Resize SQL pool on configuration reload

Fixes #2541

diff --git a/src/ejabberd_rdbms.erl b/src/ejabberd_rdbms.erl
index d2c338548708d185f7effdd0b66d94f056dfcb35..2b69258e5eeb45fca5abc195e0e06251b5feacd6 100644 (file)
--- a/src/ejabberd_rdbms.erl
+++ b/src/ejabberd_rdbms.erl
@@ -71,7 +71,7 @@ get_spec(Host) ->
 
 -spec config_reloaded() -> ok.
 config_reloaded() ->
-    lists:foreach(fun start_host/1, ejabberd_config:get_myhosts()).
+    lists:foreach(fun reload_host/1, ejabberd_config:get_myhosts()).
 
 -spec start_host(binary()) -> ok.
 start_host(Host) ->
@@ -96,6 +96,10 @@ stop_host(Host) ->
     supervisor:delete_child(?MODULE, SupName),
     ok.
 
+-spec reload_host(binary()) -> ok.
+reload_host(Host) ->
+    ejabberd_sql_sup:reload(Host).
+
 %% Returns {true, App} if we have configured sql for the given host
 needs_sql(Host) ->
     LHost = jid:nameprep(Host),

diff --git a/src/ejabberd_sql_sup.erl b/src/ejabberd_sql_sup.erl
index b6315c175e8cbf5a1ead199b26d7b7be8bd8b2da..eaaef5fc899252945178a1116d6af6b9b0f4680a 100644 (file)
--- a/src/ejabberd_sql_sup.erl
+++ b/src/ejabberd_sql_sup.erl
@@ -31,21 +31,19 @@
 
 -export([start_link/1, init/1, add_pid/2, remove_pid/2,
         get_pids/1, get_random_pid/1, transform_options/1,
-        opt_type/1]).
+        reload/1, opt_type/1]).
 
 -include("logger.hrl").
+-include_lib("stdlib/include/ms_transform.hrl").
 
 -define(PGSQL_PORT, 5432).
-
 -define(MYSQL_PORT, 3306).
-
 -define(DEFAULT_POOL_SIZE, 10).
-
 -define(DEFAULT_SQL_START_INTERVAL, 30).
-
 -define(CONNECT_TIMEOUT, 500).
 
--record(sql_pool, {host, pid}).
+-record(sql_pool, {host :: binary(),
+                  pid  :: pid()}).
 
 start_link(Host) ->
     ejabberd_mnesia:create(?MODULE, sql_pool,
@@ -59,9 +57,6 @@ start_link(Host) ->
                          ?MODULE, [Host]).
 
 init([Host]) ->
-    StartInterval = ejabberd_config:get_option(
-                      {sql_start_interval, Host},
-                      ?DEFAULT_SQL_START_INTERVAL),
     Type = ejabberd_config:get_option({sql_type, Host}, odbc),
     PoolSize = get_pool_size(Type, Host),
     case Type of
@@ -72,16 +67,37 @@ init([Host]) ->
         _ ->
             ok
     end,
+    {ok, {{one_for_one, PoolSize * 10, 1},
+         [child_spec(I, Host) || I <- lists:seq(1, PoolSize)]}}.
 
-    {ok,
-     {{one_for_one, PoolSize * 10, 1},
-      lists:map(fun (I) ->
-                       {I,
-                        {ejabberd_sql, start_link,
-                         [Host, StartInterval * 1000]},
-                        transient, 2000, worker, [?MODULE]}
-               end,
-               lists:seq(1, PoolSize))}}.
+reload(Host) ->
+    Type = ejabberd_config:get_option({sql_type, Host}, odbc),
+    NewPoolSize = get_pool_size(Type, Host),
+    OldPoolSize = ets:select_count(
+                   sql_pool,
+                   ets:fun2ms(
+                     fun(#sql_pool{host = H}) when H == Host ->
+                             true
+                     end)),
+    reload(Host, NewPoolSize, OldPoolSize).
+
+reload(Host, NewPoolSize, OldPoolSize) ->
+    Sup = gen_mod:get_module_proc(Host, ?MODULE),
+    if NewPoolSize == OldPoolSize ->
+           ok;
+       NewPoolSize > OldPoolSize ->
+           lists:foreach(
+             fun(I) ->
+                     Spec = child_spec(I, Host),
+                     supervisor:start_child(Sup, Spec)
+             end, lists:seq(OldPoolSize+1, NewPoolSize));
+       OldPoolSize > NewPoolSize ->
+           lists:foreach(
+             fun(I) ->
+                     supervisor:terminate_child(Sup, I),
+                     supervisor:delete_child(Sup, I)
+             end, lists:seq(NewPoolSize+1, OldPoolSize))
+    end.
 
 get_pids(Host) ->
     Rs = mnesia:dirty_read(sql_pool, Host),
@@ -123,6 +139,13 @@ get_pool_size(SQLType, Host) ->
     end,
     PoolSize.
 
+child_spec(I, Host) ->
+    StartInterval = ejabberd_config:get_option(
+                      {sql_start_interval, Host},
+                      ?DEFAULT_SQL_START_INTERVAL),
+    {I, {ejabberd_sql, start_link, [Host, timer:seconds(StartInterval)]},
+     transient, 2000, worker, [?MODULE]}.
+
 transform_options(Opts) ->
     lists:foldl(fun transform_options/2, [], Opts).