"Visibility-Timeout"
- AWS SQS:Visibility timeout、long polling 與 Lambda event source 的成本與失敗形狀
SQS deep article:visibility timeout 對齊 consumer 處理時間(ChangeMessageVisibility)、long vs short polling 的 cost 取捨(WaitTimeSeconds)、SQS + Lambda event source mapping(batch size / batch window / 並行 ramp-up)、DLQ + redrive policy(maxReceiveCount)、message size 與 extended client、per-request cost 模型;含 5 個 production 故障演練(VT < 處理時間 redelivery、polling 設定省成本、Lambda 部分失敗整批重投、DLQ maxReceiveCount、FIFO 吞吐上限)