KomachiHeartbeat

🚅Vital monitoring Elixir Web application.🚄

This respects Rails's KomachiHeartbeat.

Usage

Mount KomachiHeartbeat at any path. We mount it for example at /ops below.

In Plug app. example

defmodule Example.Router do
  use Plug.Router

  plug(:match)
  plug(:dispatch)

  forward("/ops", to: KomachiHeartbeat)
end

In Phoenix app. example

defmodule ExampleWeb.Router do
  use ExampleWeb, :router

  forward("/ops", KomachiHeartbeat)
end

KomachiHeartbeat provides 2 endpoints.

• GET /MOUNT_PATH/heartbeat : Monitor the server is OK. Response 200 "heartbeat:ok" or 503 "heartbeat:NG".
• GET /MOUNT_PATH/stats : Monitor the server statistics. Response 200 JSON or 503 JSON.

Extend KomachiHeartbeat

You can extend KomachiHeartbeat to write vital plugins. Vital plugins should implement KomachiHeartbeat.Vital.

defmodule ExampleVital do
  alias  KomachiHeartbeat.Vital

  @behaviour Vital

  @impl Vital
  def init, do: nil

  @impl Vital
  def stats, do: {:ok, %{example: 42}}

  @impl Vital
  def vital, do: :ok
end

Add this at config. In Plug app :

forward("/ops", to: KomachiHeartbeat, init_opts: [vitals: []])

In Phoenix app :

forward("/ops", KomachiHeartbeat, vitals: [])

Now GET /MOUNT_PATH/heartbeat calls ExampleVital.vital/0 & response heartbeat:ok. GET /MOUNT_PATH/stats calls ExampleVital.stats/0 & response {"example": 42}.

BeamVital

We have a vital to observe BEAM VM. It's BeamVital.

To config this, in Plug app :

forward("/ops", to: KomachiHeartbeat, init_opts: [vitals: [KomachiHeartbeat.BeamVital]])

In Phoenix app :

forward("/ops", KomachiHeartbeat, vitals: [KomachiHeartbeat.BeamVital])

Then GET /MOUNT_PATH/stats responses JSON like this.

{
  "context_switches": 118,
  "gc": {
    "count": 28,
    "words_reclaimed": 10385
  },
  "io": {
    "in": 204,
    "out": 228
  },
  "memory": {
    "atom": 804813,
    "binary": 587056,
    "code": 14787824,
    "ets": 8421128,
    "processes": 13062992
  },
  "port_count": 7,
  "process_count": 272,
  "reductions": 6719,
  "run_queue": 1,
  "scheduler_usage": {
    "1": 1.5975716910296348e-5,
    "2": 1.4977518744364708e-5,
    "3": 6.3936000063936e-5,
    "4": 1.7984155958600475e-5,
    "5": 0.0011898428149764476,
    "6": 1.6977538716278364e-5,
    "7": 2.197613391856444e-5,
    "8": 2.1967882955119614e-5,
    "9": 3.09616385298615e-5,
    "10": 1.9971879593532307e-5,
    "11": 1.8977985536777338e-5,
    "12": 1.797169458103487e-5,
    "13": 1.697179288023305e-5,
    "14": 2.49564759060199e-5,
    "15": 1.6969421103172084e-5,
    "16": 1.3974343106057279e-5
  }
}

Installation

Add :komachi_heartbeat at mix.exs.

def deps do
  [
    {:komachi_heartbeat, "~> 0.5"}
  ]
end

Copyright and License

Copyright (c) 2018 ne_Sachirou

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.