Python Distributed Hash Table

Documentation can be found at kademlia.readthedocs.org.

This library is an asynchronous Python implementation of the Kademlia distributed hash table. It uses Twisted to provide asynchronous communication. The nodes communicate using RPC over UDP to communiate, meaning that it is capable of working behind a NAT.

This library aims to be as close to a reference implementation of the Kademlia paper as possible.

Installation

pip install kademlia

Usage

This assumes you have a working familiarity with Twisted.

Assuming you want to connect to an existing network (run the standalone server example below if you don't have a network):

from twisted.internet import reactor
from twisted.python import log
from kademlia.network import Server
import sys

# log to std out
log.startLogging(sys.stdout)

def quit(result):
    print "Key result:", result
    reactor.stop()

def get(result, server):
    return server.get("a key").addCallback(quit)

def done(found, server):
    log.msg("Found nodes: %s" % found)
    return server.set("a key", "a value").addCallback(get, server)

server = Server()
# next line, or use reactor.listenUDP(5678, server.protocol)
server.listen(5678)
server.bootstrap([('127.0.0.1', 1234)]).addCallback(done, server)

reactor.run()

Check out the examples folder for other examples.

Stand-alone Server

If all you want to do is run a local server, just start the example server:

twistd -noy examples/server.tac

Running Tests

To run tests:

trial kademlia

Logging

This library uses the standard Python logging library. To see debut output printed to STDOUT, for instance, use:

import logging

log = logging.getLogger('rpcudp')
log.setLevel(logging.DEBUG)
log.addHandler(logging.StreamHandler())

Running Tests

To run tests:

pip install -r dev-requirements.txt
python -m unittest

Fidelity to Original Paper

The current implementation should be an accurate implementation of all aspects of the paper save one - in Section 2.3 there is the requirement that the original publisher of a key/value republish it every 24 hours. This library does not do this (though you can easily do this manually).