Powerful in-memory key/value storage for Elixir

caching, distributed-systems, lru, expiration, transactions



Build Status Coverage Status Hex.pm Version Documentation

Cachex is an extremely fast in-memory key/value store with support for many useful features:

  • Time-based key expirations
  • Maximum size protection
  • Pre/post execution hooks
  • Proactive/reactive cache warming
  • Transactions and row locking
  • Asynchronous write operations
  • Distribution across app nodes
  • Syncing to a local filesystem
  • Idomatic cache streaming
  • Batched write operations
  • User command invocation
  • Statistics gathering

All of these features are optional and are off by default so you can pick and choose those you wish to enable.

Table of Contents


As of v0.8.0, Cachex is available on Hex. You can install the package via:

def deps do
  [{:cachex, "~> 3.3"}]


In the most typical use of Cachex, you only need to add your cache as a child of your application. If you created your project via Mix (passing the --sup flag) this is handled in lib/my_app/application.ex. This file will already contain an empty list of children to add to your application - simply add entries for your cache to this list:

children = [
  {Cachex, name: :my_cache_name}

If you wish to start a cache manually (for example, in iex), you can just use Cachex.start_link/2:

Cachex.start_link(name: :my_cache)

For anything else, please see the documentation.


There are some very trivial benchmarks available using Benchee in the benchmarks/ directory. You can run the benchmarks using the following command:

# default benchmarks, no modifiers
$ mix bench

# enable underlying table compression
$ CACHEX_BENCH_COMPRESS=true mix bench

# use a state instead of a cache name
$ CACHEX_BENCH_STATE=true mix bench

# use a lock write context for all writes

Any combination of these environment variables is also possible, to allow you to test and benchmark your specific workflows.


If you feel something can be improved, or have any questions about certain behaviours or pieces of implementation, please feel free to file an issue. Proposed changes should be taken to issues before any PRs to avoid wasting time on code which might not be merged upstream.

If you do make changes to the codebase, please make sure you test your changes thoroughly, and include any unit tests alongside new or changed behaviours. Cachex currently uses the excellent excoveralls to track code coverage.

$ mix test # --exclude=distributed to skip slower tests
$ mix credo
$ mix coveralls
$ mix coveralls.html && open cover/excoveralls.html