatically check the objects you selected before the synchronization.

Precautions

To ensure tasks can run normally, DRS provides automatic pre-check. Before starting a DRS task, DRS checks the configurations and conditions of the source and destination databases. For details about the main check items and handling suggestions, see Pre-check Items. In addition to the pre-check items, you need to pay attention to the items listed in Table 4.

Procedure

1. On the Data Synchronization Management page, click Create Synchronization Task.
2. On the Create Synchronization Instance page, select a region and project, specify the task name, description, and the synchronization instance details, and click Create Now.
   • Task information description
     Figure 1 Synchronization task information
     

     Table 5 Task information

     Parameter	Description
     Region	The region where the replication instance is deployed. You can change the region.
     Project	The project corresponds to the current region and can be changed.
     Task Name	The task name must start with a letter and consist of 4 to 50 characters. It can contain only letters, digits, hyphens (-), and underscores (_).
     Description	The description consists of a maximum of 256 characters and cannot contain special characters !=<>'&"\

   • Synchronization instance information
     Figure 2 Synchronization instance information
     

     Table 6 Synchronization instance settings

     Parameter	Description
     Data Flow	Select To the cloud. The destination database is Databases on the current cloud.
     Source DB Engine	Select DB2 for LUW.
     Destination DB Engine	Select GaussDB(DWS).
     Network Type	Public network is used as an example. Available options: Public network, VPC, VPN or Direct Connect VPC is suitable for data synchronization between cloud databases of the same account in the same region and VPC. Public network is suitable for data synchronization from on-premises or external cloud databases to the destination databases bound with an EIP. VPN or Direct Connect is suitable for data synchronization from on-premises databases to cloud databases, between databases of different accounts in the same region on the cloud, or between databases across regions on the cloud using a VPN, Direct Connect, Cloud Connect, VPCEP, or a VPC peering connection.
     Destination DB Instance	The GaussDB(DWS) instance you created.
     Synchronization Instance Subnet	Select the subnet where the synchronization instance is located. You can also click View Subnets to go to the network console to view the subnet where the instance resides. By default, the DRS instance and the destination DB instance are in the same subnet. You need to select the subnet where the DRS instance resides, and there are available IP addresses for the subnet. To ensure that the synchronization instance is successfully created, only subnets with DHCP enabled are displayed.
     Synchronization Mode	The synchronization mode supported by a DRS task. Full+Incremental is used as an example. For details about the underlying working principles for full or incremental synchronization, see Product Architecture and Function Principles. Full+Incremental This synchronization mode allows you to synchronize data in real time. After a full synchronization initializes the destination database, an incremental synchronization parses logs to ensure data consistency between the source and destination databases. NOTE: If you select Full+Incremental, data generated during the full synchronization will be continuously synchronized to the destination database, and the source remains accessible. Incremental Through log parsing, incremental data generated on the source database is synchronized to the destination database.
     Specify EIP	This parameter is available when you select Public network for Network Type. Select an EIP to be bound to the DRS instance. DRS will automatically bind the specified EIP to the DRS instance and unbind the EIP after the task is complete. For details about the data transfer fee generated using a public network, see EIP Price Calculator.

   • AZ
     Figure 3 AZ
     

     Table 7 Task AZ

     Parameter	Description
     AZ	Select the AZ where you want to create the DRS task. Selecting the one housing the source or destination database can provide better performance.

   • Enterprise Project and Tags
     Figure 4 Enterprise Project and Tags
     

     Table 8 Enterprise Project and Tags

     Parameter	Description
     Enterprise Project	An enterprise project you would like to use to centrally manage your cloud resources and members. Select an enterprise project from the drop-down list. The default project is default. For more information about enterprise project, see Enterprise Management User Guide. To customize an enterprise project, click Enterprise in the upper right corner of the console. The Enterprise Project Management Service page is displayed. For details, see Creating an Enterprise Project in Enterprise Management User Guide.
     Tags	Tags a task. This configuration is optional. Adding tags helps you better identify and manage your tasks. Each task can have up to 20 tags. If your organization has configured tag policies for DRS, add tags to tasks based on the policies. If a tag does not comply with the policies, task creation may fail. Contact your organization administrator to learn more about tag policies. After a task is created, you can view its tag details on the Tags tab. For details, see Tag Management.

   

   If a task fails to be created, DRS retains the task for three days by default. After three days, the task automatically stops.

3. On the Configure Source and Destination Databases page, specify source and destination database information and click Test Connection for both the source and destination databases to check whether they have been connected to the synchronization instance. After the connection tests are successful, click Next.
   Figure 5 Source database information
   

   Table 9 Source database settings

   Parameter	Description
   IP Address or Domain Name	IP address or domain name of the source DB2 for LUW database.
   Port	The port of the source database. Range: 1 – 65535
   Database Username	The username for accessing the source DB2 for LUW database.
   Database Password	The password for the source database username.
   Database Name	The name of the database to which the synchronization objects belong in the source DB2 for LUW.
   SSL Connection	SSL encrypts the connections between the source and destination databases. If SSL is enabled, upload the SSL CA root certificate. Currently, only DB2 for LUW 10.5 and later versions support SSL. DB2 for LUW 9.7 and 10.1 do not support SSL. NOTE: The maximum size of a single certificate file that can be uploaded is 500 KB. If the SSL certificate is not used, your data may be at risk. Three certificate files need to be uploaded for the DB2 for LUW SSL connection: JKS, kdb, and sth DRS does not verify the kdb and sth certificates during the connection test. You need to ensure that the files are correct to prevent subsequent task failures.
   Synchronize Driver	You need to manually add and upload the JDBC driver package corresponding to the source DB2 for LUW, and then test the connection.

   

   The IP address, username, and password of the source database are encrypted and stored in DRS and will be cleared after the task is deleted.

   Figure 6 Destination database information
   

   Table 10 Destination database settings

   Parameter	Description
   DB Instance Name	The GaussDB(DWS) instance that you selected during task creation and cannot be changed.
   Database Username	The username for logging in to the destination database.
   Database Password	Password for the destination database username.

   

   The username and password of the destination database are encrypted and stored in DRS, and will be cleared after the task is deleted.

4. On the Set Synchronization Task page, select the synchronization object, enter the name of the destination database, and click Next.
   Figure 7 Synchronization Mode
   

   Table 11 Synchronization object

   Parameter	Description
   Synchronization Object Type	You can select Table structure, Data, or Index for Synchronization Object Type for full synchronization. Data is selected by default. If Table structure is selected, the destination database cannot contain tables whose names are the same as the source tables to be synchronized. If Table structure is not selected, the destination database must have tables that match the source tables, and the table structure must be the same as the selected source table structures.
   Synchronize DML	Select the DML operations to be synchronized. By default, all DML operations are selected. If you do not select Delete, DELETE statements in the incremental data of the source database will not be synchronized, which may cause a data inconsistency. As a result, there may be a data conflict or the task may fail.
   Synchronization Object	The left pane displays the source database objects, and the right pane displays the selected objects. You can select Tables or Import object files for Synchronization Object based on your service requirements. If the synchronization objects in source and destination databases have different names, you can map the source object name to the destination one. For details, see Changing Object Names (Mapping Object Names). For details about how to import an object file, see Importing Synchronization Objects. NOTE: To quickly select the desired database objects, you can use the search function. If there are changes made to the source databases or objects, click in the upper right corner to update the objects to be synchronized. If an object name contains spaces, 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 name of the selected synchronization object cannot contain spaces.

5. On the Check Task page, check the synchronization 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 Solutions to Failed Check Items in Data Replication Service User Guide.

   • If all check items are successful, click Next.
     Figure 8 Pre-check
     
     

     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.

6. On the displayed page, specify Start Time, Send Notifications, SMN Topic, Delay Threshold (s), and Stop Abnormal Tasks After, confirm that the configured information is correct, select the check box before the agreement, and click Submit to submit the task.
   Figure 9 Task startup settings
   

   Table 12 Task startup settings

   Parameter	Description
   Start Time	Set Start Time to Start upon task creation or Start at a specified time based on site requirements. NOTE: After a synchronization task is started, the performance of the source and destination databases may be affected. You are advised to start a synchronization task during off-peak hours.
   Send Notifications	This parameter is optional. After enabled, select a SMN topic. If the status, latency metric, or data of the migration task is abnormal, DRS will send you a notification.
   SMN Topic	This parameter is available only after you enable Send Notifications and create a topic on the SMN console and add a subscriber. For details, see Simple Message Notification User Guide.
   Delay Threshold (s)	During an incremental synchronization, a synchronization delay indicates a time difference (in seconds) of synchronization between the source and destination database. If the synchronization delay exceeds the threshold you specify, DRS will send alarms to the specified recipients. The value ranges from 0 to 3,600. To avoid repeated alarms caused by the fluctuation of delay, an alarm is sent only after the delay has exceeded the threshold for six minutes. NOTE: If the delay threshold is set to 0, no notifications will be sent to the recipient. In the early stages of an incremental synchronization, the synchronization delay is long because a large quantity of data is awaiting synchronization. In this case, no notifications will be sent. Before setting the delay threshold, enable Send Notifications.
   Data Exception Notification	This parameter is optional. After enabled, DRS will send a notification if the task data is abnormal.
   Stop Abnormal Tasks After	Number of days after which an abnormal task is automatically stopped. The value must range from 14 to 100. The default value is 14. NOTE: You can set this parameter only for pay-per-use tasks. Tasks in the abnormal state are still charged. If tasks remain in the abnormal state for a long time, they cannot be resumed. Abnormal tasks run longer than the period you set (unit: day) will automatically stop to avoid unnecessary fees.

7. After the task is submitted, you can view and manage it on the Data Synchronization 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.
   • By default, DRS retains a task in the Configuration state for three days. After three days, DRS automatically deletes background resources, but the task status remains unchanged. When you configure the task again, DRS applies for resources for the task again. In this case, the IP address of the DRS instance changes.
   • For a public network task, DRS needs to delete background resources after you stop the task. The EIP bound to the task cannot be restored to the Unbound state until background resources are deleted.