A "demo framework" for building a decentralized gossip based distributed system with accrual failure 
detection. It's also an implementation of: The Phi Accrual Failure Detector[1] and Amazon's paper on Gossip[2].

[1] http://ddg.jaist.ac.jp/pub/HDY+04.pdf
[2] http://www.cs.cornell.edu/home/rvr/papers/flowgossip.pdf

External Dependencies needed for this example, not included in the AWF distribution:
json-simple ("A simple Java toolkit for JSON") http://code.google.com/p/json-simple/ (Apache License 2.0)

Usage:

There are two configuration points (per node), 'seed' and 'address' you need to change before you are ready to start 
your cluster.
They are located in the MessagingService class. The seed should be a stable node that new nodes will use for bootstrapping 
into the existing cluster. The address is you local ip and port that other nodes in the cluster will connect to.
Your seed will have seed == address (that is how a seed is defined). 

Example 1.
A two node cluster, running on the same machine
Node A (seed node). seed = 127.0.0.1:14922, address = 127.0.0.1:14922 
Node B. seed = 127.0.0.1:14922, address = 127.0.0.1:14923

Example 2
A three node cluster, running on three different machines
Node A (seed node). seed = 192.168.0.1:14922, address = 192.168.0.1:14922 
Node B. seed = 192.168.0.1:14922, address = 192.168.0.2:14923
Node C. seed = 192.168.0.1:14922, address = 192.168.0.3:14924