Revert "feat: concurrent connections limiter (#696)" (#750)

This reverts commit de2f305.

apps/api_accounts/lib/api_accounts/key.ex

@@ -18,8 +18,6 @@ defmodule ApiAccounts.Key do
     field(:requested_date, :datetime)
     field(:approved, :boolean, default: false)
     field(:locked, :boolean, default: false)
-    field(:static_concurrent_limit, :integer)
-    field(:streaming_concurrent_limit, :integer)
     field(:daily_limit, :integer)
     field(:rate_request_pending, :boolean, default: false)
     field(:api_version, :string)
@@ -30,7 +28,7 @@ defmodule ApiAccounts.Key do
   @doc false
   def changeset(struct, params \\ %{}) do
     fields = ~w(
-      created requested_date approved locked static_concurrent_limit streaming_concurrent_limit daily_limit rate_request_pending api_version description allowed_domains
+      created requested_date approved locked daily_limit rate_request_pending api_version description allowed_domains
     )a
     cast(struct, params, fields)
   end

apps/api_web/config/config.exs

@@ -28,23 +28,7 @@ config :api_web, :rate_limiter,
   limiter: ApiWeb.RateLimiter.ETS,
   max_anon_per_interval: 5_000,
   max_registered_per_interval: 100_000,
-  wait_time_ms: 0,
-  connection_opts: [
-    coder: Memcache.Coder.JSON
-  ]
-
-config :api_web, :rate_limiter_concurrent,
-  enabled: false,
-  memcache: false,
-  log_statistics: true,
-  limit_users: false,
-  # How many seconds tolerated when calculating whether a connection is still open
-  # 45 - 30 (see ApiWeb.EventStream.Initialize's timeout value) gives us a buffer of 15 seconds:
-  heartbeat_tolerance: 45,
-  # Default concurrent connections - these can be overridden on a per-key basis in the admin UI:
-  max_anon_static: 5,
-  max_registered_streaming: 10,
-  max_registered_static: 20
+  wait_time_ms: 0
 
 config :api_web, ApiWeb.Plugs.ModifiedSinceHandler, check_caller: false
 

apps/api_web/config/dev.exs

@@ -28,5 +28,3 @@ config :logger, :console, format: "[$level] $message\n", level: :debug
 # Do not configure such in production as keeping
 # and calculating stacktraces is usually expensive.
 config :phoenix, :stacktrace_depth, 20
-
-config :api_web, :rate_limiter_concurrent, enabled: false, memcache: false

apps/api_web/config/prod.exs

@@ -54,10 +54,6 @@ config :ehmon, :report_mf, {:ehmon, :info_report}
 
 config :logster, :filter_parameters, ~w(password password_confirm)
 
-config :api_web, :rate_limiter_concurrent,
-  enabled: true,
-  memcache: true
-
 config :api_web, :rate_limiter,
   clear_interval: 60_000,
   max_anon_per_interval: 20,

apps/api_web/config/test.exs

@@ -26,7 +26,3 @@ config :recaptcha,
 
 # Print only warnings and errors during test
 config :logger, level: :warn
-
-config :api_web, :rate_limiter_concurrent,
-  enabled: false,
-  memcache: false

apps/api_web/lib/api_web.ex

@@ -15,9 +15,7 @@ defmodule ApiWeb do
     # no cover
     children = [
       # Start the endpoint when the application starts
-      ApiWeb.RateLimiter.Memcache.Supervisor,
       ApiWeb.RateLimiter,
-      ApiWeb.RateLimiter.RateLimiterConcurrent,
       {RequestTrack, [name: ApiWeb.RequestTrack]},
       ApiWeb.EventStream.Supervisor,
       ApiWeb.Endpoint,

apps/api_web/lib/api_web/api_controller_helpers.ex

@@ -27,7 +27,6 @@ defmodule ApiWeb.ApiControllerHelpers do
       plug(:split_include)
       plug(ApiWeb.Plugs.ModifiedSinceHandler, caller: __MODULE__)
       plug(ApiWeb.Plugs.RateLimiter)
-      plug(ApiWeb.Plugs.RateLimiterConcurrent)
 
       def index(conn, params), do: ApiControllerHelpers.index(__MODULE__, conn, params)
 

apps/api_web/lib/api_web/event_stream.ex

@@ -7,7 +7,6 @@ defmodule ApiWeb.EventStream do
   import Plug.Conn
   alias __MODULE__.Supervisor
   alias ApiWeb.Plugs.CheckForShutdown
-  alias ApiWeb.RateLimiter.RateLimiterConcurrent
   require Logger
 
   @enforce_keys [:conn, :pid, :timeout]
@@ -54,13 +53,6 @@ defmodule ApiWeb.EventStream do
 
   @spec hibernate_loop(state) :: Plug.Conn.t()
   def hibernate_loop(state) do
-    if Map.has_key?(state.conn.assigns, :api_user) do
-      # Update the concurrent rate limit cache to ensure any flushing doesn't impact long-running connections:
-      RateLimiterConcurrent.add_lock(state.conn.assigns.api_user, self(), true)
-    else
-      Logger.warn("#{__MODULE__} missing_api_user - cannot rate limit!")
-    end
-
     case receive_result(state) do
       {:continue, state} ->
         :proc_lib.hibernate(__MODULE__, :hibernate_loop, [state])
@@ -138,13 +130,6 @@ defmodule ApiWeb.EventStream do
   end
 
   defp unsubscribe(state) do
-    if Map.has_key?(state.conn.assigns, :api_user) do
-      # clean up our concurrent connections lock:
-      RateLimiterConcurrent.remove_lock(state.conn.assigns.api_user, self(), true)
-    else
-      Logger.warn("#{__MODULE__} missing_api_user - cannot rate limit!")
-    end
-
     # consume any extra messages received after unsubscribing
     receive do
       {:events, _} ->

apps/api_web/lib/api_web/rate_limiter/memcache.ex

@@ -4,16 +4,16 @@ defmodule ApiWeb.RateLimiter.Memcache do
   """
   @behaviour ApiWeb.RateLimiter.Limiter
   alias ApiWeb.RateLimiter.Memcache.Supervisor
-  use GenServer
 
   @impl ApiWeb.RateLimiter.Limiter
   def start_link(opts) do
-    GenServer.start_link(__MODULE__, opts, name: __MODULE__)
-  end
+    clear_interval_ms = Keyword.fetch!(opts, :clear_interval)
+    clear_interval = div(clear_interval_ms, 1000)
+
+    connection_opts =
+      [ttl: clear_interval * 2] ++ ApiWeb.config(RateLimiter.Memcache, :connection_opts)
 
-  @impl true
-  def init(opts) do
-    {:ok, opts}
+    Supervisor.start_link(connection_opts)
   end
 
   @impl ApiWeb.RateLimiter.Limiter

apps/api_web/lib/api_web/rate_limiter/memcache/supervisor.ex

@@ -4,30 +4,17 @@ defmodule ApiWeb.RateLimiter.Memcache.Supervisor do
   """
   @worker_count 5
   @registry_name __MODULE__.Registry
-  @rate_limit_config Application.compile_env!(:api_web, :rate_limiter)
-
-  use Agent
-
-  def start_link(_) do
-    clear_interval_ms = Keyword.fetch!(@rate_limit_config, :clear_interval)
-    clear_interval = div(clear_interval_ms, 1000)
-    connection_opts_config = Keyword.fetch!(@rate_limit_config, :connection_opts)
-    connection_opts = [ttl: clear_interval * 2] ++ connection_opts_config
 
+  def start_link(connection_opts) do
     registry = {Registry, keys: :unique, name: @registry_name}
 
-    children =
-      if memcache_required?() do
-        workers =
-          for i <- 1..@worker_count do
-            Supervisor.child_spec({Memcache, [connection_opts, [name: worker_name(i)]]}, id: i)
-          end
-
-        [registry | workers]
-      else
-        [registry]
+    workers =
+      for i <- 1..@worker_count do
+        Supervisor.child_spec({Memcache, [connection_opts, [name: worker_name(i)]]}, id: i)
       end
 
+    children = [registry | workers]
+
     Supervisor.start_link(
       children,
       strategy: :rest_for_one,
@@ -44,13 +31,7 @@ defmodule ApiWeb.RateLimiter.Memcache.Supervisor do
     {:via, Registry, {@registry_name, index}}
   end
 
-  defp memcache_required? do
-    (ApiWeb.RateLimiter.RateLimiterConcurrent.enabled?() and
-       ApiWeb.RateLimiter.RateLimiterConcurrent.memcache?()) or
-      ApiWeb.config(:rate_limiter, :limiter) == ApiWeb.RateLimiter.Memcache
-  end
-
-  def random_child do
+  defp random_child do
     worker_name(:rand.uniform(@worker_count))
   end
 end