MySQL to Kingbase

NineData Data Replication supports schema replication, full data replication, and incremental replication from MySQL-compatible data sources to Kingbase.

Overview

Use this workflow to migrate MySQL data to Kingbase and keep the target database updated with incremental source changes.

Before you begin

Add the source and target data sources to NineData. For details, see Add Data Source.
The supported MySQL source versions range from 5.1 to 9.0.
The target data source must be Kingbase V9 or V8.

The source and target accounts must have the following permissions:

Replication Type	Source Data Source	Target Data Source
Schema Replication	SELECT permission	Schema Owner
Full Replication	SELECT permission	Schema Owner
Incremental Replication	SELECT, REPLICATION CLIENT, REPLICATION SLAVE permissions	Schema Owner

For incremental replication, the source data source must have Binlog enabled, with the following parameters:
- binlog_format=ROW
- binlog_row_image=FULL
  tip
  If the source data source is a standby database, enable log_slave_updates to capture the complete Binlog.
If the source and target data sources were added to NineData in different regions, add the IP address of each NineData server to the other data source's whitelist. You can view both IP addresses on the "Source & Target" tab when you create a replication task.

Restrictions

Incremental replication does not support synchronizing DDL operations from the source.
Data replication applies only to user databases. System databases are not replicated. For MySQL data sources, system databases include information_schema, mysql, performance_schema, and sys.
Before data synchronization, evaluate source and target performance, and run synchronization during off-peak hours when possible. Full data initialization consumes read and write resources on both sides and increases database load.
Make sure each replicated table has a primary key or unique constraint, and that column names are unique. Otherwise, duplicate rows may be synchronized.

Procedure

Log in to the NineData Console.
In the left navigation pane, click Replication > Data Replication.
On the Replication page, click Create Replication in the upper-right corner.

On the Source & Target tab, configure the fields in the following table, and click Next.

Parameter	Description
Name	Enter a name for the data synchronization task. To make the task easier to find and manage later, use a meaningful name. Up to 64 characters are supported.
Source	The data source that contains the objects to synchronize.
Target	The data source that receives the synchronized objects.
Target DB	Select the target database to which data is synchronized.
Target Object Name	Select the case conversion rule for object names after they are migrated from the source to the target. Convert all to Lowercase: Regardless of the naming rule on the source, all target names are lowercase. Consistent with Source: Keep the naming rule of the source. Convert all to Uppercase: Regardless of the naming rule on the source, all target names are uppercase.
Type	Select the replication type. Schema: Synchronize only the database and table schemas of the source data source, without synchronizing data. Full: Synchronize all objects and data from the source data source, namely full data replication. The switch on the right enables periodic full replication. For more information, see Periodic Full Replication. Incremental: After full synchronization is complete, perform incremental synchronization based on the logs of the source data source.
Incremental Started	Required only when Type is Incremental. From Started: Use the current replication task start time as the baseline for incremental replication. Customized Time: Select the point in time from which incremental replication starts. You can select a time zone based on the region of your business. If the configured time point is earlier than the current replication task start time and DDL operations occurred during that period, the replication task will fail.
Spec (Unavailable only when Schema is selected)	The specification of the replication task. A larger specification provides a higher replication rate. Hover over the icon to view the rate and configuration information of each specification. Each specification shows the available quantity and total quantity. When the available quantity is 0, the specification is grayed out and cannot be selected.
If target table already exists (Required when Schema is selected)	Pre-Check Error and Stop Task: Stop the task when a table with the same name is detected during the precheck stage. Skip and Continue Task: When a table with the same name is detected during the precheck stage, display a prompt and continue the task. During schema replication, ignore the table with the same name. If you also perform data replication, data is appended to the table with the same name and existing data is not overwritten. Delete Objects and Rewrite: When a table with the same name is detected during the precheck stage, display a prompt and continue the task. During schema replication, delete the table with the same name in the target database and replicate the table schema again based on the source database. If you also perform data replication, data is written after schema replication is complete.
Target Table Exists Data (Required when Full is selected)	Pre-Check Error and Stop Task: Stop the task when data is detected in the target table during the precheck stage. Ignore existing target data and append to it.: When data is detected in the target table during the precheck stage, ignore that data and append other data. Clear target existing data before write: When data is detected in the target table during the precheck stage, delete that data and write it again.
Incremental data conflict handling strategy for target table (Required when Incremental is selected)	Runtime error: During incremental replication, report an error when target data already exists and wait for manual intervention. Do not update target data: During incremental replication, do not write data when target data already exists, and continue subsequent tasks. Update target data: During incremental replication, overwrite the target data when target data already exists.

On the Objects tab, configure the parameters in the table, and click Next.

Parameter	Description
Replication Objects	Select the content to replicate. You can select All Objects to replicate all content in the source database, or select Customized Object, select the content to replicate in the Source Object list, and click > to add it to the Target Object list on the right.

To create multiple replication links with the same replication objects, create a configuration file and import it when creating a task. Click Import Config in the upper-right corner, click Download Template to download the configuration file template, edit the file, and then click Upload to upload it for batch import. Configuration file description:

Parameter	Description
`source_table_name`	The source table name of the object to synchronize.
`destination_table_name`	The target table name that receives the synchronized object.
`source_schema_name`	The source schema name of the object to synchronize.
`destination_schema_name`	The target schema name that receives the synchronized object.
`source_database_name`	The source database name of the object to synchronize.
`target_database_name`	The target database name that receives the synchronized object.
`column_list`	The list of columns to synchronize.
`extra_configuration`	Additional configuration information. This field supports: `column_rules`: Defines column mappings and value rules. Field descriptions: `column_name`: Original column name. `destination_column_name`: Specifies the target column name. `column_value`: Specifies the column value, which can be an SQL function or a constant value. `filter_condition`: Specifies row-level data filtering conditions. Only rows that meet the conditions are replicated.

tip

Example of extra_configuration:

{
  "extra_config":{
    "column_rules":[
      {
        "column_name": "created_time", // Specifies the original column name to be mapped.
        "destination_column_name": "migrated_time", // Maps the target column name to "migrated_time".
        "column_value": "current_timestamp()" // Changes the column value to the current timestamp.
      }
    ],
    "filter_condition": "id != 0" // Only rows whose ID is not 0 are synchronized.
  }
}

For a complete example of the configuration file, see the downloaded template.

On the "Mapping" tab, choose different operations based on the selected replication type, and click Save and Pre-Check. If the source and target data sources are updated during mapping configuration, click Refresh Metadata in the upper-right corner of the page to refresh the source and target data source information.
- Includes Schema: Configure the table name after synchronization to the target data source.
- Does not include Schema: The system selects the database with the same name in the target data source by default. If no such database exists, select the target database manually. The table names and column names in the target database must match the synchronization objects. If they do not match, map the table names and column names manually.
You can also perform these actions:
- Click Mapping & Filtering to customize the column names after synchronization to the target data source.
- On the Mapping & Filtering page, click Data Filter to configure filtering conditions by using comparison expressions. Only data that meets the filtering conditions is synchronized to the target data source. For example, if the filtering condition is set to emp_no>=10005, data whose emp_no column value is less than 10005 is not synchronized to the target data source.
- Click the icon to the right of "Target Table" to search for a table name and replace it with the target name.
- Enter a table name in the Search Table text box in the upper-right corner to quickly locate the target table.
- Click Batch Configuration in the upper-right corner to define common rules in batches, such as table name and column name case conversion, prefix or suffix addition, and replacement, so that mapping configuration can be applied uniformly to a large number of tables and columns.

On the Pre-check tab, wait for the system to complete the precheck. After the precheck is passed, click Launch.
- Select Enable data consistency comparison to start a data consistency comparison task based on the source data source after synchronization completes. Based on the selected Type, Enable data consistency comparison starts at these times:
  - Schema: Starts after schema replication is complete.
  - Schema+Full: Starts after full replication is complete.
  - Full: Starts after full replication is complete.
  - Schema+Full+Incremental, Incremental: Starts when incremental data is consistent with the source data source for the first time and Delay is 0 seconds. You can click View Details and view the synchronization delay on the Details page.
- If the precheck fails, click Details in the Actions column for the failed check item, review the cause, fix the issue, and then click Check Again to run the precheck again until it passes.
- Items with Warning in Result can be fixed or ignored based on your requirements.
On the Launch page, the Launch Successfully prompt appears, indicating that the synchronization task has started. You can then perform these actions:
- Click View Details to view the execution status of each stage of the synchronization task.
- Click Back to list to return to the Replication task list page.

View replication results

Log in to the NineData Console.
In the navigation menu, click Replication > Data Replication.

On the Replication page, click the Task ID of the target synchronization task. The task details page shows the following information.

result

Number	Function	Description
1	Sync Delay	The synchronization delay between the source and target data sources. `0` seconds means the target has caught up with the source, so you can switch traffic based on your migration plan.
2	Configure Alerts	When the task fails, the system notifies the selected channel through the configured alert.
3	More	Pause: Pause the task. Only tasks with Running status are selectable. Duplicate: Create a new replication task with the same configuration as the current task. Terminate: Terminate tasks that are incomplete or still listening (that is, in incremental synchronization). After a task is terminated, it cannot be restarted, so proceed with caution. If the synchronization objects contain triggers, trigger replication options appear for selection. Delete: Delete the task. Once deleted, it cannot be recovered, so proceed with caution.
4	Structure Replication (displayed in scenarios involving structure replication)	Displays the progress and detailed information of structure replication. Click Log to view the execution logs of structure replication. Click the to view the latest information. Click View DDL in the Actions column for the target object in the list to view SQL replay.
5	Full Replication (displayed in scenarios involving full replication)	Displays the progress and detailed information of full replication. Click Monitor to view various monitoring indicators during full replication. During full replication, you can also click Flow Control Settings on the monitoring page to limit the rate of writing to the target data source per second. The unit is rows/second. Click Log to view the execution logs of full replication. Click the to view the latest information.
6	Incremental Replication (displayed in scenarios involving incremental replication)	Displays incremental replication indicators. Click View Threads to view the operations currently being executed by the current replication task, including: Thread ID: Replication tasks are executed in multiple threads, and this shows the current thread number. Execute SQL: Details of the SQL statement currently being executed by the current thread. Response Time: The response time of the current thread. If this value increases, it indicates that the current thread may be stuck for some reason. Event Time: The timestamp when the current thread was started. Status: The status of the current thread. Click Flow Control Settings to limit the rate of writing to the target data source per second. The unit is rows/second. Click Log to view the execution logs of incremental replication. Click the to view the latest information.
7	Modify Object	Displays the modification records of synchronization objects. Click Modify Objects to configure the synchronization objects. Click the to view the latest information.
8	Data Comparison	Displays the comparison results between the source and target data sources. If data comparison is not enabled, click Enable Comparison on the page to enable it. Click Re-compare to rerun the comparison for the current source and target data sources. Click Stop to stop the comparison task immediately after it starts. Click Log to view the execution logs of consistency comparison. Click Monitor (displayed only in data comparison) to view the trend chart of RPS (records per second) comparison. Click Details to view earlier records. Click the in the Actions column in the comparison list (displayed under the Data tab only when inconsistencies are found) to view details of the comparison between the source and target data sources. Click the in the Actions column in the comparison list (displayed only when inconsistencies are found): Generate change SQL. You can copy this SQL to the target data source and run it to fix the mismatch.
9	Expand	Displays detailed information of the current replication task. Common actions: Export table configuration: Export the current task's database and table configuration so you can quickly import it when creating another replication task with the same objects. Alert Rules: Configure alerts for the current task.

Appendix 1: Precheck items

Check item	What NineData checks
Source Data Source Connection Check	Checks the source data source gateway status, instance accessibility, username, and password.
Target Data Source Connection Check	Checks the target data source gateway status, instance accessibility, username, and password.
Target Database Permission Check	Checks whether the target database account has the required permissions.
Source Database Permission Check	Checks whether the source database account has the required permissions.
Source Database log_slave_updates Support Check	Checks whether `log_slave_updates` is set to `ON` when the source database is a standby database.
Source and Target Database Version Check	Checks whether the source and target database versions are compatible.
Source Database Binlog Enabled Check	Checks whether Binlog is enabled for the source database.
Source Database Binlog Format Support Check	Checks whether the source database `binlog_format` is `ROW`.
Source Database binlog_row_image Support Check	Checks whether the source database `binlog_row_image` is `FULL`.
Target Database Data Existence Check	Checks whether data already exists in the target database for the objects to replicate.
Target Database Same Name Object Existence Check	Checks whether objects with the same names already exist in the target database.

Introduction to Data Replication

MySQL to Kingbase

Overview​

Before you begin​

Restrictions​

Procedure​

View replication results​

Appendix 1: Precheck items​

Related documents​