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Using an Open-Source Kafka Trigger

This section describes how to create an open-source Kafka trigger and configure an event to trigger a function.

If you use an open-source Kafka trigger for a function, FunctionGraph periodically polls messages from a specific topic in Kafka and passes the messages as an input parameter to invoke the function.

For details about the differences between DMS for Kafka and open-source Kafka, see Comparing DMS for Kafka and Open-Source Kafka.

Prerequisites

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

• You have created a function.
• You have enabled VPC access for the function. For details, see Configuring the Network.

Creating an Open-Source 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 Kafka (OPENSOURCEKAFKA).
   • Connection Address: Addresses of brokers running Kafka. Separate the addresses with commas (,).
   • Topic: Enter one or more topics.
   • Batch Size: Maximum number of data records that can be processed by the function at a time.

5. Click OK.
   

   The network configuration must be the same as that of the ECS where Kafka is deployed, including the VPC and subnet.

Enabling a Kafka Trigger

By default, open-source Kafka triggers are disabled. To use such a trigger, click Enable on the Trigger page.

If a trigger cannot be disabled, contact technical support.

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 (OPENSOURCEKAFKA) to use the built-in 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.

Parent topic: Creating Triggers