Ant-inspired query routing performance in dynamic peer-to-peer networks

P2P Networks are highly dynamic structures since their nodes - peer users keep joining and leaving continuously. In the paper, we study the effects of network change rates on query routing efficiency. First, the problem background is described and abstract system model is defined. The system characteristics and behavior are analyzed and abstracted with a set of measurable metrics. The paper studies Mute query routing protocol and compares its behavior to previously suggested routing protocols. The chosen routing technique makes use of cached metadata from previous answer messages (analogy to ants laying feromone). The paper also discusses mechanisms for broken path detection and metadata maintenance. Further, simulations in various dynamic network environments are presented and discussed: the degree of network dynamics varies from one node departure and node join per ten queries generated to five node departures and joins per one generated query. Several metrics are used to clarify the protocol behavior even with high rate of node departures, but it is shown that above a certain threshold it literally breaks down and exhibits considerable efficiency degradation