Kafka Keyless Producer In Java

Question

I am new to the kafka eco system and in my case I'm using a Java producer but have no need for sending a key along with the record value which is serialized Avro. Is there a way to build a Java Producer to will not send keys, or are keys a requirement when sending messages in Kafka?

Answer 1

Like @gasparms said, there are built-in ways to produce without sending in a key. Most people use Kafka this way, since they just want to be able to send a stream of messages, with no key. Using keys is only really required if you need log compaction

Here's a really good explanation - https://stackoverflow.com/a/29515696/236528

Answer 2

ProducerRecord has several constructors, one of them don't have value for the key, so you don't have to indicate it.

Example:

Properties props = new Properties();
props.put("bootstrap.servers", "localhost:9092");
props.put("acks", "all");
props.put("retries", 0);
props.put("batch.size", 16384);
props.put("linger.ms", 1);
props.put("buffer.memory", 33554432);
props.put("key.serializer", "org.apache.kafka.common.serialization.StringSerializer");
props.put("value.serializer", "org.apache.kafka.common.serialization.StringSerializer");

Producer<String, String> producer = new KafkaProducer<>(props);
for(int i = 0; i < 100; i++)
    producer.send(new ProducerRecord<>("my-topic", "myValue"));

producer.close();