Statix

Statix is an Elixir client for StatsD-compatible servers. It is focused on speed without sacrificing simplicity, completeness, or correctness.

What makes Statix the fastest library around:

• direct sending to the socket ^[1]
• caching of the UDP packets header
• usage of IO lists

^[1] In contrast with process-based clients, Statix has lower memory consumption and higher throughput – Statix v1.0.0 does about 876640 counter increments per flush:

It is possible to measure it yourself.

for _ <- 1..10_000 do
  Task.start(fn ->
    for _ <- 1..10_000 do
      StatixSample.increment("sample", 1)
    end
  end)
end

Make sure you have StatsD server running to get more realistic results.

Installation

Add Statix as a dependency to your mix.exs file:

def application() do
  [applications: [:statix]]
end

defp deps() do
  [{:statix, ">= 0.0.0"}]
end

Then run mix deps.get in your shell to fetch the dependencies.

Usage

A module that uses Statix becomes a socket connection:

defmodule MyApp.Statix do
  use Statix
end

Before using connection the connect/0 function needs to be invoked. In general, this function is called when your application starts (for example, in its start/2 callback):

def start(_type, _args) do
  :ok = MyApp.Statix.connect()
  # ...
end

Once the Statix connection is open, its increment/1,2, decrement/1,2, gauge/2, set/2, timing/2, and measure/2 functions can be used to push metrics to the StatsD-compatible server.

event/2,3 and service_check/2,3 are DataDog StatsD protocol extensions not supported by standard StatsD servers.

Sampling

Sampling is supported via the :sample_rate option:

MyApp.Statix.increment("page_view", 1, sample_rate: 0.5)

The UDP packet will only be sent to the server about half of the time, but the resulting value will be adjusted on the server according to the given sample rate.

NOTE: sampling is applied to all functions except event/2,3 and service_check/2,3.

Tags

Tags are a way of adding dimensions to metrics:

MyApp.Statix.gauge("memory", 1, tags: ["region:east"])

Configuration

Statix can be configured globally with:

config :statix,
  prefix: "sample",
  host: "stats.tld",
  port: 8181

and on a per connection basis as well:

config :statix, MyApp.Statix,
  port: 8811

The defaults are:

• prefix: nil
• host: "127.0.0.1"
• port: 8125

Note: by default, configuration is evaluated once, at compile time. If you plan using other configuration at runtime, you must specify the :runtime_config option:

defmodule MyApp.Statix do
  use Statix, runtime_config: true
end

License

This software is licensed under the ISC license.