This book proposes a search technique and a replication scheme for unstructured P2P networks. The proposed search scheme - distributed search technique (DST) is formulated with the aim of achieving effective query load balancing, high hit ratio, low network traffic and adaptive behavior for unstructured P2P networks. DST effectively alleviates the partial coverage problem and the majority of nodes, excluding free-riders, are covered during searching. The duplicate messages are effectively routed. Specialized peers are given importance while routing. The proposed replication scheme known as "Q-replication" employs Q-learning for the autonomous replication of objects. The Q-replication effectively distributes the popular objects and thereby contributes to the improvement of success rate and fault tolerance without depending on search paths.
