kBuckets

K-buckets are a data structure used in distributed hash tables (DHTs) to efficiently manage and organize peer information in a peer-to-peer (P2P) network. The term "k-bucket" originates from the Kademlia protocol, which is one of the most well-known DHTs. Each k-bucket is a list that holds a limited number of contact information for other peers in the network.

The primary purpose of k-buckets is to maintain a balanced and efficient routing table. Each peer in the network has a set of k-buckets, with each bucket corresponding to a range of peer IDs. The size of each bucket is typically limited to a constant value, denoted as "k". This ensures that the routing table remains manageable and scalable, even as the network grows.

When a peer wants to find another peer, it uses the k-buckets to determine which peers are closest to the target peer ID. The peer then sends queries to the peers in the appropriate k-bucket, which helps in efficiently locating the target peer. This process is repeated iteratively, with each step bringing the search closer to the target.

K-buckets also play a crucial role in maintaining the network's resilience and fault tolerance. When a peer fails or leaves the network, its contact information is removed from the k-buckets of other peers. Additionally, k-buckets help in refreshing the contact information of peers, ensuring that the network remains up-to-date and functional.

In summary, k-buckets are a fundamental component of distributed hash tables, enabling efficient peer discovery, routing, and network maintenance in peer-to-peer networks. Their design and implementation are crucial for the performance and scalability of DHT-based systems.