Hi,
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.
DNS lookups fail as no DNS, but appear to go into a retry loop, before ATS then
attempts DNS failover, but as there are no nameservers configured, this doesn't
seem to work properly, and it gets into an infinite loop of trying to failover
and logging failure messages.
Mar 09 15:12:45 - INFO - [Mar 9 15:12:45.652] Server {0x2b71ac0a52c0} WARNING:
failover: connection to DNS server 127.0.0.1 lost, retrying
Mar 09 15:12:45 - INFO - [Mar 9 15:12:45.663] Server {0x2b71ac0a52c0} WARNING:
failover: connection to DNS server 127.0.0.1 lost, retrying
Mar 09 15:12:45 - INFO - [Mar 9 15:12:45.674] Server {0x2b71ac0a52c0} WARNING:
failover: connection to DNS server 127.0.0.1 lost, retrying
Mar 09 15:12:45 - INFO - [Mar 9 15:12:45.685] Server {0x2b71ac0a52c0} WARNING:
failover: connection to DNS server 127.0.0.1 lost, retrying
...
While the request itself times out, these messages are logged every 11
milliseconds or so until the process is stopped.
Is there a way to stop this happening? ATS seems to be trying to fail over DNS
even when there is nothing configured in terms of nameservers:
CONFIG proxy.config.dns.round_robin_nameservers INT 0
CONFIG proxy.config.dns.nameservers STRING NULL
Is there a way to disable DNS lookups completely? There are other DNS-related
parameters but none of them seem to do that (there is
proxy.config.http.no_dns_just_forward_to_parent but it doesn't seem to change
anything).
Thanks
Greg
