QQ: fix bug with discards using a consumer_id()

Fixes a pattern matching bug for discards that come in after a consumer
has been cancelled. Because the rabbit_fifo_client does not keep
the integer consumer key after cancellation, late acks, returns, and
discards use the full {CTag, Pid} consumer id version.

As this is a state machine change the machine version has been
increased to 5.

The same bug is present for the `modify` command also however as
AMQP does not allow late settlements we don't have to make this
fix conditional on the machine version as it cannot happen.

Author: kjnilsson

deps/rabbit/src/rabbit_fifo.erl

@@ -265,15 +265,27 @@ apply(Meta, #settle{msg_ids = MsgIds,
         _ ->
             {State, ok}
     end;
-apply(Meta, #discard{consumer_key = ConsumerKey,
-                     msg_ids = MsgIds},
+apply(#{machine_version := 4} = Meta,
+      #discard{consumer_key = ConsumerKey,
+               msg_ids = MsgIds},
       #?STATE{consumers = Consumers } = State0) ->
+    %% buggy version that would have not found the consumer if the ConsumerKey
+    %% was a consumer_id()
     case find_consumer(ConsumerKey, Consumers) of
         {ConsumerKey, #consumer{} = Con} ->
             discard(Meta, MsgIds, ConsumerKey, Con, true, #{}, State0);
         _ ->
             {State0, ok}
     end;
+apply(Meta, #discard{consumer_key = ConsumerKey,
+                     msg_ids = MsgIds},
+      #?STATE{consumers = Consumers } = State0) ->
+    case find_consumer(ConsumerKey, Consumers) of
+        {ActualConsumerKey, #consumer{} = Con} ->
+            discard(Meta, MsgIds, ActualConsumerKey, Con, true, #{}, State0);
+        _ ->
+            {State0, ok}
+    end;
 apply(Meta, #return{consumer_key = ConsumerKey,
                     msg_ids = MsgIds},
       #?STATE{consumers = Cons} = State) ->
@@ -291,13 +303,14 @@ apply(Meta, #modify{consumer_key = ConsumerKey,
                     msg_ids = MsgIds},
       #?STATE{consumers = Cons} = State) ->
     case find_consumer(ConsumerKey, Cons) of
-        {ConsumerKey, #consumer{checked_out = Checked}}
+        {ActualConsumerKey, #consumer{checked_out = Checked}}
           when Undel == false ->
-            return(Meta, ConsumerKey, MsgIds, DelFailed,
+            return(Meta, ActualConsumerKey, MsgIds, DelFailed,
                    Anns, Checked, [], State);
-        {ConsumerKey, #consumer{} = Con}
+        {ActualConsumerKey, #consumer{} = Con}
           when Undel == true ->
-            discard(Meta, MsgIds, ConsumerKey, Con, DelFailed, Anns, State);
+            discard(Meta, MsgIds, ActualConsumerKey,
+                    Con, DelFailed, Anns, State);
         _ ->
             {State, ok}
     end;
@@ -898,13 +911,14 @@ get_checked_out(CKey, From, To, #?STATE{consumers = Consumers}) ->
     end.
 
 -spec version() -> pos_integer().
-version() -> 4.
+version() -> 5.
 
 which_module(0) -> rabbit_fifo_v0;
 which_module(1) -> rabbit_fifo_v1;
 which_module(2) -> rabbit_fifo_v3;
 which_module(3) -> rabbit_fifo_v3;
-which_module(4) -> ?MODULE.
+which_module(4) -> ?MODULE;
+which_module(5) -> ?MODULE.
 
 -define(AUX, aux_v3).
 
@@ -2520,15 +2534,15 @@ make_checkout({_, _} = ConsumerId, Spec0, Meta) ->
 make_settle(ConsumerKey, MsgIds) when is_list(MsgIds) ->
     #settle{consumer_key = ConsumerKey, msg_ids = MsgIds}.
 
--spec make_return(consumer_id(), [msg_id()]) -> protocol().
+-spec make_return(consumer_key(), [msg_id()]) -> protocol().
 make_return(ConsumerKey, MsgIds) ->
     #return{consumer_key = ConsumerKey, msg_ids = MsgIds}.
 
 -spec is_return(protocol()) -> boolean().
 is_return(Command) ->
     is_record(Command, return).
 
--spec make_discard(consumer_id(), [msg_id()]) -> protocol().
+-spec make_discard(consumer_key(), [msg_id()]) -> protocol().
 make_discard(ConsumerKey, MsgIds) ->
     #discard{consumer_key = ConsumerKey, msg_ids = MsgIds}.
 
@@ -2701,7 +2715,10 @@ convert(Meta, 1, To, State) ->
 convert(Meta, 2, To, State) ->
     convert(Meta, 3, To, rabbit_fifo_v3:convert_v2_to_v3(State));
 convert(Meta, 3, To, State) ->
-    convert(Meta, 4, To, convert_v3_to_v4(Meta, State)).
+    convert(Meta, 4, To, convert_v3_to_v4(Meta, State));
+convert(Meta, 4, To, State) ->
+    %% no conversion needed, this version only includes a logic change
+    convert(Meta, 5, To, State).
 
 smallest_raft_index(#?STATE{messages = Messages,
                             ra_indexes = Indexes,

deps/rabbit/test/quorum_queue_SUITE.erl

@@ -174,6 +174,7 @@ all_tests() ->
      per_message_ttl_expiration_too_high,
      consumer_priorities,
      cancel_consumer_gh_3729,
+     cancel_consumer_gh_12424,
      cancel_and_consume_with_same_tag,
      validate_messages_on_queue,
      amqpl_headers,
@@ -3600,6 +3601,37 @@ cancel_consumer_gh_3729(Config) ->
 
     ok = rabbit_ct_client_helpers:close_channel(Ch).
 
+cancel_consumer_gh_12424(Config) ->
+    QQ = ?config(queue_name, Config),
+
+    Server = rabbit_ct_broker_helpers:get_node_config(Config, 0, nodename),
+    Ch = rabbit_ct_client_helpers:open_channel(Config, Server),
+
+    ExpectedDeclareRslt0 = #'queue.declare_ok'{queue = QQ, message_count = 0, consumer_count = 0},
+    DeclareRslt0 = declare(Ch, QQ, [{<<"x-queue-type">>, longstr, <<"quorum">>}]),
+    ?assertMatch(ExpectedDeclareRslt0, DeclareRslt0),
+
+    ok = publish(Ch, QQ),
+
+    ok = subscribe(Ch, QQ, false),
+
+    DeliveryTag = receive
+                      {#'basic.deliver'{delivery_tag = DT}, _} ->
+                          DT
+                  after 5000 ->
+                            flush(100),
+                            ct:fail("basic.deliver timeout")
+                  end,
+
+    ok = cancel(Ch),
+
+    R = #'basic.reject'{delivery_tag = DeliveryTag, requeue = false},
+    ok = amqp_channel:cast(Ch, R),
+    wait_for_messages(Config, [[QQ, <<"0">>, <<"0">>, <<"0">>]]),
+
+    ok.
+
+    %% Test the scenario where a message is published to a quorum queue
 cancel_and_consume_with_same_tag(Config) ->
     %% https://github.com/rabbitmq/rabbitmq-server/issues/5927
     QQ = ?config(queue_name, Config),

deps/rabbit/test/rabbit_fifo_SUITE.erl

@@ -42,12 +42,12 @@ groups() ->
     ].
 
 init_per_group(tests, Config) ->
-    [{machine_version, 4} | Config];
+    [{machine_version, 5} | Config];
 init_per_group(machine_version_conversion, Config) ->
     Config.
 
 init_per_testcase(_Testcase, Config) ->
-    FF = ?config(machine_version, Config) == 4,
+    FF = ?config(machine_version, Config) == 5,
     ok = meck:new(rabbit_feature_flags, [passthrough]),
     meck:expect(rabbit_feature_flags, is_enabled, fun (_) -> FF end),
     Config.
@@ -804,6 +804,19 @@ discarded_message_with_dead_letter_handler_emits_log_effect_test(Config) ->
 
     ok.
 
+discard_after_cancel_test(Config) ->
+    Cid = {?FUNCTION_NAME_B, self()},
+    {State0, _} = enq(Config, 1, 1, first, test_init(test)),
+    {State1, #{key := _CKey,
+               next_msg_id := MsgId}, _Effects1} =
+        checkout(Config, ?LINE, Cid, 10, State0),
+    {State2, _, _} = apply(meta(Config, ?LINE),
+                           rabbit_fifo:make_checkout(Cid, cancel, #{}), State1),
+    {State, _, _} = apply(meta(Config, ?LINE),
+                          rabbit_fifo:make_discard(Cid, [MsgId]), State2),
+    ct:pal("State ~p", [State]),
+    ok.
+
 enqueued_msg_with_delivery_count_test(Config) ->
     State00 = init(#{name => test,
                      queue_resource => rabbit_misc:r(<<"/">>, queue, <<"test">>),
@@ -2786,45 +2799,9 @@ modify_test(Config) ->
 
     ok.
 
-ttb_test(Config) ->
-    S0 = init(#{name => ?FUNCTION_NAME,
-                queue_resource =>
-                    rabbit_misc:r("/", queue, ?FUNCTION_NAME_B)}),
-
-
-    S1 = do_n(5_000_000,
-           fun (N, Acc) ->
-                   I = (5_000_000 - N),
-                   element(1, enq(Config, I, I, ?FUNCTION_NAME_B, Acc))
-           end, S0),
-
-
-
-    {T1, _Res} = timer:tc(fun () ->
-                               do_n(100, fun (_, S) ->
-                                               term_to_binary(S),
-                                               S1 end, S1)
-                       end),
-    ct:pal("T1 took ~bus", [T1]),
-
-
-    {T2, _} = timer:tc(fun () ->
-                               do_n(100, fun (_, S) -> term_to_iovec(S), S1 end, S1)
-                       end),
-    ct:pal("T2 took ~bus", [T2]),
-
-    ok.
-
 %% Utility
 %%
 
-do_n(0, _, A) ->
-    A;
-do_n(N, Fun, A0) ->
-    A = Fun(N, A0),
-    do_n(N-1, Fun, A).
-
-
 init(Conf) -> rabbit_fifo:init(Conf).
 make_register_enqueuer(Pid) -> rabbit_fifo:make_register_enqueuer(Pid).
 apply(Meta, Entry, State) -> rabbit_fifo:apply(Meta, Entry, State).