On Mar 9, 2015, at 10:44 AM, Greg O'Rawe <Greg.O'Rawe@owmobility.com> wrote:

I have a deployment of ATS 3.2.0 as a forward proxy where there is no access to DNS (no nameserver entry in the /etc/resolv.conf file). The origin server IP address is normally supplied by a request header which calls the API to set the target address but in some cases the header is not present. The setup is not transparent so the client destination IP address is that of the ATS and so can’t be used, resulting in DNS lookups.

First, that’s a really old version of ATS, one that is EOLifed already. You should consider upgrading to an LTS version.

That much said, there are a few options to examine:

proxy.config.http.no_origin_server_dns  (0 by default)
proxy.config.dns.failover_number  (5 by default)
proxy.config.dns.lookup_timeout (20 by default)

There are a few others that might be related. Also, i thought we had a Jira about not successfully being able to use that first setting, but I can’t find it. Try it, and see what happens.

— Leif