Very slow dns lookup using proxy_pass

[justin]

I am seeing very slow DNS lookup times ( > 2 seconds ) using proxy_pass,
even though dig response times on the server are quick. Here is the nginx
configuration block:

  location ~ ^/v1/(?<url>.*)  {
    resolver 8.8.4.4 4.4.4.4 valid=300s;
    resolver_timeout 10s;
    proxy_pass https://$remote_user.mydomain.com/api/;
    proxy_hide_header Vary;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_connect_timeout 10s;
    proxy_read_timeout 60s;
    proxy_ssl_session_reuse on;
  }

I am using Google Public DNS. Here is a result from: dig demo.mydomain.com

; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.17.rc1.el6_4.6 <<>> demo.mydomain.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 37997
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;demo.mydomain.com.		IN	A

;; ANSWER SECTION:
demo.mydomain.com.	299	IN	A	X.X.X.X

;; Query time: 187 msec
;; SERVER: 8.8.4.4#53(8.8.4.4)
;; WHEN: Fri Jan  3 19:40:32 2014
;; MSG SIZE  rcvd: 50

Any ideas why this is so slow, and solutions?

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,246001,246001#msg-246001