What is Cache

Much recent work on building scalable peer-to-peer (P2P) systems has focused on distributed hash tables (DHTs), which have become in a powerful building block when designing distributed decentralized behaviors. However, the lookup in the DHT structure itself, rather than the key-based lookup in the data stored in the DHT introduces a series of new challenges. The purpose of this chapter is to review the most outstanding research efforts, many of them from the Grid community, addressing the problem of resource discovery on DHTs. First, the authors present a simple taxonomy and the key internal design and behavior of each contribution, identifying their main strengths and weaknesses. Later, some discussion will be presented and finally, the authors’ personal approach to the problem will be described and compared with previous ones.