Depends entirely on how your site is built (e.g. is it mod_perl or not), but I like to insert code that constructs the DB handle at a known point ... that is to say, not “lazily” ... specifically so that I can gracefully deal with the proverbial “ka-ka” when (not if) “it happens.”   If the operation fails, it will throw an exception which I can catch, so I can respond by throwing up a “this site is temporarily unavailable” message instead of ... well ... throwing up.   :-}