diff options
| -rw-r--r-- | src/rabbit_mnesia.erl | 97 |
1 files changed, 55 insertions, 42 deletions
diff --git a/src/rabbit_mnesia.erl b/src/rabbit_mnesia.erl index 0cea9ecc70..b0d7c9b84f 100644 --- a/src/rabbit_mnesia.erl +++ b/src/rabbit_mnesia.erl @@ -60,6 +60,9 @@ -include("rabbit.hrl"). +%% This is safe because ordsets are lists. +-define(empty_set(Set), (Set =:= [])). + %%---------------------------------------------------------------------------- -ifdef(use_specs). @@ -67,12 +70,12 @@ -export_type([node_type/0, cluster_status/0]). -type(node_type() :: disc | ram). --type(cluster_status() :: {ordsets:ordset(node()), ordsets:ordset(node()), - ordsets:ordset(node())}). +-type(node_set() :: ordsets:ordset(node())). +-type(cluster_status() :: {node_set(), node_set(), node_set()}). %% Main interface -spec(init/0 :: () -> 'ok'). --spec(join_cluster/2 :: ([node()], node_type()) -> 'ok'). +-spec(join_cluster/2 :: (node(), node_type()) -> 'ok'). -spec(reset/0 :: () -> 'ok'). -spec(force_reset/0 :: () -> 'ok'). -spec(update_cluster_nodes/1 :: (node()) -> 'ok'). @@ -80,13 +83,13 @@ -spec(forget_cluster_node/2 :: (node(), boolean()) -> 'ok'). %% Various queries to get the status of the db --spec(status/0 :: () -> [{'nodes', [{node_type(), [node()]}]} | - {'running_nodes', [node()]}]). +-spec(status/0 :: () -> [{'nodes', [{node_type(), node_set()}]} | + {'running_nodes', node_set()}]). -spec(is_db_empty/0 :: () -> boolean()). -spec(is_clustered/0 :: () -> boolean()). --spec(all_clustered_nodes/0 :: () -> [node()]). --spec(clustered_disc_nodes/0 :: () -> [node()]). --spec(running_clustered_nodes/0 :: () -> [node()]). +-spec(all_clustered_nodes/0 :: () -> node_set()). +-spec(clustered_disc_nodes/0 :: () -> node_set()). +-spec(running_clustered_nodes/0 :: () -> node_set()). -spec(node_type/0 :: () -> node_type()). -spec(dir/0 :: () -> file:filename()). -spec(table_names/0 :: () -> [atom()]). @@ -94,7 +97,7 @@ {'error', any()}). %% Operations on the db and utils, mainly used in `rabbit_upgrade' and `rabbit' --spec(init_db/3 :: ([node()], node_type(), boolean()) -> 'ok'). +-spec(init_db/3 :: (node_set(), node_type(), boolean()) -> 'ok'). -spec(empty_ram_only_tables/0 :: () -> 'ok'). -spec(create_tables/0 :: () -> 'ok'). -spec(copy_db/1 :: (file:filename()) -> rabbit_types:ok_or_error(any())). @@ -148,7 +151,7 @@ init_from_config() -> rabbit_log:warning("Could not find any suitable node amongst the " "ones provided in the configuration: ~p~n", [TryNodes]), - init(true, [node()]) + init(true, ordsets:from_list([node()])) end. %% Make the node join a cluster. The node will be reset automatically @@ -166,7 +169,7 @@ init_from_config() -> %% all in the same cluster, we simply pick the first online node and %% we cluster to its cluster. join_cluster(DiscoveryNode, NodeType) -> - case is_disc_and_clustered() andalso [node()] =:= clustered_disc_nodes() of + case is_disc_and_clustered() andalso is_only_disc_node() of true -> e(clustering_only_disc_node); _ -> ok end, @@ -222,8 +225,7 @@ reset(Force) -> %% resetting. Force=true here so that reset still works %% when clustered with a node which is down. init_db_with_mnesia(AllNodes, node_type(), false, true), - case is_disc_and_clustered() andalso - [node()] =:= clustered_disc_nodes() + case is_disc_and_clustered() andalso is_only_disc_node() of true -> e(resetting_only_disc_node); false -> ok @@ -256,7 +258,7 @@ change_cluster_node_type(Type) -> {ok, Status} -> Status; {error, _Reason} -> e(cannot_connect_to_cluster) end, - Node = case RunningNodes of + Node = case ordsets:to_list(RunningNodes) of [] -> e(no_online_cluster_nodes); [Node0|_] -> Node0 end, @@ -315,7 +317,7 @@ forget_cluster_node(Node, RemoveWhenOffline) -> remove_node_offline_node(Node) -> case {ordsets:del_element(Node, running_nodes(all_clustered_nodes())), node_type()} of - {[], disc} -> + {Nodes, disc} when ?empty_set(Nodes) -> %% Note that while we check if the nodes was the last to %% go down, apart from the node we're removing from, this %% is still unsafe. Consider the situation in which A and @@ -324,18 +326,18 @@ remove_node_offline_node(Node) -> %% and B goes down. In this case, C is the second-to-last, %% but we don't know that and we'll remove B from A %% anyway, even if that will lead to bad things. - case ordsets:subtract(running_clustered_nodes(), - ordsets:from_list([node(), Node])) of - [] -> start_mnesia(), - try - [mnesia:force_load_table(T) || - T <- rabbit_mnesia:table_names()], - forget_cluster_node(Node, false), - ensure_mnesia_running() - after - stop_mnesia() - end; - _ -> e(not_last_node_to_go_down) + case ?empty_set(ordsets:subtract(running_clustered_nodes(), + ordsets:from_list([node(), Node]))) + of true -> start_mnesia(), + try + [mnesia:force_load_table(T) || + T <- rabbit_mnesia:table_names()], + forget_cluster_node(Node, false), + ensure_mnesia_running() + after + stop_mnesia() + end; + false -> e(not_last_node_to_go_down) end; {_, _} -> e(removing_node_from_offline_node) @@ -347,8 +349,8 @@ remove_node_offline_node(Node) -> %%---------------------------------------------------------------------------- status() -> - IfNonEmpty = fun (_, []) -> []; - (Type, Nodes) -> [{Type, Nodes}] + IfNonEmpty = fun (_, Nodes) when ?empty_set(Nodes) -> []; + (Type, Nodes) -> [{Type, ordsets:to_list(Nodes)}] end, [{nodes, (IfNonEmpty(disc, clustered_disc_nodes()) ++ IfNonEmpty(ram, clustered_ram_nodes()))}] ++ @@ -362,8 +364,8 @@ is_db_empty() -> table_names()). is_clustered() -> - Nodes = all_clustered_nodes(), - [node()] =/= Nodes andalso [] =/= Nodes. + AllNodes = all_clustered_nodes(), + not is_only_node(AllNodes) andalso not ?empty_set(AllNodes). is_disc_and_clustered() -> node_type() =:= disc andalso is_clustered(). @@ -464,7 +466,7 @@ node_info() -> node_type() -> DiscNodes = clustered_disc_nodes(), - case DiscNodes =:= [] orelse ordsets:is_element(node(), DiscNodes) of + case ?empty_set(DiscNodes) orelse ordsets:is_element(node(), DiscNodes) of true -> disc; false -> ram end. @@ -696,13 +698,13 @@ check_cluster_consistency(Node) -> %%-------------------------------------------------------------------- on_node_up(Node) -> - case running_clustered_disc_nodes() =:= [Node] of + case is_only_node(Node, running_clustered_disc_nodes()) of true -> rabbit_log:info("cluster contains disc nodes again~n"); false -> ok end. on_node_down(_Node) -> - case running_clustered_disc_nodes() =:= [] of + case ?empty_set(running_clustered_disc_nodes()) of true -> rabbit_log:info("only running disc node went down~n"); false -> ok end. @@ -1004,11 +1006,13 @@ leave_cluster() -> case {is_clustered(), running_nodes(ordsets:del_element(node(), all_clustered_nodes()))} of - {false, []} -> ok; - {_, AllNodes} -> case lists:any(fun leave_cluster/1, AllNodes) of - true -> ok; - false -> e(no_running_cluster_nodes) - end + {false, Nodes} when ?empty_set(Nodes) -> + ok; + {_, AllNodes} -> + case lists:any(fun leave_cluster/1, AllNodes) of + true -> ok; + false -> e(no_running_cluster_nodes) + end end. leave_cluster(Node) -> @@ -1040,9 +1044,9 @@ stop_mnesia() -> ensure_mnesia_not_running(). change_extra_db_nodes(ClusterNodes0, Force) -> - ClusterNodes = lists:usort(ClusterNodes0) -- [node()], - case mnesia:change_config(extra_db_nodes, ClusterNodes) of - {ok, []} when not Force andalso ClusterNodes =/= [] -> + ClusterNodes = ordsets:del_element(node(), ClusterNodes0), + case mnesia:change_config(extra_db_nodes, ordsets:to_list(ClusterNodes)) of + {ok, []} when not Force andalso not ?empty_set(ClusterNodes) -> throw({error, {failed_to_cluster_with, ClusterNodes, "Mnesia could not connect to any nodes."}}); {ok, Nodes} -> @@ -1167,3 +1171,12 @@ error_description(removing_node_from_offline_node) -> "from must be a disc node and all the other nodes must be offline."; error_description(no_running_cluster_nodes) -> "You cannot leave a cluster if no online nodes are present.". + +is_only_node(Node, Nodes) -> + ordsets:is_element(Node, Nodes) andalso ordsets:size(Nodes) =:= 1. + +is_only_node(Nodes) -> + is_only_node(node(), Nodes). + +is_only_disc_node() -> + is_only_node(clustered_disc_nodes()). |