Q:

zeromq persistence patterns

Who has to manages the persistent in the ZeroMQ?
When we use the ZeroMQ clients in Python language, what are the plug-ins/modules available to manage the persistent?
I would like to know the patterns to use the ZeroMQ.

A:

As far as I know, Zeromq does not have any persistence. It is out of scope for it and needs to be handled by the end user. Just like serializing the message. 
In C#, I have used db4o to add persistence. Typically I persist the object in its raw state, then serialize it and send it to ZMQ socket. Btw, this was for PUB/SUB pair.

A:

On the application ends you can persist accordingly, for example I've built a persistance layer in node.js which communicated to back-end php calls and via websockets. 
The persistance aspect held messages for a certain period of time (http://en.wikipedia.org/wiki/Time_to_live) this was to give clients a chance to connect. I used in-memory data structures but I toyed with the idea of using redis to gain on-disk persistance.

