diff --git a/src/gm.erl b/src/gm.erl index 492117d17fe7..008a29151eaa 100644 --- a/src/gm.erl +++ b/src/gm.erl @@ -760,6 +760,9 @@ handle_info({'DOWN', MRef, process, _Pid, Reason}, end; handle_info(_, State) -> %% Discard any unexpected messages, such as late replies from neighbour_call/2 + %% TODO: For #gm_group{} related info messages, it could be worthwhile to + %% change_view/2, as this might reflect an alteration in the gm group, meaning + %% we now need to update our state. see rabbitmq-server#914. noreply(State). terminate(Reason, #state { module = Module, callback_args = Args }) -> @@ -1596,7 +1599,9 @@ check_membership(Self, #gm_group{members = M} = Group) -> Group; false -> throw(lost_membership) - end. + end; +check_membership(_Self, {error, not_found}) -> + throw(lost_membership). check_membership(GroupName) -> case dirty_read_group(GroupName) of diff --git a/src/rabbit_mirror_queue_coordinator.erl b/src/rabbit_mirror_queue_coordinator.erl index 221f11f18a01..017d1d1fa202 100644 --- a/src/rabbit_mirror_queue_coordinator.erl +++ b/src/rabbit_mirror_queue_coordinator.erl @@ -355,6 +355,15 @@ handle_cast({gm_deaths, DeadGMPids}, DeadPids), rabbit_mirror_queue_misc:add_mirrors(QueueName, ExtraNodes, async), noreply(State); + {ok, _MPid0, DeadPids, _ExtraNodes} -> + %% see rabbitmq-server#914; + %% Different slave is now master, stop current coordinator normally. + %% Initiating queue is now slave and the least we could do is report + %% deaths which we 'think' we saw. + %% NOTE: Reported deaths here, could be inconsistant. + rabbit_mirror_queue_misc:report_deaths(MPid, false, QueueName, + DeadPids), + {stop, normal, State}; {error, not_found} -> {stop, normal, State} end; diff --git a/src/rabbit_mirror_queue_misc.erl b/src/rabbit_mirror_queue_misc.erl index 83350920e6c9..4205fabb83d6 100644 --- a/src/rabbit_mirror_queue_misc.erl +++ b/src/rabbit_mirror_queue_misc.erl @@ -76,7 +76,7 @@ remove_from_queue(QueueName, Self, DeadGMPids) -> rabbit_misc:execute_mnesia_transaction( fun () -> %% Someone else could have deleted the queue before we - %% get here. + %% get here. Or, gm group could've altered. see rabbitmq-server#914 case mnesia:read({rabbit_queue, QueueName}) of [] -> {error, not_found}; [Q = #amqqueue { pid = QPid, @@ -90,7 +90,16 @@ remove_from_queue(QueueName, Self, DeadGMPids) -> AlivePids = [Pid || {_GM, Pid} <- AliveGM], Alive = [Pid || Pid <- [QPid | SPids], lists:member(Pid, AlivePids)], - {QPid1, SPids1} = promote_slave(Alive), + {QPid1, SPids1} = case Alive of + [] -> + %% GM altered, & if all pids are + %% perceived as dead, rather do + %% do nothing here, & trust the + %% promoted slave to have updated + %% mnesia during the alteration. + {QPid, SPids}; + _ -> promote_slave(Alive) + end, Extra = case {{QPid, SPids}, {QPid1, SPids1}} of {Same, Same} -> @@ -98,7 +107,8 @@ remove_from_queue(QueueName, Self, DeadGMPids) -> _ when QPid =:= QPid1 orelse QPid1 =:= Self -> %% Either master hasn't changed, so %% we're ok to update mnesia; or we have - %% become the master. + %% become the master. If gm altered, + %% we have no choice but to proceed. Q1 = Q#amqqueue{pid = QPid1, slave_pids = SPids1, gm_pids = AliveGM}, diff --git a/src/rabbit_mirror_queue_slave.erl b/src/rabbit_mirror_queue_slave.erl index 6f46cdc69881..2cb445518071 100644 --- a/src/rabbit_mirror_queue_slave.erl +++ b/src/rabbit_mirror_queue_slave.erl @@ -225,9 +225,15 @@ handle_call({gm_deaths, DeadGMPids}, From, _ -> %% master has changed to not us gen_server2:reply(From, ok), - %% assertion, we don't need to add_mirrors/2 in this - %% branch, see last clause in remove_from_queue/2 - [] = ExtraNodes, + %% see rabbitmq-server#914; + %% It's not always guaranteed that we won't have ExtraNodes. + %% If gm alters, master can change to not us with extra nodes, + %% in which case we attempt to add mirrors on those nodes. + case ExtraNodes of + [] -> void; + _ -> rabbit_mirror_queue_misc:add_mirrors( + QName, ExtraNodes, async) + end, %% Since GM is by nature lazy we need to make sure %% there is some traffic when a master dies, to %% make sure all slaves get informed of the