Retrieving Kafka Messages from a Production

Using the Business Service

InterSystems provides a built-in business operation that can be used to retrieve messages from a Kafka topic without needing to write custom code. To use this business operation:

1. Add EnsLib.Kafka.ServiceOpens in a new tab to your production. See Adding Business Hosts.

2. Configure settings of this business host as described in Kafka Settings.

The business service periodically polls the configured Kafka topic for new messages. For each new message, the business service creates a message of type EnsLib.Kafka.MessageOpens in a new tab and populates that with the message contents, and then forwards the message to the configured targets within the production using asynchronous requests.

For details on this message class, see Kafka Message Class.

Using the Adapter

If the built-in Kafka business service does not meet your needs, you can directly use the Kafka inbound adapter as follows:

1. Create a custom business service class:

   • Your business service class should extend Ens.BusinessServiceOpens in a new tab.

   • In your class, the ADAPTER parameter should equal EnsLib.Kafka.InboundAdapterOpens in a new tab.

   • Your class should implement the OnProcessInput() method:

     Method OnProcessInput(pInput As %Net.Remote.Object, 
                           Output pOutput As %RegisteredObject) As %Status {
     }

     

   • Add your business service to your production. See Adding Business Hosts.

   • Configure settings of this business host as described in Kafka Settings.

See Also

• Kafka Settings

• Sending Messages to Kafka from a Production

• Using the Kafka Messaging API (for use without a production)