Dead-Letter Queues

A Dead-Letter Queue (DLQ) is a specialized storage area used in messaging systems to hold messages that cannot be successfully processed or delivered to their intended destination. When a message repeatedly fails to be delivered or processed due to errors, the system moves it to the DLQ instead of discarding it. This allows for troubleshooting, analysis, or manual handling of problematic messages. Essentially, the DLQ acts as a safety net, ensuring that problematic messages are isolated for review without blocking or disrupting the overall messaging flow.