Research and Improvement of Mechanism of Searching Resource in Chord Network

Chord is a typical model of structured P2P network. However, there are some problems for the mechanism of searching resources in Chord, such as too much redundant information in the routing tables of nodes, the deviation of needed times of forwarding lookup messages among searching resources whose key values are located in different areas of identifier space, some available routing information being not used and the difficulty for supporting complex lookup, e.t. This paper proposes a scheme to add routing information to the routing tables. Meanwhile, it holds down the scale of routing tables by merging the items that have redundant information. In most cases, it makes the nodes actually have even less items in the routing tables than they used to. It also has the advantage that the deviation of time of routing a lookup message becomes smaller. Thus, it makes the performance of resource search more stable, the average hops of routing a lookup message diminished, the memory needed by the routing tables much less and the time of the transact shorter.