REDMAN Replica Retrieval Effectiveness

We propose to consider three main factors to determine the effectiveness of RR strategies:

• the overhead imposed in terms of both memory required to maintain IRPs and messages exchanged to retrieve the requested resources at runtime;
• the scalability when applied to large deployment environments;
• the accuracy, i.e., the found/searched resource ratio in the finite time interval spent for the retrieval of the requested resource.

Different RR strategies can decide different trade-offs among these factors. In particular, the memory and network overhead imposed by IRP dissemination is often traded against the overhead required at provision time for resource discovery (the growth of IRP diffusion costs usually corresponds to a decrease of runtime retrieval costs). Therefore, the choice of the optimal RR strategy depends on the characteristics of supported applications and of the deployment scenario, e.g., on the expected ratio between the number of searches and of replica instantiations, the frequency with which replicas leave/enter the dense MANET, the time requirements for discovering the requested resources, and the size of retrieval messages and IRPs.