From a68f457d66c50db544faab316b648b68e69b7a8a Mon Sep 17 00:00:00 2001
From: Karl Nilsson <kjnilsson@gmail.com>
Date: Tue, 23 Apr 2024 16:07:38 +0100
Subject: [PATCH] Better handle QQ delete member operation when member already
 removed

(cherry picked from commit 02b62746bceed3085f99c574cc7a2440b63e9807)
---
 deps/rabbit/src/rabbit_quorum_queue.erl | 11 ++++++----
 deps/rabbit/test/quorum_queue_SUITE.erl | 27 +++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/deps/rabbit/src/rabbit_quorum_queue.erl b/deps/rabbit/src/rabbit_quorum_queue.erl
index ec996ba9e180..40f5087d249d 100644
--- a/deps/rabbit/src/rabbit_quorum_queue.erl
+++ b/deps/rabbit/src/rabbit_quorum_queue.erl
@@ -128,7 +128,7 @@
 -define(START_CLUSTER_RPC_TIMEOUT, 60_000). %% needs to be longer than START_CLUSTER_TIMEOUT
 -define(TICK_TIMEOUT, 5000). %% the ra server tick time
 -define(DELETE_TIMEOUT, 5000).
--define(ADD_MEMBER_TIMEOUT, 5000).
+-define(MEMBER_CHANGE_TIMEOUT, 20_000).
 -define(SNAPSHOT_INTERVAL, 8192). %% the ra default is 4096
 
 %%----------- QQ policies ---------------------------------------------------
@@ -1199,7 +1199,7 @@ add_member(Q, Node) ->
     add_member(Q, Node, promotable).
 
 add_member(Q, Node, Membership) ->
-    add_member(Q, Node, Membership, ?ADD_MEMBER_TIMEOUT).
+    add_member(Q, Node, Membership, ?MEMBER_CHANGE_TIMEOUT).
 
 add_member(VHost, Name, Node, Timeout) when is_binary(VHost) ->
     %% NOTE needed to pass mixed cluster tests.
@@ -1276,8 +1276,11 @@ delete_member(Q, Node) when ?amqqueue_is_quorum(Q) ->
             %% deleting the last member is not allowed
             {error, last_node};
         Members ->
-            case ra:remove_member(Members, ServerId) of
-                {ok, _, _Leader} ->
+            case ra:remove_member(Members, ServerId, ?MEMBER_CHANGE_TIMEOUT) of
+                Res when element(1, Res) == ok orelse
+                         Res == {error, not_member} ->
+                    %% if not a member we can still proceed with updating the
+                    %% mnesia record and clean up server if still running
                     Fun = fun(Q1) ->
                                   update_type_state(
                                     Q1,
diff --git a/deps/rabbit/test/quorum_queue_SUITE.erl b/deps/rabbit/test/quorum_queue_SUITE.erl
index 2c70cf8d8ea8..ec6e211f39d0 100644
--- a/deps/rabbit/test/quorum_queue_SUITE.erl
+++ b/deps/rabbit/test/quorum_queue_SUITE.erl
@@ -59,6 +59,7 @@ groups() ->
                                             delete_member_queue_not_found,
                                             delete_member,
                                             delete_member_not_a_member,
+                                            delete_member_member_already_deleted,
                                             node_removal_is_quorum_critical]
                        ++ memory_tests()},
                       {cluster_size_3, [], [
@@ -1955,6 +1956,32 @@ delete_member_not_a_member(Config) ->
                  rpc:call(Server, rabbit_quorum_queue, delete_member,
                           [<<"/">>, QQ, Server])).
 
+delete_member_member_already_deleted(Config) ->
+    [Server, Server2] = Servers = rabbit_ct_broker_helpers:get_node_configs(Config, nodename),
+    NServers = length(Servers),
+    Ch = rabbit_ct_client_helpers:open_channel(Config, Server),
+    QQ = ?config(queue_name, Config),
+    RaName = ra_name(QQ),
+    ?assertEqual({'queue.declare_ok', QQ, 0, 0},
+                 declare(Ch, QQ, [{<<"x-queue-type">>, longstr, <<"quorum">>}])),
+    ?awaitMatch(NServers, count_online_nodes(Server, <<"/">>, QQ), ?DEFAULT_AWAIT),
+    ServerId = {RaName, Server},
+    ServerId2 = {RaName, Server2},
+    %% use are APU directory to simulate situation where the ra:remove_server/2
+    %% call timed out but later succeeded
+    ?assertMatch(ok,
+                 rpc:call(Server2, ra, leave_and_terminate,
+                          [quorum_queues, ServerId, ServerId2])),
+
+    %% idempotent by design
+    ?assertEqual(ok,
+                 rpc:call(Server, rabbit_quorum_queue, delete_member,
+                          [<<"/">>, QQ, Server2])),
+    {ok, Q} = rpc:call(Server, rabbit_amqqueue, lookup, [QQ, <<"/">>]),
+    #{nodes := Nodes} = amqqueue:get_type_state(Q),
+    ?assertEqual(1, length(Nodes)),
+    ok.
+
 delete_member_during_node_down(Config) ->
     [Server, DownServer, Remove] = Servers = rabbit_ct_broker_helpers:get_node_configs(
                                                Config, nodename),