in docker/data-generator/src/main/java/org/apache/flink/playground/datagen/Producer.java [79:88]
private Properties getProperties() {
final Properties props = new Properties();
props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, brokers);
props.put(ProducerConfig.ACKS_CONFIG, "all");
props.put(ProducerConfig.RETRIES_CONFIG, 0);
props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, LongSerializer.class);
props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, TransactionSerializer.class);
return props;
}