From MariaDB to GaussDB(for MySQL)_Data Replication Service

Supported Source and Destination Databases

**Table 1** Supported databases
Source DB	Destination DB
On-premises MariaDB 10.0, 10.1, 10.2, 10.3, 10.4 and 10.5 ECS-hosted MariaDB 10.0, 10.1, 10.2, 10.3, 10.4 and 10.5 Other cloud MariaDB 10.0, 10.1, 10.2, 10.3, 10.4 and 10.5	GaussDB(for MySQL) Primary/Standby

Supported Synchronization Objects

Table 2 lists the objects that can be synchronized in different scenarios. DRS will automatically check the objects you selected before the synchronization.

**Table 2** Supported synchronization objects
Type	Precautions
Objects	Tables, primary key indexes, unique indexes, common indexes, stored procedures, views, and functions can be synchronized. Only MyISAM and InnoDB tables can be synchronized. Events and triggers cannot be synchronized. Table names cannot be mapped for tables on which views, stored procedures, and functions depend. When table name mapping is used in a synchronization task, foreign key constraints of the table cannot be synchronized. During database name mapping, if the objects to be synchronized contain stored procedures, views, and functions, these objects cannot be synchronized in the full synchronization phase, resulting in inconsistent objects. If the database table name contains characters other than letters, digits, and underscores (_), or the mapped database table name contains hyphens (-) and number signs (#), the name length cannot exceed 42 characters. The DDL operation of renaming an unselected table is filtered out during the synchronization. As a result, the task may fail or data may be inconsistent. If you rename table A to the name of table B and tables A and B are selected for synchronization, this RENAME statement will not be filtered out. If you rename table A to the name of table B but table B is not synchronized, this RENAME statement will be filtered out. You are not advised to perform the rename operation in the many-to-one synchronization scenario. Otherwise, the task may fail or data may be inconsistent. If there is a table containing fields of the longtext or longblob type in the synchronization object, you are advised to create a DRS task with large specifications. Otherwise, capture OOM may occur.

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 3. 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 in the DRS task as soon as possible to prevent automatic retry after a task failure. Automatic retry will lock the database accounts.

**Table 3** Database account permission
Type	Incremental and Full+Incremental
Source database user	SELECT, SHOW VIEW, EVENT, LOCK TABLES, RELOAD, REPLICATION SLAVE, REPLICATION CLIENT (or BINLOG MONIOTOR, changed to this permission in MariaDB 10.5 and later versions)
Destination database user	The root account of GaussDB(for MySQL) has the following permissions by default: SELECT, CREATE, DROP, DELETE, INSERT, UPDATE, ALTER, CREATE VIEW, CREATE ROUTINE, and REFERENCES If the destination database version is in the range 8.0.14 to 8.0.18, the SESSION_VARIABLES_ADMIN permission is required.

Suggestions

When a task is being started or in the full synchronization phase, do not perform DDL operations on the source database. Otherwise, the task may be abnormal.
To keep data consistency before and after the synchronization, ensure that no data is written to the destination database during the synchronization.

The success of database synchronization depends on environment and manual operations. To ensure a smooth synchronization, perform a synchronization trial before you start the synchronization to help you detect and resolve problems in advance.
You are advised to start your synchronization task during off-peak hours by setting Start Time to Start at a specified time. A less active database is easier to synchronize successfully. If the data is fairly static, there is less likely to be any severe performance impacts during the synchronization.
- If network bandwidth is not limited, the query rate of the source database increases by about 50 MB/s during full synchronization, and two to four CPUs are occupied.
- The data being synchronized may be locked by other transactions for a long period of time, resulting in read timeout.
- When DRS concurrently reads data from a database, it will use about 6 to 10 sessions. The impact of the connections on services must be considered.
- If you read a table, especially a large table, during the full migration, the exclusive lock on that table may be blocked.
- For more information about the impact of DRS on databases, see How Does DRS Affect the Source and Destination Databases?
Data-Level Comparison
To obtain accurate comparison results, compare data at a specified time point during off-peak hours. If it is needed, select Start at a specified time for Comparison Time. Due to slight time difference and continuous operations on data, data inconsistency may occur, reducing the reliability and validity of the comparison results.

Precautions

The full+incremental synchronization consists of four phases: task startup, full synchronization, incremental synchronization, and task completion. To ensure smooth synchronization, read the following notes before creating a synchronization task.

**Table 4** Precautions
Type	Restrictions
Starting a task	Source database parameter requirements: During the incremental synchronization, the binlog of the source MariaDB database must be enabled and use the row-based format. If the storage space is sufficient, store the source database binlog for as long as possible. The recommended retention period is three days. If this period is set to 0, the synchronization may fail. If the source database is a self-managed MariaDB database, set expire_logs_days to specify the binlog retention period. Set expire_logs_day to a proper value to ensure that the binlog does not expire before data transfer resumes. This ensures that services can be recovered after interruption. If the source database is an RDS for MariaDB instance, set the binlog retention period by following the instructions provided in RDS User Guide. Enable GTID for the source database. If GTID is not enabled for the source database, primary/standby switchover is not supported. DRS tasks will be interrupted and cannot be restored during a switchover. During an incremental synchronization, the source MariaDB database server_id must be set to a value ranging from 1 to 4294967296. Source database object requirements: The source database names cannot contain non-ASCII characters, or the following characters: '<`>/\" The source table and view names cannot contain non-ASCII characters, or the following characters: '<>/\" The source database name or mapped name cannot start with ib_logfile or be ib_buffer_pool, ib_doublewrite, ibdata1 or ibtmp1. Destination database parameter requirements: Data cannot be synchronized from a newer version database to an older version database. The character set of the destination database must be the same as that of the source database. The time zone of the destination database must be the same as that of the source database. During a synchronization, a large amount of data is written to the destination database. If the value of the max_allowed_packet parameter of the destination database is too small, data cannot be written. You are advised to set the max_allowed_packet parameter to a value greater than 100 MB. If the MyISAM tables are included in the synchronization objects, the sql_mode parameter in the destination database cannot contain the no_engine_substitution parameter. Otherwise, the synchronization fails. Destination database object requirements: The destination database must be a primary/standby GaussDB(for MySQL) instance. The destination DB instance is running properly. If the destination DB instance type is primary/standby, the replication status must also be normal. The destination DB instance must have sufficient storage space. If the destination database (excluding the system database) has the same name as the source database, the table structures in the destination database must be consistent with those in the source database. The source database names mapped to the destination database cannot contain the following characters: dots (.), angle brackets (<>), backslash (\), and single quotation marks (') Other notes: If the DCC does not support instances with 4 vCPUs and 8 GB memory or higher instance specifications, the synchronization task cannot be created. Objects that have dependencies must be synchronized at the same time to avoid synchronization failure. Common dependencies: tables referenced by views, views referenced by views, views and tables referenced by stored procedures/functions/triggers, and tables referenced by primary and foreign keys If a physically generated column in a table is generated based on a time type, the data in the column may be inconsistent. If the source database contains any table without a primary key defined, the table-level many-to-one synchronization is not supported. The source and destination databases cannot contain tables that have the same names but do not have primary keys. If the source database contains non-standard floating-point data and the data can be written in loose mode but cannot be written in strict mode, there may be data inconsistency during synchronization. The source database does not support the reset master or reset master to command, which may cause DRS task failures or data inconsistency. If the source MariaDB database does not support TLS1.2, you need to submit an application to the O&M personnel before using SSL to test the connection. Before creating a DRS task, if concurrency control rules of SQL statements are configured for the source database, the DRS task may fail. Resumable upload is supported, but data may be repeatedly inserted into a table that does not have a primary key. The destination table can contain more columns than the source table. However, the following failures must be avoided: Assume that extra columns on the destination cannot be null or have default values. If newly inserted data records are synchronized from the source to the destination, the extra columns will become null, which does not meet the requirements of the destination and will cause the task to fail. Assume that extra columns on the destination must be fixed at a default value and have a unique constraint. If newly inserted data records are synchronized from the source to the destination, the extra columns will contain multiple default values. That does not meet the unique constraint of the destination and will cause the task to fail. The source database does not support point-in-time recovery (PITR). The destination database cannot be restored to a point in time when a full synchronization was being performed. Cascade operations cannot be performed on tables with foreign keys. If the foreign key index of a table is a common index, the table structure may fail to be created. You are advised to use a unique index. Binlogs cannot be forcibly deleted. Otherwise, the synchronization task fails. The partitioned table does not support column mapping. After a task is created, the destination database cannot be set to read-only. During table-level synchronization, in the many-to-one scenario where an additional column is set as the source column on the data processing page, if there is a mapped table in the destination database, delete the table or clear data in the table in the destination database. Otherwise, the composite primary key will not be created by adding additional columns. This will cause data conflicts during data synchronization. If the data conflicts are ignored, there may be data inconsistencies. If index synchronization is required for a DRS task, the destination database table cannot contain indexes with the same name but different columns. In the full phase, DRS ignores the existing indexes with the same name. In the incremental phase, DDL operations on indexes based on the index name trigger misplacement.
Full synchronization	Do not change the port of the source and destination databases, or change or delete the passwords and permissions of the source and destination database users. Otherwise, the task may fail. Do not run any DDL statement in the source database. Otherwise, data may be inconsistent or the task may fail. Do not write data to the destination database. Otherwise, data may be inconsistent. Data inconsistency may occur when the MyISAM table is modified during a full synchronization.
Incremental synchronization	Do not change the port of the source and destination databases, or change or delete the passwords and permissions of the source and destination database users. Otherwise, the task may fail. Do not write data to the destination database. Otherwise, data may be inconsistent. During incremental synchronization, some DDL operations are supported. In one-to-one synchronization, the following DDL operations are synchronized by default: CREATE_TABLE, RENAME_TABLE, ADD_COLUMN, MODIFY_COLUMN, CHANGE_COLUMN, DROP_COLUMN, DROP_INDEX, ADD_INDEX, CREATE_INDEX, RENAME_INDEX, DROP_TABLE, TRUNCATE_TABLE, DROP_PARTITION, RENAME_COLUMN, DROP_PRIMARY_KEY and ADD_PRIMARY_KEY. You can select the DDL operations to be synchronized on the object selection page as required. Incremental synchronization supports table renaming. Ensure that both the source and destination tables are selected. You can add additional objects during an incremental synchronization. During table-level synchronization, online DDL can be used for incremental synchronization. For details, see Does DRS Support Online DDL for Real-Time Synchronization?
Synchronization comparison	You are advised to compare data during off-peak hours of the source database to prevent inconsistent data from being falsely reported and reduce the impact on the source database and DRS tasks. During incremental synchronization, if data is written to the source database, the comparison results may be inconsistent. Data cannot be compared during full synchronization. Do not limit the synchronization speed during data comparison.

Procedure

This section describes how to use DRS to configure a real-time synchronization task from MariaDB to GaussDB(for MySQL) over a public network.

On the Data Synchronization Management page, click Create Synchronization Task.

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 details

Figure 2 Synchronization instance details

**Table 6** Synchronization instance settings
Parameter	Description
Data Flow	Select To the cloud. The destination database must be a database on the current cloud.
Source DB Engine	Select MariaDB.
Destination DB Engine	Select GaussDB(for MySQL).
Network Type	Available options: VPC, Public network and VPN or Direct Connect. Public network is the default value and is used as an example. VPC is suitable for data synchronization between cloud databases of the same account in the same region. 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 synchronization of data between on-premises databases and cloud databases, between cloud databases of different accounts in the same region, or between cloud databases across regions.
DRS Task Type	Type of the DRS task. The value can be Single-AZ or Dual-AZ. Dual-AZ: This architecture provides HA, improving the reliability of DRS tasks. After a dual-AZ task is created, DRS creates two subtasks, each running in the primary and standby AZs. If the subtask in the primary AZ fails, DRS automatically starts the subtask in the standby AZ to continue the synchronization. This deployment is for scenarios where there is a lot of service data, long-term synchronization is required, and there are strict limits on how much service downtime can be tolerated. Single-AZ: Single-node deployment is used. The synchronization task will be created on only one node to save money. This deployment is for scenarios where there is a small amount of service data, short-term synchronization is required, and there is no requirement on service downtime. This option is available only in specific scenarios. For details, see Performing a Switchover for a Dual-AZ Task.
Destination DB Instance	The GaussDB(for MySQL) 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 without interrupting services. After a full synchronization initializes the destination database, an incremental synchronization initiates and parses logs to ensure data consistency between the source and destination databases. 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. The number of specified EIPs must be the consistent with that of DB instances. For details about the data transfer fee generated using a public network, see EIP Price Calculator.

Task Type

Figure 3 Specifications

**Table 7** Task type information
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. If DRS Task Type is set to Dual-AZ, you can specify Primary AZ and Standby AZ. Figure 4 AZ

Enterprise Project and Tags

Figure 5 Enterprise projects 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.

On the Configure Source and Destination Databases page, wait until the synchronization instance is created. Then, 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, select the check box before the agreement and click Next.

Source database information

Figure 6 Source database information

**Table 9** Source database information
Parameter	Description
IP Address or Domain Name	The IP address or domain name of the source database.
Port	The port of the source database. Range: 1 – 65535
Database Username	The username for accessing the source database.
Database Password	The password for the database username. You can change the password if necessary. To change the password, perform the following operation after the task is created: If the task is in the Starting, Full synchronization, Incremental synchronization, or Incremental synchronization failed status, in the Connection Information area on the Basic Information tab, click Modify Connection Details. In the displayed dialog box, change the password.
SSL Connection	SSL encrypts the connections between the source and destination databases. If SSL is enabled, upload the SSL CA root certificate. NOTE: The maximum size of a single certificate file that can be uploaded is 500 KB. If SSL is disabled, your data may be at risk.

The IP address, domain name, username, and password of the source database are encrypted and stored in the system until the task is deleted.

Destination database configuration

Figure 7 Destination database information

**Table 10** Destination database settings
Parameter	Description
DB Instance Name	The GaussDB(for MySQL) instance you selected when creating the task. The parameter cannot be changed.
Database Username	The username for accessing the destination database.
Database Password	Password for logging in to the destination database.
SSL Connection	If SSL connection is required, enable SSL on the destination database, ensure that related parameters have been correctly configured, and upload an SSL certificate. NOTE: The maximum size of a single certificate file that can be uploaded is 500 KB. If SSL is disabled, your data may be at risk.

The username and password of the destination database are encrypted and stored in the database and the synchronization instance during the synchronization. After the task is deleted, the username and password are permanently deleted.

On the Set Synchronization Task page, select the objects to be synchronized, and then click Next.

Figure 8 Synchronization objects

**Table 11** Synchronization mode and object
Parameter	Description
Flow Control	You can choose whether to control the flow. Flow Control takes effect in the full phase only. Yes You can customize the maximum synchronization speed. During the full synchronization, the synchronization speed of each task (or each subtask in multi-task mode) does not exceed the value of this parameter. 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 Always. 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 9 Flow control No The synchronization 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: The flow control mode takes effect only in the full synchronization phase. You can also change the flow control mode after creating a task. For details, see Modifying the Flow Control Mode.
Incremental Conflict Policy	The conflict policy refers to the conflict handling policy during incremental synchronization. By default, conflicts in the full synchronization phase are ignored. Select any of the following conflict policies: Ignore The system will skip the conflicting data and continue the subsequent synchronization process. Overwrite Conflicting data will be overwritten.
Filter DROP DATABASE	During real-time synchronization, executing DDL operations on the source database may affect the synchronization performance. To reduce the risk of synchronization failure, DRS allows you to filter out DDL operations. Currently, only the delete operations on databases can be filtered by default. If you select Yes, the database deletion operation performed on the source database is not synchronized during data synchronization. If you select No, related operations are synchronized to the destination database during data synchronization.
Synchronize	Normal indexes and incremental DDLs can be synchronized. You can determine whether to synchronize data based on service requirements.
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.
Data Synchronization Topology	This parameter is available when Incremental DDLs is selected for Synchronize. Data synchronization supports multiple synchronization topologies. You can plan your synchronization instances based on service requirements. For details, see Data Synchronization Topologies. NOTE: Data Synchronization Topology can be selected only for whitelisted users. You need to submit a service ticket to apply for this function. In the upper right corner of the management console, choose Service Tickets > Create Service Ticket to submit a service ticket.
Synchronize DDLs	This parameter is available when Incremental DDLs is selected for Synchronize. Select DDL type for incremental synchronization. You can select Default or Custom based on your service requirements. Default During database-level synchronization, all DDL operations in the binlog related to database objects, except DDL related to permissions, are synchronized to the destination. Common DDL statements are CREATE_TABLE and RENAME_TABLE. During table-level synchronization, only DDL operations in the binlog related to the selected tables are synchronized. Common DDL statements are ADD_COLUMN, MODIFY_COLUMN, and ALTER_COLUMN. Custom: You can select the DDL type to be synchronized as required. The DDL types supported by different data flow types are displayed on the GUI. If Incremental DDLs is selected for Synchronize, but no DDL type is selected for Custom, DDLs will not be synchronized by default. NOTE: Only whitelisted users can synchronize incremental DDL operations. You need to submit a service ticket to apply for this function. In the upper right corner of the management console, choose Service Tickets > Create Service Ticket to submit a service ticket. One-to-one and one-to-many scenarios: If the DDL usage of the source and destination databases must be consistent, high-risk DDLs must be synchronized. If you do not want a high-risk DDL to be performed in the destination, deselect the high-risk DDL to protect destination data. However, this may cause the synchronization to fail. However, filtering DDL may cause synchronization to fail, for example, column deletion. Many-to-one scenarios: Synchronize only the Add Column operation, or tasks may fail or data may be inconsistent due to changes in destination tables.
Synchronization Object	The left pane displays the source database objects, and the right pane displays the selected objects. You can select Tables, Import object file, or Databases for Synchronization Object as required. 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). If the database table name contains characters other than letters, digits, and underscores (_), or the mapped database table name contains hyphens (-) and number signs (#), the name length cannot exceed 42 characters. In the many-to-one scenario, if you want to change the saved database mapping name during table-level synchronization, you need to expand the database. 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.

On the Process Data page, set the filtering rules for data processing.
- If data processing is not required, click Next.
- If data processing is required, select Data filtering, Additional Columns, or Processing Columns. For details about how to configure related rules, see Processing Data.
Figure 10 Processing data
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 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.

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 11 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.

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.

From MariaDB to GaussDB(for MySQL)