A simple, open, server-to-server webhook-based pubsub (publish/subscribe) protocol for any web accessible resources. Parties (servers) speaking the PubSubHubbub protocol can get near-instant notifications (via webhook callbacks) when a topic (resource URL) they're interested in is updated. The protocol in a nutshell is as follows: An resource URL (a "topic") declares its Hub server(s) in its HTTP Headers, via Link: <hub url>; rel=”hub” .
NGINX HTTP Push Module About This module turns Nginx into an adept HTTP Push and Comet server. It takes care of all the connection juggling, and exposes a simple interface to broadcast messages to clients via plain old HTTP requests. This lets you write live-updating asynchronous web applications as easily as their oldschool classic counterparts, since your code does not need to manage requests with delayed responses.
The Advanced Message Queuing Protocol (AMQP) is an open standard application layer protocol for message-oriented middleware. The defining features of AMQP are message orientation, queuing, routing (including point-to-point and publish-and-subscribe), reliability and security. Overview AMQP is a binary, application layer protocol, designed to efficiently support a wide variety of messaging applications and communication patterns. It provides flow controlled, message-oriented communication with message-delivery guarantees such as at-most-once (where each message is delivered once or never), at-least-once (where each message is certain to be delivered, but may do so multiple times) and exactly-once (where the message will always certainly arrive and do so only once), and authentication and/or encryption based on SASL and/or TLS. It assumes an underlying reliable transport layer protocol such as Transmission Control Protocol (TCP). AMQP