Paxos

An Abortable Παξος Implementation for Consensus based on Leslie Lamport's paper, "Paxos Made Simple".

Requires Elixir >= 1.13 and OTP >= 23.

This multi-file setup using Mix is currently broken when run in the Vagrant testing VM on Windows. Please instead refer to the single-file built by /build.sh.

Setup

Install mix dependencies with mix deps.get.
Run tests with iex -S mix run test/test_script.exs
- Alternatively, silence extraneous output from test scripts with: iex -S mix run test/test_script.exs > /dev/null
- Or to run tests, whilst logging results into a file and to the console, use: iex -S mix run test/test_script.exs 2>&1 >/dev/null | tee results.txt

Using the original test files

To support using Mix to compile the project, the test files were slightly modified, to perform these changes, please do the following:

Update test_with_mix/test_harness.ex to include files compiled by Mix.

Modify line 54, to include -S mix at the end.
The line should now appear as follows:

cmd = "elixir --sname " <> (hd String.split(Atom.to_string(node), "@")) <> " --no-halt --erl \"-detached\" --erl \"-kernel prevent_overlapping_partitions false\" -S mix"

Comment out uuid.ex from test_script.exs as it's included in the project and thus compiled by mix (also make sure the project files are commented out as these are also included by Mix).
The start of test_script.exs should now appear as follows:

 # Replace with your own implementation source files
 # IEx.Helpers.c "beb.ex", "."
 # IEx.Helpers.c "paxos.ex", "."
 
 # Do not modify the following ##########
 IEx.Helpers.c "test_with_mix/test_harness.ex", "."
 IEx.Helpers.c "test_with_mix/paxos_test.ex", "."
 IEx.Helpers.c "test_with_mix/test_util.ex", "."
 # IEx.Helpers.c "uuid.ex", "."

Notes

For debugging/presentation purposes, Logger.flush() has been included frequently (for coherent log presentation). These MUST be removed before production - particularly if the Console backend is not to be used!

Running with IEx

Simply use:

iex -S mix

# (or)
iex -S "mix" "run" "example_commands.exs"

(or, alternatively, on Windows Powershell):

iex.bat -S mix

# (or)
iex.bat -S "mix" "run" "example_commands.exs"

Installation

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

def deps do
  [
    {:paxos, "~> 0.2.6"},
    
    # or
    {:paxos, git: "https://github.com/SamJakob/paxos", tag: "v0.2.6"},
  ]
end

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