Re-evaluate stream SAC group after connection down event

The same connection can contain several consumers belonging to a SAC
group (group key = vhost + stream + consumer name). The whole new group
must be re-evaluated to select a new active consumer after the consumers
of the down connection are removed from it.

The previous behavior would not re-evaluate the new group and could
select a consumer from the down connection, letting the group with only
inactive consumers, as the selected active consumer would never receive
the activation message from the stream SAC coordinator.

This commit fixes this problem by removing the consumers of the down
down connection from the affected groups and then performing the
appropriate operations for the groups to keep on consuming (e.g.
notifying an active consumer that it needs to step down).

References #13372
This commit is contained in:
Arnaud Cogoluègnes 2025-03-31 14:59:59 +02:00
parent 12e600a791
commit 602b6acd7d
No known key found for this signature in database
GPG Key ID: D5C8C4DFAD43AFA8
3 changed files with 222 additions and 75 deletions

View File

@ -229,7 +229,7 @@ apply(#command_unregister_consumer{vhost = VirtualHost,
of
{value, Consumer} ->
G1 = remove_from_group(Consumer, Group0),
handle_consumer_removal(G1, Consumer, Stream, ConsumerName);
handle_consumer_removal(G1, Stream, ConsumerName, Consumer#consumer.active);
false ->
{Group0, []}
end,
@ -414,50 +414,44 @@ handle_connection_down(Pid,
{State0, []};
{Groups, PidsGroups1} ->
State1 = State0#?MODULE{pids_groups = PidsGroups1},
%% iterate other the groups that this PID affects
maps:fold(fun({VirtualHost, Stream, ConsumerName}, _,
{#?MODULE{groups = ConsumerGroups} = S0, Eff0}) ->
case lookup_group(VirtualHost,
Stream,
ConsumerName,
ConsumerGroups)
of
undefined -> {S0, Eff0};
#group{consumers = Consumers} ->
%% iterate over the consumers of the group
%% and unregister the ones from this PID.
%% It may not be optimal, computing the new active consumer
%% from the purged group and notifying the remaining consumers
%% appropriately should avoid unwanted notifications and even rebalancing.
lists:foldl(fun (#consumer{pid = P,
subscription_id =
SubId},
{StateSub0, EffSub0})
when P == Pid ->
{StateSub1, ok, E} =
?MODULE:apply(#command_unregister_consumer{vhost
=
VirtualHost,
stream
=
Stream,
consumer_name
=
ConsumerName,
connection_pid
=
Pid,
subscription_id
=
SubId},
StateSub0),
{StateSub1, EffSub0 ++ E};
(_Consumer, Acc) -> Acc
end,
{S0, Eff0}, Consumers)
end
end,
{State1, []}, Groups)
maps:fold(fun(G, _, Acc) ->
handle_group_after_connection_down(Pid, Acc, G)
end, {State1, []}, Groups)
end.
handle_group_after_connection_down(Pid,
{#?MODULE{groups = Groups0} = S0, Eff0},
{VirtualHost, Stream, ConsumerName}) ->
case lookup_group(VirtualHost,
Stream,
ConsumerName,
Groups0) of
undefined ->
{S0, Eff0};
#group{consumers = Consumers0} = G0 ->
%% remove the connection consumers from the group state
%% keep flags to know what happened
{Consumers1, ActiveRemoved, AnyRemoved} =
lists:foldl(
fun(#consumer{pid = P, active = S}, {L, ActiveFlag, _}) when P == Pid ->
{L, S or ActiveFlag, true};
(C, {L, ActiveFlag, AnyFlag}) ->
{L ++ [C], ActiveFlag, AnyFlag}
end, {[], false, false}, Consumers0),
case AnyRemoved of
true ->
G1 = G0#group{consumers = Consumers1},
{G2, Effects} = handle_consumer_removal(G1, Stream, ConsumerName, ActiveRemoved),
Groups1 = update_groups(VirtualHost,
Stream,
ConsumerName,
G2,
Groups0),
{S0#?MODULE{groups = Groups1}, Effects ++ Eff0};
false ->
{S0, Eff0}
end
end.
do_register_consumer(VirtualHost,
@ -576,9 +570,9 @@ do_register_consumer(VirtualHost,
handle_consumer_removal(#group{consumers = []} = G, _, _, _) ->
{G, []};
handle_consumer_removal(#group{partition_index = -1} = Group0,
Consumer, Stream, ConsumerName) ->
case Consumer of
#consumer{active = true} ->
Stream, ConsumerName, ActiveRemoved) ->
case ActiveRemoved of
true ->
%% this is the active consumer we remove, computing the new one
Group1 = compute_active_consumer(Group0),
case lookup_active_consumer(Group1) of
@ -589,11 +583,11 @@ handle_consumer_removal(#group{partition_index = -1} = Group0,
%% no active consumer found in the group, nothing to do
{Group1, []}
end;
#consumer{active = false} ->
false ->
%% not the active consumer, nothing to do.
{Group0, []}
end;
handle_consumer_removal(Group0, Consumer, Stream, ConsumerName) ->
handle_consumer_removal(Group0, Stream, ConsumerName, ActiveRemoved) ->
case lookup_active_consumer(Group0) of
{value,
#consumer{pid = ActPid, subscription_id = ActSubId} =
@ -612,7 +606,7 @@ handle_consumer_removal(Group0, Consumer, Stream, ConsumerName) ->
Stream, ConsumerName, false, true)]}
end;
false ->
case Consumer#consumer.active of
case ActiveRemoved of
true ->
%% the active one is going away, picking a new one
#consumer{pid = P, subscription_id = SID} =

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@ -312,29 +312,27 @@ ensure_monitors_test(_) ->
ok.
handle_connection_down_test(_) ->
handle_connection_down_sac_should_get_activated_test(_) ->
Stream = <<"stream">>,
ConsumerName = <<"app">>,
GroupId = {<<"/">>, Stream, ConsumerName},
Pid0 = self(),
Pid1 = spawn(fun() -> ok end),
Group =
cgroup([consumer(Pid0, 0, true), consumer(Pid1, 1, false),
consumer(Pid0, 2, false)]),
State0 =
state(#{GroupId => Group},
#{Pid0 => maps:from_list([{GroupId, true}]),
Pid1 => maps:from_list([{GroupId, true}])}),
Group = cgroup([consumer(Pid0, 0, true),
consumer(Pid1, 1, false),
consumer(Pid0, 2, false)]),
State0 = state(#{GroupId => Group},
#{Pid0 => maps:from_list([{GroupId, true}]),
Pid1 => maps:from_list([{GroupId, true}])}),
{#?STATE{pids_groups = PidsGroups1, groups = Groups1} = State1,
Effects1} =
rabbit_stream_sac_coordinator:handle_connection_down(Pid0, State0),
rabbit_stream_sac_coordinator:handle_connection_down(Pid0, State0),
assertSize(1, PidsGroups1),
assertSize(1, maps:get(Pid1, PidsGroups1)),
assertSendMessageEffect(Pid1, 1, Stream, ConsumerName, true, Effects1),
?assertEqual(#{GroupId => cgroup([consumer(Pid1, 1, true)])},
Groups1),
{#?STATE{pids_groups = PidsGroups2, groups = Groups2} = _State2,
assertHasGroup(GroupId, cgroup([consumer(Pid1, 1, true)]), Groups1),
{#?STATE{pids_groups = PidsGroups2, groups = Groups2},
Effects2} =
rabbit_stream_sac_coordinator:handle_connection_down(Pid1, State1),
assertEmpty(PidsGroups2),
@ -343,6 +341,168 @@ handle_connection_down_test(_) ->
ok.
handle_connection_down_sac_active_does_not_change_test(_) ->
Stream = <<"stream">>,
ConsumerName = <<"app">>,
GroupId = {<<"/">>, Stream, ConsumerName},
Pid0 = self(),
Pid1 = spawn(fun() -> ok end),
Group = cgroup([consumer(Pid1, 0, true),
consumer(Pid0, 1, false),
consumer(Pid0, 2, false)]),
State = state(#{GroupId => Group},
#{Pid0 => maps:from_list([{GroupId, true}]),
Pid1 => maps:from_list([{GroupId, true}])}),
{#?STATE{pids_groups = PidsGroups, groups = Groups},
Effects} =
rabbit_stream_sac_coordinator:handle_connection_down(Pid0, State),
assertSize(1, PidsGroups),
assertSize(1, maps:get(Pid1, PidsGroups)),
assertEmpty(Effects),
assertHasGroup(GroupId, cgroup([consumer(Pid1, 0, true)]), Groups),
ok.
handle_connection_down_sac_no_more_consumers_test(_) ->
Stream = <<"stream">>,
ConsumerName = <<"app">>,
GroupId = {<<"/">>, Stream, ConsumerName},
Pid0 = self(),
Group = cgroup([consumer(Pid0, 0, true),
consumer(Pid0, 1, false)]),
State = state(#{GroupId => Group},
#{Pid0 => maps:from_list([{GroupId, true}])}),
{#?STATE{pids_groups = PidsGroups, groups = Groups},
Effects} =
rabbit_stream_sac_coordinator:handle_connection_down(Pid0, State),
assertEmpty(PidsGroups),
assertEmpty(Groups),
assertEmpty(Effects),
ok.
handle_connection_down_sac_no_consumers_in_down_connection_test(_) ->
Stream = <<"stream">>,
ConsumerName = <<"app">>,
GroupId = {<<"/">>, Stream, ConsumerName},
Pid0 = self(),
Pid1 = spawn(fun() -> ok end),
Group = cgroup([consumer(Pid1, 0, true),
consumer(Pid1, 1, false)]),
State = state(#{GroupId => Group},
#{Pid0 => maps:from_list([{GroupId, true}]), %% should not be there
Pid1 => maps:from_list([{GroupId, true}])}),
{#?STATE{pids_groups = PidsGroups, groups = Groups},
Effects} =
rabbit_stream_sac_coordinator:handle_connection_down(Pid0, State),
assertSize(1, PidsGroups),
assertSize(1, maps:get(Pid1, PidsGroups)),
assertEmpty(Effects),
assertHasGroup(GroupId, cgroup([consumer(Pid1, 0, true), consumer(Pid1, 1, false)]),
Groups),
ok.
handle_connection_down_super_stream_active_stays_test(_) ->
Stream = <<"stream">>,
ConsumerName = <<"app">>,
GroupId = {<<"/">>, Stream, ConsumerName},
Pid0 = self(),
Pid1 = spawn(fun() -> ok end),
Group = cgroup(1, [consumer(Pid0, 0, false),
consumer(Pid0, 1, true),
consumer(Pid1, 2, false),
consumer(Pid1, 3, false)]),
State = state(#{GroupId => Group},
#{Pid0 => maps:from_list([{GroupId, true}]),
Pid1 => maps:from_list([{GroupId, true}])}),
{#?STATE{pids_groups = PidsGroups, groups = Groups},
Effects} =
rabbit_stream_sac_coordinator:handle_connection_down(Pid1, State),
assertSize(1, PidsGroups),
assertSize(1, maps:get(Pid0, PidsGroups)),
assertEmpty(Effects),
assertHasGroup(GroupId, cgroup(1, [consumer(Pid0, 0, false), consumer(Pid0, 1, true)]),
Groups),
ok.
handle_connection_down_super_stream_active_changes_test(_) ->
Stream = <<"stream">>,
ConsumerName = <<"app">>,
GroupId = {<<"/">>, Stream, ConsumerName},
Pid0 = self(),
Pid1 = spawn(fun() -> ok end),
Group = cgroup(1, [consumer(Pid0, 0, false),
consumer(Pid1, 1, true),
consumer(Pid0, 2, false),
consumer(Pid1, 3, false)]),
State = state(#{GroupId => Group},
#{Pid0 => maps:from_list([{GroupId, true}]),
Pid1 => maps:from_list([{GroupId, true}])}),
{#?STATE{pids_groups = PidsGroups, groups = Groups},
Effects} =
rabbit_stream_sac_coordinator:handle_connection_down(Pid0, State),
assertSize(1, PidsGroups),
assertSize(1, maps:get(Pid1, PidsGroups)),
assertSendMessageSteppingDownEffect(Pid1, 1, Stream, ConsumerName, Effects),
assertHasGroup(GroupId, cgroup(1, [consumer(Pid1, 1, false), consumer(Pid1, 3, false)]),
Groups),
ok.
handle_connection_down_super_stream_activate_in_remaining_connection_test(_) ->
Stream = <<"stream">>,
ConsumerName = <<"app">>,
GroupId = {<<"/">>, Stream, ConsumerName},
Pid0 = self(),
Pid1 = spawn(fun() -> ok end),
Group = cgroup(1, [consumer(Pid0, 0, false),
consumer(Pid0, 1, true),
consumer(Pid1, 2, false),
consumer(Pid1, 3, false)]),
State = state(#{GroupId => Group},
#{Pid0 => maps:from_list([{GroupId, true}]),
Pid1 => maps:from_list([{GroupId, true}])}),
{#?STATE{pids_groups = PidsGroups, groups = Groups},
Effects} =
rabbit_stream_sac_coordinator:handle_connection_down(Pid0, State),
assertSize(1, PidsGroups),
assertSize(1, maps:get(Pid1, PidsGroups)),
assertSendMessageEffect(Pid1, 3, Stream, ConsumerName, true, Effects),
assertHasGroup(GroupId, cgroup(1, [consumer(Pid1, 2, false), consumer(Pid1, 3, true)]),
Groups),
ok.
handle_connection_down_super_stream_no_active_removed_or_present_test(_) ->
Stream = <<"stream">>,
ConsumerName = <<"app">>,
GroupId = {<<"/">>, Stream, ConsumerName},
Pid0 = self(),
Pid1 = spawn(fun() -> ok end),
%% this is a weird case that should not happen in the wild,
%% we test the logic in the code nevertheless.
%% No active consumer in the group
Group = cgroup(1, [consumer(Pid0, 0, false),
consumer(Pid0, 1, false),
consumer(Pid1, 2, false),
consumer(Pid1, 3, false)]),
State = state(#{GroupId => Group},
#{Pid0 => maps:from_list([{GroupId, true}]),
Pid1 => maps:from_list([{GroupId, true}])}),
{#?STATE{pids_groups = PidsGroups, groups = Groups},
Effects} =
rabbit_stream_sac_coordinator:handle_connection_down(Pid0, State),
assertSize(1, PidsGroups),
assertSize(1, maps:get(Pid1, PidsGroups)),
assertEmpty(Effects),
assertHasGroup(GroupId, cgroup(1, [consumer(Pid1, 2, false), consumer(Pid1, 3, false)]),
Groups),
ok.
assertSize(Expected, []) ->
?assertEqual(Expected, 0);
assertSize(Expected, Map) when is_map(Map) ->
@ -353,6 +513,9 @@ assertSize(Expected, List) when is_list(List) ->
assertEmpty(Data) ->
assertSize(0, Data).
assertHasGroup(GroupId, Group, Groups) ->
?assertEqual(#{GroupId => Group}, Groups).
consumer(Pid, SubId, Active) ->
#consumer{pid = Pid,
subscription_id = SubId,

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@ -598,26 +598,16 @@ augment_infos_with_user_provided_connection_name(Infos,
end.
close(Transport,
#stream_connection{socket = S, virtual_host = VirtualHost,
outstanding_requests = Requests},
#stream_connection{socket = S},
#stream_connection_state{consumers = Consumers}) ->
[begin
%% we discard the result (updated requests) because they are no longer used
_ = maybe_unregister_consumer(VirtualHost, Consumer,
single_active_consumer(Properties),
Requests),
case Log of
undefined ->
ok; %% segment may not be defined on subscription (single active consumer)
L ->
osiris_log:close(L)
end
end
|| #consumer{log = Log,
configuration =
#consumer_configuration{properties = Properties}} =
Consumer
<- maps:values(Consumers)],
end || #consumer{log = Log} <- maps:values(Consumers)],
Transport:shutdown(S, write),
Transport:close(S).