Nussknacker Cloud Hosted Kafka Topics
Description
You can use Kafka topics hosted in Nussknacker Cloud as a source or sink for your streaming scenarios. As the result, you can also use these internal topics for communication between scenarios. Unlike in the case of externally hosted Kafka topics, there is no need to define a Kafka integration to use internally hosted Kafka topics.
Adding a new topic
Topics have to be explicitly defined via the Topics page: follow the Topic link is the top right part of the screen and choose ADD TOPIC button.
Parameters and configuration
| Name | Description |
|---|---|
| Topic name | This will be a name of the Kafka topic you will create |
| Topic description | Narrative of your choice |
| Content type | With schema - you will need to define Avro schema for the topic. W/o schema - in this case Nussknacker will not be able to help with field names and data type related validation of SpEL expressions. If Kafka messages content is in the JSON format, you can still use dynamic field access to access fields of the Kafka messages. |
| Avro schema | Avro schema for the topic; read this section to understand the role of topic schema. |
Advanced parameters
| Name | Description |
|---|---|
| Acknowledgement | Consult Kafka documentation for the meaning of this parameter |
| Max messages size | This is the max.message.bytes Kafka configuration parameter. Effectively, this is the size of the biggest message that can be added to the topic. |
| Retention time | Consult Kafka documentation for the meaning of this parameter |
Additional info
Check schema for the example-input topic (go to Topics page) to get a first idea how Avro schema looks like.