Architecture & DesignIntermediate
Dead Letter Queue (DLQ)
PronunciationDED LET-er kyoo
Definition
A Dead Letter Queue (DLQ) is a holding area in a messaging system for messages that cannot be processed successfully after a set number of attempts.
Where you hear it
In asynchronous architectures, event-driven systems, and message broker configurations.
Examples
The background worker moved the malformed JSON message to the DLQ after three failed retries.
We set up an alert to notify the engineering team whenever a message lands in the payment service DLQ.
Common mistake
Thinking a DLQ solves the processing error automatically, when it actually just stores the failed messages for later inspection and manual debugging.
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