Peer Caching for Faster Lookups in P2P Systems

In particular, we address the problem of each peer choosing the k best pointers to store in addition to its index pointers to minimize the average query lookup times. We focus on two popular P2P systems, namely Pastry and Chord: we exploit the inherent structure of these systems to develop efficient, scalable algorithms for optimally choosing the k additional pointers. Simulations with Chord and Pastry demonstrate that our algorithms are very effective in reducing the lookup times significantly. Our approach is particularly useful for applications such as name services in mobile environments or location services, where we can expect a low churn rate for peers and a relatively higher churn rate for objects.