diff options
Diffstat (limited to 'lib/pleroma/gun/connection_pool')
| -rw-r--r-- | lib/pleroma/gun/connection_pool/reclaimer.ex | 85 | ||||
| -rw-r--r-- | lib/pleroma/gun/connection_pool/worker.ex | 133 | ||||
| -rw-r--r-- | lib/pleroma/gun/connection_pool/worker_supervisor.ex | 45 |
3 files changed, 263 insertions, 0 deletions
diff --git a/lib/pleroma/gun/connection_pool/reclaimer.ex b/lib/pleroma/gun/connection_pool/reclaimer.ex new file mode 100644 index 000000000..cea800882 --- /dev/null +++ b/lib/pleroma/gun/connection_pool/reclaimer.ex @@ -0,0 +1,85 @@ +defmodule Pleroma.Gun.ConnectionPool.Reclaimer do + use GenServer, restart: :temporary + + @registry Pleroma.Gun.ConnectionPool + + def start_monitor do + pid = + case :gen_server.start(__MODULE__, [], name: {:via, Registry, {@registry, "reclaimer"}}) do + {:ok, pid} -> + pid + + {:error, {:already_registered, pid}} -> + pid + end + + {pid, Process.monitor(pid)} + end + + @impl true + def init(_) do + {:ok, nil, {:continue, :reclaim}} + end + + @impl true + def handle_continue(:reclaim, _) do + max_connections = Pleroma.Config.get([:connections_pool, :max_connections]) + + reclaim_max = + [:connections_pool, :reclaim_multiplier] + |> Pleroma.Config.get() + |> Kernel.*(max_connections) + |> round + |> max(1) + + :telemetry.execute([:pleroma, :connection_pool, :reclaim, :start], %{}, %{ + max_connections: max_connections, + reclaim_max: reclaim_max + }) + + # :ets.fun2ms( + # fn {_, {worker_pid, {_, used_by, crf, last_reference}}} when used_by == [] -> + # {worker_pid, crf, last_reference} end) + unused_conns = + Registry.select( + @registry, + [ + {{:_, :"$1", {:_, :"$2", :"$3", :"$4"}}, [{:==, :"$2", []}], [{{:"$1", :"$3", :"$4"}}]} + ] + ) + + case unused_conns do + [] -> + :telemetry.execute( + [:pleroma, :connection_pool, :reclaim, :stop], + %{reclaimed_count: 0}, + %{ + max_connections: max_connections + } + ) + + {:stop, :no_unused_conns, nil} + + unused_conns -> + reclaimed = + unused_conns + |> Enum.sort(fn {_pid1, crf1, last_reference1}, {_pid2, crf2, last_reference2} -> + crf1 <= crf2 and last_reference1 <= last_reference2 + end) + |> Enum.take(reclaim_max) + + reclaimed + |> Enum.each(fn {pid, _, _} -> + DynamicSupervisor.terminate_child(Pleroma.Gun.ConnectionPool.WorkerSupervisor, pid) + end) + + :telemetry.execute( + [:pleroma, :connection_pool, :reclaim, :stop], + %{reclaimed_count: Enum.count(reclaimed)}, + %{max_connections: max_connections} + ) + + {:stop, :normal, nil} + end + end +end diff --git a/lib/pleroma/gun/connection_pool/worker.ex b/lib/pleroma/gun/connection_pool/worker.ex new file mode 100644 index 000000000..fec9d0efa --- /dev/null +++ b/lib/pleroma/gun/connection_pool/worker.ex @@ -0,0 +1,133 @@ +defmodule Pleroma.Gun.ConnectionPool.Worker do + alias Pleroma.Gun + use GenServer, restart: :temporary + + @registry Pleroma.Gun.ConnectionPool + + def start_link([key | _] = opts) do + GenServer.start_link(__MODULE__, opts, name: {:via, Registry, {@registry, key}}) + end + + @impl true + def init([_key, _uri, _opts, _client_pid] = opts) do + {:ok, nil, {:continue, {:connect, opts}}} + end + + @impl true + def handle_continue({:connect, [key, uri, opts, client_pid]}, _) do + with {:ok, conn_pid} <- Gun.Conn.open(uri, opts), + Process.link(conn_pid) do + time = :erlang.monotonic_time(:millisecond) + + {_, _} = + Registry.update_value(@registry, key, fn _ -> + {conn_pid, [client_pid], 1, time} + end) + + send(client_pid, {:conn_pid, conn_pid}) + + {:noreply, + %{key: key, timer: nil, client_monitors: %{client_pid => Process.monitor(client_pid)}}, + :hibernate} + else + err -> + {:stop, {:shutdown, err}, nil} + end + end + + @impl true + def handle_cast({:add_client, client_pid}, state) do + case handle_call(:add_client, {client_pid, nil}, state) do + {:reply, conn_pid, state, :hibernate} -> + send(client_pid, {:conn_pid, conn_pid}) + {:noreply, state, :hibernate} + end + end + + @impl true + def handle_cast({:remove_client, client_pid}, state) do + case handle_call(:remove_client, {client_pid, nil}, state) do + {:reply, _, state, :hibernate} -> + {:noreply, state, :hibernate} + end + end + + @impl true + def handle_call(:add_client, {client_pid, _}, %{key: key} = state) do + time = :erlang.monotonic_time(:millisecond) + + {{conn_pid, _, _, _}, _} = + Registry.update_value(@registry, key, fn {conn_pid, used_by, crf, last_reference} -> + {conn_pid, [client_pid | used_by], crf(time - last_reference, crf), time} + end) + + state = + if state.timer != nil do + Process.cancel_timer(state[:timer]) + %{state | timer: nil} + else + state + end + + ref = Process.monitor(client_pid) + + state = put_in(state.client_monitors[client_pid], ref) + {:reply, conn_pid, state, :hibernate} + end + + @impl true + def handle_call(:remove_client, {client_pid, _}, %{key: key} = state) do + {{_conn_pid, used_by, _crf, _last_reference}, _} = + Registry.update_value(@registry, key, fn {conn_pid, used_by, crf, last_reference} -> + {conn_pid, List.delete(used_by, client_pid), crf, last_reference} + end) + + {ref, state} = pop_in(state.client_monitors[client_pid]) + Process.demonitor(ref) + + timer = + if used_by == [] do + max_idle = Pleroma.Config.get([:connections_pool, :max_idle_time], 30_000) + Process.send_after(self(), :idle_close, max_idle) + else + nil + end + + {:reply, :ok, %{state | timer: timer}, :hibernate} + end + + @impl true + def handle_info(:idle_close, state) do + # Gun monitors the owner process, and will close the connection automatically + # when it's terminated + {:stop, :normal, state} + end + + # Gracefully shutdown if the connection got closed without any streams left + @impl true + def handle_info({:gun_down, _pid, _protocol, _reason, []}, state) do + {:stop, :normal, state} + end + + # Otherwise, shutdown with an error + @impl true + def handle_info({:gun_down, _pid, _protocol, _reason, _killed_streams} = down_message, state) do + {:stop, {:error, down_message}, state} + end + + @impl true + def handle_info({:DOWN, _ref, :process, pid, reason}, state) do + :telemetry.execute( + [:pleroma, :connection_pool, :client_death], + %{client_pid: pid, reason: reason}, + %{key: state.key} + ) + + handle_cast({:remove_client, pid}, state) + end + + # LRFU policy: https://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.55.1478 + defp crf(time_delta, prev_crf) do + 1 + :math.pow(0.5, 0.0001 * time_delta) * prev_crf + end +end diff --git a/lib/pleroma/gun/connection_pool/worker_supervisor.ex b/lib/pleroma/gun/connection_pool/worker_supervisor.ex new file mode 100644 index 000000000..39615c956 --- /dev/null +++ b/lib/pleroma/gun/connection_pool/worker_supervisor.ex @@ -0,0 +1,45 @@ +defmodule Pleroma.Gun.ConnectionPool.WorkerSupervisor do + @moduledoc "Supervisor for pool workers. Does not do anything except enforce max connection limit" + + use DynamicSupervisor + + def start_link(opts) do + DynamicSupervisor.start_link(__MODULE__, opts, name: __MODULE__) + end + + def init(_opts) do + DynamicSupervisor.init( + strategy: :one_for_one, + max_children: Pleroma.Config.get([:connections_pool, :max_connections]) + ) + end + + def start_worker(opts, retry \\ false) do + case DynamicSupervisor.start_child(__MODULE__, {Pleroma.Gun.ConnectionPool.Worker, opts}) do + {:error, :max_children} -> + if retry or free_pool() == :error do + :telemetry.execute([:pleroma, :connection_pool, :provision_failure], %{opts: opts}) + {:error, :pool_full} + else + start_worker(opts, true) + end + + res -> + res + end + end + + defp free_pool do + wait_for_reclaimer_finish(Pleroma.Gun.ConnectionPool.Reclaimer.start_monitor()) + end + + defp wait_for_reclaimer_finish({pid, mon}) do + receive do + {:DOWN, ^mon, :process, ^pid, :no_unused_conns} -> + :error + + {:DOWN, ^mon, :process, ^pid, :normal} -> + :ok + end + end +end |