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emqx
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Shared subscriber should be keyed by SharedName + Topic 

Prior to this change, if a producer session produces to two
or more shared subscriber groups, the previously picked subscriber
for sticky strategy may not be a valid member for the next group.
This commit is contained in:
spring2maz 2018-09-27 21:50:23 +02:00 committed by Feng Lee
parent 96b5d71a67
commit 3bab3cbd2a
1 changed files with 14 additions and 13 deletions
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27
src/emqx_shared_sub.erl
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@ -89,7 +89,7 @@ dispatch(Group, Topic, Delivery = #delivery{message = Msg, results = Results}) -
end.
pick(sticky, ClientId, Group, Topic) ->
Sub0 = erlang:get(shared_sub_sticky),
Sub0 = erlang:get({shared_sub_sticky, Group, Topic}),
case is_sub_alive(Sub0) of
true ->
%% the old subscriber is still alive
@ -99,32 +99,33 @@ pick(sticky, ClientId, Group, Topic) ->
%% randomly pick one for the first message
Sub = do_pick(random, ClientId, Group, Topic),
%% stick to whatever pick result
erlang:put(shared_sub_sticky, Sub),
erlang:put({shared_sub_sticky, Group, Topic}, Sub),
Sub
end;
pick(Strategy, ClientId, Group, Topic) ->
do_pick(Strategy, ClientId, Group, Topic).
do_pick(Strategy, ClientId, Group, Topic) ->
All = subscribers(Group, Topic),
pick_subscriber(Strategy, ClientId, All).
case subscribers(Group, Topic) of
[] -> false;
[Sub] -> Sub;
All -> pick_subscriber(Group, Topic, Strategy, ClientId, All)
end.
pick_subscriber(_, _ClientId, []) -> false;
pick_subscriber(_, _ClientId, [Sub]) -> Sub;
pick_subscriber(Strategy, ClientId, Subs) ->
Nth = do_pick_subscriber(Strategy, ClientId, length(Subs)),
pick_subscriber(Group, Topic, Strategy, ClientId, Subs) ->
Nth = do_pick_subscriber(Group, Topic, Strategy, ClientId, length(Subs)),
lists:nth(Nth, Subs).
do_pick_subscriber(random, _ClientId, Count) ->
do_pick_subscriber(_Group, _Topic, random, _ClientId, Count) ->
rand:uniform(Count);
do_pick_subscriber(hash, ClientId, Count) ->
do_pick_subscriber(_Group, _Topic, hash, ClientId, Count) ->
1 + erlang:phash2(ClientId) rem Count;
do_pick_subscriber(round_robin, _ClientId, Count) ->
Rem = case erlang:get(shared_sub_round_robin) of
do_pick_subscriber(Group, Topic, round_robin, _ClientId, Count) ->
Rem = case erlang:get({shared_sub_round_robin, Group, Topic}) of
undefined -> 0;
N -> (N + 1) rem Count
end,
_ = erlang:put(shared_sub_round_robin, Rem),
_ = erlang:put({shared_sub_round_robin, Group, Topic}, Rem),
Rem + 1.
subscribers(Group, Topic) ->