A scalable peer-to-peer lookup service for internet applications
For convenience, Chord nodes are implemented as goroutines. Chord nodes communicate asynchronously with other Chord nodes using JSON messages over zeroMQ sockets. The IP address and port number of a node's socket is its access point (address).
Chord nodes reveive JSON request messages from the coordinator or other Chord nodes and respond to the sender (or reply-to address specified) directly.
The JSON request messages among the Chord nodes and the coordinator are as follows:
{"do": "join-ring", "sponsoring-node": address } instructing the receipient node to join the Chord ring by contacting the (existing) Chord sponsoring node with the given address.
{"do": "leave-ring" "mode": "immediate or orderly"} instructing the receipient node to leave the ring immediately (without informing any other nodes) or in an orderly manner (by informing other nodes and transferring its bucket contents to others)
{"do": "stabilize-ring" }
{"do": "init-ring-fingers" }
{"do": "fix-ring-fingers" }
{"do": "ring-notify", "reply-to": address }
{"do": "get-ring-fingers", "reply-to": address }
{"do": "find-ring-successor", "reply-to": address}
{"do": "find-ring-predecessor", "reply-to": address}
{"do": "put", "data": { "key" : "a key", "value" : "a value" }, "reply-to": address} instructing the receipient node to store the given (key,value) pair in the appropriate ring node.
{"do": "get", "data": { "key" : "a key" }, "reply-to": address} instructing the receipient node to retrieve the value associated with the key stored in the ring.
{"do": "remove", "data": { "key" : "a key" }, "reply-to": address} instructing the receipient node to remove the (key,value) pair from the ring.
{"do": "list-items", "reply-to": address} instructing the receipient node to respond with a list of the key-value pairs stored at its bucket.
@inproceedings{consistenthashing,
title = {Chord: A scalable peer-to-peer lookup service for internet applications},
author = {Ion Stoica, Robert Morris, David Karger, M. Frans Kaashoek and Hari Balakrishnan},
booktitle = {Proceedings of the 2001 conference on Applications, technologies, architectures, and protocols for computer communications},
series = {SIGCOMM '01},
year = {2001},
location = {California, USA},
pages = {149-160}
}