RPC and MessageQueues in node.js

Question

What are the good use cases for using RPC over MQ ? If a node process wants to talk to a java program, can we use RabbitMQ ? What are the other alternatives ? what nowjs or dNode does that can not be done with socket.io ? There are many modules in node.js on either RPC or MQ.. Do they all cater to some specific need ?

EDIT:

What I am looking for ?

1. How do you do a RPC style of full duplex communication between browser/client and server? I think the answer would be socket.io or nowjs or dNode.. Please add if there are more.

2. How does your node process talk to other processes in a heterogeneous system ? This might be necessary if you want to offload some of your CPU bound task to other processes... For example between node.js process and a Java process. There can be 3 different ways of doing that. Which one is suitable for what ?

   i. publish-subscribe

   ii. request-response

   iii. push-pull

3. When would you use xmpp and not rabbitMQ ?

Answer 1

1. Yes, NowJS or dnode are good choices.
2. redis pub sub might work for you, as would using rabbit. Depends on your use-case.
3. I don't think xmpp and rabbit are comparable? rabbit is for messaging, xmpp is a chat protocol (like what google chat uses, I think).

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