假設有個create order saga行緊
1. create order (order-service) < committed
2. update product quantity (warehouse-service) < not yet committed
如果呢個時候有條transaction去query order-service就會睇到個order record, 喺strong consistency底下係唔應該發生, 因為create order sage都未行完
除非另外起個consensus protocol, 預先將要commit既sql放入redis之類既cache layer, 然後同一時間叫咁多個services一齊commit transaction
有錯請指教
