How to handle invalid messages in Kafka?

In Kafka, handling invalid messages is usually implemented at the consumer level. Main approaches:

1. Validation upon receipt: when reading a message from the topic, check its correctness (e.g., format, schema).
2. Error handling: if the message is invalid, you can:
   • Log the error and skip the message.
   • Send the message to a separate "dead-letter" topic for further analysis.
   • Implement retry attempts with limits.

Example: in Java, using Kafka Consumer, you can send a message to a dead-letter topic upon a parsing error:

try {
    MyObject obj = parse(message.value());
    // process obj
} catch (Exception e) {
    // send to dead-letter topic
    producer.send(new ProducerRecord<>("dead-letter-topic", message.key(), message.value()));
}

Thus, invalid messages do not block the processing flow and are stored for further analysis.