Why EdgeX Store&Foreward does not guarantee messages are sent in order?

[amunozh]

According to Store&Forward documentation, EdgeX does not guarantee messages are sent in the same order they were received. Why? How Store&Forward is implemented? Is there a way to guarantee the order?

[cloudxxx8]

Store and Forward uses retry mechanism, so the service can't guarantee which event is sent out sucessfully first.
Also, the nature of message bus is asynchornous, the sending order won't be guaranteed.
https://stackoverflow.com/questions/30955110/is-message-order-preserved-in-mqtt-messages

The implementation is in https://github.com/edgexfoundry/app-functions-sdk-go

[amunozh]

Is there an easy way to guarantee ordering with Redis? Is it necessary to implement a custom storage?

[cloudxxx8]

You can implement the server side to sort the origin timestamp