HAProxy log outgoing requests

Right now it's not possible to disable logs based on ACLs (though it's in the roadmap). In the mean time, you should understand that logs are defined by the frontend. Thus, you could have two frontends, one public and one private which make use of the same backend. The private frontend would not log while the public one would.

In general it's not adviced to disable logging, it makes detecting bugs much longer. You could alternatively use "option dontlog-normal" to only log unexpected events (timeouts, errors, etc...). That sensibly reduces the amount of logs and you still keep traces of events you should care about.

Another option might be mod_forensic, can easily log the request and headers etc. Beware of disk space usage though, on a heavy load web-site mod_forensic can easily produce tens of Gigs per day.

http://httpd.apache.org/docs/2.2/mod/mod_log_forensic.html