Add Pleroma.JobQueueMonitor

lib/pleroma/job_queue_monitor.ex

@@ -0,0 +1,115 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2019 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.JobQueueMonitor do
+  use GenServer
+
+  @initial_state %{workers: %{}, queues: %{}, processed_jobs: 0, enqueued: 0}
+  @queue %{processed_jobs: 0, success: 0, failure: 0, enqueued: 0}
+  @operation %{processed_jobs: 0, success: 0, failure: 0, enqueued: 0}
+
+  def start_link(_) do
+    GenServer.start_link(__MODULE__, @initial_state, name: __MODULE__)
+  end
+
+  @impl true
+  def init(state) do
+    :telemetry.attach("oban-monitor-failure", [:oban, :failure], &handle_event/4, nil)
+    :telemetry.attach("oban-monitor-success", [:oban, :success], &handle_event/4, nil)
+
+    {:ok, state}
+  end
+
+  def stats do
+    GenServer.call(__MODULE__, :stats)
+  end
+
+  def enqueue({:ok, job}) do
+    meta = Map.take(job, [:args, :queue, :worker])
+    GenServer.cast(__MODULE__, {:process_enqueue, meta})
+
+    {:ok, job}
+  end
+
+  def enqueue(result), do: result
+
+  def handle_event([:oban, status], %{duration: duration}, meta, _) do
+    GenServer.cast(__MODULE__, {:process_event, status, duration, meta})
+  end
+
+  @impl true
+  def handle_call(:stats, _from, state) do
+    {:reply, state, state}
+  end
+
+  def handle_cast({:process_enqueue, meta}, state) do
+    state =
+      state
+      |> Map.update!(:workers, fn workers ->
+        workers
+        |> Map.put_new(meta.worker, %{})
+        |> Map.update!(meta.worker, &update_worker(&1, :enqueue, meta))
+      end)
+      |> Map.update!(:queues, fn workers ->
+        workers
+        |> Map.put_new(meta.queue, @queue)
+        |> Map.update!(meta.queue, fn queue -> Map.update!(queue, :enqueued, &(&1 + 1)) end)
+      end)
+      |> Map.update!(:enqueued, &(&1 + 1))
+
+    {:noreply, state}
+  end
+
+  @impl true
+  def handle_cast({:process_event, status, duration, meta}, state) do
+    state =
+      state
+      |> Map.update!(:workers, fn workers ->
+        workers
+        |> Map.put_new(meta.worker, %{})
+        |> Map.update!(meta.worker, &update_worker(&1, status, meta, duration))
+      end)
+      |> Map.update!(:queues, fn workers ->
+        workers
+        |> Map.put_new(meta.queue, @queue)
+        |> Map.update!(meta.queue, &update_queue(&1, status, meta, duration))
+      end)
+      |> Map.update!(:processed_jobs, &(&1 + 1))
+      |> decr_enqueued()
+
+    {:noreply, state}
+  end
+
+  defp update_worker(worker, status, meta, duration \\ 0) do
+    worker
+    |> Map.put_new(meta.args["op"], @operation)
+    |> Map.update!(meta.args["op"], &update_op(&1, status, meta, duration))
+  end
+
+  defp update_op(op, :enqueue, _meta, _duration) do
+    op
+    |> Map.update!(:enqueued, &(&1 + 1))
+  end
+
+  defp update_op(op, status, _meta, _duration) do
+    op
+    |> Map.update!(:processed_jobs, &(&1 + 1))
+    |> Map.update!(status, &(&1 + 1))
+    |> decr_enqueued()
+  end
+
+  defp update_queue(queue, status, _meta, _duration) do
+    queue
+    |> Map.update!(:processed_jobs, &(&1 + 1))
+    |> Map.update!(status, &(&1 + 1))
+    |> decr_enqueued()
+  end
+
+  defp decr_enqueued(map) do
+    Map.update!(map, :enqueued, fn
+      0 -> 0
+      enqueued -> enqueued - 1
+    end)
+  end
+end