An Efficient Publish-subscribe Protocol for Collaborative Content Delivery - Ex-PUSH

Distributed systems have rapidly changed the face of Internet Technology. Web syndication is a competitive collaborative content delivery system over the cloud, which refers to making web feeds/ material available from a site to other people with a summary of the website´s content including the recent updates. The relevance of web syndication has been remarkable in the fields of e-Governance, e-Commerce etc. It endows the ability of subscribing to a desired feed and obtain the contents using the highly scalable web syndication formats RSS (Rich Site Summary)[2] and Atom. Two common protocols used for web pub-sub architecture is the PubSubHubub (PUSH) and Atom, out of which the PubSubHubub[1] is the widely used and very popular. This paper proposes an improvised version of the PUSH named as Ex-PUSH protocol. The Ex-PUSH protocol implements a hybrid filtering technique of feeds and a Poll based Pull strategy for pulling of updates in addition to the existing Push strategy. In addition it includes a Publishers cache that gives two way benefit of trust reinforcement and building of a trust database (TDB) for future data mining. The sample survey shows that the protocol can decrease the total cost of network, save bandwidth and improve scalability.