We have recently proposed a semi-decentralized collaborative hosting system Wikipedia. In this system, individuals willing to help host Wikipedia join their computer to an overlay network of nodes, which handles a significant part of Wikipedia's workload, resulting in reduced operational cost for Wikipedia.

 

We achieve this by letting the collaborative overlay host replicas of the most popular Wikipedia content. This content, however, can be updated by any end user at any time, so a consistency protocol is necessary to keep all replicas up to date.

 

This purpose of this project is to develop real-world implementations of our proposed consistency protocols, which so far have been tested only on (trace-driven) simulation environments. These consistency protocols are based on two main ideas:

a) An adapted version of the SpiderCast protocol which allows the creation of a separate suboverlay for each replicated object.

b) A gossiping protocol that runs on top of the SpiderCast overlay. The responsibilities of this protocol are i) to allow efficient propagation of updates across object suboverlays, and ii) to allow nodes keep up-to-date views of their neighbors in the global collaborative overlay (for maintenance purposes).

 

Hands-on experience in network programming is required.