MQTT vs. XMPP Which Should I Choose?

问题:

Overview

I am sending messages back and forth between a client (Android phone) and a Server (Windows Server). Using a persistent connection over TCP, which protocol would be the best solution. I am looking at performance, scalability, size of messages, and battery life. The messages must arrive at the destination in order and can not be duplicates.

MQTT

This seems like the better solution, but there seems to be little examples of large implementation with lots of users. I am not sure if I can integrate this into the windows server, or if it would have to be another application or server running. Finally there seems to be a lack of information on it in general.

XMPP

This seems to have lots of implementation, examples, and even a book : ). However the main purpose seems to be for instant messaging clients and things like Google talk. Will this be an optimal solution to messaging between server and client. I know currently XMPP is mostly used in client to server to client architectures.

Please correct me if I am wrong and thanks in advance for any guidance.

回答1:

It depends on what you are trying to do and what hardware you are running.

MQTT has very low keep-alive traffic. XMPP is a an IM protocol, and has a much, much higher overhead in handling presence messages between all the clients.

If you have a small memory footprint constraint, then having to handle the XML parser may make the use of XMPP impossible.

Keep in mind that MQTT stands for Message Queue Telemetry Transport, i.e., it is a transport protocol and does not define the message format at all - you will have to supply this; XMPP is an Instant Messaging protocol which carefully defines all the message formats and requires that all messages be in XML.

In addition to all this: MQTT is a publish subscribe protocol, XMPP is an instant messaging protocol that can be extended (using XEP-0060) to support publish subscribe. You need to consider this when you architect your system.

We are finding MQTT to be the quiet achiever. Your milage might be different.

It all depends ...

Track down the recent announcement by LinkedIn where they discuss their use of MQTT in their mobile app.

Cheers Mark

(BTW Andy was slightly off in his reference to us. We are at Centre for Educational Innovation & Technology (CEIT), The University of Queensland, Brisbane, Australia)

回答2:

I think that in short the MQTT advantages over XMPP are:

• Throughput capacity: less overhead, more lightweight
• Binary vs plain text
• QoS in place (Fire-and-forget, At-least-once and Exactly-once)
• Pub/Sub in place (XMPP requires extension XEP- 0060)
• No need for an XML parser

回答3:

I think you are probably correcting your assessment of XMPP in that it is a primarily chat-oriented protocol - it is also quite heavyweight and uses XML extensively making it verbose. I know that folks at CEIT at the Uni of Brisbane have specifically studied the differences and optimal uses for the two protocols. MQTT is very lightweight and low power - it has been used for telemetry and sensor applications for over 10 years and has been deployed on a very large scale by IBM and partners. Folks are now finding that a simple protocol like this is ideal for mobile development.

What exactly are you looking to achieve? The mqtt.org site aims to provide good links to content. There are also IRC channels and mailing lists about it. How can we help?