* src/odbc/ejabberd_odbc_sup.erl: Add an odbc_pool_size config file option to choose the number of SQL

connection in each pool (EJAB-58).
* src/odbc/ejabberd_odbc.erl: Add an odbc_keepalive_interval config file option to perform a keep
alive query at given interval (EJAB-206).

SVN Revision: 879

src/odbc/ejabberd_odbc.erl

@@ -18,7 +18,8 @@
 	 sql_query_t/1,
 	 sql_transaction/2,
 	 escape/1,
-	 escape_like/1]).
+	 escape_like/1,
+	 keep_alive/1]).
 
 %% gen_server callbacks
 -export([init/1,
@@ -37,6 +38,8 @@
 -define(PGSQL_PORT, 5432).
 -define(MYSQL_PORT, 3306).
 
+-define(KEEPALIVE_QUERY, "SELECT 1;").
+
 %%%----------------------------------------------------------------------
 %%% API
 %%%----------------------------------------------------------------------
@@ -51,7 +54,7 @@ sql_query(Host, Query) ->
 		    {sql_query, Query}, 60000).
 
 %% SQL transaction based on a list of queries
-%% This function automatically 
+%% This function automatically
 sql_transaction(Host, Queries) when is_list(Queries) ->
     F = fun() ->
 		lists:foreach(fun(Query) ->
@@ -112,6 +115,14 @@ escape_like(C)  -> odbc_queries:escape(C).
 %%          {stop, Reason}
 %%----------------------------------------------------------------------
 init([Host]) ->
+    case ejabberd_config:get_local_option({odbc_keepalive_interval, Host}) of
+	Interval when is_integer(Interval) ->
+	    timer:apply_interval(Interval*1000, ?MODULE, keep_alive, [self()]);
+	undefined ->
+	    ok;
+	_Other ->
+	    ?ERROR_MSG("Wrong odbc_keepalive_interval definition '~p' for host ~p.~n", [_Other, Host])
+    end,
     SQLServer = ejabberd_config:get_local_option({odbc_server, Host}),
     case SQLServer of
 	%% Default pgsql port
@@ -128,7 +139,6 @@ init([Host]) ->
 	    odbc_connect(SQLServer)
     end.
 
-
 %%----------------------------------------------------------------------
 %% Func: handle_call/3
 %% Returns: {reply, Reply, State}          |
@@ -220,7 +230,7 @@ execute_transaction(State, F, NRestarts) ->
 %% Open an ODBC database connection
 odbc_connect(SQLServer) ->
     case odbc:connect(SQLServer,[{scrollable_cursors, off}]) of
-	{ok, Ref} -> 
+	{ok, Ref} ->
 	    erlang:monitor(process, Ref),
 	    {ok, #state{db_ref = Ref, db_type = odbc}};
 	{error, Reason} ->
@@ -238,7 +248,7 @@ odbc_connect(SQLServer) ->
 %% Open a database connection to PostgreSQL
 pgsql_connect(Server, Port, DB, Username, Password) ->
     case pgsql:connect(Server, DB, Username, Password, Port) of
-	{ok, Ref} -> 
+	{ok, Ref} ->
 	    {ok, #state{db_ref = Ref, db_type = pgsql}};
 	{error, Reason} ->
 	    ?ERROR_MSG("PostgreSQL connection failed: ~p~n", [Reason]),
@@ -306,3 +316,7 @@ mysql_item_to_odbc(Columns, Recs) ->
     {selected,
      [element(2, Column) || Column <- Columns],
      [list_to_tuple(Rec) || Rec <- Recs]}.
+
+% perform a harmless query on all opened connexions to avoid connexion close.
+keep_alive(PID) ->
+    gen_server:call(PID, {sql_query, ?KEEPALIVE_QUERY}, 60000).

src/odbc/ejabberd_odbc_sup.erl

@@ -10,6 +10,7 @@
 -author('alexey@sevcom.net').
 -vsn('$Revision$ ').
 
+%% API
 -export([start_link/1,
 	 init/1,
 	 get_pids/1,
@@ -18,13 +19,23 @@
 
 -include("ejabberd.hrl").
 
+-define(DEFAULT_POOL_SIZE, 10).
+
 start_link(Host) ->
     supervisor:start_link({local, gen_mod:get_module_proc(Host, ?MODULE)},
 			  ?MODULE, [Host]).
 
 init([Host]) ->
-    % TODO
-    N = 10,
+    N = case ejabberd_config:get_local_option({odbc_pool_size, Host}) of
+	    I when is_integer(I) ->
+		I;
+	    undefined ->
+		?DEFAULT_POOL_SIZE;
+	    Other ->
+		?ERROR_MSG("Wrong odbc_pool_size definition '~p' for host ~p, default to ~p~n",
+			   [Other, Host, ?DEFAULT_POOL_SIZE]),
+		?DEFAULT_POOL_SIZE
+	end,
     {ok, {{one_for_one, 10, 6},
 	  lists:map(
 	    fun(I) ->
@@ -45,4 +56,3 @@ get_pids(Host) ->
 get_random_pid(Host) ->
     Pids = get_pids(Host),
     lists:nth(erlang:phash(now(), length(Pids)), Pids).
-