Merge pull request #12740 from rabbitmq/mergify/bp/v4.0.x/pr-12727

By @Ayanda-D: Ensure only alive leaders and followers when fetching QQ replica states (backport #12727)

Author: michaelklishin

deps/rabbit/src/rabbit_quorum_queue.erl

@@ -441,19 +441,28 @@ become_leader0(QName, Name) ->
 -spec all_replica_states() -> {node(), #{atom() => atom()}}.
 all_replica_states() ->
     Rows0 = ets:tab2list(ra_state),
-    Rows = lists:map(fun
-                         ({K, follower, promotable}) ->
-                             {K, promotable};
-                         ({K, follower, non_voter}) ->
-                             {K, non_voter};
-                         ({K, S, _}) ->
-                             %% voter or unknown
-                             {K, S};
-                         (T) ->
-                             T
-                     end, Rows0),
+    Rows = lists:filtermap(
+                    fun
+                        (T = {K, _, _}) ->
+                            case whereis(K) of
+                                undefined ->
+                                    false;
+                                P when is_pid(P) ->
+                                    {true, to_replica_state(T)}
+                            end;
+                        (_T) ->
+                            false
+                    end, Rows0),
     {node(), maps:from_list(Rows)}.
 
+to_replica_state({K, follower, promotable}) ->
+    {K, promotable};
+to_replica_state({K, follower, non_voter}) ->
+    {K, non_voter};
+to_replica_state({K, S, _}) ->
+    %% voter or unknown
+    {K, S}.
+
 -spec list_with_minimum_quorum() -> [amqqueue:amqqueue()].
 list_with_minimum_quorum() ->
     Queues = rabbit_amqqueue:list_local_quorum_queues(),

deps/rabbit/test/quorum_queue_SUITE.erl

@@ -97,7 +97,8 @@ groups() ->
                                             force_all_queues_shrink_member_to_current_member,
                                             force_vhost_queues_shrink_member_to_current_member,
                                             policy_repair,
-                                            gh_12635
+                                            gh_12635,
+                                            replica_states
                                            ]
                        ++ all_tests()},
                       {cluster_size_5, [], [start_queue,
@@ -4355,6 +4356,54 @@ requeue_multiple_false(Config) ->
     ?assertEqual(#'queue.delete_ok'{message_count = 0},
                  amqp_channel:call(Ch, #'queue.delete'{queue = QQ})).
 
+replica_states(Config) ->
+    [Server | _] = Servers = rabbit_ct_broker_helpers:get_node_configs(Config, nodename),
+    Ch = rabbit_ct_client_helpers:open_channel(Config, Server),
+
+    [?assertEqual({'queue.declare_ok', Q, 0, 0},
+                 declare(Ch, Q, [{<<"x-queue-type">>, longstr, <<"quorum">>}]))
+        || Q <- [<<"Q1">>, <<"Q2">>, <<"Q3">>]],
+
+    Qs = rabbit_ct_broker_helpers:rpc(Config, 0, rabbit_amqqueue, list, []),
+
+    [Q1_ClusterName, Q2_ClusterName, Q3_ClusterName] =
+        [begin
+            {ClusterName, _} = amqqueue:get_pid(Q),
+            ClusterName
+         end
+            || Q <- Qs, amqqueue:get_type(Q) == rabbit_quorum_queue],
+
+    Result1 = rabbit_misc:append_rpc_all_nodes(Servers, rabbit_quorum_queue, all_replica_states, []),
+    ct:pal("all replica states: ~tp", [Result1]),
+
+    lists:map(fun({_Node, ReplicaStates}) ->
+                ?assert(maps:is_key(Q1_ClusterName, ReplicaStates)),
+                ?assert(maps:is_key(Q2_ClusterName, ReplicaStates)),
+                ?assert(maps:is_key(Q3_ClusterName, ReplicaStates))
+             end, Result1),
+
+    %% Unregister a few queues (same outcome of 'noproc')
+    rabbit_ct_broker_helpers:rpc(Config, Server, erlang, unregister, [Q2_ClusterName]),
+    rabbit_ct_broker_helpers:rpc(Config, Server, erlang, unregister, [Q3_ClusterName]),
+
+    ?assert(undefined == rabbit_ct_broker_helpers:rpc(Config, Server, erlang, whereis, [Q2_ClusterName])),
+    ?assert(undefined == rabbit_ct_broker_helpers:rpc(Config, Server, erlang, whereis, [Q3_ClusterName])),
+
+    Result2 = rabbit_misc:append_rpc_all_nodes(Servers, rabbit_quorum_queue, all_replica_states, []),
+    ct:pal("replica states with a node missing Q1 and Q2: ~tp", [Result2]),
+
+    lists:map(fun({Node, ReplicaStates}) ->
+                if Node == Server ->
+                    ?assert(maps:is_key(Q1_ClusterName, ReplicaStates)),
+                    ?assertNot(maps:is_key(Q2_ClusterName, ReplicaStates)),
+                    ?assertNot(maps:is_key(Q3_ClusterName, ReplicaStates));
+                true ->
+                    ?assert(maps:is_key(Q1_ClusterName, ReplicaStates)),
+                    ?assert(maps:is_key(Q2_ClusterName, ReplicaStates)),
+                    ?assert(maps:is_key(Q3_ClusterName, ReplicaStates))
+                end
+             end, Result2).
+
 %%----------------------------------------------------------------------------
 
 same_elements(L1, L2)

deps/rabbit/test/unit_quorum_queue_SUITE.erl

@@ -7,7 +7,7 @@
 
 all() ->
     [
-     all_replica_states_includes_nonvoters,
+     all_replica_states_includes_alive_nonvoters,
      filter_nonvoters,
      filter_quorum_critical_accounts_nonvoters,
      ra_machine_conf_delivery_limit
@@ -97,27 +97,29 @@ filter_nonvoters(_Config) ->
     [Q4] = rabbit_quorum_queue:filter_promotable(Qs, Ss),
     ok.
 
-all_replica_states_includes_nonvoters(_Config) ->
+all_replica_states_includes_alive_nonvoters(_Config) ->
     ets:new(ra_state, [named_table, public, {write_concurrency, true}]),
+    QPids = start_qprocs(_AliveQs = [q1, q2, q3, q4]),
     ets:insert(ra_state, [
                           {q1, leader, voter},
                           {q2, follower, voter},
                           {q3, follower, promotable},
                           {q4, init, unknown},
-                          %% pre ra-2.7.0
-                          {q5, leader},
-                          {q6, follower}
+                          %% queues in ra_state but not alive
+                          {q5, leader, voter},
+                          {q6, follower, noproc}
                          ]),
     {_, #{
           q1 := leader,
           q2 := follower,
           q3 := promotable,
-          q4 := init,
-          q5 := leader,
-          q6 := follower
-         }} = rabbit_quorum_queue:all_replica_states(),
+          q4 := init
+         } = ReplicaStates} = rabbit_quorum_queue:all_replica_states(),
+    ?assertNot(maps:is_key(q5, ReplicaStates)),
+    ?assertNot(maps:is_key(q6, ReplicaStates)),
 
     true = ets:delete(ra_state),
+    _ = stop_qprocs(QPids),
     ok.
 
 make_ra_machine_conf(Q0, Arg, Pol, OpPol) ->
@@ -128,3 +130,13 @@ make_ra_machine_conf(Q0, Arg, Pol, OpPol) ->
                                           {definition, [{<<"delivery-limit">>,OpPol}]}]),
     rabbit_quorum_queue:ra_machine_config(Q).
 
+start_qprocs(Qs) ->
+    [begin
+        QPid = spawn(fun() -> receive done -> ok end end),
+        erlang:register(Q, QPid),
+        QPid
+     end || Q <- Qs].
+
+stop_qprocs(Pids) ->
+    [erlang:send(P, done)|| P <- Pids].
+