Wave

A horizontally distributed ledger. Wave builds on a few key components:

1. It implements the invariants and data structures necessary to do simple double-entry accounting using postgreSQL as a storage layer.
2. It wraps this state machine over the consensus protocol RAFT via rabbitmq/ra.
3. It exposes an api interface to read/write to the ledger.

High Level Goals

• There are three nodes - a single leader and two followers
• It will accept writes (CREATE TABLE, INSERT) on the leader and
• accept reads (SELECT) on any node. All nodes will always contain the same data.
• Supported Ledger Operations:

1. create a ledger
2. create more than one account on the ledger
3. add a CR entry
4. add a DR entry
5. retrieve a balance

Postgres Setup

Using the docker-compose up OR

The application must be able to connect to three postgres instances with a database called wave_ledger on ports 5432, 5433, 5344. Via psql:

psql -U user -p 5432
postgres=# CREATE DATABASE wave_ledger;
CREATE DATABASE

Node Setup

In three seperate terminals:

iex --name wave-one@127.0.0.1 --cookie wave -S mix

iex --name wave-two@127.0.0.1 --cookie wave -S mix

iex --name wave-three@127.0.0.1 --cookie wave -S mix

Installation

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

def deps do
  [
    {:wave, "~> 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/wave.