A distributed hash table (DHT) is a distributed system that provides a lookup service similar to a hash table: key-value pairs are stored in a DHT, and any participating node can efficiently retrieve the value associated with a given key. The main advantage of a DHT is that nodes can be added or removed with minimum work around re-distributing keys.
DHTs characteristically emphasize the following properties:
- Autonomy and decentralization: the nodes collectively form the system without any central coordination
- Fault tolerance: the system should be reliable (in some sense) even with nodes continuously joining, leaving, and failing
- Scalability: the system should function efficiently even with thousands or millions of node
Chord and Pastry use Distributed Hashing Table Systems.
Refer to below article for good introduction on Chord.
https://www.cse.iitd.ernet.in/~srsarangi/courses/2020/col_819_2020/docs/chord.pdf
