This is an implementation for the DHT "Chord", as presented in the paper https://pdos.csail.mit.edu/papers/chord:sigcomm01/chord_sigcomm.pdf written in Erlang, for the Distributed Systems Course, 9th Semester, National Technical University of Athens.
Authors: Vasilis Kontonis, Michalis Kokologiannakis.
Course info and details (in greek): http://www.cslab.ntua.gr/courses/distrib/
This program is distributed under the GPL, version 3 or later. Please see the COPYING file for details.
In order to use the tool, you only need a working version of Erlang.
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Download ChordEr's sources or clone this repository.
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For a default build (w/ eventual consistency):
make -
For linearizability (w/ chain replication):
make chain -
To build test functions:
make test
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To create a ring, open an Erlang shell and enter the command:
dht:join(Int).where Int is any integer.
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To add nodes in an existing ring enter the command:
dht:join(Int, Node).where Int is any integer, and Node a process already in the ring.
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To remove a node from an existing ring use:
dht:stop(Node). -
To insert data enter the command:
dht:store(Key, Value, Node). -
To delete data enter the command:
dht:remove(Key, Node) -
To search for a key and its corresponding data use:
dht:locate(Key, Node). -
To get the data from all nodes use:
dht:locate("*", Node).
Some features of ChordEr are:
- Support for concurrent node joins
- Efficient implementation of finger tables
- Logarithmic data lookup time (O(log n))
- Logarithmic time for node joins (O(log n))
- Data replication (default: eventual consistency -- linearizability w/ chain replication also offered)