Self-Build MySQL to Tencent Cloud MySQL

NineData data replication supports the synchronization of self-built MySQL to Tencent Cloud MySQL, supports ECS self-built, TencentDB MySQL and TDSQL-C MySQL, and easily realizes data migration to the cloud.

Prerequisite

• The purchased Tencent Cloud instance is located in one of the following regions: East China (Shanghai), Southwest (Chongqing), Southwest (Chengdu), North China (Beijing), East China (Nanjing), South China (Guangzhou) .

• Added source and target data sources to NineData. For how to add, see Adding Data Sources .

• The versions of the source and target data sources are shown in the table below. Note that the source version must be less than or equal to the target data source version.

  Source	Target
  MySQL 8.0	TencentDB/TDSQL-C MySQL 8.0
  MySQL 5.7	TencentDB/TDSQL-C MySQL 8.0、5.7
  MySQL 5.6	TencentDB/TDSQL-C MySQL 8.0、5.7、5.6
  MySQL 5.5、5.1	TencentDB/TDSQL-C MySQL 8.0、5.7、5.6、5.5
  MySQL 5.5	（ECS Self-Build）MySQL 8.0、5.7、5.6、5.5
  MySQL 5.1	（ECS Self-Build）MySQL 8.0、5.7、5.6、5.5、5.1

• The source data source must enable Binlog, and the related parameters of Binlog are set as follows:

  • binlog_format=ROW
  • binlog_row_image=FULL
  tip

  If the source data source is the standby database, in order to obtain the complete Binlog, the log_slave_updates parameter must be turn on.

Restrictions

• The data replication function is only for the user databases in the data source, and the system databases will not be replicated. For example: information_schema, mysql, performance_schema, sys databases in MySQL type data sources will not be replicated.
• The account for source data must have SELECT (for replicate database structure and full data), SHOW VIEW (for replicate views), and REPLICATION CLIENT, REPLICATION SLAVE (for replicate incremental data) privileges on the objects to be replicated. The account for target must have DML and DDL privileges.
• Before performing data synchronization, user need to evaluate the performance of the source data source and the target data source, and it is recommended to perform data synchronization during off-peak time. Otherwise, the full data initialization will occupy a certain amount of read and write resources of the source data source and the target data source, increasing database load.
• During the synchronization process, if the source data contains views, functions, stored procedures, triggers, and events, after synchronizing to the target data source, the definer of the above objects information will be modified in the target data source to the account that accesses the target data source in the current synchronization task.
• It is necessary to ensure that each table in the synchronization object has a primary key or unique constraint, and the column name is unique, otherwise the same data may be synchronized repeatedly.
• During the synchronization process, if there are triggers in the source, the system will not synchronize the triggers until the incremental synchronization ends.

Step 1: Add Tencent Cloud MySQL data source to NineData

NineData supports multiple ways to add Tencent Cloud MySQL data source. This article takes public network connection as an example to add.

1. Add the NineData public IP address 121.199.39.25 to the IP allowlist of the Tencent Cloud instance to allow NineData to access the instance. How to add, please refer to the following help documents:

   • Tencent cloud database MySQL setting security group rules
   • Tencent Cloud Cloud Server Create Security Group
   • TDSQL-C MySQL create and manage cloud database security groups

2. Configure cloud vendor access credentials in the NineData console.

3. Log in to the NineData Console.

   And in the left navigation bar, click **Datasource**>**Datasource**.

4. Click Create Datasource in the upper right corner of the page. On the Create Datasource page, configure parameters according to the table below.

   Parameters	Descriptions
   Name	Enter the name of the data source. For the convenience of subsequent search and management, please try to use a meaningful name.
   Datasource Location	Select Tencent Cloud。
   Environments	PROD(Production) and DEV(Development) environments are provided by default, and also allow customerized environments. Note : In organizational mode , the database environment can also be applied to permission policy management. For example, the production environment administrator role by default only supports access to data sources in the production environment and cannot access data sources in other environments. For more information, see Managing Roles.
   Instance Type	Select the instance type based on the actual situation.
   DB Type	Select MySQL。
   Connection	Select IP Address。
   Access Method	Select Instance ID。
   Access Credentials	Select the cloud vendor access credentials configured in Step 2.
   Region	Select the region where your database instance is located.
   Instance ID	Select the Tencent MySQL instance ID you created.
   DB Account	Enter the user name for accessing the database.
   DB Password	Enter the password corresponding to the username for accessing the database.
   Encryption	By default there is no need to change this option, if you need to connect via SSL encryption, please refer to the official documentation.

   tip

   NineData will automatically add NineData's public IP address to the IP whitelist in the database instance you selected, and you don't need to add it manually.

5. After all configurations are completed, click the Connection Test to the right of the DB Password to test whether the data source can be accessed normally, and if the Connection Succeeded , click Create Datasource to complete the addition of the data source. Otherwise, correct the connection settings until the connection test is successful.

Step 2: Copy the self-built MySQL data to the Tencent Cloud MySQL data source

Commercialization Notice

NineData’s data replication product has been commercialized. You can still use 10 replication tasks for free, with the following considerations:

• Among the 10 replication tasks, you can include 1 Incremental task, with a specification of Micro.

• Tasks with a status of Terminated do not count towards the 10-task limit. If you have already created 10 replication tasks and want to create more, you can terminate previous replication tasks and then create new ones.

• When creating replication tasks, you can only select the Spec you have purchased. Specifications that have not been purchased will be grayed out and cannot be selected. If you need to purchase additional specifications, please contact us through the customer service icon at the bottom right of the page.

1. Log in to the NineData Console.

2. Click on Replication > Data Replication in the left navigation bar.

3. On the Replication page, click on Create Replication in the top right corner.

4. On the Source & Target tab, configure according to the table below, and click Next.

   Parameter	Description
   Name	Enter the name of the data synchronization task for easy search and management. Please use meaningful names. Up to 64 characters are supported.
   Source	Data source where the synchronization object is located.
   Target	Data source receiving the synchronized object.
   Replication Mode (MySQL only)	Choose the replication mode, available only for replication tasks between MySQL instances. Uni-directional: Unidirectional data replication task from the source data source to the target data source. Bi-directional: Bidirectional incremental data replication task between source and target data sources.
   Type	Shown only when Replication Mode is Uni-directional. Schema: Syncs only the schema of the source data source, not the data. Full: Syncs all objects and data from the source data source, i.e., full data replication. Incremental: After full synchronization, performs incremental synchronization based on the source data source's logs. Click the icon to uncheck certain operation types according to your needs. Once unchecked, these operations will be ignored during incremental synchronization. Note: You can also click to expand Target Table Preparation to select the handling strategy in case of same-named tables or identical data.
   Forward Type	Replication type from the source data source to the target data source, shown only when Replication Mode is Bi-directional. Refer to Type above for available options. Incremental is selected by default and cannot be disabled. Click the icon to uncheck certain operation types according to your needs. Once unchecked, these operations will be ignored during incremental synchronization.
   Forward Incremental Started	Needed to select when Replication Mode is Bi-directional and Forward Type is only Incremental. From Started: Starts incremental replication based on the current replication task start time. Customized Time: Choose the time point to start incremental replication. You can select the time zone according to your business region. If you configure the time point to be before the current replication task start time, the replication task will fail if there are DDL operations during that time period.
   Reverse Type	Replication type from the target data source to the source data source, shown only when Replication Mode is Bi-directional. Only supports Incremental, and is selected by default and cannot be disabled.
   Support DDL Replication	When performing incremental replication, whether to replicate DDL operations. Shown only when Replication Mode is Bi-directional. Forward replication supported, reverse not supported: Incremental DDL operations in the source data source will be synchronized to the target data source. In this scenario, do not perform DDL operations in the reverse task (target data source), as the task may fail. Not supported: All incremental DDL operations will not be synchronized. In this scenario, do not perform DDL operations in either the source or target data source, as the task may fail.
   Incremental Started	Needed to select when Replication Mode is Uni-directional and Type is only Incremental. From Started: Starts incremental replication based on the current replication task start time. Customized Time: Choose the time point to start incremental replication. You can select the time zone according to your business region. If you configure the time point to be before the current replication task start time, the replication task will fail if there are DDL operations during that time period.
   Target Table Preparation	If target table already exists (Select Schema): 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 structural replication, ignore this same-named table. If you are also replicating data, the data will be appended to the same-named table without overwriting existing data. 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 structural replication, delete the same-named table in the target database and replicate the table structure based on the source database. If you are also replicating data, the data will be written after the table structure replication is completed. Keep Schema and Clear Data, then Rewrite (Selectable when performing both structural and data replication): When a table with the same name is detected during the precheck stage, display a prompt and continue the task. During structural replication, retain the table structure in the target database and clear the data in the same-named table when data replication starts, then replicate from the original table. Target Table Exists Data (Unselected when Schema is selected): Pre-Check Error and Stop Task: Stop the task when data is detected in the target table during the precheck stage. Ignore the existing data and append : Ignore the data detected in the target table during the precheck stage and append other data. Clear the existing data before write: Delete the data detected in the target table during the precheck stage and rewrite.

5. On the Objects tab, configure the following parameters, then click Next.

   Parameter	Description
   Replication Objects	Choose what to replicate. You can select All Objects to replicate all contents of the source database, or choose Customized Object, select the items to be replicated in the Source Object list, and click > to add them to the right Target Object list.
   Blacklist (Optional)	Click Add to add a blacklist record, select the databases or objects to be added to the blacklist. These contents will not be replicated. This is used to exclude certain databases or objects in the case of full database replication for Customized Object or Full Instance. Left dropdown: Select the name of the database to be added to the blacklist. Right dropdown: Select the objects in the corresponding database. You can click to select multiple objects; leave it blank to add the entire database to the blacklist. If you want to add multiple databases to the blacklist, you can click the Add button below.

   If you need to create multiple identical replication links, you can create a configuration file and import it when creating a new task. Click Import Config at the top right corner, then click Download Template to download the configuration file template to your local machine. After editing, click Upload to upload the configuration file for batch import.

   Parameter	Description
   source_table_name	Name of the source table containing the objects to be synchronized.
   destination_table_name	Name of the target table receiving the synchronized objects.
   source_schema_name	Name of the source schema containing the objects to be synchronized.
   destination_schema_name	Name of the target schema receiving the synchronized objects.
   source_database_name	Name of the source database containing the objects to be synchronized.
   target_database_name	Name of the target database receiving the synchronized objects.
   column_list	List of columns to be synchronized.
   extra_configuration	Additional configuration information can be set here: column_rules: Used to define column mapping and value rules. Field descriptions: column_name: Original column name. destination_column_name: Target column name. column_value: Value to assign, which can be an SQL function or a constant. filter_condition: Used to specify row-level filtering conditions; only rows that meet the criteria will be copied.

   tip

   • An example of the extra_configuration content is as follows:

     {
       "extra_config": {
         "column_rules": [
           {
             "column_name": "created_time", // Original column name to map.
             "destination_column_name": "migrated_time", // Target column name mapped to "migrated_time".
             "column_value": "current_timestamp()" // Change the column value to the current timestamp.
           }
         ],
         "filter_condition": "id != 0" // Only rows where ID is not 0 will be synchronized.
       }
     }

   • For a complete example of the configuration file, refer to the downloaded template.

6. On the "Mapping" tab, choose different operations based on the selected replication type. If updates occur in the source and target data sources during the configuration mapping phase, you can click the Refresh Metadata button in the upper right corner of the page to refresh the information of the source and target data sources.

   • Includes Schema: Configure the table name after synchronization to the target data source. Click Save and Pre-Check.

   • Excludes Schema: The system automatically selects the same-named database in the target data source, if it exists; otherwise, you need to manually select the target database. The table names and column names in the target database need to match the synchronization objects. If they don't match, you can manually map the table names and column names.

   You can click Mapping & Filtering on the right side of the page to customize the column names after synchronization to the target data source. Additionally, you can set Data Filter, and only data that meets the filtering conditions will be synchronized to the target data source. Taking the test data table employees as an example, if you set the filtering condition to emp_no>=10005, data with emp_no less than 10005 will not be synchronized to the target data source.

7. On the "Pre-check" tab, wait for the system to complete the precheck. After passing the precheck, click Launch.

   tip

   • You can check Enable data consistency comparison. After the synchronization task is completed, automatically start data consistency comparison based on the source data source to ensure data consistency on both ends. The startup timing of Enable data consistency comparison based on your selection of Type is as follows:
     • Schema: Starts after structural replication is completed.
     • Schema + Full, Full: Starts after full replication is completed.
     • Schema + Full + Incremental, Incremental: Starts when incremental data is first consistent with the source data source and Delay is 0 seconds. You can click View Details to view the synchronization delay on the Details page.
   • If the precheck fails, you need to click Details in the Actions column on the right of the target check item, identify the reason for the failure, manually fix it, and then click Check Again to perform the precheck again until it passes.
   • For check items with Result as Warning, you can repair or ignore them based on the specific situation.

8. On the Launch page, you will receive a prompt Launch Successfully, indicating that the synchronization task has started. At this point, you can:

   • Click View Details to view the execution status of the synchronization task at each stage.
   • Click Back to list to return to the Replication task list page.

View Sync Results

1. Log in to the NineData Console.

2. Click on Replication > Data Replication in the left navigation bar.

3. On the Replication page, click on the Task ID of the target synchronization task, the page details are as follows.

   

   Number	Function	Description
   1	Sync Delay	The data synchronization delay between the source data source and the target data source. 0 seconds means there is no delay between the two ends, at which point you can choose to switch the business to the target data source for smooth migration.
   2	Configure Alerts	After configuring alerts, the system will notify you in the way you choose when the task fails. For more information, please refer to Operations Monitoring Introduction.
   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: End tasks that are unfinished or listening (i.e., in incremental synchronization). Once the task is terminated, it cannot be restarted, so please proceed with caution. If the synchronization objects contain triggers, a trigger replication option will pop up, please select as needed. Delete: Delete the task. Once the task is deleted, it cannot be recovered, so please proceed with caution.
   4	Structure Replication (displayed in scenarios involving structure replication)	Displays the progress and detailed information of structure replication. Click on Log on the right side of the page: View the execution logs of structure replication. Click on on the right side of the page: View the latest information. Click on View DDL in the Actions column on the right side of the target object in the list: View SQL playback.
   5	Full Replication (displayed in scenarios involving full replication)	Displays the progress and detailed information of full replication. Click on Monitor on the right side of the page: View various monitoring indicators during full replication. During full replication, you can also click on Flow Control Settings on the right side of the monitoring indicator page to limit the rate of writing to the target data source per second. The unit is rows/second. Click on Log on the right side of the page: View the execution logs of full replication. Click on on the right side of the page: View the latest information.
   6	Incremental Replication (displayed in scenarios involving incremental replication)	Displays various monitoring indicators of incremental replication. Click on View Threads on the right side of the page: View the operations currently being executed by the current replication task, including: Thread ID: Replication tasks are executed in multiple threads, displaying the current thread number in progress. 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 on Flow Control Settings on the right side of the page: Limit the rate of writing to the target data source per second. The unit is rows/second. Click on Log on the right side of the page: View the execution logs of incremental replication. Click on on the right side of the page: View the latest information.
   7	Modify Object	Displays the modification records of synchronization objects. Click on Modify Objects on the right side of the page to configure the synchronization objects. Click on on the right side of the page: View the latest information.
   8	Data Comparison	Displays the comparison results between the source data source and the target data source. If you have not enabled data comparison, please click on Enable Comparison on the page. Click on Re-compare on the right side of the page: Re-initiate the comparison between the current source and target data sources. Click on Stop on the right side of the page: After the comparison task starts, you can click this button to stop the comparison task immediately. Click on Log on the right side of the page: View the execution logs of consistency comparison. Click on Monitor (displayed only in data comparison): View the trend chart of RPS (records per second) comparison. Click on Details to view earlier records. Click on in the Actions column on the right side of the comparison list (displayed under the Data tab only in the case of inconsistency): View details of the comparison between the source and target sides. Click on in the Actions column on the right side of the comparison list (displayed only in the case of inconsistency): Generate change SQL. You can directly copy this SQL to the target data source to execute and modify the inconsistent content.
   9	Expand	Display detailed information of the current replication task. Common Options: Export table configuration: Export the current task's database and table configuration, allowing for quick import when creating a new replication task. This helps rapidly establish multiple replication links with the same replication objects. Alert Rules: Configure the alarm strategy for the current task.

Related Documents

Introduction to Data Replication