EctoFacade

EctoFacade can be used as interface through which you can query multiple repositories. Main objective of this is to use separate separate repository for writes and separate repository for reads.

For example:

Lets say you have PostgreSQL database replicated to 4 different slave nodes that should be used for reads only. With this small library you can do that!

Installation

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

Usage

defmodule MyApp.FacadeRepo do
  use EctoFacade.Repo,
    master_repo: MyApp.Repo,
    read_repos: [MyApp.ReadReplicaOne, MyApp.ReadReplicaTwo],
    algorithm: MyApp.Repo.ReadAlgorithm
end

MyApp.FacadeRepo.all(MyApp.SomeSchema) # and other operations that you would do with ecto repo

Possible algorithms for selecting repository for read operation:

• EctoFacade.Algorithms.Random - selects randomly repository
• EctoFacade.Algorithms.Roundrobin - selects next repository in list till last and then goes again from beginning
• EctoFacade.Algorithms.WeightRoundrobin - selects next repository in list depending on weight. Check module documentation for more info.

or your own that implement behaviour EctoFacade.Algorithm.

for more information please check documentation

Usage (testing)

When in test just configure you FacadeRepo to use only master repository. This way you won't have issues with separate repositories with Sandbox Ecto adapter.

Documentation

Hex.pm