CORAL WIKI
Actors
Getting started
Overview
KafkaProducerActor
The KafkaProducerActor is a Coral Actor that can write to Kafka.
Creating a KafkaProducerActor
The creation JSON of the KafkaProducerActor (see Coral Actor) has "type": "kafka-producer".
The params value is a JSON with the following fields:
| field | type | required | description |
|---|---|---|---|
topic |
String | yes | the name of the Kafka topic |
kafka |
JSON | yes | the configuration parameters for the Kafka producer |
The properties of the kafka attribute should include at least the following:
| field | type | required | description |
|---|---|---|---|
metadata.broker.list |
string | yes | the brokers to use initially. |
The producer type is configured as async. You can change this, but the KafkaProducerActor is designed for non-blocking communication with Kafka.
Other properties may be supplied cf. the Kafka producer properties.
Example
{
"data": {
"type": "actors",
"attributes": {
"type": "kafka-producer",
"params": {
"topic": "test"
"kafka" : {
"metadata.broker.list": "broker1:9092,broker2:9092,broker3:9092"
}
}
}
}
}Trigger
The KafkaProducerActor only does useful work if the trigger is connected. The trigger JSON needs to contain a field message.
The value of this field is send to Kafka. The optional field key contains the key to use.
Example
{
"key": "somekey",
"message": {
"key1": "value1",
"key2": "value2"
}
}Emit
The KafkaProducerActor emits nothing.
Conceptually, the Kafka stream can be thought of as emit.
State
The KafkaProducerActor keeps no state.
Collect
The KafkaProducerActor does not collect state from other actors.
Timer
The KafkaProducerActor does not provide timer actions.