Output Kafka Event Adapter

Output Kafka event adapter is used to send events to a specific Web service location using POST. This feature is donated by Andres Gomez Ferrer. For more information on Apache Kafka, go to Apache Kafka documentation.

Configuring output Kafka event adapter

You can configure the Kafka output event adapter using the management console or using a configuration file.

Configure using the management console

Follow the steps below to configure output Kafka event adapter using the management console. This deploys the event adapter in the <PRODUCT_HOME>/repository/deployment/server/outputeventadaptors/ directory.

Log in to the product's management console, and click Configure.
Click Output Event Adaptors in the Event Processor Configs menu, and then click Add Output Event Adaptor.
Enter details as shown in the below example.
Click Add Event Adaptor.

Configure using a configuration file

Follow the steps below to configure output Kafka event adapter using a configuration file.

Create an XML file with the following output Kafka event adapter configurations. Output event adapter implementation must start with <outputEventAdaptor> as the root element.

<outputEventAdaptor name="kafkaOutputEventAdaptor" statistics="disable"
  trace="disable" type="kafka" xmlns="http://wso2.org/carbon/eventadaptormanager">
  <property name="optional.configuration">socket.timeout.ms:8000</property>
  <property name="meta.broker.list">localhost:9092</property>
</outputEventAdaptor>

Add the XML file to the <PRODUCT_HOME>/repository/deployment/server/outputeventadaptors/ directory. Since hot deployment is supported in the product, you can simply add/remove output event adapter configuration files to deploy/undeploy output event adapters to/from the server.

After an adapter is successfully added, it gets added to the list of adapters displayed under Event Processor Configs in the Configure menu of the product's management console. Click Edit to change its configuration and redeploy it. This opens an XML-based editor allowing you to edit the event adapter configurations from the UI. Do your modifications and click Update. You can also delete it, enable/disable statistics or enable/disable tracing on it using the provided options in the UI.

Configuring output Kafka event adapter message properties

The configured output event adapters are used in event formatters. With output event adapter message properties, event formatters are able to extract data from event streams and format the output events. Message properties specific to output event adapters of the kafka type can be configured as follows.

Log into the CEP Management Console. For detailed instructions, see Running the Product.
In the Main tab, click Event Streams to open the Available Event Streams page.
Click the Outflows link of the event stream to which the relevant input event adapter is connected. As a result, Event In-Flows (<Output_Event_Adapter_Name>) opens.
Click on the relevant event formatter name to open the Event Formatter Details page.
The message properties of a kafka output event adapter are described below. Change the property values as required.
Property Description
Topic Kafka Topic of the Kafka.
Output Event Type The outgoing event type to be mapped. The output Kafka event adapter supports JSON, text, and XML mappings.

Property	Description
Topic Kafka	Topic of the Kafka.
Output Event Type	The outgoing event type to be mapped. The output Kafka event adapter supports JSON, text, and XML mappings.