Hi ShardingSphere community, We are going to add a new feature - shadow database, this feature is designed to allow dirty data to be written to the shadow database when applying the online environment for pressure measurement, the relevant issue is : https://github.com/apache/incubator-shardingsphere/issues/3269
We want to do this through SQL parse and add router, add a tag field in sql, and according to this field, route to shadow database. Here is a simple design，and we chose the second way. because ThreadLocal might introduce other problems. [image: sharding-shadow.png] Comments or Suggestions on this design are welcome! Thanks! -- Zhiyi Yan (Zhyee) Apache ShardingSphere
