Sending Synchronous messages in kafka?

Question

How to send Synchronous messages in kafka?
One way of achieving it could be by setting the properties parameter
max.in.flight.requests.per.connection = 1.

But I want to know if there is an even direct or alternate way of sending Synchronous messages in kafka. (something like producer.syncSend(...) etc).

Answer 1

The producer API returns a Future from send. You can call Future#get to block until the sending has completed.

See this example from the Javadocs:

If you want to simulate a simple blocking call you can call the get() method immediately:

 byte[] key = "key".getBytes();
 byte[] value = "value".getBytes();
 ProducerRecord<byte[],byte[]> record = 
     new ProducerRecord<byte[],byte[]>("my-topic", key, value)
 producer.send(record).get();