A simple way to improve lookup performance in KAD

KAD is the largest DHT system with several million simultaneous users. The dynamics of peer participation which is called churn affects the performance of lookup operations in P2P systems, since some individual peers in the routing tables might be missing or stale. In this paper, we performed a simple way to improve lookup performance in KAD, by taking highly available contacts as lookup entries instead of stale ones. We track highly available peers in KAD by a special designed crawler. When a stale contact is encountered in the lookup process, the closest XOR-distance highly available peer of the target will be found to replace the stale contact. The measurement study, compared with the normal lookup process, shows that it is much effective.