This is really going to be more of a cache-flush issue, considering how quickly it will recover.<p>Bouncing the front-end is likely to expose the backend (say, a php site) to the traffic load usually handled by varnish. This is likely to bring that (and its db, etc) down very quickly.<p>But the good news is that all you need to do is ship a new vcl file and there's no need to patch/rebuild varnishd binaries.