Ravi Sir's Cards › AWS
Idempotent consumer
This revision card explains Idempotent consumer. It starts from the need that exactly-once myths hide poison and lag. It describes at-least-once + versioned upsert; DLQ; IteratorAge alarm. The how-to section notes reportBatchItemFailures , then DLQ , then alarm age , then backfill Export then tail. An example on the card is vikram Patil rehearses poison replay before launch.
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What this card says
Why do we need it?
Exactly-once myths hide poison and lag.
What is it?
At-least-once + versioned upsert; DLQ; IteratorAge alarm.
IteratorAge
How to do it
ReportBatchItemFailures → DLQ → alarm age → backfill Export then tail.
Example
Vikram Patil rehearses poison replay before launch.