no drop active connections

6 files changed, 374 insertions, 119 deletions

diff --git a/lib/pleroma/gun/conn.ex b/lib/pleroma/gun/conn.ex
index 9e5c2b184..906607b28 100644
--- a/lib/pleroma/gun/conn.ex
+++ b/lib/pleroma/gun/conn.ex
@@ -6,17 +6,24 @@ defmodule Pleroma.Gun.Conn do
   @moduledoc """
   Struct for gun connection data
   """
+  @type gun_state :: :open | :up | :down
+  @type conn_state :: :init | :active | :idle
+
   @type t :: %__MODULE__{
           conn: pid(),
-          state: atom(),
+          gun_state: gun_state(),
           waiting_pids: [pid()],
+          conn_state: conn_state(),
+          used_by: [pid()],
           last_reference: pos_integer(),
           crf: float()
         }
 
   defstruct conn: nil,
-            state: :open,
+            gun_state: :open,
             waiting_pids: [],
+            conn_state: :init,
+            used_by: [],
             last_reference: :os.system_time(:second),
             crf: 1
 end
diff --git a/lib/pleroma/gun/connections.ex b/lib/pleroma/gun/connections.ex
index 73d54e94d..e3d392de7 100644
--- a/lib/pleroma/gun/connections.ex
+++ b/lib/pleroma/gun/connections.ex
@@ -14,7 +14,7 @@ defmodule Pleroma.Gun.Connections do
           opts: keyword()
         }
 
-  defstruct conns: %{}, opts: []
+  defstruct conns: %{}, opts: [], queue: []
 
   alias Pleroma.Gun.API
   alias Pleroma.Gun.Conn
@@ -27,8 +27,8 @@ defmodule Pleroma.Gun.Connections do
   @impl true
   def init(opts), do: {:ok, %__MODULE__{conns: %{}, opts: opts}}
 
-  @spec get_conn(String.t(), keyword(), atom()) :: pid()
-  def get_conn(url, opts \\ [], name \\ :default) do
+  @spec checkin(String.t(), keyword(), atom()) :: pid()
+  def checkin(url, opts \\ [], name \\ :default) do
     opts = Enum.into(opts, %{})
 
     uri = URI.parse(url)
@@ -53,7 +53,7 @@ defmodule Pleroma.Gun.Connections do
 
     GenServer.call(
       name,
-      {:conn, %{opts: opts, uri: uri}}
+      {:checkin, %{opts: opts, uri: uri}}
     )
   end
 
@@ -68,28 +68,57 @@ defmodule Pleroma.Gun.Connections do
     GenServer.call(name, {:state})
   end
 
+  def checkout(conn, pid, name \\ :default) do
+    GenServer.cast(name, {:checkout, conn, pid})
+  end
+
+  def process_queue(name \\ :default) do
+    GenServer.cast(name, {:process_queue})
+  end
+
   @impl true
-  def handle_call({:conn, %{opts: opts, uri: uri}}, from, state) do
+  def handle_cast({:checkout, conn_pid, pid}, state) do
+    {key, conn} = find_conn(state.conns, conn_pid)
+    used_by = List.keydelete(conn.used_by, pid, 0)
+    conn_state = if used_by == [], do: :idle, else: conn.conn_state
+    state = put_in(state.conns[key], %{conn | conn_state: conn_state, used_by: used_by})
+    {:noreply, state}
+  end
+
+  @impl true
+  def handle_cast({:process_queue}, state) do
+    case state.queue do
+      [{from, key, uri, opts} | _queue] ->
+        try_to_checkin(key, uri, from, state, Map.put(opts, :from_cast, true))
+
+      [] ->
+        {:noreply, state}
+    end
+  end
+
+  @impl true
+  def handle_call({:checkin, %{opts: opts, uri: uri}}, from, state) do
     key = compose_key(uri)
 
     case state.conns[key] do
-      %{conn: conn, state: conn_state, last_reference: reference, crf: last_crf} = current_conn
-      when conn_state == :up ->
+      %{conn: conn, gun_state: gun_state} = current_conn when gun_state == :up ->
         time = current_time()
-        last_reference = time - reference
+        last_reference = time - current_conn.last_reference
 
-        current_crf = crf(last_reference, 100, last_crf)
+        current_crf = crf(last_reference, 100, current_conn.crf)
 
         state =
           put_in(state.conns[key], %{
             current_conn
             | last_reference: time,
-              crf: current_crf
+              crf: current_crf,
+              conn_state: :active,
+              used_by: [from | current_conn.used_by]
           })
 
         {:reply, conn, state}
 
-      %{state: conn_state, waiting_pids: pids} when conn_state in [:open, :down] ->
+      %{gun_state: gun_state, waiting_pids: pids} when gun_state in [:open, :down] ->
         state = put_in(state.conns[key].waiting_pids, [from | pids])
         {:noreply, state}
 
@@ -99,22 +128,7 @@ defmodule Pleroma.Gun.Connections do
         if Enum.count(state.conns) < max_connections do
           open_conn(key, uri, from, state, opts)
         else
-          [{close_key, least_used} | _conns] =
-            state.conns
-            |> Enum.filter(fn {_k, v} -> v.waiting_pids == [] end)
-            |> Enum.sort(fn {_x_k, x}, {_y_k, y} ->
-              x.crf < y.crf and x.last_reference < y.last_reference
-            end)
-
-          :ok = API.close(least_used.conn)
-
-          state =
-            put_in(
-              state.conns,
-              Map.delete(state.conns, close_key)
-            )
-
-          open_conn(key, uri, from, state, opts)
+          try_to_checkin(key, uri, from, state, opts)
         end
     end
   end
@@ -122,14 +136,44 @@ defmodule Pleroma.Gun.Connections do
   @impl true
   def handle_call({:state}, _from, state), do: {:reply, state, state}
 
+  defp try_to_checkin(key, uri, from, state, opts) do
+    unused_conns =
+      state.conns
+      |> Enum.filter(fn {_k, v} ->
+        v.conn_state == :idle and v.waiting_pids == [] and v.used_by == []
+      end)
+      |> Enum.sort(fn {_x_k, x}, {_y_k, y} ->
+        x.crf < y.crf and x.last_reference < y.last_reference
+      end)
+
+    case unused_conns do
+      [{close_key, least_used} | _conns] ->
+        :ok = API.close(least_used.conn)
+
+        state =
+          put_in(
+            state.conns,
+            Map.delete(state.conns, close_key)
+          )
+
+        open_conn(key, uri, from, state, opts)
+
+      [] ->
+        queue =
+          if List.keymember?(state.queue, from, 0),
+            do: state.queue,
+            else: state.queue ++ [{from, key, uri, opts}]
+
+        state = put_in(state.queue, queue)
+        {:noreply, state}
+    end
+  end
+
   @impl true
   def handle_info({:gun_up, conn_pid, _protocol}, state) do
     conn_key = compose_key_gun_info(conn_pid)
     {key, conn} = find_conn(state.conns, conn_pid, conn_key)
 
-    # Send to all waiting processes connection pid
-    Enum.each(conn.waiting_pids, fn waiting_pid -> GenServer.reply(waiting_pid, conn_pid) end)
-
     # Update state of the current connection and set waiting_pids to empty list
     time = current_time()
     last_reference = time - conn.last_reference
@@ -138,12 +182,17 @@ defmodule Pleroma.Gun.Connections do
     state =
       put_in(state.conns[key], %{
         conn
-        | state: :up,
+        | gun_state: :up,
           waiting_pids: [],
           last_reference: time,
-          crf: current_crf
+          crf: current_crf,
+          conn_state: :active,
+          used_by: conn.waiting_pids ++ conn.used_by
       })
 
+    # Send to all waiting processes connection pid
+    Enum.each(conn.waiting_pids, fn waiting_pid -> GenServer.reply(waiting_pid, conn_pid) end)
+
     {:noreply, state}
   end
 
@@ -154,7 +203,7 @@ defmodule Pleroma.Gun.Connections do
 
     Enum.each(conn.waiting_pids, fn waiting_pid -> GenServer.reply(waiting_pid, nil) end)
 
-    state = put_in(state.conns[key].state, :down)
+    state = put_in(state.conns[key].gun_state, :down)
     {:noreply, state}
   end
 
@@ -177,7 +226,7 @@ defmodule Pleroma.Gun.Connections do
     end)
   end
 
-  defp open_conn(key, uri, _from, state, %{proxy: {proxy_host, proxy_port}} = opts) do
+  defp open_conn(key, uri, from, state, %{proxy: {proxy_host, proxy_port}} = opts) do
     host = to_charlist(uri.host)
     port = uri.port
 
@@ -202,9 +251,15 @@ defmodule Pleroma.Gun.Connections do
         put_in(state.conns[key], %Conn{
           conn: conn,
           waiting_pids: [],
-          state: :up
+          gun_state: :up,
+          conn_state: :active,
+          used_by: [from]
         })
 
+      if opts[:from_cast] do
+        GenServer.reply(from, conn)
+      end
+
       {:reply, conn, state}
     else
       error ->
@@ -219,6 +274,13 @@ defmodule Pleroma.Gun.Connections do
 
     with {:ok, conn} <- API.open(host, port, opts) do
       state =
+        if opts[:from_cast] do
+          put_in(state.queue, List.keydelete(state.queue, from, 0))
+        else
+          state
+        end
+
+      state =
         put_in(state.conns[key], %Conn{
           conn: conn,
           waiting_pids: [from]
diff --git a/lib/pleroma/http/connection.ex b/lib/pleroma/http/connection.ex
index 39c0fff43..d4e6d0f99 100644
--- a/lib/pleroma/http/connection.ex
+++ b/lib/pleroma/http/connection.ex
@@ -10,8 +10,7 @@ defmodule Pleroma.HTTP.Connection do
   @options [
     connect_timeout: 10_000,
     timeout: 20_000,
-    pool: :federation,
-    version: :master
+    pool: :federation
   ]
 
   require Logger
@@ -61,7 +60,7 @@ defmodule Pleroma.HTTP.Connection do
   end
 
   defp get_conn_for_gun(url, options, pool) do
-    case Pleroma.Gun.Connections.get_conn(url, options, pool) do
+    case Pleroma.Gun.Connections.checkin(url, options, pool) do
       nil ->
         options
 
diff --git a/lib/pleroma/http/http.ex b/lib/pleroma/http/http.ex
index 5c0d66955..0a7db737f 100644
--- a/lib/pleroma/http/http.ex
+++ b/lib/pleroma/http/http.ex
@@ -45,15 +45,27 @@ defmodule Pleroma.HTTP do
 
       params = Keyword.get(options, :params, [])
 
-      %{}
-      |> Builder.method(method)
-      |> Builder.url(url)
-      |> Builder.headers(headers)
-      |> Builder.opts(options)
-      |> Builder.add_param(:body, :body, body)
-      |> Builder.add_param(:query, :query, params)
-      |> Enum.into([])
-      |> (&Tesla.request(Connection.new(options), &1)).()
+      request =
+        %{}
+        |> Builder.method(method)
+        |> Builder.url(url)
+        |> Builder.headers(headers)
+        |> Builder.opts(options)
+        |> Builder.add_param(:body, :body, body)
+        |> Builder.add_param(:query, :query, params)
+        |> Enum.into([])
+
+      client = Connection.new(options)
+      response = Tesla.request(client, request)
+
+      if adapter_gun? do
+        %{adapter: {_, _, [adapter_options]}} = client
+        pool = adapter_options[:pool]
+        Pleroma.Gun.Connections.checkout(adapter_options[:conn], self(), pool)
+        Pleroma.Gun.Connections.process_queue(pool)
+      end
+
+      response
     rescue
       e ->
         {:error, e}
diff --git a/test/gun/connections_test.exs b/test/gun/connections_test.exs
index cc3675ad9..39f77070a 100644
--- a/test/gun/connections_test.exs
+++ b/test/gun/connections_test.exs
@@ -34,12 +34,26 @@ defmodule Gun.ConnectionsTest do
   end
 
   test "opens connection and reuse it on next request", %{name: name, pid: pid} do
-    conn = Connections.get_conn("http://some-domain.com", [genserver_pid: pid], name)
+    conn = Connections.checkin("http://some-domain.com", [genserver_pid: pid], name)
 
     assert is_pid(conn)
     assert Process.alive?(conn)
 
-    reused_conn = Connections.get_conn("http://some-domain.com", [genserver_pid: pid], name)
+    self = self()
+
+    %Connections{
+      conns: %{
+        "http:some-domain.com:80" => %Conn{
+          conn: ^conn,
+          gun_state: :up,
+          waiting_pids: [],
+          used_by: [{^self, _}],
+          conn_state: :active
+        }
+      }
+    } = Connections.get_state(name)
+
+    reused_conn = Connections.checkin("http://some-domain.com", [genserver_pid: pid], name)
 
     assert conn == reused_conn
 
@@ -47,23 +61,53 @@ defmodule Gun.ConnectionsTest do
       conns: %{
         "http:some-domain.com:80" => %Conn{
           conn: ^conn,
-          state: :up,
-          waiting_pids: []
+          gun_state: :up,
+          waiting_pids: [],
+          used_by: [{^self, _}, {^self, _}],
+          conn_state: :active
+        }
+      }
+    } = Connections.get_state(name)
+
+    :ok = Connections.checkout(conn, self, name)
+
+    %Connections{
+      conns: %{
+        "http:some-domain.com:80" => %Conn{
+          conn: ^conn,
+          gun_state: :up,
+          waiting_pids: [],
+          used_by: [{^self, _}],
+          conn_state: :active
+        }
+      }
+    } = Connections.get_state(name)
+
+    :ok = Connections.checkout(conn, self, name)
+
+    %Connections{
+      conns: %{
+        "http:some-domain.com:80" => %Conn{
+          conn: ^conn,
+          gun_state: :up,
+          waiting_pids: [],
+          used_by: [],
+          conn_state: :idle
         }
       }
     } = Connections.get_state(name)
   end
 
   test "reuses connection based on protocol", %{name: name, pid: pid} do
-    conn = Connections.get_conn("http://some-domain.com", [genserver_pid: pid], name)
+    conn = Connections.checkin("http://some-domain.com", [genserver_pid: pid], name)
     assert is_pid(conn)
     assert Process.alive?(conn)
 
-    https_conn = Connections.get_conn("https://some-domain.com", [genserver_pid: pid], name)
+    https_conn = Connections.checkin("https://some-domain.com", [genserver_pid: pid], name)
 
     refute conn == https_conn
 
-    reused_https = Connections.get_conn("https://some-domain.com", [genserver_pid: pid], name)
+    reused_https = Connections.checkin("https://some-domain.com", [genserver_pid: pid], name)
 
     refute conn == reused_https
 
@@ -73,12 +117,12 @@ defmodule Gun.ConnectionsTest do
       conns: %{
         "http:some-domain.com:80" => %Conn{
           conn: ^conn,
-          state: :up,
+          gun_state: :up,
           waiting_pids: []
         },
         "https:some-domain.com:443" => %Conn{
           conn: ^https_conn,
-          state: :up,
+          gun_state: :up,
           waiting_pids: []
         }
       }
@@ -86,7 +130,7 @@ defmodule Gun.ConnectionsTest do
   end
 
   test "process gun_down message", %{name: name, pid: pid} do
-    conn = Connections.get_conn("http://gun_down.com", [genserver_pid: pid], name)
+    conn = Connections.checkin("http://gun_down.com", [genserver_pid: pid], name)
 
     refute conn
 
@@ -94,7 +138,7 @@ defmodule Gun.ConnectionsTest do
       conns: %{
         "http:gun_down.com:80" => %Conn{
           conn: _,
-          state: :down,
+          gun_state: :down,
           waiting_pids: _
         }
       }
@@ -102,7 +146,7 @@ defmodule Gun.ConnectionsTest do
   end
 
   test "process gun_down message and then gun_up", %{name: name, pid: pid} do
-    conn = Connections.get_conn("http://gun_down_and_up.com", [genserver_pid: pid], name)
+    conn = Connections.checkin("http://gun_down_and_up.com", [genserver_pid: pid], name)
 
     refute conn
 
@@ -110,13 +154,13 @@ defmodule Gun.ConnectionsTest do
       conns: %{
         "http:gun_down_and_up.com:80" => %Conn{
           conn: _,
-          state: :down,
+          gun_state: :down,
           waiting_pids: _
         }
       }
     } = Connections.get_state(name)
 
-    conn = Connections.get_conn("http://gun_down_and_up.com", [genserver_pid: pid], name)
+    conn = Connections.checkin("http://gun_down_and_up.com", [genserver_pid: pid], name)
 
     assert is_pid(conn)
     assert Process.alive?(conn)
@@ -125,7 +169,7 @@ defmodule Gun.ConnectionsTest do
       conns: %{
         "http:gun_down_and_up.com:80" => %Conn{
           conn: _,
-          state: :up,
+          gun_state: :up,
           waiting_pids: []
         }
       }
@@ -136,7 +180,7 @@ defmodule Gun.ConnectionsTest do
     tasks =
       for _ <- 1..5 do
         Task.async(fn ->
-          Connections.get_conn("http://some-domain.com", [genserver_pid: pid], name)
+          Connections.checkin("http://some-domain.com", [genserver_pid: pid], name)
         end)
       end
 
@@ -153,7 +197,7 @@ defmodule Gun.ConnectionsTest do
       conns: %{
         "http:some-domain.com:80" => %Conn{
           conn: conn,
-          state: :up,
+          gun_state: :up,
           waiting_pids: []
         }
       }
@@ -162,41 +206,49 @@ defmodule Gun.ConnectionsTest do
     assert Enum.all?(conns, fn res -> res == conn end)
   end
 
-  test "remove frequently used", %{name: name, pid: pid} do
-    Connections.get_conn("https://some-domain.com", [genserver_pid: pid], name)
+  test "remove frequently used and idle", %{name: name, pid: pid} do
+    self = self()
+    conn1 = Connections.checkin("https://some-domain.com", [genserver_pid: pid], name)
 
-    for _ <- 1..4 do
-      Connections.get_conn("http://some-domain.com", [genserver_pid: pid], name)
-    end
+    [conn2 | _conns] =
+      for _ <- 1..4 do
+        Connections.checkin("http://some-domain.com", [genserver_pid: pid], name)
+      end
 
     %Connections{
       conns: %{
         "http:some-domain.com:80" => %Conn{
-          conn: _,
-          state: :up,
-          waiting_pids: []
+          conn: ^conn2,
+          gun_state: :up,
+          waiting_pids: [],
+          conn_state: :active,
+          used_by: [{^self, _}, {^self, _}, {^self, _}, {^self, _}]
         },
         "https:some-domain.com:443" => %Conn{
-          conn: _,
-          state: :up,
-          waiting_pids: []
+          conn: ^conn1,
+          gun_state: :up,
+          waiting_pids: [],
+          conn_state: :active,
+          used_by: [{^self, _}]
         }
       },
       opts: [max_connections: 2, timeout: 10]
     } = Connections.get_state(name)
 
-    conn = Connections.get_conn("http://another-domain.com", [genserver_pid: pid], name)
+    :ok = Connections.checkout(conn1, self, name)
+
+    conn = Connections.checkin("http://another-domain.com", [genserver_pid: pid], name)
 
     %Connections{
       conns: %{
         "http:another-domain.com:80" => %Conn{
           conn: ^conn,
-          state: :up,
+          gun_state: :up,
           waiting_pids: []
         },
         "http:some-domain.com:80" => %Conn{
           conn: _,
-          state: :up,
+          gun_state: :up,
           waiting_pids: []
         }
       },
@@ -211,12 +263,12 @@ defmodule Gun.ConnectionsTest do
       api = Pleroma.Config.get([API])
       Pleroma.Config.put([API], API.Gun)
       on_exit(fn -> Pleroma.Config.put([API], api) end)
-      conn = Connections.get_conn("http://httpbin.org", [], name)
+      conn = Connections.checkin("http://httpbin.org", [], name)
 
       assert is_pid(conn)
       assert Process.alive?(conn)
 
-      reused_conn = Connections.get_conn("http://httpbin.org", [], name)
+      reused_conn = Connections.checkin("http://httpbin.org", [], name)
 
       assert conn == reused_conn
 
@@ -224,7 +276,7 @@ defmodule Gun.ConnectionsTest do
         conns: %{
           "http:httpbin.org:80" => %Conn{
             conn: ^conn,
-            state: :up,
+            gun_state: :up,
             waiting_pids: []
           }
         }
@@ -235,12 +287,12 @@ defmodule Gun.ConnectionsTest do
       api = Pleroma.Config.get([API])
       Pleroma.Config.put([API], API.Gun)
       on_exit(fn -> Pleroma.Config.put([API], api) end)
-      conn = Connections.get_conn("https://httpbin.org", [], name)
+      conn = Connections.checkin("https://httpbin.org", [], name)
 
       assert is_pid(conn)
       assert Process.alive?(conn)
 
-      reused_conn = Connections.get_conn("https://httpbin.org", [], name)
+      reused_conn = Connections.checkin("https://httpbin.org", [], name)
 
       assert conn == reused_conn
 
@@ -248,52 +300,54 @@ defmodule Gun.ConnectionsTest do
         conns: %{
           "https:httpbin.org:443" => %Conn{
             conn: ^conn,
-            state: :up,
+            gun_state: :up,
             waiting_pids: []
           }
         }
       } = Connections.get_state(name)
     end
 
-    test "remove frequently used", %{name: name, pid: pid} do
+    test "remove frequently used and idle", %{name: name, pid: pid} do
+      self = self()
       api = Pleroma.Config.get([API])
       Pleroma.Config.put([API], API.Gun)
       on_exit(fn -> Pleroma.Config.put([API], api) end)
 
-      Connections.get_conn("https://www.google.com", [genserver_pid: pid], name)
+      conn = Connections.checkin("https://www.google.com", [genserver_pid: pid], name)
 
       for _ <- 1..4 do
-        Connections.get_conn("https://httpbin.org", [genserver_pid: pid], name)
+        Connections.checkin("https://httpbin.org", [genserver_pid: pid], name)
       end
 
       %Connections{
         conns: %{
           "https:httpbin.org:443" => %Conn{
             conn: _,
-            state: :up,
+            gun_state: :up,
             waiting_pids: []
           },
           "https:www.google.com:443" => %Conn{
             conn: _,
-            state: :up,
+            gun_state: :up,
             waiting_pids: []
           }
         },
         opts: [max_connections: 2, timeout: 10]
       } = Connections.get_state(name)
 
-      conn = Connections.get_conn("http://httpbin.org", [genserver_pid: pid], name)
+      :ok = Connections.checkout(conn, self, name)
+      conn = Connections.checkin("http://httpbin.org", [genserver_pid: pid], name)
 
       %Connections{
         conns: %{
           "http:httpbin.org:80" => %Conn{
             conn: ^conn,
-            state: :up,
+            gun_state: :up,
             waiting_pids: []
           },
           "https:httpbin.org:443" => %Conn{
             conn: _,
-            state: :up,
+            gun_state: :up,
             waiting_pids: []
           }
         },
@@ -301,59 +355,173 @@ defmodule Gun.ConnectionsTest do
       } = Connections.get_state(name)
     end
 
-    test "remove earlier used", %{name: name, pid: pid} do
+    test "remove earlier used and idle", %{name: name, pid: pid} do
+      self = self()
       api = Pleroma.Config.get([API])
       Pleroma.Config.put([API], API.Gun)
       on_exit(fn -> Pleroma.Config.put([API], api) end)
 
-      Connections.get_conn("https://www.google.com", [genserver_pid: pid], name)
-      Connections.get_conn("https://www.google.com", [genserver_pid: pid], name)
+      Connections.checkin("https://www.google.com", [genserver_pid: pid], name)
+      conn = Connections.checkin("https://www.google.com", [genserver_pid: pid], name)
 
       Process.sleep(1_000)
-      Connections.get_conn("https://httpbin.org", [genserver_pid: pid], name)
-      Connections.get_conn("https://httpbin.org", [genserver_pid: pid], name)
+      Connections.checkin("https://httpbin.org", [genserver_pid: pid], name)
+      Connections.checkin("https://httpbin.org", [genserver_pid: pid], name)
 
       %Connections{
         conns: %{
           "https:httpbin.org:443" => %Conn{
             conn: _,
-            state: :up,
+            gun_state: :up,
             waiting_pids: []
           },
           "https:www.google.com:443" => %Conn{
-            conn: _,
-            state: :up,
+            conn: ^conn,
+            gun_state: :up,
             waiting_pids: []
           }
         },
         opts: [max_connections: 2, timeout: 10]
       } = Connections.get_state(name)
 
+      :ok = Connections.checkout(conn, self, name)
+      :ok = Connections.checkout(conn, self, name)
       Process.sleep(1_000)
-      conn = Connections.get_conn("http://httpbin.org", [genserver_pid: pid], name)
+      conn = Connections.checkin("http://httpbin.org", [genserver_pid: pid], name)
 
       %Connections{
         conns: %{
           "http:httpbin.org:80" => %Conn{
             conn: ^conn,
-            state: :up,
+            gun_state: :up,
             waiting_pids: []
           },
           "https:httpbin.org:443" => %Conn{
             conn: _,
-            state: :up,
+            gun_state: :up,
             waiting_pids: []
           }
         },
         opts: [max_connections: 2, timeout: 10]
       } = Connections.get_state(name)
     end
+
+    test "doesn't drop active connections on pool overflow addinng new requests to the queue", %{
+      name: name,
+      pid: pid
+    } do
+      api = Pleroma.Config.get([API])
+      Pleroma.Config.put([API], API.Gun)
+      on_exit(fn -> Pleroma.Config.put([API], api) end)
+
+      self = self()
+      Connections.checkin("https://www.google.com", [genserver_pid: pid], name)
+      conn1 = Connections.checkin("https://www.google.com", [genserver_pid: pid], name)
+      conn2 = Connections.checkin("https://httpbin.org", [genserver_pid: pid], name)
+
+      %Connections{
+        conns: %{
+          "https:httpbin.org:443" => %Conn{
+            conn: ^conn2,
+            gun_state: :up,
+            waiting_pids: [],
+            conn_state: :active,
+            used_by: [{^self, _}]
+          },
+          "https:www.google.com:443" => %Conn{
+            conn: ^conn1,
+            gun_state: :up,
+            waiting_pids: [],
+            conn_state: :active,
+            used_by: [{^self, _}, {^self, _}]
+          }
+        },
+        opts: [max_connections: 2, timeout: 10]
+      } = Connections.get_state(name)
+
+      task =
+        Task.async(fn -> Connections.checkin("http://httpbin.org", [genserver_pid: pid], name) end)
+
+      task_pid = task.pid
+
+      :ok = Connections.checkout(conn1, self, name)
+
+      Process.sleep(1_000)
+
+      %Connections{
+        conns: %{
+          "https:httpbin.org:443" => %Conn{
+            conn: ^conn2,
+            gun_state: :up,
+            waiting_pids: [],
+            conn_state: :active,
+            used_by: [{^self, _}]
+          },
+          "https:www.google.com:443" => %Conn{
+            conn: ^conn1,
+            gun_state: :up,
+            waiting_pids: [],
+            conn_state: :active,
+            used_by: [{^self, _}]
+          }
+        },
+        queue: [{{^task_pid, _}, "http:httpbin.org:80", _, _}],
+        opts: [max_connections: 2, timeout: 10]
+      } = Connections.get_state(name)
+
+      :ok = Connections.checkout(conn1, self, name)
+
+      %Connections{
+        conns: %{
+          "https:httpbin.org:443" => %Conn{
+            conn: ^conn2,
+            gun_state: :up,
+            waiting_pids: [],
+            conn_state: :active,
+            used_by: [{^self, _}]
+          },
+          "https:www.google.com:443" => %Conn{
+            conn: ^conn1,
+            gun_state: :up,
+            waiting_pids: [],
+            conn_state: :idle,
+            used_by: []
+          }
+        },
+        queue: [{{^task_pid, _}, "http:httpbin.org:80", _, _}],
+        opts: [max_connections: 2, timeout: 10]
+      } = Connections.get_state(name)
+
+      :ok = Connections.process_queue(name)
+      conn = Task.await(task)
+
+      %Connections{
+        conns: %{
+          "https:httpbin.org:443" => %Conn{
+            conn: ^conn2,
+            gun_state: :up,
+            waiting_pids: [],
+            conn_state: :active,
+            used_by: [{^self, _}]
+          },
+          "http:httpbin.org:80" => %Conn{
+            conn: ^conn,
+            gun_state: :up,
+            waiting_pids: [],
+            conn_state: :active,
+            used_by: [{^task_pid, _}]
+          }
+        },
+        queue: [],
+        opts: [max_connections: 2, timeout: 10]
+      } = Connections.get_state(name)
+    end
   end
 
   describe "with proxy usage" do
     test "proxy as ip", %{name: name, pid: pid} do
       conn =
-        Connections.get_conn(
+        Connections.checkin(
           "http://proxy_string.com",
           [genserver_pid: pid, proxy: {{127, 0, 0, 1}, 8123}],
           name
@@ -363,7 +531,7 @@ defmodule Gun.ConnectionsTest do
         conns: %{
           "http:proxy_string.com:80" => %Conn{
             conn: ^conn,
-            state: :up,
+            gun_state: :up,
             waiting_pids: []
           }
         },
@@ -371,7 +539,7 @@ defmodule Gun.ConnectionsTest do
       } = Connections.get_state(name)
 
       reused_conn =
-        Connections.get_conn(
+        Connections.checkin(
           "http://proxy_string.com",
           [genserver_pid: pid, proxy: {{127, 0, 0, 1}, 8123}],
           name
@@ -382,7 +550,7 @@ defmodule Gun.ConnectionsTest do
 
     test "proxy as host", %{name: name, pid: pid} do
       conn =
-        Connections.get_conn(
+        Connections.checkin(
           "http://proxy_tuple_atom.com",
           [genserver_pid: pid, proxy: {'localhost', 9050}],
           name
@@ -392,7 +560,7 @@ defmodule Gun.ConnectionsTest do
         conns: %{
           "http:proxy_tuple_atom.com:80" => %Conn{
             conn: ^conn,
-            state: :up,
+            gun_state: :up,
             waiting_pids: []
           }
         },
@@ -400,7 +568,7 @@ defmodule Gun.ConnectionsTest do
       } = Connections.get_state(name)
 
       reused_conn =
-        Connections.get_conn(
+        Connections.checkin(
           "http://proxy_tuple_atom.com",
           [genserver_pid: pid, proxy: {'localhost', 9050}],
           name
@@ -411,7 +579,7 @@ defmodule Gun.ConnectionsTest do
 
     test "proxy as ip and ssl", %{name: name, pid: pid} do
       conn =
-        Connections.get_conn(
+        Connections.checkin(
           "https://proxy_string.com",
           [genserver_pid: pid, proxy: {{127, 0, 0, 1}, 8123}],
           name
@@ -421,7 +589,7 @@ defmodule Gun.ConnectionsTest do
         conns: %{
           "https:proxy_string.com:443" => %Conn{
             conn: ^conn,
-            state: :up,
+            gun_state: :up,
             waiting_pids: []
           }
         },
@@ -429,7 +597,7 @@ defmodule Gun.ConnectionsTest do
       } = Connections.get_state(name)
 
       reused_conn =
-        Connections.get_conn(
+        Connections.checkin(
           "https://proxy_string.com",
           [genserver_pid: pid, proxy: {{127, 0, 0, 1}, 8123}],
           name
@@ -440,7 +608,7 @@ defmodule Gun.ConnectionsTest do
 
     test "proxy as host and ssl", %{name: name, pid: pid} do
       conn =
-        Connections.get_conn(
+        Connections.checkin(
           "https://proxy_tuple_atom.com",
           [genserver_pid: pid, proxy: {'localhost', 9050}],
           name
@@ -450,7 +618,7 @@ defmodule Gun.ConnectionsTest do
         conns: %{
           "https:proxy_tuple_atom.com:443" => %Conn{
             conn: ^conn,
-            state: :up,
+            gun_state: :up,
             waiting_pids: []
           }
         },
@@ -458,7 +626,7 @@ defmodule Gun.ConnectionsTest do
       } = Connections.get_state(name)
 
       reused_conn =
-        Connections.get_conn(
+        Connections.checkin(
           "https://proxy_tuple_atom.com",
           [genserver_pid: pid, proxy: {'localhost', 9050}],
           name
diff --git a/test/http_test.exs b/test/http_test.exs
index 460f8f7c2..b88e3b605 100644
--- a/test/http_test.exs
+++ b/test/http_test.exs
@@ -71,11 +71,18 @@ defmodule Pleroma.HTTPTest do
 
     options = [adapter: [pool: :federation]]
 
-    assert {:ok, resp} =
-             Pleroma.HTTP.request(:get, "https://httpbin.org/user-agent", "", [], options)
+    assert {:ok, resp} = Pleroma.HTTP.get("https://httpbin.org/user-agent", [], options)
 
     adapter_opts = resp.opts[:adapter]
 
+    assert resp.status == 200
+
     assert adapter_opts[:url] == "https://httpbin.org/user-agent"
+    state = Pleroma.Gun.Connections.get_state(:federation)
+    conn = state.conns["https:httpbin.org:443"]
+
+    assert conn.conn_state == :idle
+    assert conn.used_by == []
+    assert state.queue == []
   end
 end