AnalyticDB for MySQL is a real-time online analytical processing (RT-OLAP) service developed by Alibaba Cloud for online data analysis with high concurrency. AnalyticDB for MySQL can analyze petabytes of data from multiple dimensions at millisecond-level timing to provide you with data-driven insights into your business. This topic describes how to synchronize data from a DRDS instance to an AnalyticDB for MySQL cluster by using Data Transmission Service (DTS). AnalyticDB for MySQL allows you to build internal business intelligence (BI) systems, interactive query systems, and real-time report systems.

Prerequisites

  • The MySQL version of the DRDS instance is MySQL 5.
  • The databases is created in the DRDS instance based on one or more ApsaraDB RDS for MySQL instances that you purchased.
  • An AnalyticDB for MySQL cluster is created. For more information, see Create an AnalyticDB for MySQL cluster.
  • The destination AnalyticDB for MySQL cluster has sufficient storage space.

Precautions

  • DTS uses read and write resources of the source and destination databases during initial full data synchronization. This may increase the database load. If the database performance is unfavorable, the specification is low, or the data volume is large, database services may become unavailable. For example, DTS occupies a large amount of read and write resources in the following cases: a large number of slow SQL queries are performed on the source database, the tables have no primary keys, or a deadlock occurs in the destination database. Before synchronizing data, you must evaluate the performance of the source and destination databases. We recommend that you synchronize data during off-peak hours. For example, you can synchronize data when the CPU usage of the source and destination databases is less than 30%.
  • We recommend that you do not perform operations such as scale-out, migration hot spot table , change shard key, and change DDL during data synchronization. Otherwise, data synchronization may fail.
  • After you change the network type of a DRDS instance during data synchronization, you must submit a ticket to modify the network connection information of the synchronization channel.

SQL operations that can be synchronized

Data manipulation language (DML) operations: INSERT, UPDATE, and DELETE

Permissions required for database accounts

Database Required permission
DRDS The REPLICATION SLAVE permission, the REPLICATION CLIENT permission, and the permission to perform SELECT operations on the required objects (These permissions are granted by DTS.)
AnalyticDB for MySQL The read/write permissions on the objects to be synchronized

Data type mappings

For more information, see Data type mappings for initial schema synchronization.

Procedure

  1. Purchase a data synchronization instance. For more information, see Purchase procedure.
    Note On the buy page, set Source Instance to DRDS, set Target Instance to AnalyticDB for MySQL, and set Synchronization Topology to One-Way Synchronization.
  2. Log on to the DTS console.
  3. In the left-side navigation pane, click Data Synchronization.
  4. At the top of the Synchronization Tasks page, select the region where the destination instance resides.
    Select a region
  5. Find the data synchronization instance and click Configure Synchronization Channel in the Actions column.
  6. Configure the source and destination instances.
    Configure the source and destination instances
    Section Parameter Description
    N/A Synchronization Task Name DTS automatically generates a task name. We recommend that you specify an informative name for easy identification. You do not need to use a unique task name.
    Source Instance Details Instance Type The value of this parameter is set to DRDS and cannot be changed.
    Instance Region The region of the source instance. The region is the same as the source region that you selected when you purchased the data synchronization instance. You cannot change the value of this parameter.
    DRDS Instance ID Select the ID of the source DRDS instance.
    Destination Instance Details Instance Type The value of this parameter is set to AnalyticDB and cannot be changed.
    Instance Region The region of the destination instance. The region is the same as the destination region that you selected when you purchased the data synchronization instance. You cannot change the value of this parameter.
    Version Select 3.0.
    Database Select the ID of the destination AnalyticDB for MySQL cluster.
    Database Account Enter the database account of the AnalyticDB for MySQL cluster. For more information about the permissions that are required for the account, see #section_51b_evg_td3.
    Database Password Enter the password of the destination database account.
  7. In the lower-right corner of the page, click Set Whitelist and Next.
    Note DTS adds the CIDR blocks of DTS servers to the whitelists of the source DRDS instance and the destination AnalyticDB for MySQL cluster. This ensures that DTS servers can connect to the source instance and the destination cluster.
  8. Configure the synchronization policy and objects.
    Configure the synchronization policy and objects
    Section Parameter Description
    Synchronization policy Initial Synchronization You must select both Initial Schema Synchronization and Initial Full Data Synchronization in most cases. After the precheck, DTS synchronizes the schemas and data of the required objects from the source instance to the destination instance. The schemas and data are the basis for subsequent incremental synchronization.
    Processing Mode In Existed Target Table
    • Clear Target Table

      Skips the Schema Name Conflict item during the precheck. Clears the data in the destination table before initial full data synchronization. If you want to synchronize your business data after testing the data synchronization task, you can select this mode.

    • Ignore

      Skips the Schema Name Conflict item during the precheck. Adds data to the existing data during initial full data synchronization. If you want to synchronize data from multiple tables to one table, you can select this mode.

    Synchronization Type

    Select the types of operations that you want to synchronize based on your business requirements.

    • Insert
    • Update
    • Delete
    Objects to be synchronized N/A

    Select tables from the Available section and click the Right arrow icon to move the tables to the Selected section.

    Note
    • You can select only tables as the objects to be synchronized.
    • You can change the names of the columns that are synchronized to the destination database by using the object name mapping feature. For more information about how to use this feature, see Specify the name of an object in the destination instance.
  9. In the lower-right corner of the page, click Next.
  10. Specify a type for the tables to be synchronized to the destination database.
    Specify a table type
    Note After you select Initial Schema Synchronization, you must specify the type, primary key column, and partition key column for the tables to be synchronized to AnalyticDB for MySQL. For more information, see CREATE TABLE.
  11. In the lower-right corner of the page, click Precheck.
    Note
    • Before you can start the data synchronization task, a precheck is performed. You can start the data synchronization task only after the task passes the precheck.
    • If the task fails to pass the precheck, click the Info icon icon next to each failed item to view details. Troubleshoot the issues based on the causes and run the precheck again.
  12. Close the Precheck dialog box after the following message is displayed: The precheck is passed.
  13. Wait until the initial synchronization is complete and the data synchronization task is in the Synchronizing state.
    On the Synchronization Tasks page, view the status of the data synchronization task.View the status of a data synchronization task.