DMS (for Kafka) Trigger

Notes and Constraints

• The regions and runtimes supported for Kafka triggers are subject to the console.
• The valid payload size of a request body is 6 MB when a Kafka trigger is used.
• In cases of Kafka data processing failure, the Kafka trigger will discard records that are larger than 6 MB.

Prerequisites

• Function and configuration:
  • You have created a function.
  • You have configured DMS agency permissions for the function. For details about how to create an agency, see Configuring Agency Permissions.
  • You have enabled VPC access for the function. For details, see Configuring Networks.
• DMS for Kafka:
  • You have created a Kafka instance. For details, see Buying an Instance.
  • You have created a topic under a Kafka instance. For details, see Creating a Topic.
  • You have configured the subnet permissions for the Kafka security group after enabling VPC access for the function. For details, see Selecting and Configuring a Kafka Security Group.

Creating a Kafka Trigger

1. Log in to the FunctionGraph console. In the navigation pane, choose Functions > Function List.
2. Click the function to be configured to go to the function details page.
3. Choose Configuration > Triggers and click Create Trigger.
   Figure 1 Creating a trigger
   

4. Configure the following parameters.

   Table 1 Parameters of a Kafka trigger

   Parameter	Description	Example Value
   Trigger Type	Select DMS (for Kafka).	DMS (for Kafka)
   Instance	Select a created Kafka instance. If no instance is available, click Create Instance.	kafka-fg
   Topic	Select a topic of the Kafka premium instance. You can create a Kafka trigger with multiple topics. You do not need to create one such trigger for each topic in the same instance. If no topic is available, click Create Topic.	topic-fg
   Batch Size	Enter the number of messages consumed from the topic each time. The value ranges from 1 to 1000.	100
   Username	Username used for connecting to the Kafka premium instance. This parameter is mandatory when SSL is enabled for the Kafka instance.	user
   Password	Password used for connecting to the Kafka premium instance. This parameter is mandatory when SSL is enabled for the Kafka instance.	***

5. Click OK.

Configuring a Kafka Event to Trigger the Function

1. Return to the FunctionGraph console. In the navigation pane, choose Functions > Function List.
2. Click the function to be configured to go to the function details page.
3. On the function details page, select a version.
4. On the Code tab page, click Test. The Configure Test Event dialog box is displayed.
5. Set the parameters described in Table 2 and click Create.

   Table 2 Test event information

   Parameter	Description	Example Value
   Configure Test Event	You can choose to create a test event or edit an existing one. Use the default option Create new test event.	Create new test event
   Event Templates	Select DMS (for Kafka) to use the built-in Kafka event template.	DMS (for Kafka)
   Event Name	The event name can contain 1 to 25 characters and must start with a letter and end with a letter or digit. Only letters, digits, underscores (_), and hyphens (-) are allowed.	kafka-123test
   Event data	The system automatically loads the built-in Kafka event template, which is used in this example without modifications.	-

6. Click Test. The function test result is displayed.

Helpful Links

• Manage function triggers through APIs. For details, see Function Trigger APIs.
• FAQ about Kafka triggers: Can I Configure a Kafka Trigger in a Different Subnet from My Function?