[sr-dev] mysql_ping in db_mysql_submit_query

As was found out in "Kamailio stops processing requests over UDP" thread, db_mysql_submit_query() in some circumstances hangs when it executes mysql_ping here: if (my_ping_interval) { t = time(0); if ((t - CON_TIMESTAMP(_h)) > my_ping_interval) { for (i=0; i < (db_mysql_auto_reconnect ? 3 : 1); i++) { if (mysql_ping(CON_CONNECTION(_h))) { LM_INFO("driver error on ping: %s\n", mysql_error(CON_CONNECTION(_h))); counter_inc(mysql_cnts_h.driver_err); } else { break; } } } ... } Comment in front of db_mysql_submit_query() function tells: * Send a SQL query to the database server. This methods tries to reconnect * to the server if the connection is gone and the auto_reconnect parameter is * enabled. It also issues a mysql_ping before the query to connect again after * a long waiting period because for some older mysql versions the auto reconnect * don't work sufficient. If auto_reconnect is enabled and the server supports it, * then the mysql_ping is probably not necessary, but its safer to do it in this * cases too. * The text was most likely written many years ago and auto reconnect now works OK in mysql versions in use today. I would like to test if the hangup could be prevented without the above code. Would it be possible to make the code optional via a compilation flag or by some other means? -- Juha