How to Analyze and Handle Duplicate Entry '2905449' for Key in TiDB CDC Data Synchronization?

This topic has been translated from a Chinese forum by GPT and might contain errors.

Original topic: tidb CDC同步数据报Duplicate entry ‘2905449’ for key 如何分析处理?

| username: 宸凡_22

[TiDB Usage Environment] Production Environment / Testing / Poc
[TiDB Version]
[Reproduction Path] What operations were performed when the issue occurred
[Encountered Issue: Issue Phenomenon and Impact]
[Resource Configuration] Go to TiDB Dashboard - Cluster Info - Hosts and take a screenshot of this page
[Attachment: Screenshot/Logs/Monitoring]

| username: tidb菜鸟一只 | Original post link

Check if this data really exists downstream.

| username: xfworld | Original post link

The primary key is duplicated…

What is the downstream?