Apply Ra commands on different nodes

This commit adds a property test that applies the same Ra commands in
the same order on two different Erlang nodes. The state in which both nodes end
up should be exactly the same.

Ideally, the two nodes should run different OTP versions because this
way we could test for any non-determinism across OTP versions.

However, for now, having a test with both nodes having the same OTP
verison is good enough because running this test with rabbit_fifo
machine version 5 fails while machine version 6 succeeds.

This reveales another interesting: The default "undefined" map order can
even be different using different Erlang nodes with the **same** OTP
version.

Author: ansd

deps/rabbit/test/rabbit_fifo_prop_SUITE.erl

@@ -3,9 +3,6 @@
 -compile(nowarn_export_all).
 -compile(export_all).
 
--export([
-         ]).
-
 -include_lib("proper/include/proper.hrl").
 -include_lib("common_test/include/ct.hrl").
 -include_lib("eunit/include/eunit.hrl").
@@ -87,7 +84,8 @@ all_tests() ->
      dlx_07,
      dlx_08,
      dlx_09,
-     single_active_ordering_02
+     single_active_ordering_02,
+     different_nodes
     ].
 
 groups() ->
@@ -1095,6 +1093,39 @@ single_active_ordering_03(_Config) ->
             false
     end.
 
+%% Test that running the state machine commands on different Erlang nodes
+%% end up in exactly the same state.
+different_nodes(Config) ->
+    Config1 = rabbit_ct_helpers:run_setup_steps(
+                Config,
+                rabbit_ct_broker_helpers:setup_steps()),
+
+    Size = 400,
+    run_proper(
+      fun () ->
+              ?FORALL({Length, Bytes, DeliveryLimit, SingleActive},
+                      frequency([{5, {undefined, undefined, undefined, false}},
+                                 {5, {oneof([range(1, 10), undefined]),
+                                      oneof([range(1, 1000), undefined]),
+                                      oneof([range(1, 3), undefined]),
+                                      oneof([true, false])
+                                     }}]),
+                      begin
+                          Conf = config(?FUNCTION_NAME,
+                                        Length,
+                                        Bytes,
+                                        SingleActive,
+                                        DeliveryLimit),
+                          ?FORALL(O, ?LET(Ops, log_gen_different_nodes(Size), expand(Ops, Conf)),
+                                  collect({log_size, length(O)},
+                                          different_nodes_prop(Config1, Conf, O)))
+                      end)
+      end, [], Size),
+
+    rabbit_ct_helpers:run_teardown_steps(
+      Config1,
+      rabbit_ct_broker_helpers:teardown_steps()).
+
 max_length(_Config) ->
     %% tests that max length is never transgressed
     Size = 1000,
@@ -1454,6 +1485,19 @@ single_active_prop(Conf0, Commands, ValidateOrder) ->
             false
     end.
 
+different_nodes_prop(Config, Conf0, Commands) ->
+    Conf = Conf0#{release_cursor_interval => 100},
+    Indexes = lists:seq(1, length(Commands)),
+    Entries = lists:zip(Indexes, Commands),
+    InitState = test_init(Conf),
+    Fun = fun(_) -> true end,
+    Vsn = 6,
+
+    {State0, _Effs0} = run_log(InitState, Entries, Fun, Vsn),
+    {State1, _Effs1} = rabbit_ct_broker_helpers:rpc(Config, ?MODULE, run_log,
+                                                    [InitState, Entries, Fun, Vsn]),
+    State0 =:= State1.
+
 messages_total_prop(Conf0, Commands) ->
     Conf = Conf0#{release_cursor_interval => 100},
     Indexes = lists:seq(1, length(Commands)),
@@ -1797,6 +1841,29 @@ log_gen_without_checkout_cancel(Size) ->
                           {1, purge}
                          ]))))).
 
+log_gen_different_nodes(Size) ->
+    Nodes = [node(),
+             fakenode@fake,
+             fakenode@fake2
+            ],
+    ?LET(EPids, vector(4, pid_gen(Nodes)),
+         ?LET(CPids, vector(4, pid_gen(Nodes)),
+              resize(Size,
+                     list(
+                       frequency(
+                         [{10, enqueue_gen(oneof(EPids))},
+                          {20, {input_event,
+                                frequency([{10, settle},
+                                           {2, return},
+                                           {2, discard},
+                                           {2, requeue}])}},
+                          {8, checkout_gen(oneof(CPids))},
+                          {2, checkout_cancel_gen(oneof(CPids))},
+                          {6, down_gen(oneof(EPids ++ CPids))},
+                          {6, nodeup_gen(Nodes)},
+                          {1, purge}
+                         ]))))).
+
 monotonic_gen() ->
     ?LET(_, integer(), erlang:unique_integer([positive, monotonic])).