Solution: Add telemetry to track metrics

lib/quantum/executor.ex

@@ -25,11 +25,15 @@ defmodule Quantum.Executor do
   @spec execute(StartOpts.t(), Job.t(), Node.t()) :: :ok
   # Execute task on all given nodes without checking for overlap
   defp execute(
-         %StartOpts{task_supervisor_reference: task_supervisor, debug_logging: debug_logging},
+         %StartOpts{
+           task_supervisor_reference: task_supervisor,
+           debug_logging: debug_logging,
+           scheduler: scheduler
+         },
          %Job{overlap: true} = job,
          node
        ) do
-    run(node, job, task_supervisor, debug_logging)
+    run(node, job, task_supervisor, debug_logging, scheduler)
 
     :ok
   end
@@ -39,7 +43,8 @@ defmodule Quantum.Executor do
          %StartOpts{
            task_supervisor_reference: task_supervisor,
            task_registry_reference: task_registry,
-           debug_logging: debug_logging
+           debug_logging: debug_logging,
+           scheduler: scheduler
          },
          %Job{overlap: false, name: job_name} = job,
          node
@@ -51,7 +56,7 @@ defmodule Quantum.Executor do
 
     case TaskRegistry.mark_running(task_registry, job_name, node) do
       :marked_running ->
-        %Task{ref: ref} = run(node, job, task_supervisor, debug_logging)
+        %Task{ref: ref} = run(node, job, task_supervisor, debug_logging, scheduler)
 
         receive do
           {^ref, _} ->
@@ -69,8 +74,8 @@ defmodule Quantum.Executor do
   end
 
   # Ececute the given function on a given node via the task supervisor
-  @spec run(Node.t(), Job.t(), GenServer.server(), boolean()) :: Task.t()
-  defp run(node, %{name: job_name, task: task}, task_supervisor, debug_logging) do
+  @spec run(Node.t(), Job.t(), GenServer.server(), boolean(), atom()) :: Task.t()
+  defp run(node, %{name: job_name, task: task}, task_supervisor, debug_logging, scheduler) do
     debug_logging &&
       Logger.debug(fn ->
         "[#{inspect(Node.self())}][#{__MODULE__}] Task for job #{inspect(job_name)} started on node #{
@@ -84,6 +89,15 @@ defmodule Quantum.Executor do
           "[#{inspect(Node.self())}][#{__MODULE__}] Execute started for job #{inspect(job_name)}"
         end)
 
+      # Note: we are intentionally mimicking the ":telemetry.span" here to keep current functionality
+      start_monotonic_time = :erlang.monotonic_time()
+
+      :telemetry.execute([:quantum, :job, :start], %{system_time: start_monotonic_time}, %{
+        job_name: job_name,
+        node: inspect(node),
+        scheduler: scheduler
+      })
+
       try do
         execute_task(task)
       catch
@@ -94,6 +108,16 @@ defmodule Quantum.Executor do
                 inspect(job_name)
               }, which failed due to: #{Exception.format(type, value, __STACKTRACE__)}"
             end)
+
+          duration = :erlang.monotonic_time() - start_monotonic_time
+
+          :telemetry.execute([:quantum, :job, :exception], %{duration: duration}, %{
+            job_name: job_name,
+            node: inspect(node),
+            reason: value,
+            stacktrace: __STACKTRACE__,
+            scheduler: scheduler
+          })
       else
         result ->
           debug_logging &&
@@ -102,6 +126,14 @@ defmodule Quantum.Executor do
                 inspect(job_name)
               }, which yielded result: #{inspect(result)}"
             end)
+
+          duration = :erlang.monotonic_time() - start_monotonic_time
+
+          :telemetry.execute([:quantum, :job, :stop], %{duration: duration}, %{
+            job_name: job_name,
+            node: inspect(node),
+            scheduler: scheduler
+          })
       end
 
       :ok

lib/quantum/executor/start_opts.ex

@@ -6,13 +6,15 @@ defmodule Quantum.Executor.StartOpts do
   @type t :: %__MODULE__{
           task_supervisor_reference: GenServer.server(),
           task_registry_reference: GenServer.server(),
-          debug_logging: boolean
+          debug_logging: boolean,
+          scheduler: atom()
         }
 
   @enforce_keys [
     :task_supervisor_reference,
     :task_registry_reference,
-    :debug_logging
+    :debug_logging,
+    :scheduler
   ]
   defstruct @enforce_keys
 end

lib/quantum/executor_supervisor.ex

@@ -19,7 +19,8 @@ defmodule Quantum.ExecutorSupervisor do
           :node_selector_broadcaster_reference,
           :task_supervisor_reference,
           :task_registry_reference,
-          :debug_logging
+          :debug_logging,
+          :scheduler
         ])
       ),
       name: name
@@ -49,7 +50,8 @@ defmodule Quantum.ExecutorSupervisor do
         Map.take(opts, [
           :task_supervisor_reference,
           :task_registry_reference,
-          :debug_logging
+          :debug_logging,
+          :scheduler
         ])
       )
 

lib/quantum/executor_supervisor/init_opts.ex

@@ -7,14 +7,16 @@ defmodule Quantum.ExecutorSupervisor.InitOpts do
           node_selector_broadcaster_reference: GenServer.server(),
           task_supervisor_reference: GenServer.server(),
           task_registry_reference: GenServer.server(),
-          debug_logging: boolean
+          debug_logging: boolean,
+          scheduler: atom()
         }
 
   @enforce_keys [
     :node_selector_broadcaster_reference,
     :task_supervisor_reference,
     :task_registry_reference,
-    :debug_logging
+    :debug_logging,
+    :scheduler
   ]
   defstruct @enforce_keys
 end

lib/quantum/executor_supervisor/start_opts.ex

@@ -8,15 +8,17 @@ defmodule Quantum.ExecutorSupervisor.StartOpts do
           node_selector_broadcaster_reference: GenServer.server(),
           task_supervisor_reference: GenServer.server(),
           task_registry_reference: GenServer.server(),
-          debug_logging: boolean()
+          debug_logging: boolean(),
+          scheduler: atom()
         }
 
   @enforce_keys [
     :name,
     :node_selector_broadcaster_reference,
     :task_supervisor_reference,
     :task_registry_reference,
-    :debug_logging
+    :debug_logging,
+    :scheduler
   ]
   defstruct @enforce_keys
 end

lib/quantum/job_broadcaster.ex

@@ -60,6 +60,16 @@ defmodule Quantum.JobBroadcaster do
               "[#{inspect(Node.self())}][#{__MODULE__}] Loading Initial Jobs from Storage, skipping config"
             end)
 
+          for %Job{state: :active, name: name} = job <- storage_jobs do
+            # Send event to telemetry incase the end user wants to monitor events
+            :telemetry.execute([:quantum, :job, :add], %{}, %{
+              job_name: name,
+              job: job,
+              node: inspect(Node.self()),
+              scheduler: scheduler
+            })
+          end
+
           storage_jobs
       end
 
@@ -99,6 +109,14 @@ defmodule Quantum.JobBroadcaster do
             "[#{inspect(Node.self())}][#{__MODULE__}] Replacing job #{inspect(job_name)}"
           end)
 
+        # Send event to telemetry incase the end user wants to monitor events
+        :telemetry.execute([:quantum, :job, :update], %{}, %{
+          job_name: job_name,
+          job: job,
+          node: inspect(Node.self()),
+          scheduler: state.scheduler
+        })
+
         :ok = storage.delete_job(storage_pid, job_name)
         :ok = storage.add_job(storage_pid, job)
 
@@ -111,6 +129,14 @@ defmodule Quantum.JobBroadcaster do
             "[#{inspect(Node.self())}][#{__MODULE__}] Replacing job #{inspect(job_name)}"
           end)
 
+        # Send event to telemetry incase the end user wants to monitor events
+        :telemetry.execute([:quantum, :job, :update], %{}, %{
+          job_name: job_name,
+          job: job,
+          node: inspect(Node.self()),
+          scheduler: state.scheduler
+        })
+
         :ok = storage.delete_job(storage_pid, job_name)
         :ok = storage.add_job(storage_pid, job)
 
@@ -122,6 +148,14 @@ defmodule Quantum.JobBroadcaster do
             "[#{inspect(Node.self())}][#{__MODULE__}] Adding job #{inspect(job_name)}"
           end)
 
+        # Send event to telemetry incase the end user wants to monitor events
+        :telemetry.execute([:quantum, :job, :add], %{}, %{
+          job_name: job_name,
+          job: job,
+          node: inspect(Node.self()),
+          scheduler: state.scheduler
+        })
+
         :ok = storage.add_job(storage_pid, job)
 
         {:noreply, [{:add, job}], %{state | jobs: Map.put(jobs, job_name, job)}}
@@ -144,6 +178,14 @@ defmodule Quantum.JobBroadcaster do
             "[#{inspect(Node.self())}][#{__MODULE__}] Replacing job #{inspect(job_name)}"
           end)
 
+        # Send event to telemetry incase the end user wants to monitor events
+        :telemetry.execute([:quantum, :job, :update], %{}, %{
+          job_name: job_name,
+          job: job,
+          node: inspect(Node.self()),
+          scheduler: state.scheduler
+        })
+
         :ok = storage.delete_job(storage_pid, job_name)
         :ok = storage.add_job(storage_pid, job)
 
@@ -155,6 +197,14 @@ defmodule Quantum.JobBroadcaster do
             "[#{inspect(Node.self())}][#{__MODULE__}] Replacing job #{inspect(job_name)}"
           end)
 
+        # Send event to telemetry incase the end user wants to monitor events
+        :telemetry.execute([:quantum, :job, :update], %{}, %{
+          job_name: job_name,
+          job: job,
+          node: inspect(Node.self()),
+          scheduler: state.scheduler
+        })
+
         :ok = storage.delete_job(storage_pid, job_name)
         :ok = storage.add_job(storage_pid, job)
 
@@ -166,6 +216,14 @@ defmodule Quantum.JobBroadcaster do
             "[#{inspect(Node.self())}][#{__MODULE__}] Adding job #{inspect(job_name)}"
           end)
 
+        # Send event to telemetry incase the end user wants to monitor events
+        :telemetry.execute([:quantum, :job, :add], %{}, %{
+          job_name: job_name,
+          job: job,
+          node: inspect(Node.self()),
+          scheduler: state.scheduler
+        })
+
         :ok = storage.add_job(storage_pid, job)
 
         {:noreply, [], %{state | jobs: Map.put(jobs, job_name, job)}}
@@ -187,12 +245,28 @@ defmodule Quantum.JobBroadcaster do
       end)
 
     case Map.fetch(jobs, name) do
-      {:ok, %{state: :active}} ->
+      {:ok, %{state: :active, name: name} = job} ->
+        # Send event to telemetry incase the end user wants to monitor events
+        :telemetry.execute([:quantum, :job, :delete], %{}, %{
+          job_name: name,
+          job: job,
+          node: inspect(Node.self()),
+          scheduler: state.scheduler
+        })
+
         :ok = storage.delete_job(storage_pid, name)
 
         {:noreply, [{:remove, name}], %{state | jobs: Map.delete(jobs, name)}}
 
-      {:ok, %{state: :inactive}} ->
+      {:ok, %{state: :inactive, name: name} = job} ->
+        # Send event to telemetry incase the end user wants to monitor events
+        :telemetry.execute([:quantum, :job, :delete], %{}, %{
+          job_name: name,
+          job: job,
+          node: inspect(Node.self()),
+          scheduler: state.scheduler
+        })
+
         :ok = storage.delete_job(storage_pid, name)
 
         {:noreply, [], %{state | jobs: Map.delete(jobs, name)}}
@@ -224,6 +298,14 @@ defmodule Quantum.JobBroadcaster do
         {:noreply, [], state}
 
       {:ok, job} ->
+        # Send event to telemetry incase the end user wants to monitor events
+        :telemetry.execute([:quantum, :job, :update], %{}, %{
+          job_name: name,
+          job: job,
+          node: inspect(Node.self()),
+          scheduler: state.scheduler
+        })
+
         jobs = Map.update!(jobs, name, &Job.set_state(&1, new_state))
 
         :ok = storage.update_job_state(storage_pid, job.name, new_state)
@@ -252,6 +334,16 @@ defmodule Quantum.JobBroadcaster do
         "[#{inspect(Node.self())}][#{__MODULE__}] Deleting all jobs"
       end)
 
+    for {name, %Job{} = job} <- jobs do
+      # Send event to telemetry incase the end user wants to monitor events
+      :telemetry.execute([:quantum, :job, :delete], %{}, %{
+        job_name: name,
+        job: job,
+        node: inspect(Node.self()),
+        scheduler: state.scheduler
+      })
+    end
+
     messages = for {name, %Job{state: :active}} <- jobs, do: {:remove, name}
 
     :ok = storage.purge(storage_pid)

lib/quantum/supervisor.ex

@@ -88,6 +88,7 @@ defmodule Quantum.Supervisor do
         |> Map.put(:task_supervisor_reference, task_supervisor_name)
         |> Map.put(:task_registry_reference, task_registry_name)
         |> Map.put(:name, executor_supervisor_name)
+        |> Map.put(:scheduler, scheduler)
       )
 
     Supervisor.init(

mix.exs

@@ -101,7 +101,8 @@ defmodule Quantum.Mixfile do
       {:ex_doc, "~> 0.19", only: [:dev, :docs], runtime: false},
       {:excoveralls, "~> 0.5", only: [:test], runtime: false},
       {:dialyxir, "~> 1.0-rc", only: [:dev], runtime: false},
-      {:credo, "~> 1.0", only: [:dev], runtime: false}
+      {:credo, "~> 1.0", only: [:dev], runtime: false},
+      {:telemetry, "~> 0.4"}
     ]
   end
 end

pages/configuration.md

@@ -154,3 +154,6 @@ Timezones can also be configured on a per-job basis. This overrides the default
   timezone: "America/New_York"
 }
 ```
+
+## Telemetry Support
+