Find out which applications on your server are the most talkative and the least ones. Understanding your applications is the key to a healthy running machine.
If your machines are repeating their messages to you, do take it seriously. Something's definetely wrong.
Your servers might be getting attacked.
or your disks might be failing...
Take actions before it's too late!
If this is recurrent, consider auditing your applications for memory leaks or upgrade your servers if needed.
Having too many 404 pages? Too many unnecessary 30X redirects?
Don't let your users be hindered by slow speeds. Monitor the logs of your HAProxy to determine which servers are the slowest to reply.
You don't have to be glued to your screen all the time.