Setup appsignal

backend/config/config.exs

@@ -15,7 +15,8 @@ config :backend, BackendWeb.Endpoint,
   url: [host: "localhost"],
   secret_key_base: "XL4NKGBN9lZMrQbMEI1KJOlwAt8S7younVJl90TdAgzmwyapr3g7BRYSNYvX0sZ9",
   render_errors: [view: BackendWeb.ErrorView, accepts: ~w(json)],
-  pubsub: [name: Backend.PubSub, adapter: Phoenix.PubSub.PG2]
+  pubsub: [name: Backend.PubSub, adapter: Phoenix.PubSub.PG2],
+  instrumenters: [Appsignal.Phoenix.Instrumenter]
 
 config :backend, Backend.Repo, queue_target: 5000
 

backend/config/releases.exs

@@ -17,6 +17,8 @@ config :backend, Backend.Repo,
 config :backend, Backend.Elasticsearch.Cluster,
   url: System.get_env("ELASTICSEARCH_URL") || "http://localhost:9200"
 
+config :appsignal, :config, revision: System.get_env("GIT_REV")
+
 port = String.to_integer(System.get_env("PORT") || "4000")
 
 config :backend, BackendWeb.Endpoint,

backend/lib/backend/application.ex

@@ -7,6 +7,13 @@ defmodule Backend.Application do
   import Backend.Util
 
   def start(_type, _args) do
+    :telemetry.attach(
+      "appsignal-ecto",
+      [:backend, :repo, :query],
+      &Appsignal.Ecto.handle_event/4,
+      nil
+    )
+
     crawl_worker_count = get_config(:crawl_workers)
 
     children = [
@@ -16,11 +23,15 @@ defmodule Backend.Application do
       BackendWeb.Endpoint,
       # Crawler children
       :hackney_pool.child_spec(:crawler, timeout: 15000, max_connections: crawl_worker_count),
-      {Task,
-       fn ->
-         Honeydew.start_queue(:crawl_queue, failure_mode: Honeydew.FailureMode.Abandon)
-         Honeydew.start_workers(:crawl_queue, Backend.Crawler, num: crawl_worker_count)
-       end},
+      Supervisor.child_spec(
+        {Task,
+         fn ->
+           Honeydew.start_queue(:crawl_queue, failure_mode: Honeydew.FailureMode.Abandon)
+           Honeydew.start_workers(:crawl_queue, Backend.Crawler, num: crawl_worker_count)
+         end},
+        id: :start_honeydew
+      ),
+      Supervisor.child_spec({Task, fn -> HTTPoison.start() end}, id: :start_httpoison),
       Backend.Scheduler,
       Backend.Elasticsearch.Cluster
     ]
@@ -31,6 +42,8 @@ defmodule Backend.Application do
         false -> children ++ [Backend.Crawler.StaleInstanceManager]
       end
 
+    add_appsignal_probes()
+
     # See https://hexdocs.pm/elixir/Supervisor.html
     # for other strategies and supported options
     opts = [strategy: :one_for_one, name: Backend.Supervisor]
@@ -43,4 +56,22 @@ defmodule Backend.Application do
     BackendWeb.Endpoint.config_change(changed, removed)
     :ok
   end
+
+  defp add_appsignal_probes do
+    Appsignal.Probes.register(:crawler, fn ->
+      %{
+        queue: %{
+          count: count,
+          in_progress: in_progress,
+          mnesia: mnesia
+        }
+      } = Honeydew.status(:crawl_queue)
+
+      memory = mnesia |> Map.get(:"honeydew_:crawl_queue") |> Keyword.get(:memory)
+
+      Appsignal.set_gauge("queue_length", count)
+      Appsignal.set_gauge("in_progress", in_progress)
+      Appsignal.set_gauge("mnesia_memory", memory)
+    end)
+  end
 end

backend/lib/backend/crawler/crawler.ex

@@ -10,6 +10,7 @@ defmodule Backend.Crawler do
   import Ecto.Query
   import Backend.Util
   require Logger
+  use Appsignal.Instrumentation.Decorators
 
   defstruct [
     # the instance domain (a string)
@@ -31,9 +32,9 @@ defmodule Backend.Crawler do
           error: String.t() | nil
         }
 
+  @decorate transaction()
   def run(domain) do
-    Logger.info("Crawling #{domain}...")
-    HTTPoison.start()
+    Logger.debug("Starting crawl of #{domain}")
 
     state = %Crawler{
       domain: domain,
@@ -59,11 +60,13 @@ defmodule Backend.Crawler do
 
   # Recursive function to check whether `domain` has an API that the head of the api_crawlers list can read.
   # If so, crawls it. If not, continues with the tail of the api_crawlers list.
+  @decorate transaction_event()
   defp crawl(%Crawler{api_crawlers: [], domain: domain} = state) do
     Logger.debug("Found no compatible API for #{domain}")
     Map.put(state, :found_api?, false)
   end
 
+  @decorate transaction_event()
   defp crawl(%Crawler{domain: domain, api_crawlers: [curr | remaining_crawlers]} = state) do
     if curr.is_instance_type?(domain) do
       Logger.debug("Found #{curr} instance")
@@ -94,6 +97,7 @@ defmodule Backend.Crawler do
   end
 
   # Save the state (after crawling) to the database.
+  @decorate transaction_event()
   defp save(%Crawler{
          domain: domain,
          result: result,
@@ -210,6 +214,7 @@ defmodule Backend.Crawler do
     |> Repo.insert_all(interactions)
   end
 
+  @decorate transaction_event()
   defp save(%{domain: domain, error: error, allows_crawling?: allows_crawling}) do
     error =
       cond do

backend/lib/backend/crawler/stale_instance_manager.ex

@@ -16,6 +16,8 @@ defmodule Backend.Crawler.StaleInstanceManager do
 
   @impl true
   def init(_opts) do
+    Logger.info("Starting crawler manager...")
+
     instance_count =
       Instance
       |> where([i], not is_nil(i.version))

backend/lib/backend/release.ex

@@ -16,7 +16,11 @@ defmodule Backend.Release do
   end
 
   def index do
+    # TODO: this isn't the right way to handle this.
+    # See https://github.com/danielberkompas/elasticsearch-elixir/issues/76
+    Application.ensure_all_started(@app)
     Index.hot_swap(Cluster, "instances")
+    :init.stop()
   end
 
   def rollback(repo, version) do

backend/lib/backend_web/endpoint.ex

@@ -1,5 +1,6 @@
 defmodule BackendWeb.Endpoint do
   use Phoenix.Endpoint, otp_app: :backend
+  use Appsignal.Phoenix
 
   socket("/socket", BackendWeb.UserSocket,
     websocket: true,

backend/mix.exs

@@ -20,7 +20,7 @@ defmodule Backend.MixProject do
   def application do
     [
       mod: {Backend.Application, []},
-      extra_applications: [:logger, :runtime_tools, :mnesia, :gollum, :ex_twilio]
+      extra_applications: [:logger, :runtime_tools, :mnesia, :gollum, :ex_twilio, :appsignal]
     ]
   end
 
@@ -53,7 +53,8 @@ defmodule Backend.MixProject do
       {:idna, "~> 5.1.2", override: true},
       {:swoosh, "~> 0.23.3"},
       {:ex_twilio, "~> 0.7.0"},
-      {:elasticsearch, "~> 1.0"}
+      {:elasticsearch, "~> 1.0"},
+      {:appsignal, "~> 1.10.1"}
     ]
   end
 

backend/mix.lock

@@ -1,4 +1,5 @@
 %{
+  "appsignal": {:hex, :appsignal, "1.10.11", "5df2546d6ea15e392a4384b175ebc1bb33f4ccf8fe9872c11542d3ae2043ff88", [:make, :mix], [{:decorator, "~> 1.2.3", [hex: :decorator, repo: "hexpm", optional: false]}, {:hackney, "~> 1.6", [hex: :hackney, repo: "hexpm", optional: false]}, {:phoenix, ">= 1.2.0", [hex: :phoenix, repo: "hexpm", optional: true]}, {:plug, ">= 1.1.0", [hex: :plug, repo: "hexpm", optional: true]}, {:poison, ">= 1.3.0", [hex: :poison, repo: "hexpm", optional: false]}], "hexpm"},
   "artificery": {:hex, :artificery, "0.4.2", "3ded6e29e13113af52811c72f414d1e88f711410cac1b619ab3a2666bbd7efd4", [:mix], [], "hexpm"},
   "base64url": {:hex, :base64url, "0.0.1", "36a90125f5948e3afd7be97662a1504b934dd5dac78451ca6e9abf85a10286be", [:rebar], [], "hexpm"},
   "certifi": {:hex, :certifi, "2.5.1", "867ce347f7c7d78563450a18a6a28a8090331e77fa02380b4a21962a65d36ee5", [:rebar3], [{:parse_trans, "~>3.3", [hex: :parse_trans, repo: "hexpm", optional: false]}], "hexpm"},
@@ -10,6 +11,7 @@
   "crontab": {:hex, :crontab, "1.1.7", "b9219f0bdc8678b94143655a8f229716c5810c0636a4489f98c0956137e53985", [:mix], [{:ecto, "~> 1.0 or ~> 2.0 or ~> 3.0", [hex: :ecto, repo: "hexpm", optional: true]}], "hexpm"},
   "db_connection": {:hex, :db_connection, "2.1.0", "122e2f62c4906bf2e49554f1e64db5030c19229aa40935f33088e7d543aa79d0", [:mix], [{:connection, "~> 1.0.2", [hex: :connection, repo: "hexpm", optional: false]}], "hexpm"},
   "decimal": {:hex, :decimal, "1.8.0", "ca462e0d885f09a1c5a342dbd7c1dcf27ea63548c65a65e67334f4b61803822e", [:mix], [], "hexpm"},
+  "decorator": {:hex, :decorator, "1.2.4", "31dfff6143d37f0b68d0bffb3b9f18ace14fea54d4f1b5e4f86ead6f00d9ff6e", [:mix], [], "hexpm"},
   "distillery": {:hex, :distillery, "2.1.1", "f9332afc2eec8a1a2b86f22429e068ef35f84a93ea1718265e740d90dd367814", [:mix], [{:artificery, "~> 0.2", [hex: :artificery, repo: "hexpm", optional: false]}], "hexpm"},
   "ecto": {:hex, :ecto, "3.1.7", "fa21d06ef56cdc2fdaa62574e8c3ba34a2751d44ea34c30bc65f0728421043e5", [:mix], [{:decimal, "~> 1.6", [hex: :decimal, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: true]}], "hexpm"},
   "ecto_sql": {:hex, :ecto_sql, "3.1.6", "1e80e30d16138a729c717f73dcb938590bcdb3a4502f3012414d0cbb261045d8", [:mix], [{:db_connection, "~> 2.0", [hex: :db_connection, repo: "hexpm", optional: false]}, {:ecto, "~> 3.1.0", [hex: :ecto, repo: "hexpm", optional: false]}, {:mariaex, "~> 0.9.1", [hex: :mariaex, repo: "hexpm", optional: true]}, {:myxql, "~> 0.2.0", [hex: :myxql, repo: "hexpm", optional: true]}, {:postgrex, "~> 0.14.0 or ~> 0.15.0", [hex: :postgrex, repo: "hexpm", optional: true]}, {:telemetry, "~> 0.4.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm"},