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
- Log in to the FunctionGraph console. In the navigation pane, choose Functions > Function List.
- Click the function to be configured to go to the function details page.
- Choose Configuration > Triggers and click Create Trigger.Figure 1 Creating a trigger
- 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.
- 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
- Return to the FunctionGraph console. In the navigation pane, choose Functions > Function List.
- Click the function to be configured to go to the function details page.
- On the function details page, select a version.
- On the Code tab page, click Test. The Configure Test Event dialog box is displayed.
- 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.
- Click Test. The function test result is displayed.