What is the Difference between Reactive Extensions and Message Queue?

Question

I am trying to understand the difference between Reactive Extensions and Message Queue? Are they competing frameworks? Can they be used in conjuction? Started programming, and trying to understand this.

Reactive Extensions: " The Reactive Extensions (Rx) is a library for composing asynchronous and event-based programs using observable sequences and LINQ-style query operators."

Message Queue: "A message queue is a queue of messages sent between applications. It includes a sequence of work objects that are waiting to be processed. "

Answer 1

Are they competing frameworks?

No, these are not competing and they are very different ideas.

RX is a library that is frequently used in applications that require real-time processing over a stream of events. RX gives you a library of functions to perform this with ease.

Message Queue (MQ) is more of an architecture component than a library. MQs are used to decouple event-producing logic and event-consuming logic. Example: on a user sign up page, you may want to perform a series of actions; one of it is sending of a welcome email to user. You may decide that you do not want the user to wait too long on the loading screen, therefore you use an MQ to simply trigger a “send welcome email” event to be processed later.

Can they be used in conjuction?

Yes. For example, in a file processing application -

1) Use RX to process a stream of CSV records

2) You can combine records, transform, etc

3) Take the final result and put it into a queue, then move on to next batch of CSV records

4) Meanwhile, a queue consumer reads that result above and performs an upload of the result to a remote file server

Answer 2

A "message queue" generically is just a list of data designed to induce behaviour in a different part of a system (maybe synchronously or not), where the elements in the list are processed in FIFO order, and typically by a part of the system that is not closely coupled to the parts which add the elements into the queue. Reactive Extensions is a set of tools designed for manipulating the temporal aspects of data flows in a system - whereas a lot of data manipulation involves specifying what processing occurs, Rx is designed to alter when processing occurs.

-- Steve Oct 8 '19 at 9:10