In FindAndModifyCmd on MongoS, we need to catch the WCOS error and run the delete-insert transaction logic created as part of SERVER-39835. If the findAndModify is not part of a multi-stmt txn, we will error.
In FindAndModifyCmd on MongoS, we need to catch the WCOS error and run the delete-insert transaction logic created as part of SERVER-39835. If the findAndModify is not part of a multi-stmt txn, we will error.