What is a DLQ (Dead Letter Queue) in the context of Kafka?

DLQ (Dead Letter Queue) in the context of Kafka is a special queue where messages that could not be processed correctly after several attempts are placed. This allows isolating problematic messages without blocking the main data processing and provides an opportunity to analyze the reasons for errors or to reprocess these messages later.

For example, if a Kafka consumer cannot parse a message due to an incorrect format, such a message can be sent to the DLQ for further analysis, while the main processing flow continues with other messages.