The Chord/DHash Project - Chord FAQ. Linux chord storage. Ceph. Chord (peer-to-peer) In computing, Chord is a protocol and algorithm for a peer-to-peer distributed hash table. A distributed hash table stores key-value pairs by assigning keys to different computers (known as "nodes"); a node will store the values for all the keys for which it is responsible.
Chord specifies how keys are assigned to nodes, and how a node can discover the value for a given key by first locating the node responsible for that key. IDs and keys are assigned an -bit identifier using consistent hashing. The SHA-1 algorithm is the base hashing function for consistent hashing. Consistent hashing is integral to the robustness and performance of Chord because both keys and IDs (IP addresses) are uniformly distributed and in the same identifier space. Consistent hashing is also necessary to let nodes join and leave the network without disruption. Using the Chord lookup protocol, node keys are arranged in a circle that has at most nodes. Each node has a successor and a predecessor. Nodes following it. The Chord/DHash Project - Overview. Open Chord.