Light-PubSubHubbub: A Lightweight Adaptation of the PubSubHubbub Protocol

Abstract—The publish-subscribe communication paradigm is widely used in systems that require a loosely coupled asyn-chronous form of interaction. The PubSubHubbub protocol is a publish-subscribe protocol for the Web that involves pub-lishers, subscribers, and hubs, which are the intermediate elements between publishers and subscribers. However, in the original implementation of the protocol, unnecessary computa-tion and network traffic occur as the sequence of exchanged messages to subscribers to retrieve a message is not optimized. In this paper, we present a lightweight version of such a proto-col, named Light-PubSubHubbub, by introducing the follow-ing changes to the communication process: (i) the publisher no longer needs to publish updated messages in a Web topic and then notify the hub since the messages are published in the hub itself; (ii) it uses the REST architectural style in order not to couple publishers, subscribers, and the hub; (iii) XML is the default format of the messages. This paper also presents the results of experiments comparing Light-PubSubHubbub with the original PubSubHubbub protocol and the JMS technology for asynchronous messaging. The obtained results have shown that Light-PubSubHubbub takes less time to answer to the client than PubSubHubbub and JMS. Keywords-asynchronous communication; publish-subscribe; PubSubHubbub; Light-PubSubHubbub I