Abstract
In DHT system the uniform design decreases the routing performance and the highly dynamic characteristic increases the maintenance overhead. To solve those problems, in this paper we introduce SAChord, a novel P2P system based on self-adaptive joining. SA-Chord gets rid of the assuming of uniform. Nodes are divided into routing nodes and non-routing nodes in terms of their capacity. Routing nodes have strong capacity and form a routing ring to perform fast routing. To reduce the effect of highly dynamic characteristic, we design a new joining algorithm to decrease the cost of building finger table.