On 17/11/2011 3:52 p.m., Schwenker, Stephen wrote:
Hey Amos,
Here are the details you asked for. I hope you see something in it that I don't.
Steve.
-----Original Message-----
From: Amos Jeffries [mailto:squid3@xxxxxxxxxxxxx]
Sent: Wednesday, November 16, 2011 4:07 PM
To: squid-users@xxxxxxxxxxxxxxx
Subject: Re: collapsed_forwarding not working as expected
On Wed, 16 Nov 2011 13:49:23 -0500, Schwenker, Stephen wrote:
Hello,
We've installed squid as an accelerator for our website, and it's
working pretty well, but we have found out that the collapsed
forwarding
is not working as expected. We ran some load tests to a single url
with
a 1 minute expiry and squid is still sending approximately 12000
request
to the back end server in a 5 minute span. If I understand the
documentation correctly, squid should only send 5 requests to the
back
end server.
Object variance can affect that. 5 requests is the best-case scenario
for a single static object representation.
What are the reply headers coming back with the object?
Here are the response coming back that I've captured from fiddler using my browser.
HTTP/1.1 200 OK
Cache-Control: public
Content-Type: text/html; charset=utf-8
Expires: Thu, 17 Nov 2011 02:41:53 GMT
Last-Modified: Thu, 17 Nov 2011 02:41:08 GMT
Vary: Accept-Encoding
I think it might be that Vary: header. Collapse can't really determine
objects as identical if the header mentioned differs from the existing
client downloads one.
An ETag header to identify whether the original object instance has
changed may be worth adding.
Server: Microsoft-IIS/7.0
X-AspNetMvc-Version: 3.0
X-AspNet-Version: 4.0.30319
X-Powered-By: ASP.NET
WS: 2-3
Date: Thu, 17 Nov 2011 02:41:08 GMT
Content-Length: 21
11/16/2011 9:41:08 PM
I've configured the following.
http_port 80 accel defaultsite=<site name> vhost
cache_peer<web server> parent 80 7 no-query no-digest originserver
sourcehash monitorurl=/statuscheck/ name=<web server> http11
... acls
... header access
Your "header access" re-writing may also affect the responses. What are
these lines?
Here is the section with the header_access rules
minimum_expiry_time 30 seconds
cache_vary on
header_access X-Powered-By deny all
header_access X-AspNetMvc-Version deny all
header_access X-AspNet-Version deny all
header_access Server deny all
via off
Okay, good, those should not be affecting it.
Amos
