[squid-users] Requests through proxy take 4x+ longer than direct to the internet

From: David Parks <davidparks21_at_yahoo.com>
Date: Thu, 18 Mar 2010 19:35:40 -0600

Hi, I set up a dev instance of squid on my windows system.

I've configured 2 browsers (Chrome & Firefox), chrome direct to the
internet, firefox through the locally running instance of squid.

I expected similar response times from the two browsers, but I consistently
see firefox (configured to proxy through squid) takes 4x+ longer.

Below are the logs showing response times from a hit on yahoo.com, the
chrome browser opened the page in ~<2 seconds.

I have used the windows binaries of squid and configured digest password
authentication, everything else (other than default port) is left as default
in the config file.

After doing a packet capture I noted the following behavior:

   - When going through the proxy: 9 GET requests are made, and 9 HTTP
responses are received in a reasonable time period (<2sec)
   - After the 9th HTTP response is sent, there is a 4 second delay until
the next GET request is made
   - Then 6 GET requests are made, and 6 HTTP responses are received in a
reasonable amount of time.
   - After the 6th GET request in this second group there is a 5 second
delay until the next GET request is made.
   - This pattern repeats its self when the proxy is in use.
   - This pattern does not occur when I am not connected through the proxy.

Any thoughts on this behavior?

Thanks much,
David

Yahoo example log:

1268958646.966 417 127.0.0.1 TCP_MISS/301 602 GET http://yahoo.com/ test
DIRECT/67.195.160.76 text/html
1268958652.263 5289 127.0.0.1 TCP_MISS/302 748 GET http://www.yahoo.com/
test DIRECT/209.191.122.70 text/html
1268958658.997 6726 127.0.0.1 TCP_MISS/200 38900 GET http://mx.yahoo.com/?
test DIRECT/209.191.122.70 text/html
1268958664.895 5132 127.0.0.1 TCP_MISS/200 1616 GET
http://d.yimg.com/a/i/ww/met/pa_icons/gmail_22_052809.gif test
DIRECT/189.254.81.8 image/gif
1268958664.908 5142 127.0.0.1 TCP_MISS/200 1118 GET
http://d.yimg.com/a/i/ww/met/pa_icons/glamout_22_012010.gif test
DIRECT/189.254.81.8 image/gif
1268958666.087 6140 127.0.0.1 TCP_MISS/200 32906 GET
http://l.yimg.com/br.yimg.com/i/img2/200911/111609_fp_movil.swf test
DIRECT/189.254.81.35 application/x-shockwave-flash
Received on Fri Mar 19 2010 - 01:35:44 MDT

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