Spawn SQL connections on demand only

src/ejabberd_option.erl

@@ -975,10 +975,10 @@ sql_start_interval() ->
 sql_start_interval(Host) ->
     ejabberd_config:get_option({sql_start_interval, Host}).
 
--spec sql_type() -> 'mssql' | 'mysql' | 'odbc' | 'pgsql' | 'sqlite' | 'undefined'.
+-spec sql_type() -> 'mssql' | 'mysql' | 'odbc' | 'pgsql' | 'sqlite'.
 sql_type() ->
     sql_type(global).
--spec sql_type(global | binary()) -> 'mssql' | 'mysql' | 'odbc' | 'pgsql' | 'sqlite' | 'undefined'.
+-spec sql_type(global | binary()) -> 'mssql' | 'mysql' | 'odbc' | 'pgsql' | 'sqlite'.
 sql_type(Host) ->
     ejabberd_config:get_option({sql_type, Host}).
 

src/ejabberd_options.erl

@@ -599,7 +599,7 @@ options() ->
       fun(Host) -> ejabberd_config:default_ram_db(Host, ejabberd_sm) end},
      {sm_use_cache,
       fun(Host) -> ejabberd_config:get_option({use_cache, Host}) end},
-     {sql_type, undefined},
+     {sql_type, odbc},
      {sql_connect_timeout, timer:seconds(5)},
      {sql_database, undefined},
      {sql_keepalive_interval, undefined},

src/ejabberd_rdbms.erl

@@ -1,122 +0,0 @@
-%%%----------------------------------------------------------------------
-%%% File    : ejabberd_rdbms.erl
-%%% Author  : Mickael Remond <mickael.remond@process-one.net>
-%%% Purpose : Manage the start of the database modules when needed
-%%% Created : 31 Jan 2003 by Alexey Shchepin <alexey@process-one.net>
-%%%
-%%%
-%%% ejabberd, Copyright (C) 2002-2019   ProcessOne
-%%%
-%%% This program is free software; you can redistribute it and/or
-%%% modify it under the terms of the GNU General Public License as
-%%% published by the Free Software Foundation; either version 2 of the
-%%% License, or (at your option) any later version.
-%%%
-%%% This program is distributed in the hope that it will be useful,
-%%% but WITHOUT ANY WARRANTY; without even the implied warranty of
-%%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-%%% General Public License for more details.
-%%%
-%%% You should have received a copy of the GNU General Public License along
-%%% with this program; if not, write to the Free Software Foundation, Inc.,
-%%% 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
-%%%
-%%%----------------------------------------------------------------------
-
--module(ejabberd_rdbms).
-
--behaviour(supervisor).
-
--author('alexey@process-one.net').
-
--export([start_link/0, init/1, stop/0,
-	 config_reloaded/0, start_host/1, stop_host/1]).
-
--include("logger.hrl").
-
-start_link() ->
-    supervisor:start_link({local, ?MODULE}, ?MODULE, []).
-
-init([]) ->
-    file:delete(ejabberd_sql:freetds_config()),
-    file:delete(ejabberd_sql:odbc_config()),
-    file:delete(ejabberd_sql:odbcinst_config()),
-    ejabberd_hooks:add(host_up, ?MODULE, start_host, 20),
-    ejabberd_hooks:add(host_down, ?MODULE, stop_host, 90),
-    ejabberd_hooks:add(config_reloaded, ?MODULE, config_reloaded, 20),
-    {ok, {{one_for_one, 10, 1}, get_specs()}}.
-
-stop() ->
-    ejabberd_hooks:delete(host_up, ?MODULE, start_host, 20),
-    ejabberd_hooks:delete(host_down, ?MODULE, stop_host, 90),
-    ejabberd_hooks:delete(config_reloaded, ?MODULE, config_reloaded, 20),
-    ejabberd_sup:stop_child(?MODULE).
-
--spec get_specs() -> [supervisor:child_spec()].
-get_specs() ->
-    lists:flatmap(
-      fun(Host) ->
-	      case get_spec(Host) of
-		  {ok, Spec} -> [Spec];
-		  undefined -> []
-	      end
-      end, ejabberd_option:hosts()).
-
--spec get_spec(binary()) -> {ok, supervisor:child_spec()} | undefined.
-get_spec(Host) ->
-    case needs_sql(Host) of
-	{true, App} ->
-	    ejabberd:start_app(App),
-	    SupName = gen_mod:get_module_proc(Host, ejabberd_sql_sup),
-	    {ok, {SupName, {ejabberd_sql_sup, start_link, [Host]},
-		  transient, infinity, supervisor, [ejabberd_sql_sup]}};
-	false ->
-	    undefined
-    end.
-
--spec config_reloaded() -> ok.
-config_reloaded() ->
-    lists:foreach(fun reload_host/1, ejabberd_option:hosts()).
-
--spec start_host(binary()) -> ok.
-start_host(Host) ->
-    case get_spec(Host) of
-	{ok, Spec} ->
-	    case supervisor:start_child(?MODULE, Spec) of
-		{ok, _PID} ->
-		    ok;
-		{error, {already_started, _}} ->
-		    ok;
-		{error, _} = Err ->
-		    erlang:error(Err)
-	    end;
-	undefined ->
-	    ok
-    end.
-
--spec stop_host(binary()) -> ok | {error, atom()}.
-stop_host(Host) ->
-    SupName = gen_mod:get_module_proc(Host, ejabberd_sql_sup),
-    case supervisor:terminate_child(?MODULE, SupName) of
-	ok -> supervisor:delete_child(?MODULE, SupName);
-	Err -> Err
-    end.
-
--spec reload_host(binary()) -> ok.
-reload_host(Host) ->
-    case needs_sql(Host) of
-	{true, _} -> ejabberd_sql_sup:reload(Host);
-	false -> ok
-    end.
-
-%% Returns {true, App} if we have configured sql for the given host
-needs_sql(Host) ->
-    LHost = jid:nameprep(Host),
-    case ejabberd_option:sql_type(LHost) of
-        mysql -> {true, p1_mysql};
-        pgsql -> {true, p1_pgsql};
-        sqlite -> {true, sqlite3};
-	mssql -> {true, odbc};
-        odbc -> {true, odbc};
-        undefined -> false
-    end.

src/ejabberd_sql.erl

@@ -141,8 +141,8 @@ sql_call(Host, Msg) ->
     Timeout = query_timeout(Host),
     case get(?STATE_KEY) of
 	undefined ->
-	    Proc = get_worker(Host),
-	    sync_send_event(Proc, {sql_cmd, Msg, current_time() + Timeout},
+	    sync_send_event(Host,
+			    {sql_cmd, Msg, current_time() + Timeout},
 			    Timeout);
 	_State ->
 	    nested_op(Msg)
@@ -161,6 +161,14 @@ keep_alive(Host, Proc) ->
 	    sync_send_event(Proc, force_timeout, Timeout)
     end.
 
+sync_send_event(Host, Msg, Timeout) when is_binary(Host) ->
+    case ejabberd_sql_sup:start(Host) of
+	ok ->
+	    Proc = get_worker(Host),
+	    sync_send_event(Proc, Msg, Timeout);
+	{error, _} = Err ->
+	    Err
+    end;
 sync_send_event(Proc, Msg, Timeout) ->
     try p1_fsm:sync_send_event(Proc, Msg, Timeout)
     catch _:{Reason, {p1_fsm, _, _}} ->
@@ -993,10 +1001,7 @@ log(Level, Format, Args) ->
     end.
 
 db_opts(Host) ->
-    Type = case ejabberd_option:sql_type(Host) of
-	       undefined -> odbc;
-	       T -> T
-	   end,
+    Type = ejabberd_option:sql_type(Host),
     Server = ejabberd_option:sql_server(Host),
     Timeout = ejabberd_option:sql_connect_timeout(Host),
     Transport = case ejabberd_option:sql_ssl(Host) of

src/ejabberd_sql_sup.erl

@@ -27,15 +27,67 @@
 
 -author('alexey@process-one.net').
 
--export([start_link/1, init/1, reload/1, is_started/1]).
+-export([start/1, stop/1, stop/0]).
+-export([start_link/0, start_link/1]).
+-export([init/1, reload/1, config_reloaded/0, is_started/1]).
 
 -include("logger.hrl").
 
+start(Host) ->
+    case is_started(Host) of
+	true -> ok;
+	false ->
+	    App = case ejabberd_option:sql_type(Host) of
+		      mysql -> p1_mysql;
+		      pgsql -> p1_pgsql;
+		      sqlite -> sqlite3;
+		      _ -> odbc
+		  end,
+	    ejabberd:start_app(App),
+	    Spec = #{id => gen_mod:get_module_proc(Host, ?MODULE),
+		     start => {ejabberd_sql_sup, start_link, [Host]},
+		     restart => transient,
+		     shutdown => infinity,
+		     type => supervisor,
+		     modules => [?MODULE]},
+	    case supervisor:start_child(ejabberd_db_sup, Spec) of
+		{ok, _} -> ok;
+		{error, {already_started, _}} -> ok;
+		{error, Why} = Err ->
+		    ?ERROR_MSG("Failed to start ~s: ~p", [?MODULE, Why]),
+		    Err
+	    end
+    end.
+
+stop(Host) ->
+    Proc = gen_mod:get_module_proc(Host, ?MODULE),
+    case supervisor:terminate_child(ejabberd_db_sup, Proc) of
+	ok -> supervisor:delete_child(ejabberd_db_sup, Proc);
+	Err -> Err
+    end.
+
+
+start_link() ->
+    supervisor:start_link({local, ?MODULE}, ?MODULE, []).
+
 start_link(Host) ->
     supervisor:start_link({local,
 			   gen_mod:get_module_proc(Host, ?MODULE)},
 			  ?MODULE, [Host]).
 
+stop() ->
+    ejabberd_hooks:delete(host_up, ?MODULE, start, 20),
+    ejabberd_hooks:delete(host_down, ?MODULE, stop, 90),
+    ejabberd_hooks:delete(config_reloaded, ?MODULE, config_reloaded, 20).
+
+init([]) ->
+    file:delete(ejabberd_sql:freetds_config()),
+    file:delete(ejabberd_sql:odbc_config()),
+    file:delete(ejabberd_sql:odbcinst_config()),
+    ejabberd_hooks:add(host_up, ?MODULE, start, 20),
+    ejabberd_hooks:add(host_down, ?MODULE, stop, 90),
+    ejabberd_hooks:add(config_reloaded, ?MODULE, config_reloaded, 20),
+    ignore;
 init([Host]) ->
     Type = ejabberd_option:sql_type(Host),
     PoolSize = get_pool_size(Type, Host),
@@ -49,6 +101,10 @@ init([Host]) ->
     end,
     {ok, {{one_for_one, PoolSize * 10, 1}, child_specs(Host, PoolSize)}}.
 
+-spec config_reloaded() -> ok.
+config_reloaded() ->
+    lists:foreach(fun reload/1, ejabberd_option:hosts()).
+
 -spec reload(binary()) -> ok.
 reload(Host) ->
     case is_started(Host) of

src/ejabberd_sup.erl

@@ -51,7 +51,7 @@ init([]) ->
 	   worker(ejabberd_shaper),
 	   supervisor(ejabberd_db_sup),
 	   supervisor(ejabberd_backend_sup),
-	   supervisor(ejabberd_rdbms),
+	   supervisor(ejabberd_sql_sup),
 	   worker(ejabberd_iq),
 	   worker(ejabberd_router),
 	   worker(ejabberd_router_multicast),