Watchman

Watchman is your friend who monitors your processes so you don't have to.

Installation

Add the following to the list of your dependencies:

def deps do
  [
    {:watchman, github: "renderedtext/ex-watchman"}
  ]
end

Also, add it to the list of your applications:

def application do
  [applications: [:watchman]]
end

First, set up the host and the port of the metrics server, and the prefix you want to use. Example:

config :watchman,
  host: "statistics.example.com"
  port: 22001,
  prefix: "my-service.prod"

To submit a simple value from your service:

Watchman.submit("users.count", 30)

To increment a simple value from your service:

Watchman.increment("users.count")

to decrement:

Watchman.decrement("users.count")

To submit a timing value:

Watchman.submit("installation.duration", 30, :timing)

To benchmark a part of your service:

Watchman.benchmark("sleep.duration", fn ->
  IO.puts "Sleeping"
  :timer.sleep(10000)
  IO.puts "Wake up"
end)

To benchmark a function in your module:

defmodule Example do
  use Watchman

  @benchmark
  def test
    :timer.sleep(10)
  end

end