feat: support node.global_gc_interval=disabled

apps/emqx_conf/i18n/emqx_conf_schema.conf

@@ -471,8 +471,8 @@ significant: later configuration files override the previous ones.
 
   node_global_gc_interval {
     desc {
-      en: """Periodic garbage collection interval."""
-      zh: """系统调优参数，设置节点运行多久强制进行一次全局垃圾回收。"""
+      en: """Periodic garbage collection interval. Set to <code>disabled</code> if not enabled."""
+      zh: """系统调优参数，设置节点运行多久强制进行一次全局垃圾回收。禁用设置为 <code>disabled</code>。"""
     }
     label {
       en: "Global GC Interval"

apps/emqx_conf/src/emqx_conf_schema.erl

@@ -468,7 +468,7 @@ fields("node") ->
             )},
         {"global_gc_interval",
             sc(
-                emqx_schema:duration(),
+                hoconsc:union([disabled, emqx_schema:duration()]),
                 #{
                     mapping => "emqx_machine.global_gc_interval",
                     default => "15m",

apps/emqx_conf/test/emqx_global_gc_SUITE.erl

@@ -29,4 +29,8 @@ t_run_gc(_) ->
     ok = timer:sleep(1500),
     {ok, MilliSecs} = emqx_global_gc:run(),
     ct:print("Global GC: ~w(ms)~n", [MilliSecs]),
-    emqx_global_gc:stop().
+    emqx_global_gc:stop(),
+    ok = emqx_config:put([node, global_gc_interval], disabled),
+    {ok, Pid} = emqx_global_gc:start_link(),
+    ?assertMatch(#{timer := undefined}, sys:get_state(Pid)),
+    ok.

apps/emqx_machine/src/emqx_global_gc.erl

@@ -82,10 +82,10 @@ code_change(_OldVsn, State, _Extra) ->
 %%--------------------------------------------------------------------
 
 ensure_timer(State) ->
-    case application:get_env(emqx_machine, global_gc_interval) of
-        undefined ->
+    case application:get_env(emqx_machine, global_gc_interval, disabled) of
+        disabled ->
             State;
-        {ok, Interval} ->
+        Interval when is_integer(Interval) ->
             TRef = emqx_misc:start_timer(Interval, run),
             State#{timer := TRef}
     end.

changes/v5.0.11-en.md

@@ -23,6 +23,8 @@
 
 - Keep MQTT v5 User-Property pairs from bridge ingested MQTT messsages to bridge target [#9398](https://github.com/emqx/emqx/pull/9398).
 
+- Disable global garbage collection by `node.global_gc_interval = disabled` [#9418](https://github.com/emqx/emqx/pull/9418)。
+
 ## Bug fixes
 
 - Fix `ssl.existingName` option of  helm chart not working [#9307](https://github.com/emqx/emqx/issues/9307).

changes/v5.0.11-zh.md

@@ -21,6 +21,8 @@
 
 - 为桥接收到的 MQTT v5 消息再转发时保留 User-Property 列表 [#9398](https://github.com/emqx/emqx/pull/9398)。
 
+- 通过 `node.global_gc_interval = disabled` 来禁用全局垃圾回收 [#9418](https://github.com/emqx/emqx/pull/9418)。
+
 ## 修复
 
 - 修复 helm chart 的 `ssl.existingName` 选项不起作用 [#9307](https://github.com/emqx/emqx/issues/9307)。