Shards

ETS tables on steroids!

Sharding support for ETS tables out-of-box.

Why might we need Sharding on ETS tables? Well, the main reason is to keep the lock contention under control, in order to scale-out ETS tables (linearly) and support higher levels of concurrency without lock issues; specially write-locks, which most of the cases might cause significant performance degradation.

Therefore, one of the most common and proven strategies to deal with these problems is Sharding or Partitioning; the principle is pretty similar to DHTs.

This is where Shards comes in. Shards is an Erlang/Elixir library compatible with the current ETS API, which implements Sharding or Partitioning on top of ETS tables, completely transparent and out-of-box.

See the getting started guide and the online documentation.

List of compatible ETS functions

Installation

Erlang

In your rebar.config:

{deps, [
  {shards, "0.6.0"}
]}.

Elixir

In your mix.exs:

def deps do
  [{:shards, "~> 0.6"}]
end

Check out the getting started guide to learn more about it.

Important links

• Documentation - Hex Docs.

• Blog Post - Transparent and out-of-box sharding support for ETS tables in Erlang/Elixir.

• ExShards – Elixir wrapper for shards; with extra and nicer functions.

• Nebulex – Distributed Caching framework for Elixir.

• KVX – Simple Elixir in-memory Key/Value Store using shards (default adapter).

• Cacherl Distributed Cache using shards.

Testing

$ make test

You can find tests results in _build/test/logs, and coverage in _build/test/cover.

NOTE: shards comes with a helper Makefile, but it is just a simple wrapper on top of rebar3, therefore, you can do everything using rebar3 directly as well (e.g.: rebar3 do ct, cover).

Building Edoc

$ make doc

NOTE: Once you run the previous command, a new folder doc is created, and you'll have a pretty nice HTML documentation.

Copyright and License

Copyright (c) 2016 Carlos Andres Bolaños R.A.

Shards source code is licensed under the MIT License.