%% The contents of this file are subject to the Mozilla Public License %% Version 1.1 (the "License"); you may not use this file except in %% compliance with the License. You may obtain a copy of the License %% at http://www.mozilla.org/MPL/ %% %% Software distributed under the License is distributed on an "AS IS" %% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See %% the License for the specific language governing rights and %% limitations under the License. %% %% The Original Code is RabbitMQ. %% %% The Initial Developer of the Original Code is GoPivotal, Inc. %% Copyright (c) 2007-2013 GoPivotal, Inc. All rights reserved. %% -module(rabbit_mnesia). -export([init/0, join_cluster/2, reset/0, force_reset/0, update_cluster_nodes/1, change_cluster_node_type/1, forget_cluster_node/2, status/0, is_clustered/0, cluster_nodes/1, node_type/0, dir/0, cluster_status_from_mnesia/0, init_db_unchecked/2, copy_db/1, check_cluster_consistency/0, ensure_mnesia_dir/0, on_node_up/1, on_node_down/1 ]). %% Used internally in rpc calls -export([node_info/0, remove_node_if_mnesia_running/1]). -include("rabbit.hrl"). %%---------------------------------------------------------------------------- -ifdef(use_specs). -export_type([node_type/0, cluster_status/0]). -type(node_type() :: disc | ram). -type(cluster_status() :: {[node()], [node()], [node()]}). %% Main interface -spec(init/0 :: () -> 'ok'). -spec(join_cluster/2 :: (node(), node_type()) -> 'ok' | {'ok', 'already_member'}). -spec(reset/0 :: () -> 'ok'). -spec(force_reset/0 :: () -> 'ok'). -spec(update_cluster_nodes/1 :: (node()) -> 'ok'). -spec(change_cluster_node_type/1 :: (node_type()) -> 'ok'). -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()]} | {'partitions', [{node(), [node()]}]}]). -spec(is_clustered/0 :: () -> boolean()). -spec(cluster_nodes/1 :: ('all' | 'disc' | 'ram' | 'running') -> [node()]). -spec(node_type/0 :: () -> node_type()). -spec(dir/0 :: () -> file:filename()). -spec(cluster_status_from_mnesia/0 :: () -> rabbit_types:ok_or_error2( cluster_status(), any())). %% Operations on the db and utils, mainly used in `rabbit_upgrade' and `rabbit' -spec(init_db_unchecked/2 :: ([node()], node_type()) -> 'ok'). -spec(copy_db/1 :: (file:filename()) -> rabbit_types:ok_or_error(any())). -spec(check_cluster_consistency/0 :: () -> 'ok'). -spec(ensure_mnesia_dir/0 :: () -> 'ok'). %% Hooks used in `rabbit_node_monitor' -spec(on_node_up/1 :: (node()) -> 'ok'). -spec(on_node_down/1 :: (node()) -> 'ok'). -endif. %%---------------------------------------------------------------------------- %% Main interface %%---------------------------------------------------------------------------- init() -> ensure_mnesia_running(), ensure_mnesia_dir(), case is_virgin_node() of true -> init_from_config(); false -> NodeType = node_type(), init_db_and_upgrade(cluster_nodes(all), NodeType, NodeType =:= ram) end, %% We intuitively expect the global name server to be synced when %% Mnesia is up. In fact that's not guaranteed to be the case - %% let's make it so. ok = global:sync(), ok. init_from_config() -> {TryNodes, NodeType} = case application:get_env(rabbit, cluster_nodes) of {ok, Nodes} when is_list(Nodes) -> Config = {Nodes -- [node()], case lists:member(node(), Nodes) of true -> disc; false -> ram end}, error_logger:warning_msg( "Converting legacy 'cluster_nodes' configuration~n ~w~n" "to~n ~w.~n~n" "Please update the configuration to the new format " "{Nodes, NodeType}, where Nodes contains the nodes that the " "node will try to cluster with, and NodeType is either " "'disc' or 'ram'~n", [Nodes, Config]), Config; {ok, Config} -> Config end, case find_good_node(nodes_excl_me(TryNodes)) of {ok, Node} -> rabbit_log:info("Node '~p' selected for clustering from " "configuration~n", [Node]), {ok, {_, DiscNodes, _}} = discover_cluster(Node), init_db_and_upgrade(DiscNodes, NodeType, true), rabbit_node_monitor:notify_joined_cluster(); none -> rabbit_log:warning("Could not find any suitable node amongst the " "ones provided in the configuration: ~p~n", [TryNodes]), init_db_and_upgrade([node()], disc, false) end. %% Make the node join a cluster. The node will be reset automatically %% before we actually cluster it. The nodes provided will be used to %% find out about the nodes in the cluster. %% %% This function will fail if: %% %% * The node is currently the only disc node of its cluster %% * We can't connect to any of the nodes provided %% * The node is currently already clustered with the cluster of the nodes %% provided %% %% Note that we make no attempt to verify that the nodes provided are %% all in the same cluster, we simply pick the first online node and %% we cluster to its cluster. join_cluster(DiscoveryNode, NodeType) -> ensure_mnesia_not_running(), ensure_mnesia_dir(), case is_only_clustered_disc_node() of true -> e(clustering_only_disc_node); false -> ok end, {ClusterNodes, _, _} = case discover_cluster(DiscoveryNode) of {ok, Res} -> Res; {error, _} = E -> throw(E) end, case me_in_nodes(ClusterNodes) of false -> %% reset the node. this simplifies things and it will be needed in %% this case - we're joining a new cluster with new nodes which %% are not in synch with the current node. I also lifts the burden %% of reseting the node from the user. reset_gracefully(), %% Join the cluster rabbit_misc:local_info_msg("Clustering with ~p as ~p node~n", [ClusterNodes, NodeType]), ok = init_db_with_mnesia(ClusterNodes, NodeType, true, true), rabbit_node_monitor:notify_joined_cluster(), ok; true -> rabbit_misc:local_info_msg("Already member of cluster: ~p~n", [ClusterNodes]), {ok, already_member} end. %% return node to its virgin state, where it is not member of any %% cluster, has no cluster configuration, no local database, and no %% persisted messages reset() -> ensure_mnesia_not_running(), rabbit_misc:local_info_msg("Resetting Rabbit~n", []), reset_gracefully(). force_reset() -> ensure_mnesia_not_running(), rabbit_misc:local_info_msg("Resetting Rabbit forcefully~n", []), wipe(). reset_gracefully() -> AllNodes = cluster_nodes(all), %% Reconnecting so that we will get an up to date nodes. We don't %% need to check for consistency because we are 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, false), case is_only_clustered_disc_node() of true -> e(resetting_only_disc_node); false -> ok end, leave_cluster(), rabbit_misc:ensure_ok(mnesia:delete_schema([node()]), cannot_delete_schema), wipe(). wipe() -> %% We need to make sure that we don't end up in a distributed %% Erlang system with nodes while not being in an Mnesia cluster %% with them. We don't handle that well. [erlang:disconnect_node(N) || N <- cluster_nodes(all)], %% remove persisted messages and any other garbage we find ok = rabbit_file:recursive_delete(filelib:wildcard(dir() ++ "/*")), ok = rabbit_node_monitor:reset_cluster_status(), ok. change_cluster_node_type(Type) -> ensure_mnesia_not_running(), ensure_mnesia_dir(), case is_clustered() of false -> e(not_clustered); true -> ok end, {_, _, RunningNodes} = case discover_cluster(cluster_nodes(all)) of {ok, Status} -> Status; {error, _Reason} -> e(cannot_connect_to_cluster) end, %% We might still be marked as running by a remote node since the %% information of us going down might not have propagated yet. Node = case RunningNodes -- [node()] of [] -> e(no_online_cluster_nodes); [Node0|_] -> Node0 end, ok = reset(), ok = join_cluster(Node, Type). update_cluster_nodes(DiscoveryNode) -> ensure_mnesia_not_running(), ensure_mnesia_dir(), Status = {AllNodes, _, _} = case discover_cluster(DiscoveryNode) of {ok, Status0} -> Status0; {error, _Reason} -> e(cannot_connect_to_node) end, case me_in_nodes(AllNodes) of true -> %% As in `check_consistency/0', we can safely delete the %% schema here, since it'll be replicated from the other %% nodes mnesia:delete_schema([node()]), rabbit_node_monitor:write_cluster_status(Status), rabbit_misc:local_info_msg("Updating cluster nodes from ~p~n", [DiscoveryNode]), init_db_with_mnesia(AllNodes, node_type(), true, true); false -> e(inconsistent_cluster) end, ok. %% We proceed like this: try to remove the node locally. If the node %% is offline, we remove the node if: %% * This node is a disc node %% * All other nodes are offline %% * This node was, at the best of our knowledge (see comment below) %% the last or second to last after the node we're removing to go %% down forget_cluster_node(Node, RemoveWhenOffline) -> case lists:member(Node, cluster_nodes(all)) of true -> ok; false -> e(not_a_cluster_node) end, case {RemoveWhenOffline, is_running()} of {true, false} -> remove_node_offline_node(Node); {true, true} -> e(online_node_offline_flag); {false, false} -> e(offline_node_no_offline_flag); {false, true} -> rabbit_misc:local_info_msg( "Removing node ~p from cluster~n", [Node]), case remove_node_if_mnesia_running(Node) of ok -> ok; {error, _} = Err -> throw(Err) end end. remove_node_offline_node(Node) -> %% Here `mnesia:system_info(running_db_nodes)' will RPC, but that's what we %% want - we need to know the running nodes *now*. If the current node is a %% RAM node it will return bogus results, but we don't care since we only do %% this operation from disc nodes. case {mnesia:system_info(running_db_nodes) -- [Node], node_type()} of {[], disc} -> start_mnesia(), try %% What we want to do here is replace the last node to %% go down with the current node. The way we do this %% is by force loading the table, and making sure that %% they are loaded. rabbit_table:force_load(), rabbit_table:wait_for_replicated(), forget_cluster_node(Node, false), force_load_next_boot() after stop_mnesia() end; {_, _} -> e(removing_node_from_offline_node) end. %%---------------------------------------------------------------------------- %% Queries %%---------------------------------------------------------------------------- status() -> IfNonEmpty = fun (_, []) -> []; (Type, Nodes) -> [{Type, Nodes}] end, [{nodes, (IfNonEmpty(disc, cluster_nodes(disc)) ++ IfNonEmpty(ram, cluster_nodes(ram)))}] ++ case is_running() of true -> RunningNodes = cluster_nodes(running), [{running_nodes, RunningNodes}, {partitions, mnesia_partitions(RunningNodes)}]; false -> [] end. mnesia_partitions(Nodes) -> Replies = rabbit_node_monitor:partitions(Nodes), [Reply || Reply = {_, R} <- Replies, R =/= []]. is_running() -> mnesia:system_info(is_running) =:= yes. is_clustered() -> AllNodes = cluster_nodes(all), AllNodes =/= [] andalso AllNodes =/= [node()]. cluster_nodes(WhichNodes) -> cluster_status(WhichNodes). %% This function is the actual source of information, since it gets %% the data from mnesia. Obviously it'll work only when mnesia is %% running. cluster_status_from_mnesia() -> case is_running() of false -> {error, mnesia_not_running}; true -> %% If the tables are not present, it means that %% `init_db/3' hasn't been run yet. In other words, either %% we are a virgin node or a restarted RAM node. In both %% cases we're not interested in what mnesia has to say. NodeType = case mnesia:system_info(use_dir) of true -> disc; false -> ram end, case rabbit_table:is_present() of true -> AllNodes = mnesia:system_info(db_nodes), DiscCopies = mnesia:table_info(schema, disc_copies), DiscNodes = case NodeType of disc -> nodes_incl_me(DiscCopies); ram -> DiscCopies end, %% `mnesia:system_info(running_db_nodes)' is safe since %% we know that mnesia is running RunningNodes = mnesia:system_info(running_db_nodes), {ok, {AllNodes, DiscNodes, RunningNodes}}; false -> {error, tables_not_present} end end. cluster_status(WhichNodes) -> {AllNodes, DiscNodes, RunningNodes} = Nodes = case cluster_status_from_mnesia() of {ok, Nodes0} -> Nodes0; {error, _Reason} -> {AllNodes0, DiscNodes0, RunningNodes0} = rabbit_node_monitor:read_cluster_status(), %% The cluster status file records the status when the node is %% online, but we know for sure that the node is offline now, so %% we can remove it from the list of running nodes. {AllNodes0, DiscNodes0, nodes_excl_me(RunningNodes0)} end, case WhichNodes of status -> Nodes; all -> AllNodes; disc -> DiscNodes; ram -> AllNodes -- DiscNodes; running -> RunningNodes end. node_info() -> {erlang:system_info(otp_release), rabbit_misc:version(), cluster_status_from_mnesia()}. node_type() -> {_AllNodes, DiscNodes, _RunningNodes} = rabbit_node_monitor:read_cluster_status(), case DiscNodes =:= [] orelse me_in_nodes(DiscNodes) of true -> disc; false -> ram end. dir() -> mnesia:system_info(directory). %%---------------------------------------------------------------------------- %% Operations on the db %%---------------------------------------------------------------------------- %% Adds the provided nodes to the mnesia cluster, creating a new %% schema if there is the need to and catching up if there are other %% nodes in the cluster already. It also updates the cluster status %% file. init_db(ClusterNodes, NodeType, CheckOtherNodes) -> Nodes = change_extra_db_nodes(ClusterNodes, CheckOtherNodes), %% Note that we use `system_info' here and not the cluster status %% since when we start rabbit for the first time the cluster %% status will say we are a disc node but the tables won't be %% present yet. WasDiscNode = mnesia:system_info(use_dir), case {Nodes, WasDiscNode, NodeType} of {[], _, ram} -> %% Standalone ram node, we don't want that throw({error, cannot_create_standalone_ram_node}); {[], false, disc} -> %% RAM -> disc, starting from scratch ok = create_schema(); {[], true, disc} -> %% First disc node up maybe_force_load(), ok; {[_ | _], _, _} -> %% Subsequent node in cluster, catch up maybe_force_load(), ok = rabbit_table:wait_for_replicated(), ok = rabbit_table:create_local_copy(NodeType) end, ensure_schema_integrity(), rabbit_node_monitor:update_cluster_status(), ok. init_db_unchecked(ClusterNodes, NodeType) -> init_db(ClusterNodes, NodeType, false). init_db_and_upgrade(ClusterNodes, NodeType, CheckOtherNodes) -> ok = init_db(ClusterNodes, NodeType, CheckOtherNodes), ok = case rabbit_upgrade:maybe_upgrade_local() of ok -> ok; starting_from_scratch -> rabbit_version:record_desired(); version_not_available -> schema_ok_or_move() end, %% `maybe_upgrade_local' restarts mnesia, so ram nodes will forget %% about the cluster case NodeType of ram -> start_mnesia(), change_extra_db_nodes(ClusterNodes, false); disc -> ok end, %% ...and all nodes will need to wait for tables rabbit_table:wait_for_replicated(), ok. init_db_with_mnesia(ClusterNodes, NodeType, CheckOtherNodes, CheckConsistency) -> start_mnesia(CheckConsistency), try init_db_and_upgrade(ClusterNodes, NodeType, CheckOtherNodes) after stop_mnesia() end. ensure_mnesia_dir() -> MnesiaDir = dir() ++ "/", case filelib:ensure_dir(MnesiaDir) of {error, Reason} -> throw({error, {cannot_create_mnesia_dir, MnesiaDir, Reason}}); ok -> ok end. ensure_mnesia_running() -> case mnesia:system_info(is_running) of yes -> ok; starting -> wait_for(mnesia_running), ensure_mnesia_running(); Reason when Reason =:= no; Reason =:= stopping -> throw({error, mnesia_not_running}) end. ensure_mnesia_not_running() -> case mnesia:system_info(is_running) of no -> ok; stopping -> wait_for(mnesia_not_running), ensure_mnesia_not_running(); Reason when Reason =:= yes; Reason =:= starting -> throw({error, mnesia_unexpectedly_running}) end. ensure_schema_integrity() -> case rabbit_table:check_schema_integrity() of ok -> ok; {error, Reason} -> throw({error, {schema_integrity_check_failed, Reason}}) end. copy_db(Destination) -> ok = ensure_mnesia_not_running(), rabbit_file:recursive_copy(dir(), Destination). force_load_filename() -> filename:join(dir(), "force_load"). force_load_next_boot() -> rabbit_file:write_file(force_load_filename(), <<"">>). maybe_force_load() -> case rabbit_file:is_file(force_load_filename()) of true -> rabbit_table:force_load(), rabbit_file:delete(force_load_filename()); false -> ok end. %% This does not guarantee us much, but it avoids some situations that %% will definitely end up badly check_cluster_consistency() -> %% We want to find 0 or 1 consistent nodes. case lists:foldl( fun (Node, {error, _}) -> check_cluster_consistency(Node); (_Node, {ok, Status}) -> {ok, Status} end, {error, not_found}, nodes_excl_me(cluster_nodes(all))) of {ok, Status = {RemoteAllNodes, _, _}} -> case ordsets:is_subset(ordsets:from_list(cluster_nodes(all)), ordsets:from_list(RemoteAllNodes)) of true -> ok; false -> %% We delete the schema here since we think we are %% clustered with nodes that are no longer in the %% cluster and there is no other way to remove %% them from our schema. On the other hand, we are %% sure that there is another online node that we %% can use to sync the tables with. There is a %% race here: if between this check and the %% `init_db' invocation the cluster gets %% disbanded, we're left with a node with no %% mnesia data that will try to connect to offline %% nodes. mnesia:delete_schema([node()]) end, rabbit_node_monitor:write_cluster_status(Status); {error, not_found} -> ok; {error, _} = E -> throw(E) end. check_cluster_consistency(Node) -> case rpc:call(Node, rabbit_mnesia, node_info, []) of {badrpc, _Reason} -> {error, not_found}; {_OTP, _Rabbit, {error, _}} -> {error, not_found}; {OTP, Rabbit, {ok, Status}} -> case check_consistency(OTP, Rabbit, Node, Status) of {error, _} = E -> E; {ok, Res} -> {ok, Res} end; {_OTP, Rabbit, _Hash, _Status} -> %% delegate hash checking implies version mismatch version_error("Rabbit", rabbit_misc:version(), Rabbit) end. %%-------------------------------------------------------------------- %% Hooks for `rabbit_node_monitor' %%-------------------------------------------------------------------- on_node_up(Node) -> case running_disc_nodes() of [Node] -> rabbit_log:info("cluster contains disc nodes again~n"); _ -> ok end. on_node_down(_Node) -> case running_disc_nodes() of [] -> rabbit_log:info("only running disc node went down~n"); _ -> ok end. running_disc_nodes() -> {_AllNodes, DiscNodes, RunningNodes} = cluster_status(status), ordsets:to_list(ordsets:intersection(ordsets:from_list(DiscNodes), ordsets:from_list(RunningNodes))). %%-------------------------------------------------------------------- %% Internal helpers %%-------------------------------------------------------------------- discover_cluster(Nodes) when is_list(Nodes) -> lists:foldl(fun (_, {ok, Res}) -> {ok, Res}; (Node, {error, _}) -> discover_cluster(Node) end, {error, no_nodes_provided}, Nodes); discover_cluster(Node) when Node == node() -> {error, {cannot_discover_cluster, "Cannot cluster node with itself"}}; discover_cluster(Node) -> OfflineError = {error, {cannot_discover_cluster, "The nodes provided are either offline or not running"}}, case rpc:call(Node, rabbit_mnesia, cluster_status_from_mnesia, []) of {badrpc, _Reason} -> OfflineError; {error, mnesia_not_running} -> OfflineError; {ok, Res} -> {ok, Res} end. schema_ok_or_move() -> case rabbit_table:check_schema_integrity() of ok -> ok; {error, Reason} -> %% NB: we cannot use rabbit_log here since it may not have been %% started yet error_logger:warning_msg("schema integrity check failed: ~p~n" "moving database to backup location " "and recreating schema from scratch~n", [Reason]), ok = move_db(), ok = create_schema() end. %% We only care about disc nodes since ram nodes are supposed to catch %% up only create_schema() -> stop_mnesia(), rabbit_misc:ensure_ok(mnesia:create_schema([node()]), cannot_create_schema), start_mnesia(), ok = rabbit_table:create(), ensure_schema_integrity(), ok = rabbit_version:record_desired(). move_db() -> stop_mnesia(), MnesiaDir = filename:dirname(dir() ++ "/"), {{Year, Month, Day}, {Hour, Minute, Second}} = erlang:universaltime(), BackupDir = rabbit_misc:format( "~s_~w~2..0w~2..0w~2..0w~2..0w~2..0w", [MnesiaDir, Year, Month, Day, Hour, Minute, Second]), case file:rename(MnesiaDir, BackupDir) of ok -> %% NB: we cannot use rabbit_log here since it may not have %% been started yet error_logger:warning_msg("moved database from ~s to ~s~n", [MnesiaDir, BackupDir]), ok; {error, Reason} -> throw({error, {cannot_backup_mnesia, MnesiaDir, BackupDir, Reason}}) end, ensure_mnesia_dir(), start_mnesia(), ok. remove_node_if_mnesia_running(Node) -> case is_running() of false -> {error, mnesia_not_running}; true -> %% Deleting the the schema copy of the node will result in %% the node being removed from the cluster, with that %% change being propagated to all nodes case mnesia:del_table_copy(schema, Node) of {atomic, ok} -> rabbit_amqqueue:forget_all_durable(Node), rabbit_node_monitor:notify_left_cluster(Node), ok; {aborted, Reason} -> {error, {failed_to_remove_node, Node, Reason}} end end. leave_cluster() -> case nodes_excl_me(cluster_nodes(all)) of [] -> ok; AllNodes -> case lists:any(fun leave_cluster/1, AllNodes) of true -> ok; false -> e(no_running_cluster_nodes) end end. leave_cluster(Node) -> case rpc:call(Node, rabbit_mnesia, remove_node_if_mnesia_running, [node()]) of ok -> true; {error, mnesia_not_running} -> false; {error, Reason} -> throw({error, Reason}); {badrpc, nodedown} -> false end. wait_for(Condition) -> error_logger:info_msg("Waiting for ~p...~n", [Condition]), timer:sleep(1000). start_mnesia(CheckConsistency) -> case CheckConsistency of true -> check_cluster_consistency(); false -> ok end, rabbit_misc:ensure_ok(mnesia:start(), cannot_start_mnesia), ensure_mnesia_running(). start_mnesia() -> start_mnesia(true). stop_mnesia() -> stopped = mnesia:stop(), ensure_mnesia_not_running(). change_extra_db_nodes(ClusterNodes0, CheckOtherNodes) -> ClusterNodes = nodes_excl_me(ClusterNodes0), case {mnesia:change_config(extra_db_nodes, ClusterNodes), ClusterNodes} of {{ok, []}, [_|_]} when CheckOtherNodes -> throw({error, {failed_to_cluster_with, ClusterNodes, "Mnesia could not connect to any nodes."}}); {{ok, Nodes}, _} -> Nodes end. check_consistency(OTP, Rabbit) -> rabbit_misc:sequence_error( [check_otp_consistency(OTP), check_rabbit_consistency(Rabbit)]). check_consistency(OTP, Rabbit, Node, Status) -> rabbit_misc:sequence_error( [check_otp_consistency(OTP), check_rabbit_consistency(Rabbit), check_nodes_consistency(Node, Status)]). check_nodes_consistency(Node, RemoteStatus = {RemoteAllNodes, _, _}) -> case me_in_nodes(RemoteAllNodes) of true -> {ok, RemoteStatus}; false -> {error, {inconsistent_cluster, rabbit_misc:format("Node ~p thinks it's clustered " "with node ~p, but ~p disagrees", [node(), Node, Node])}} end. check_version_consistency(This, Remote, Name) -> check_version_consistency(This, Remote, Name, fun (A, B) -> A =:= B end). check_version_consistency(This, Remote, Name, Comp) -> case Comp(This, Remote) of true -> ok; false -> version_error(Name, This, Remote) end. version_error(Name, This, Remote) -> {error, {inconsistent_cluster, rabbit_misc:format("~s version mismatch: local node is ~s, " "remote node ~s", [Name, This, Remote])}}. check_otp_consistency(Remote) -> check_version_consistency(erlang:system_info(otp_release), Remote, "OTP"). check_rabbit_consistency(Remote) -> check_version_consistency( rabbit_misc:version(), Remote, "Rabbit", fun rabbit_misc:version_minor_equivalent/2). %% This is fairly tricky. We want to know if the node is in the state %% that a `reset' would leave it in. We cannot simply check if the %% mnesia tables aren't there because restarted RAM nodes won't have %% tables while still being non-virgin. What we do instead is to %% check if the mnesia directory is non existant or empty, with the %% exception of the cluster status files, which will be there thanks to %% `rabbit_node_monitor:prepare_cluster_status_file/0'. is_virgin_node() -> case rabbit_file:list_dir(dir()) of {error, enoent} -> true; {ok, []} -> true; {ok, [File1, File2]} -> lists:usort([dir() ++ "/" ++ File1, dir() ++ "/" ++ File2]) =:= lists:usort([rabbit_node_monitor:cluster_status_filename(), rabbit_node_monitor:running_nodes_filename()]); {ok, _} -> false end. find_good_node([]) -> none; find_good_node([Node | Nodes]) -> case rpc:call(Node, rabbit_mnesia, node_info, []) of {badrpc, _Reason} -> find_good_node(Nodes); %% old delegate hash check {_OTP, _Rabbit, _Hash, _} -> find_good_node(Nodes); {OTP, Rabbit, _} -> case check_consistency(OTP, Rabbit) of {error, _} -> find_good_node(Nodes); ok -> {ok, Node} end end. is_only_clustered_disc_node() -> node_type() =:= disc andalso is_clustered() andalso cluster_nodes(disc) =:= [node()]. me_in_nodes(Nodes) -> lists:member(node(), Nodes). nodes_incl_me(Nodes) -> lists:usort([node()|Nodes]). nodes_excl_me(Nodes) -> Nodes -- [node()]. e(Tag) -> throw({error, {Tag, error_description(Tag)}}). error_description(clustering_only_disc_node) -> "You cannot cluster a node if it is the only disc node in its existing " " cluster. If new nodes joined while this node was offline, use " "'update_cluster_nodes' to add them manually."; error_description(resetting_only_disc_node) -> "You cannot reset a node when it is the only disc node in a cluster. " "Please convert another node of the cluster to a disc node first."; error_description(not_clustered) -> "Non-clustered nodes can only be disc nodes."; error_description(cannot_connect_to_cluster) -> "Could not connect to the cluster nodes present in this node's " "status file. If the cluster has changed, you can use the " "'update_cluster_nodes' command to point to the new cluster nodes."; error_description(no_online_cluster_nodes) -> "Could not find any online cluster nodes. If the cluster has changed, " "you can use the 'update_cluster_nodes' command."; error_description(cannot_connect_to_node) -> "Could not connect to the cluster node provided."; error_description(inconsistent_cluster) -> "The nodes provided do not have this node as part of the cluster."; error_description(not_a_cluster_node) -> "The node selected is not in the cluster."; error_description(online_node_offline_flag) -> "You set the --offline flag, which is used to remove nodes remotely from " "offline nodes, but this node is online."; error_description(offline_node_no_offline_flag) -> "You are trying to remove a node from an offline node. That is dangerous, " "but can be done with the --offline flag. Please consult the manual " "for rabbitmqctl for more information."; error_description(removing_node_from_offline_node) -> "To remove a node remotely from an offline node, the node you are removing " "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.".