Using a Kafka Trigger

Prerequisites

Before creating a trigger, ensure that you have prepared the following:

• You have created a function. For details, see Creating a Function from Scratch.
• You have enabled VPC access for the function. For details, see Configuring the Network.
• You have created a Kafka instance. For details, see "Creating an Instance" in the Distributed Message Service for Kafka User Guide.
• You have created a topic under a Kafka instance. For details, see section "Creating a Topic" in the Distributed Message Service for Kafka User Guide.

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. Set the following parameters:
   • Trigger Type: Select DMS (for Kafka).
   • Instance: Select a Kafka premium instance.
   • Topic: Select a topic of the Kafka premium instance.
   • Batch Size: Set the number of messages to be retrieved from a topic each time.
   • Username: Enter the username of the instance if SSL has been enabled for it.
   • Password: Enter the password of the instance if SSL has been enabled for it.

5. Click OK.
   

   • After VPC access is enabled, you need to configure corresponding subnet permissions for the Kafka security group. For details about how to configure VPC access, see Configuring the Network.
   • 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.
     Figure 2 Selecting multiple topics
     

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 1 and click Save.

   Table 1 Test event information

   Parameter	Description
   Configure Test Event	You can choose to create a test event or edit an existing one. Use the default option Create new test event.
   Event Template	Select kafka-event-template.
   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. For example, 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.