README.md

Overview

Kashup is a red, tomatoey, distributed, in-memory key/value store, with configurable event streaming and element expiration.

Kashup

Kashup works by assigning a key/pid pair to an interim table, which allows a pid to be retrieved with a key. During a Kashup.get/1 call, Kashup uses the provided key to retrieve the pid for the GenServer that was spawned on key/value pair creation, and assigned to manage the state of the value for said key.

This design naturally enables a cluster of BEAM nodes to operate on a single cache, using the same semantics as if the nodes were only a single BEAM instance communicating with itself.

Configuration

Kashup can be configured to stream cache operation events and enforce expiration times on key/value pairs.

Enabling Kashup configuration features requires a :kashup block in your application's config file. The following few sections describe the available configuration fields.

Event Streaming

To enable event streaming, add a the following field to the :kashup config block:

config :kashup,
  events: true

The event handler that Kashup currently ships with emits event messages to the running node's console. There are plans for a future release to provide an event handler behavior allowing custom event handling solutions.

Element Expiration

To enable expiration, provide an integer representing the number of seconds a key/value pair should be valid for to an :expiration block.

For example, valid for one day:

config :kashup,
  expiration: 60 * 60 * 24

For those who prefer to be explicit, :infinity can be provided to indicate persistant elements.

Basic Demo

The events have been separated out from the IEx output for readability

config.exs

config :kashup,
  events: :true
  expiration: 5

Unix shell

$ iex --sname node@host -S mix run

IEx

iex(node@host)1> Kashup.put(:request, %{url: "app.com"})
:ok
iex(node@host)2> Kashup.get(:request)
{:ok, %{url: "app.com"}}
iex(node@host)3> Kashup.get(:request)
{:error, :not_found}
iex(node@host)4> Kashup.delete(:request)
:ok

Event Stream

[KASHUP] event: :started, pid: #PID<0.266.0>, time: 2020-07-26 02:51:39.257257Z
[KASHUP] event: {:put, [key: :request, value: %{url: "app.com"}], :create}, pid: #PID<0.266.0>, time: 2020-07-26 02:51:50.363260Z
[KASHUP] event: {:get, [key: :request]}, pid: #PID<0.266.0>, time: 2020-07-26 02:51:54.389043Z
[KASHUP] event: {:expired, [pid: #PID<0.271.0>, value: %{url: "app.com"}]}, pid: #PID<0.266.0>, time: 2020-07-26 02:51:55.389990Z
[KASHUP] event: {:get, [key: :request]}, pid: #PID<0.266.0>, time: 2020-07-26 02:52:02.821462Z
[KASHUP] event: {:delete, [key: :request]}, pid: #PID<0.266.0>, time: 2020-07-26 02:52:10.813540Z