Nifty is a transparent communication layer that masks partial network partitions. Partial partitions are a special kind of network partitions that divides the cluster into three groups of nodes (group 1, 2, and 3) such that groups 1 and 2 are disconnected from each other while nodes in group 3 can communicate with all cluster nodes (See figure below). Nifty follows a peer-to-peer design in which every node in the cluster runs a Nifty process. These processes collaborate in monitoring cluster connectivity. When Nifty detects a partial partition, it detours the traffic around the partition through intermediate nodes (e.g., nodes in group 3 in the figure).
In order to use Nifty, you need to have OVS installed already, with a bridge called br0. To do that, you can use the following commands (make sure to replace $INTERFACE_NAME (e.g., if0) and $IP_ADDRESS with their actual vales):
$ sudo apt-get update
$ sudo apt-get install openvswitch-switch -y
$ sudo ovs-vsctl init
$ sudo ovs-vsctl add-br br0
$ sudo ovs-vsctl add-port br0 $INTERFACE_NAME
$ sudo ifconfig br0 $IP_ADDRESS netmask 255.255.255.0 up
$ sudo ifconfig $INTERFACE_NAME 0 After that, you can just use
$ maketo compile the code and generate the executables.
There are two main executables. Nifty and Partitioner. Nifty is the fault tolerance layer that protects against partial network partitions, whereas Partitioner is a simple tool that can be used to inject partial partitions (for testing purposes). Both of these require OVS and assume the bridge is called br0 (see setup above).
The deploy directory contains scripts for deploying Nifty on a cluster.
The examples direcotry contains examples of using Nifty with diffirent systems.
The examples/simple example directory contains a simple example that demonstrates the functionality of Nifty.