Copy data between kafka topics using kafka connectors

Question

I'm new to Kafka, now I need to copy data from one kafka topic to another. I'm wondering what are the possible ways to do so? The ways I can think of are following:

1. Kakfa consumer + Kafka producer
2. Kafka streams
3. Kafka sink connector + producer
4. Kafka consumer + source connector

My questions is: is that possible to use two kafka connectors in between? Eg sink connector + source connector. Is so, could you please provide me some good examples? Or some hints of how to do so?

Thanks in advance!

Answer 1

All the methods you listed are possible. Which one is the best really depends on the control you want over the process or whether it's a one off operation or something you want to keep running.

Kafka Streams offers a easy way to flow one topic into another via the DSL

You could do something like (demo code obviously not for production:):

Properties props = new Properties();
props.put(StreamsConfig.APPLICATION_ID_CONFIG, "streams-wordcount");
props.put(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");
props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");

final Serde<byte[]> bytesSerdes = Serdes.ByteArray();
final StreamsBuilder builder = new StreamsBuilder();
KStream<byte[], byte[]> input = builder.stream(
        "input-topic",
        Consumed.with(bytesSerdes, bytesSerdes)
);
input.to("output-topic", Produced.with(bytesSerdes, bytesSerdes));

final KafkaStreams streams = new KafkaStreams(builder.build(), props);
try {
    streams.start();
    Thread.sleep(60000L);
} catch (Exception e) {
    e.printStackTrace();
} finally {
    streams.close();
}