ExampleDistributedSystem

Setup

open a shell and run

iex --name [email protected] -S mix

open another shell and run

iex --name [email protected] -S mix

open a third shell and run

iex --name [email protected] -S mix

The naming is not arbitrary, these are the names supported in the config file, any other name would have to added to the config file before running the app. Because the nodes connecting depends on whats in the config file.

The testing of various criteria is a bit manual currently, you stop senior node and watch elections happen and the next senior node take over, start the senior node again and watch the junior node surrender control. Notice the effect of adding a junior node to the cluster or removing it, do the same for senior nodes.

Added a two important functions

leave_cluster --> called as ExampleDistributedSystem.leave_cluster from terminal

All it does is kill the node's process hence it will not be available in the cluster any longer. To rejoin cluster call ExampleDistributedSystem.start("","") in the same iex shell.

check_state

This function when called should show you the state of the current nodes's brain/Genserver

Improvements to be made.

• make the name discovery of nodes and connection dynamic and not static

Installation

If available in Hex, the package can be installed by adding example_distributed_system to your list of dependencies in mix.exs:

def deps do
  [
    {:example_distributed_system, "~> 0.1.0"}
  ]
end

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/example_distributed_system.