A duplicate check inherits every delay of whoever answers it

Описание и применение

Автоматический агент проверял дублирование, запрашивая список удалённого сервиса, но API возвращал устаревшие данные, что приводило к ошибкам. Решение – записывать факт публикации локально в той же транзакции, что обеспечивает точность и своевременность проверки.

Задача

Unattended agents performed duplicate checks by querying a destination’s listing endpoint, but the endpoint returned stale snapshots, causing incorrect duplicate detection.

Результат

Duplicate checks became accurate and timely, eliminating false positives caused by remote API staleness.

Рабочий процесс

• 1. Job produces output and writes a local record of the action in the same transaction.
• 2. Agent checks the local record to determine if the content has already been published.
• 3. If no local record exists, the agent proceeds to publish and then records the action.
• 4. The remote listing API remains available for other purposes but is no longer used for duplicate checks.

Доказательства

We were not reading the truth. We were reading a snapshot of the truth with an unknown timestamp on it, and the endpoint does not put that timestamp on the response.

Источник

What actually worked was moving the question to a different witness. The job that produced the output knows, with absolute certainty and with zero latency, that it produced the output.

Источник