Merge pull request #9757 from rabbitmq/improve-are_cmqs_user-callback

rabbit_deprecated_features: Improve reliability of the `classic_queue_mirroring` callback

Author: dumbbell

deps/rabbit/src/rabbit_mirror_queue_misc.erl

@@ -951,7 +951,7 @@ are_cmqs_permitted() ->
 are_cmqs_used(_) ->
     case rabbit_khepri:get_feature_state() of
         enabled ->
-            are_cmqs_used1();
+            false;
         _ ->
             %% If we are using Mnesia, we want to check manually if the table
             %% exists first. Otherwise it can conflict with the way
@@ -962,8 +962,16 @@ are_cmqs_used(_) ->
             RuntimeParamsReady = lists:member(
                                    rabbit_runtime_parameters, AllTables),
             case RuntimeParamsReady of
-                true  -> are_cmqs_used1();
-                false -> false
+                true ->
+                    %% We also wait for the table because it could exist but
+                    %% may be unavailable. For instance, Mnesia needs another
+                    %% replica on another node before it considers it to be
+                    %% available.
+                    rabbit_table:wait(
+                      [rabbit_runtime_parameters], _Retry = true),
+                    are_cmqs_used1();
+                false ->
+                    false
             end
     end.