From MySQL to Kafka

Supported Source and Destination Databases

Prerequisites

• You have logged in to the DRS console.
• For details about the DB types and versions supported by real-time synchronization, see Real-Time Synchronization.

Suggestions

• 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.
• It is recommended that you start a task during off-peak hours to minimize the impact of synchronization on your services.

Precautions

Before creating a synchronization task, read the following notes:

Procedure

1. On the Data Synchronization Management page, click Create Synchronization Task.
2. On the Create Synchronization Instance page, specify the task name, description, and the synchronization instance details, and click Next.

   Table 3 Task and recipient description

   Parameter	Description
   Region	The region where the synchronization 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 !=<>'&"\

   Table 4 Synchronization instance settings

   Parameter	Description
   Data Flow	Choose Self-built to self-built.
   Source DB Engine	Select MySQL.
   Destination DB Engine	Select Kafka.
   Network Type	The Public network is used as an example. Available options: VPC, Public network and VPN or Direct Connect
   AZ	Select the AZ where you want to create the DRS instance. Selecting the one housing the source or destination database can provide better performance. If Instance Type is set to primary/standby, you can specify Primary AZ and Standby AZ.
   VPC	Select an available VPC.
   Synchronization Instance Subnet	Select the subnet where the synchronization instance is located. You can also click View Subnet 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 ensure that there are available IP addresses. To ensure that the synchronization instance is successfully created, only subnets with DHCP enabled are displayed.
   Security Group	Select a security group. You can use security group rules to allow or deny access to the instance.
   Synchronization Mode	Incremental Through log parsing, incremental data generated on the source database is synchronized to the destination database. During synchronization, the source database continues to provide services for external systems with zero downtime.
   Tags	This setting is optional. Adding tags helps you better identify and manage your tasks. Each task can have up to 20 tags. 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 ends.

3. 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.

   Table 5 Source database settings

   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.
   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 the SSL certificate is not used, your data may be at risk.

   

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

   Table 6 Source database information

   Parameter	Description
   IP Address or Domain Name	The IP address or domain name of the destination database.
   Security Protocol	Available options: PLAINTEXT, SSL, SASL_PLAINTEXT, and SASL_SSL. For details, see Kafka Authentication.

4. On the Set Synchronization Task page, select the synchronization policy, objects, and data format, and click Next.

   Table 7 Synchronization Object

   Parameter	Description
   Topic Synchronization Policy	Topic synchronization policy. The options are as follows: Select A specified topic if the data volume of the source database is small. Select Auto-generated topics if each table contains a lot of data. Then, the system automatically generates a topic for each table.
   Topic	Select the topic to be synchronized to the destination database. This parameter is available when the topic is set to A specified topic.
   Topic Name Format	Topic name format. This parameter is available when Topic Synchronization Policy is set to Auto-generated topics. Only variables database and tablename are supported. The other characters must be constants. Replace $database$ with the database name and $tablename$ with the table name. For example, if this parameter is set to $database$-$tablename$ and the database name is db1, and the table name is tab1, the topic name is db1-tab1. If DDL statements are synchronized, $tablename$ is empty and the topic name is db1.
   Number of Partitions	This parameter is available when Topic Synchronization Policy is set to Auto-generated topics. The number of partitions of a topic. Each topic can have multiple partitions. More partitions can provide higher throughput but consume more resources. Set the number of partitions based on the actual situation of brokers.
   Replication Factor	This parameter is available when Topic Synchronization Policy is set to Auto-generated topics. Number of copies of a topic. Each topic can have multiple copies, and the copies are placed on different brokers in a cluster. The number of copies cannot exceed the number of brokers. Otherwise, the topic fails to be created.
   Synchronize Topic To	The policy for synchronizing topics to the Kafka partitions. If topics are synchronized to different partitions by hash value of the database and table names, the performance on a single table query can be improved. If topics are synchronized to partition 0, strong consistency can be obtained but write performance is impacted. If topics are synchronized to different partitions by hash value of the primary key, one table corresponds to one topic. This prevents data from being written to the same partition, and consumers can obtain data from different partitions concurrently.
   Data Format in Kafka	Select the data format to be delivered from MySQL to Kafka. JSON: JSON message format, which is easy to interpret but takes up more space. JSON-C: A data format that is compatible with multiple batch and stream computing frameworks. For details, see Kafka Message Format.
   Synchronization Object	Available options: Tables and Databases. 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 Mapping Object Names.

5. On the Process Data page, select the columns to be processed.
   • If data processing is not required, click Next.
   • If you need to process columns, set processing rules by referring to Processing Data.

6. 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.
   • If all check items are successful, 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.

7. On the displayed page, specify Start Time, confirm that the configured information is correct, and click Submit to submit the task.

   Table 8 Task startup settings

   Parameter	Description
   Started 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.

8. 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.