Merge pull request #10337 from rabbitmq/loic-revert-cqv2-default

Revert "Default to classic queues v2"

Author: michaelklishin

deps/rabbit/BUILD.bazel

@@ -85,8 +85,6 @@ _APP_ENV = """[
 	                         ]},
 	    {halt_on_upgrade_failure, true},
 	    {ssl_apps, [asn1, crypto, public_key, ssl]},
-	    %% classic queue storage implementation version
-	    {classic_queue_default_version, 2},
 	    %% see rabbitmq-server#114
 	    {mirroring_flow_control, true},
 	    {mirroring_sync_batch_size, 4096},

deps/rabbit/Makefile

@@ -65,8 +65,6 @@ define PROJECT_ENV
 	                         ]},
 	    {halt_on_upgrade_failure, true},
 	    {ssl_apps, [asn1, crypto, public_key, ssl]},
-	    %% classic queue storage implementation version
-	    {classic_queue_default_version, 2},
 	    %% see rabbitmq-server#114
 	    {mirroring_flow_control, true},
 	    {mirroring_sync_batch_size, 4096},

deps/rabbit/priv/schema/rabbit.schema

@@ -2485,7 +2485,7 @@ end}.
 
 {translation, "rabbit.classic_queue_default_version",
     fun(Conf) ->
-        case cuttlefish:conf_get("classic_queue.default_version", Conf, 2) of
+        case cuttlefish:conf_get("classic_queue.default_version", Conf, 1) of
             1 -> 1;
             2 -> 2;
             _ -> cuttlefish:unset()

deps/rabbit/src/rabbit_amqqueue_process.erl

@@ -470,12 +470,12 @@ init_queue_mode(Mode, State = #q {backing_queue = BQ,
 
 init_queue_version(Version0, State = #q {backing_queue = BQ,
                                          backing_queue_state = BQS}) ->
-    %% When the version is undefined we use the default version 2.
+    %% When the version is undefined we use the default version 1.
     %% We want to BQ:set_queue_version in all cases because a v2
     %% policy might have been deleted, for example, and we want
     %% the queue to go back to v1.
     Version = case Version0 of
-        undefined -> rabbit_misc:get_env(rabbit, classic_queue_default_version, 2);
+        undefined -> rabbit_misc:get_env(rabbit, classic_queue_default_version, 1);
         _ -> Version0
     end,
     BQS1 = BQ:set_queue_version(Version, BQS),

deps/rabbit/src/rabbit_variable_queue.erl

@@ -489,11 +489,10 @@ process_recovery_terms(Terms) ->
         PRef      -> {PRef, Terms}
     end.
 
-%% If queue-version is undefined, we assume v2 starting with RabbitMQ 3.13.0.
 queue_version(Q) ->
     Resolve = fun(_, ArgVal) -> ArgVal end,
     case rabbit_queue_type_util:args_policy_lookup(<<"queue-version">>, Resolve, Q) of
-        undefined -> rabbit_misc:get_env(rabbit, classic_queue_default_version, 2);
+        undefined -> rabbit_misc:get_env(rabbit, classic_queue_default_version, 1);
         Vsn when is_integer(Vsn) -> Vsn;
         Vsn -> binary_to_integer(Vsn)
     end.

deps/rabbitmq_management/test/rabbit_mgmt_http_SUITE.erl

@@ -1065,21 +1065,21 @@ queues_test(Config) ->
                    auto_delete => false,
                    exclusive   => false,
                    arguments   => #{},
-                   storage_version => 2},
+                   storage_version => 1},
                  #{name        => <<"foo">>,
                    vhost       => <<"/">>,
                    durable     => true,
                    auto_delete => false,
                    exclusive   => false,
                    arguments   => #{},
-                   storage_version => 2}], Queues),
+                   storage_version => 1}], Queues),
     assert_item(#{name        => <<"foo">>,
                   vhost       => <<"/">>,
                   durable     => true,
                   auto_delete => false,
                   exclusive   => false,
                   arguments   => #{},
-                  storage_version => 2}, Queue),
+                  storage_version => 1}, Queue),
 
     http_delete(Config, "/queues/%2F/foo", {group, '2xx'}),
     http_delete(Config, "/queues/%2F/baz", {group, '2xx'}),
@@ -2274,8 +2274,8 @@ queue_pagination_test(Config) ->
     ?assertEqual(1, maps:get(page, PageOfTwo)),
     ?assertEqual(2, maps:get(page_size, PageOfTwo)),
     ?assertEqual(2, maps:get(page_count, PageOfTwo)),
-    assert_list([#{name => <<"test0">>, vhost => <<"/">>, storage_version => 2},
-                 #{name => <<"test2_reg">>, vhost => <<"/">>, storage_version => 2}
+    assert_list([#{name => <<"test0">>, vhost => <<"/">>, storage_version => 1},
+                 #{name => <<"test2_reg">>, vhost => <<"/">>, storage_version => 1}
                 ], maps:get(items, PageOfTwo)),
 
     SortedByName = http_get(Config, "/queues?sort=name&page=1&page_size=2", ?OK),

release-notes/3.13.0.md

@@ -64,6 +64,20 @@ Once all nodes are upgraded to 3.13.0, these irregularities will go away.
 Mixed version clusters are a mechanism that allows rolling upgrade and are not meant to be run for extended
 periods of time (no more than a few hours).
 
+### Recommended Post-upgrade Procedures
+
+#### Switch Classic Queues to CQv2
+
+We recommend switching classic queues to CQv2 after **all cluster nodes** have been upgrades,
+at first using policies, and then eventually using a setting in `rabbitmq.conf`. Upgrading
+classic queues to CQv2 at boot time using the configuration file setting can be
+potentially unsafe in environments where deprecated classic mirrored queues still exist.
+
+For new clusters, adopting CQv2 from the start is highly recommended:
+
+``` ini
+classic_queue.default_version = 2
+```
 
 
 ## Compatibility Notes
@@ -240,25 +254,23 @@ Release notes are kept under [rabbitmq-server/release-notes](https://github.com/
 
    GitHub issue: [#8218](https://github.com/rabbitmq/rabbitmq-server/pull/8218)
 
- * Reduced memory footprint, improved memory use predictability and throughput of classic queues (version 2, or CQv2).
-   This particularly benefits classic queues with longer backlogs.
-
-   Classic queue v2 (CQv2) storage implementation **is now the default**. It is possible to switch
-   the default back to CQv1 using `rabbitmq.conf`:
+ * Revisited peer discovery implementation that further reduces the probability of two or more
+   sets of nodes [forming separate clusters](https://www.rabbitmq.com/cluster-formation.html#initial-formation-race-condition) when **all** cluster nodes are created at the same time and boot in parallel.
 
-   ``` ini
-   # uses CQv1 by default
-   classic_queue.default_version = 1
-   ```
+   GitHub issue: [#9797](https://github.com/rabbitmq/rabbitmq-server/pull/9797)
 
-   Individual queues can be declared by passing `x-queue-version` argument and/or through a `queue-version` policy.
+ * Classic queue storage v2 (CQv2) has matured and is now recommended for all users.
 
-   GitHub issue: [#8308](https://github.com/rabbitmq/rabbitmq-server/pull/8308)
+   We recommend switching classic queues to CQv2 after **all cluster nodes** have been upgrades,
+   at first using policies, and then eventually using a setting in `rabbitmq.conf`. Upgrading
+   classic queues to CQv2 at boot time using the configuration file setting can be
+   potentially unsafe in environments where deprecated classic mirrored queues still exist.
 
- * Revisited peer discovery implementation that further reduces the probability of two or more
-   sets of nodes [forming separate clusters](https://www.rabbitmq.com/cluster-formation.html#initial-formation-race-condition) when **all** cluster nodes are created at the same time and boot in parallel.
+   For new clusters, adopt CQv2 from the start by setting `classic_queue.default_version` in `rabbitmq.conf`:
 
-   GitHub issue: [#9797](https://github.com/rabbitmq/rabbitmq-server/pull/9797)
+   ``` ini
+   classic_queue.default_version = 2
+   ```
 
  * Non-mirrored classic queues: optimizations of storage for larger (greater than 4 kiB) messages.