Java Producer: Synchronous send vs Asynchronous send

[SMJ]

We have an application which sends items in a list to a kafka topic. The item will be removed from the list only if there were no exceptions encountered while sending. How can I implement this using the onCompletion() method in asynchronous send() ?

- We don't want to use synchronous send() because of the performance issues. Does synchronous send() block until the message has been received by the topic? 

- 

kafkaProducer.send(new ProducerRecord<>(topic, null, value, key, value), new Callback() {

@Override
	public void onCompletion(RecordMetadata recordMetadata, Exception e) {
	success = true;
	if (e == null) {
	LOG.info("Successfully sent to topic: " + topic);
	} else {
	Log.error("Exception");
	}

[xinyi...@gmail.com]

KafkaProducer.send() is asynchronous.

https://kafka.apache.org/090/javadoc/index.html?org/apache/kafka/clients/producer/KafkaProducer.html  

The send() method is asynchronous. When called it adds the record to a buffer of pending record sends and immediately returns. This allows the producer to batch together individual records for efficiency.