Add src/hk_browser_sup.erl

src/hk_browser_sup.erl

@@ -0,0 +1,37 @@
+%%%-------------------------------------------------------------------
+%%% @doc HK-BROWSER plane supervisor: the session registry and the
+%%% session pool are two independent children (not one
+%%% `simple_one_for_one' supervisor mixing a singleton with dynamic
+%%% children, which OTP does not allow) so that neither can take the
+%%% other down. `one_for_one': the registry restarting (it holds no
+%%% durable state other than in-memory pid mappings, which are
+%%% rebuilt as sessions re-register) does not restart live sessions,
+%%% and a session-pool restart storm does not restart the registry.
+%%% @end
+%%%-------------------------------------------------------------------
+-module(hk_browser_sup).
+-behaviour(supervisor).
+
+-export([start_link/0, init/1]).
+
+start_link() ->
+    hk_sup_util:start_link_retry(
+        fun() -> supervisor:start_link({local, ?MODULE}, ?MODULE, []) end).
+
+init([]) ->
+    SupFlags = #{strategy => one_for_one, intensity => 10, period => 10},
+    Children = [
+        #{id => hk_browser_registry,
+          start => {hk_browser_registry, start_link, []},
+          restart => permanent,
+          shutdown => 5000,
+          type => worker,
+          modules => [hk_browser_registry]},
+        #{id => hk_browser_session_sup,
+          start => {hk_browser_session_sup, start_link, []},
+          restart => permanent,
+          shutdown => infinity,
+          type => supervisor,
+          modules => [hk_browser_session_sup]}
+    ],
+    {ok, {SupFlags, Children}}.