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%%============================================================================== |
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%% Copyright 2017 Erlang Solutions Ltd. |
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%% |
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%% Licensed under the Apache License, Version 2.0 (the "License"); |
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%% you may not use this file except in compliance with the License. |
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%% You may obtain a copy of the License at |
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%% |
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%% http://www.apache.org/licenses/LICENSE-2.0 |
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%% |
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%% Unless required by applicable law or agreed to in writing, software |
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%% distributed under the License is distributed on an "AS IS" BASIS, |
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%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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%% See the License for the specific language governing permissions and |
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%% limitations under the License. |
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%%============================================================================== |
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-module(mod_global_distrib_server_sup). |
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-author('piotr.nosek@erlang-solutions.com'). |
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-behaviour(supervisor). |
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-include("mongoose.hrl"). |
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-export([start_link/1, init/1]). |
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-export([get_connection/1, is_available/1]). |
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-export([start_pool/4, stop_pool/2]). |
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-ignore_xref([start_link/1]). |
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%%-------------------------------------------------------------------- |
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%% API |
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%%-------------------------------------------------------------------- |
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-spec start_link(Server :: jid:lserver()) -> {ok, pid()} | {error, any()}. |
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start_link(Server) -> |
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SupName = mod_global_distrib_utils:server_to_sup_name(Server), |
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supervisor:start_link({local, SupName}, ?MODULE, [Server]). |
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-spec get_connection(Server :: jid:lserver()) -> {ok, pid()} | {error, not_available}. |
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get_connection(Server) -> |
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try mod_global_distrib_server_mgr:get_connection(Server) |
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%% Possible issues: |
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%% - {'EXIT', {noproc, _}} |
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%% - {case_clause,{'EXIT',{no_connections... |
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catch Class:Reason:Stacktrace -> |
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?LOG_ERROR(#{what => gd_get_connection_failed, server => Server, |
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class => Class, reason => Reason, stacktrace => Stacktrace}), |
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%% May be caused by missing server_sup or missing connection manager |
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%% The former occurs when a process tries to send a message to Server |
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%% for the first time. |
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%% The latter occurs when some other process already started server_sup, |
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%% which hasn't started manager yet. |
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%% In both cases the caller should attempt to start server_sup, |
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%% so the main outgoing_conns_sup becomes a synchronisation point |
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%% because it's impossible to learn that the server_sup is `already_started` |
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%% without it finishing the init first (thus finishing the init of mgr as well). |
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%% |
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%% TODO: Write a test for it, once we establish a good way to reproduce |
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%% race conditions in tests! |
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{error, not_available} |
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end. |
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-spec is_available(Server :: jid:lserver()) -> boolean(). |
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is_available(Server) -> |
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pong == mod_global_distrib_server_mgr:ping_proc(Server). |
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-spec start_pool(Supervisor :: pid(), |
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Endpoint :: mod_global_distrib_utils:endpoint(), |
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Server :: jid:lserver(), |
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ConnOpts :: map()) -> |
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{ok, atom(), pid()} | {error, any()}. |
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start_pool(Supervisor, Endpoint, Server, #{connections_per_endpoint := PoolSize}) -> |
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PoolRef = endpoint_to_atom(Endpoint), |
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PoolParams = [ |
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PoolRef, |
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{mod_global_distrib_connection, start_link, [Endpoint, Server]}, |
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[{pool_size, PoolSize}] |
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], |
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PoolSpec = #{ |
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id => Endpoint, |
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start => {cpool, new_pool_sup, PoolParams}, |
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restart => temporary, |
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shutdown => 5000, |
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type => supervisor, |
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modules => dynamic |
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}, |
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{ok, PoolPid} = supervisor:start_child(Supervisor, PoolSpec), |
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{ok, PoolRef, PoolPid}. |
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-spec stop_pool(Supervisor :: pid(), Endpoint :: mod_global_distrib_utils:endpoint()) -> |
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ok | {error, any()}. |
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stop_pool(Supervisor, Endpoint) -> |
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ok = supervisor:terminate_child(Supervisor, Endpoint), |
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supervisor:delete_child(Supervisor, Endpoint). |
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%%-------------------------------------------------------------------- |
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%% supervisor callback |
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%%-------------------------------------------------------------------- |
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init([Server]) -> |
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SupFlags = #{ strategy => rest_for_one, intensity => 5, period => 5 }, |
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MgrName = mod_global_distrib_utils:server_to_mgr_name(Server), |
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ServerMgrSpec = #{ |
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id => MgrName, |
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start => {mod_global_distrib_server_mgr, start_link, [Server, self()]}, |
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restart => transient, |
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shutdown => 5000, |
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type => worker, |
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modules => dynamic |
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}, |
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{ok, {SupFlags, [ServerMgrSpec]}}. |
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%%-------------------------------------------------------------------- |
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%% Helpers |
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%%-------------------------------------------------------------------- |
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-spec endpoint_to_atom(mod_global_distrib_utils:endpoint()) -> atom(). |
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endpoint_to_atom({IP, Port}) -> |
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list_to_atom(inet:ntoa(IP) ++ "_" ++ integer_to_list(Port)). |