Sonyflakex

Sonyflake is a distributed unique ID generator inspired by Twitter's Snowflake.

This is an Elixir implementation of the original sony/sonyflake, which is written in Go.

Sonyflake focuses on lifetime and performance on many host/core environment. So it has a different bit assignment from Snowflake. A Sonyflake ID is composed of

39 bits for time in units of 10 msec
 8 bits for a sequence number
16 bits for a machine id

As a result, Sonyflake has the following advantages and disadvantages:

• The lifetime (174 years) is longer than that of Snowflake (69 years)
• It can work in more distributed machines (2^{16) than Snowflake (2}10)
• It can generate 2^8 IDs per 10 msec at most in a single machine/thread (slower than Snowflake)

However, if you want more generation rate in a single host, you can run multiple Sonyflake ID generators concurrently.

Installation

Add sonyflakex to your list of dependencies in mix.exs:

def deps do
  [
    {:sonyflakex, "~> 0.2.0"}
  ]
end

Then update your dependencies with the following command:

mix deps.get

Usage

Add Sonyflakex as one of your application's root supervisor child in application.ex.

defmodule MyApp do
  use Application

  @impl Application
  def start(_type, _args) do
    children = [
      Sonyflakex,
      # other dependencies 
    ]
    Supervisor.start_link(children, strategy: :one_for_one)
  end
end

This configuration will register the default Sonyflakex GenServer using the module name and you can generate a new ID by using the following call.

Sonyflakex.next_id()

Limitations

Like the reference implementation in Go, the default Sonyflakex GenServer will pause the process execution for a few milliseconds in case the sequence number in the 10 ms windows overflows. This behaviour prevents the generation of duplicated IDs. However, if you need to generate more than 2^8 IDs in a 10 ms window of time, it can create a performance bottleneck for your system.

If you need to generate a higher volume of IDs in short periods of time, then you might need to run a pool of multiple Sonyflakex GenServers (each with a unique machine ID).

Pending

• Callback to check machine ID is unique.

License

The MIT License (MIT)

See LICENSE for details.