in flume-kafka-channel/src/main/java/org/apache/flume/channel/kafka/KafkaChannel.java [134:145]
public void start() {
logger.info("Starting Kafka Channel: {}", getName());
producer = new KafkaProducer<String, byte[]>(producerProps);
if (useKafkaTransactions) {
logger.debug("Initializing Kafka Transaction");
producer.initTransactions();
}
// We always have just one topic being read by one thread
logger.info("Topic = {}", topic.get());
counter.start();
super.start();
}