feat(ds): Make session poll interval configurable

apps/emqx/src/emqx_persistent_message.erl

@@ -58,7 +58,7 @@ storage_backend() ->
 %% `emqx_persistent_session_ds':
 -spec force_ds() -> boolean().
 force_ds() ->
-    emqx_config:get([session_persistence, force_ds]).
+    emqx_config:get([session_persistence, force_persistence]).
 
 storage_backend(#{
     builtin := #{enable := true, n_shards := NShards, replication_factor := ReplicationFactor}

apps/emqx/src/emqx_persistent_session_ds.erl

@@ -349,11 +349,11 @@ handle_timeout(
     Session = #{id := Id, inflight := Inflight0, receive_maximum := ReceiveMaximum}
 ) ->
     {Publishes, Inflight} = emqx_persistent_message_ds_replayer:poll(Id, Inflight0, ReceiveMaximum),
-    %% TODO: make these values configurable:
+    IdlePollInterval = emqx_config:get([session_persistence, idle_poll_interval]),
     Timeout =
         case Publishes of
             [] ->
-                100;
+                IdlePollInterval;
             [_ | _] ->
                 0
         end,

apps/emqx/src/emqx_schema.erl

@@ -1772,6 +1772,23 @@ fields("session_persistence") ->
                         <<"builtin">> => #{}
                     }
                 }
+            )},
+        {"idle_poll_interval",
+            sc(
+                duration(),
+                #{
+                    default => 100,
+                    desc => ?DESC(session_ds_idle_poll_interval)
+                }
+            )},
+        {"force_persistence",
+            sc(
+                boolean(),
+                #{
+                    default => false,
+                    %% Only for testing, shall remain hidden
+                    importance => ?IMPORTANCE_HIDDEN
+                }
             )}
     ];
 fields("session_storage_backend") ->