Re: [squid-users] unexplainable MISSes (squid 2.7stable9)

On 11/09/2010 04:35 AM, Amos Jeffries wrote:

> Unique ETag headers are required for that.
>
Hi Amos,

I have understood as far but I still cant get my setup to behave as
intended: to keep distinct versions of the same URL in cache until they
expire. Distinct based on ETag value/ Vary header values.

Here's what happens:

****************
**A request of a logged in user (identified by the X-Username header as
"X-Username: v81krndgi9jw8Oq7RqP9gpj/XkIgZGFzY2FsdQ==|Plone Default" and
"ETag: |dascalu|Plone Default|1|False|||||358134") takes the object in
cache:

1289284280.898 4387 127.0.0.1 TCP_MISS/200 76574 GET
http://127.0.0.1:3128/VirtualHostBase/http/www.somewebsite.com:80/www/SITE/VirtualHostRoot/
- FIRST_PARENT_MISS/17 text/html

[Host: 127.0.0.1:3128\r\nUser-Agent: Mozilla/5.0 (X11; U; Linux i686;
en-US; rv:1.9.1.9) Gecko/20100330 Fedora/3.5.9-1.fc11
Firefox/3.5.9\r\nAccept:
text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8\r\nAccept-Language:
en-us,en;q=0.5\r\nAccept-Encoding: gzip,deflate\r\nAccept-Charset:
ISO-8859-1,utf-8;q=0.7,*;q=0.7\r\nReferer:
http://www.somewebsite.com/portal_cache_settings/old-policy/rules/frontpage?portal_status_message=Changes%2520saved.\r\nCookie:
__utma=173508663.4134765344646281700.1250060356.1289254636.1289283144.57; __utmc=173508663;
__utmz=173508663.1289208944.50.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none);
__ac="v81krndgi9jw8Oq7RqP9gpj/XkIgZGFzY2FsdQ=="; plone_skin="Plone
Default"; __utmb=173508663.8.10.1289283144\r\nX-Username:
v81krndgi9jw8Oq7RqP9gpj/XkIgZGFzY2FsdQ==|Plone
Default\r\nX-Forwarded-For: 109.99.31.143\r\nX-Forwarded-Host:
www.somewebsite.com\r\nX-Forwarded-Server:
www.somewebsite.com\r\nConnection: Keep-Alive\r\n]

[HTTP/1.0 200 OK\r\nServer: Zope/(Zope 2.9.10-final, python 2.4.3,
linux2) ZServer/1.1 Plone/2.5.5\r\nDate: Tue, 09 Nov 2010 06:31:20
GMT\r\nContent-Length: 75865\r\nContent-Language: en\r\nExpires: Tue, 09
Nov 2010 06:31:24 GMT\r\nVary: Accept-Encoding, Accept,
X-Username\r\nLast-Modified: Fri, 28 Nov 2008 07:19:49 GMT\r\nETag:
|dascalu|Plone Default|1|False|||||358134\r\nX-Caching-Rule-Id:
frontpage\r\nCache-Control: max-age=5, s-maxage=3600,
public\r\nContent-Type: text/html;charset=utf-8\r\nX-Header-Set-Id:
cache-with-etag-in-proxy\r\nX-Cache: MISS from
squid1.somewebsite.com\r\nX-Cache-Lookup: MISS from
squid1.somewebsite.com:3128\r\nVia: 1.0 squid1.somewebsite.com:3128
(squid/2.7.STABLE9)\r\nConnection: keep-alive\r\n\r]

*****************
**A second request of the same user will be served from cache:

1289284489.560 0 127.0.0.1 TCP_MEM_HIT/200 76582 GET
http://127.0.0.1:3128/VirtualHostBase/http/www.somewebsite.com:80/www/SITE/VirtualHostRoot/
- NONE/- text/html

[Host: 127.0.0.1:3128\r\nUser-Agent: Mozilla/5.0 (X11; U; Linux i686;
en-US; rv:1.9.1.9) Gecko/20100330 Fedora/3.5.9-1.fc11
Firefox/3.5.9\r\nAccept:
text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8\r\nAccept-Language:
en-us,en;q=0.5\r\nAccept-Encoding: gzip,deflate\r\nAccept-Charset:
ISO-8859-1,utf-8;q=0.7,*;q=0.7\r\nReferer:
http://www.somewebsite.com/\r\nCookie:
__utma=173508663.4134765344646281700.1250060356.1289254636.1289283144.57; __utmc=173508663;
__utmz=173508663.1289208944.50.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none);
__ac="v81krndgi9jw8Oq7RqP9gpj/XkIgZGFzY2FsdQ=="; plone_skin="Plone
Default"; __utmb=173508663.9.10.1289283144\r\nX-Username:
v81krndgi9jw8Oq7RqP9gpj/XkIgZGFzY2FsdQ==|Plone
Default\r\nX-Forwarded-For: 109.99.31.143\r\nX-Forwarded-Host:
www.somewebsite.com\r\nX-Forwarded-Server:
www.somewebsite.com\r\nConnection: Keep-Alive\r\n]

[HTTP/1.0 200 OK\r\nServer: Zope/(Zope 2.9.10-final, python 2.4.3,
linux2) ZServer/1.1 Plone/2.5.5\r\nDate: Tue, 09 Nov 2010 06:31:20
GMT\r\nContent-Length: 75865\r\nContent-Language: en\r\nExpires: Tue, 09
Nov 2010 06:31:24 GMT\r\nVary: Accept-Encoding, Accept,
X-Username\r\nLast-Modified: Fri, 28 Nov 2008 07:19:49 GMT\r\nETag:
|dascalu|Plone Default|1|False|||||358134\r\nX-Caching-Rule-Id:
frontpage\r\nCache-Control: max-age=5, s-maxage=3600,
public\r\nContent-Type: text/html;charset=utf-8\r\nX-Header-Set-Id:
cache-with-etag-in-proxy\r\nAge: 209\r\nX-Cache: HIT from
squid1.somewebsite.com\r\nX-Cache-Lookup: HIT from
squid1.somewebsite.com:3128\r\nVia: 1.0 squid1.somewebsite.com:3128
(squid/2.7.STABLE9)\r\nConnection: keep-alive\r\n\r]

******************
**A request from an Anonymous user (X-Username: Anonymous) will fetch a
new version into the cache AND invalidate the above logged in user. The
responce ETag is distinct from the logged in user (ETag:
||XXXDesign2006|1|False|||||358134)

1289284576.228 858 127.0.0.1 TCP_MISS/200 10900 GET
http://127.0.0.1:3128/VirtualHostBase/http/www.somewebsite.com:80/www/SITE/VirtualHostRoot/
- FIRST_PARENT_MISS/110 text/html

[Host: 127.0.0.1:3128\r\nIf-None-Match:
|1|False|||||358134\r\nIf-Modified-Since: Fri, 28 Nov 2008 07:19:49
GMT\r\nAccept: text/html, image/jpeg;q=0.9, image/png;q=0.9,
text/*;q=0.9, image/*;q=0.9, */*;q=0.8\r\nAccept-Encoding: x-gzip,
x-deflate, gzip, deflate\r\nAccept-Charset: utf-8, utf-8;q=0.5,
*;q=0.5\r\nAccept-Language: en-US, en\r\nCookie:
__utmz=173508663.1289234747.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none);
__utma=173508663.1869602660.1289234747.1289256045.1289283795.7;
__utmb=173508663.3.10.1289283795\r\nX-Username:
Anonymous\r\nX-Forwarded-For: 109.99.31.143\r\nX-Forwarded-Host:
www.somewebsite.com\r\nX-Forwarded-Server:
www.somewebsite.com\r\nConnection: Keep-Alive\r\n]

[HTTP/1.0 200 OK\r\nServer: Zope/(Zope 2.9.10-final, python 2.4.3,
linux2) ZServer/1.1 Plone/2.5.5\r\nDate: Tue, 09 Nov 2010 06:36:16
GMT\r\nContent-Length: 10155\r\nContent-Language:
en\r\nContent-Encoding: gzip\r\nExpires: Tue, 09 Nov 2010 06:36:20
GMT\r\nVary: Accept-Encoding, Accept,
X-Username,\r\n%09Accept-Encoding\r\nLast-Modified: Fri, 28 Nov 2008
07:19:49 GMT\r\nETag:
||XXXDesign2006|1|False|||||358134\r\nX-Caching-Rule-Id:
frontpage\r\nCache-Control: max-age=5, s-maxage=3600,
public\r\nContent-Type: text/html;charset=utf-8\r\nX-Header-Set-Id:
cache-with-etag-in-proxy\r\nX-Cache: MISS from
squid1.somewebsite.com\r\nX-Cache-Lookup: MISS from
squid1.somewebsite.com:3128\r\nVia: 1.0 squid1.somewebsite.com:3128
(squid/2.7.STABLE9)\r\nConnection: keep-alive\r\n\r]

*****************

As a result subsequent requests from the logged in user will result in a
MISS. This brakes the hole purpuse of the accelerator since anonymous
and CMS users will invalidate each other's cached objects ...

Please show me what am I doing wrong? Alternatively could you point me
to the place in squid sources where these decisions are taken? Maybe I
can better understand what I should do by looking at the code.

Many thanks,
Adrian
Received on Tue Nov 09 2010 - 06:56:14 MST