DMS (for Kafka) Trigger

Notes and Constraints

• Kafka triggers are supported in all regions except LA-Sao Paulo1. You can check whether the trigger type is supported on 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. For details, see .

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	Mandatory. Select DMS (for Kafka).	DMS (for Kafka)
   Instance	Mandatory. Select a created Kafka instance. If no instance is available, click Create Instance.	kafka-fg
   Topic	Mandatory. 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	Mandatory. Enter the number of messages consumed from the topic each time. The value ranges from 1 to 1000.	100

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 Save.

   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?