So, we use Squid 3 here (3.0.STABLE8-3+lenny4), pretty standard configuration (no dansguardian or similar) + NTLM authentication with LDAP background, circa 1000 users on a busy day, and our acls reference some external files (allowed/blocked sites/ip addresses).
On Squid 2.X we used to be capable of reloading it's configuration (to add or sites or addresses to rules, etc) and squid would not stop serving during the reload. Since we changed to 3.0, that seems to be impossible: everytime we use reload (or -k reconfigure) it stop serving requests for as long as 2 minutes, and clients receive a Configured proxy is not accepting connections message.
I checked the documentation and got nothing about it, does anyone else suffer from this problem or is it a isolated case on my setup? Also, if you have Squid 3.0 and doesn't suffer from this problem, how is your squid configured?