How would you design retries for a queue consumer without making failures worse?

Design retry, backoff, and poison message policy

Explains retry strategy for transient failures and poison-message handling for permanent failures.

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I would retry transient failures with bounded attempts and backoff, not an immediate tight loop. For example, a temporary HTTP 503 from a dependency can be retried after delay. A validation error or unknown message schema is probably not fixed by retrying. After max attempts or a known permanent failure, the message goes to a dead-letter or quarantine path for inspection.

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Transient versus permanent failures, exponential backoff, max attempts, poison messages, dead-lettering, and alerting.

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Retries recover transient failures only when attempts are bounded and delayed. Permanent validation errors, incompatible messages, and deterministic code failures need quarantine or dead-letter handling instead of another immediate attempt.
I would retry transient failures with bounded attempts and backoff, not an immediate tight loop. For example, a temporary HTTP 503 from a dependency can be retried after delay. A validation error or unknown message schema is probably not fixed by retrying. After max attempts or a known permanent failure, the message goes to a dead-letter or quarantine path for inspection.
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I would classify failures in the handler. Transient dependency failures, throttling, timeouts, validation errors, authorization failures, and code bugs need different treatment. Backoff protects dependencies from retry storms. A poison message needs enough context to inspect and replay after a fix. I would also make retries idempotent, because each attempt may partially progress before failing.

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Retrying permanent validation errors forever.
Using immediate retries that hammer a failing dependency.
No maximum attempts or dead-letter path.
Retrying non-idempotent handlers without protection.

How would you design retries for a queue consumer without making failures worse?

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