QQ/Streams: Ensure open file handles are closed when a queue is deleted.

If a stream or quorum queue has opened a file to read a consumer message
and the queue is deleted the file handle reference is lost and kept
open until the end of the channel lifetime.

Author: kjnilsson

deps/rabbit/src/rabbit_fifo_client.erl

@@ -14,6 +14,7 @@
 -export([
          init/1,
          init/2,
+         close/1,
          checkout/4,
          cancel_checkout/3,
          enqueue/3,
@@ -755,6 +756,13 @@ handle_ra_event(QName, Leader, close_cached_segments,
 handle_ra_event(_QName, _Leader, {machine, eol}, State) ->
     {eol, [{unblock, cluster_name(State)}]}.
 
+-spec close(rabbit_fifo_client:state()) -> ok.
+close(#state{cached_segments = undefined}) ->
+    ok;
+close(#state{cached_segments = {_, _, Flru}}) ->
+    _ = ra_flru:evict_all(Flru),
+    ok.
+
 %% @doc Attempts to enqueue a message using cast semantics. This provides no
 %% guarantees or retries if the message fails to achieve consensus or if the
 %% servers sent to happens not to be available. If the message is sent to a

deps/rabbit/src/rabbit_queue_type.erl

@@ -407,7 +407,9 @@ remove(QRef, #?STATE{ctxs = Ctxs0} = State) ->
     case maps:take(QRef, Ctxs0) of
         error ->
             State;
-        {_, Ctxs} ->
+        {#ctx{module = Mod,
+              state = S}, Ctxs} ->
+            ok = Mod:close(S),
             State#?STATE{ctxs = Ctxs}
     end.
 
@@ -495,11 +497,10 @@ init() ->
 
 -spec close(state()) -> ok.
 close(#?STATE{ctxs = Contexts}) ->
-    maps:foreach(
-      fun (_, #ctx{module = Mod,
-                   state = S}) ->
-              ok = Mod:close(S)
-      end, Contexts).
+    maps:foreach(fun (_, #ctx{module = Mod,
+                              state = S}) ->
+                         ok = Mod:close(S)
+                 end, Contexts).
 
 -spec new(amqqueue:amqqueue(), state()) -> state().
 new(Q, State) when ?is_amqqueue(Q) ->

deps/rabbit/src/rabbit_quorum_queue.erl

@@ -159,7 +159,6 @@
 -define(RPC_TIMEOUT, 1000).
 -define(START_CLUSTER_TIMEOUT, 5000).
 -define(START_CLUSTER_RPC_TIMEOUT, 60_000). %% needs to be longer than START_CLUSTER_TIMEOUT
--define(FORCE_CHECKPOINT_RPC_TIMEOUT, 15_000).
 -define(TICK_INTERVAL, 5000). %% the ra server tick time
 -define(DELETE_TIMEOUT, 5000).
 -define(MEMBER_CHANGE_TIMEOUT, 20_000).
@@ -230,8 +229,8 @@ init(Q) when ?is_amqqueue(Q) ->
     {ok, rabbit_fifo_client:init(Servers, SoftLimit)}.
 
 -spec close(rabbit_fifo_client:state()) -> ok.
-close(_State) ->
-    ok.
+close(State) ->
+    rabbit_fifo_client:close(State).
 
 -spec update(amqqueue:amqqueue(), rabbit_fifo_client:state()) ->
     rabbit_fifo_client:state().

deps/rabbit/test/quorum_queue_SUITE.erl

@@ -197,6 +197,7 @@ all_tests() ->
      requeue_multiple_true,
      requeue_multiple_false,
      subscribe_from_each,
+     dont_leak_file_handles,
      leader_health_check
     ].
 
@@ -1647,6 +1648,54 @@ subscribe_from_each(Config) ->
 
     ok.
 
+dont_leak_file_handles(Config) ->
+
+    [Server0 | _] = Servers = rabbit_ct_broker_helpers:get_node_configs(Config, nodename),
+
+    Ch = rabbit_ct_client_helpers:open_channel(Config, Server0),
+    #'confirm.select_ok'{} = amqp_channel:call(Ch, #'confirm.select'{}),
+    QQ = ?config(queue_name, Config),
+    ?assertEqual({'queue.declare_ok', QQ, 0, 0},
+                 declare(Ch, QQ, [{<<"x-queue-type">>, longstr, <<"quorum">>}])),
+    [begin
+         publish_confirm(Ch, QQ)
+     end || _ <- Servers],
+    timer:sleep(100),
+    %% roll the wal to force consumer messages to be read from disk
+    [begin
+         ok = rpc:call(S, ra_log_wal, force_roll_over, [ra_log_wal])
+     end || S <- Servers],
+    timer:sleep(256),
+
+    C = rabbit_ct_client_helpers:open_channel(Config, Server0),
+    [_, NCh1] = rpc:call(Server0, rabbit_channel, list, []),
+    qos(C, 1, false),
+    subscribe(C, QQ, false),
+    [begin
+         receive
+             {#'basic.deliver'{delivery_tag = DeliveryTag}, _} ->
+                 amqp_channel:call(C, #'basic.ack'{delivery_tag = DeliveryTag})
+         after 5000 ->
+                   flush(1),
+                   ct:fail("basic.deliver timeout")
+         end
+     end || _ <- Servers],
+    flush(1),
+    [{_, MonBy2}] = rpc:call(Server0, erlang, process_info, [NCh1, [monitored_by]]),
+    NumMonRefsBefore = length([M || M <- MonBy2, is_reference(M)]),
+    %% delete queue
+    ?assertMatch(#'queue.delete_ok'{},
+                 amqp_channel:call(Ch, #'queue.delete'{queue = QQ})),
+    [{_, MonBy3}] = rpc:call(Server0, erlang, process_info, [NCh1, [monitored_by]]),
+    NumMonRefsAfter = length([M || M <- MonBy3, is_reference(M)]),
+    %% this isn't an ideal way to assert this but every file handle creates
+    %% a monitor that (currenlty?) is a reference so we assert that we have
+    %% fewer reference monitors after
+    ?assert(NumMonRefsAfter < NumMonRefsBefore),
+
+    rabbit_ct_client_helpers:close_channel(C),
+    ok.
+
 gh_12635(Config) ->
     % https://github.com/rabbitmq/rabbitmq-server/issues/12635
     [Server0, _Server1, Server2] =
@@ -4964,3 +5013,7 @@ ensure_qq_proc_dead(Config, Server, RaName) ->
             ensure_qq_proc_dead(Config, Server, RaName)
     end.
 
+lsof_rpc() ->
+    Cmd = rabbit_misc:format(
+            "lsof -p ~ts", [os:getpid()]),
+    os:cmd(Cmd).