[Zope-CMF] Zope, CMF, Plone, Squid, Apache and Caching
Hardy, Matthew
mphardy@engin.umich.edu
Thu, 10 Jul 2003 14:22:17 -0400
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Hello,
I have been trying to piece together the various caching solutions used =
with Zope over the past few weeks and have come across some =
inconsistancies I can't explain without a broader sense of how all the =
code work together. I'm hoping someone with a deeper knowledge of how =
things work could explain the following or at least point me in the =
right direction.
1) CMF Caching Policy Manager works on *some* objects but not all.
I am currently using CMF Caching Policy Manager to prevent pages viewed =
by authenticated users from being picked up by Squid. This would be a =
security issue since the same URL might provide different information =
for anonymous and authenticated users.
So I have two policies, one with a predicate: "python:member!=3DNone" =
with no-cache checked and another policy with predicate: =
"python:member=3D=3DNone" with no-cache unchecked and a max-age set. =
This seems to work, however I can't get CMF Caching Policy Manager to =
add any headers to images. Images are sent with nothing more than a =
Last-Modified header which does get it cached but i'd like to have more =
control.
2) Http Accelerator can't associate with anything in a Plone Site.
If you get the list of everything http_accelerator can associate with in =
its Associate tab nothing in a Plone Site object shows up. Since i'm =
using Squid I would like the PURGE ICP functionality to operate as it is =
intended but nothing of use is in the list of associatable objects.
3) Ram Cache Manager can't associate with anything in a Plone Site.
The same problem I have with Http Accelerator carries over to the Ram =
Cache Manager when you try to associate objects to it. In the Plone =
Book "Slot caching" is discussed using the RAM Cache Manager but if you =
can't associate it with any objects in Plone I don't see how this would =
work.
I have spent considerable effort on this project and have made some good =
progress. I am documenting it all on my wiki: =
http://matthardy.us/mywiki/HighPerformanceZope
I have gotten most of the issues worked out but this caching stuff is a =
real pain to understand if you don't know exactly what happens during =
each request and how CMF/Plone interact with Zope. Once I get this all =
working I plan on polishing it up and adding it as a HowTo to Zope.org's =
literary collection.
Thanks in advance for any help you can furnish.
Matt Hardy
mphardy@umich.edu
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<P><FONT SIZE=3D2>Hello,<BR>
<BR>
I have been trying to piece together the various caching solutions used =
with Zope over the past few weeks and have come across some =
inconsistancies I can't explain without a broader sense of how all the =
code work together. I'm hoping someone with a deeper knowledge of =
how things work could explain the following or at least point me in the =
right direction.<BR>
<BR>
1) CMF Caching Policy Manager works on *some* objects but not all.<BR>
<BR>
I am currently using CMF Caching Policy Manager to prevent pages viewed =
by authenticated users from being picked up by Squid. This would =
be a security issue since the same URL might provide different =
information for anonymous and authenticated users.<BR>
<BR>
So I have two policies, one with a predicate: =
"python:member!=3DNone" with no-cache checked and another =
policy with predicate: "python:member=3D=3DNone" with no-cache =
unchecked and a max-age set. This seems to work, however I can't =
get CMF Caching Policy Manager to add any headers to images. =
Images are sent with nothing more than a Last-Modified header which does =
get it cached but i'd like to have more control.<BR>
<BR>
2) Http Accelerator can't associate with anything in a Plone Site.<BR>
<BR>
If you get the list of everything http_accelerator can associate with in =
its Associate tab nothing in a Plone Site object shows up. Since =
i'm using Squid I would like the PURGE ICP functionality to operate as =
it is intended but nothing of use is in the list of associatable =
objects.<BR>
<BR>
3) Ram Cache Manager can't associate with anything in a Plone Site.<BR>
<BR>
The same problem I have with Http Accelerator carries over to the Ram =
Cache Manager when you try to associate objects to it. In the =
Plone Book "Slot caching" is discussed using the RAM Cache =
Manager but if you can't associate it with any objects in Plone I don't =
see how this would work.<BR>
<BR>
<BR>
<BR>
I have spent considerable effort on this project and have made some good =
progress. I am documenting it all on my wiki: <A =
HREF=3D"http://matthardy.us/mywiki/HighPerformanceZope">http://matthardy.=
us/mywiki/HighPerformanceZope</A><BR>
<BR>
I have gotten most of the issues worked out but this caching stuff is a =
real pain to understand if you don't know exactly what happens during =
each request and how CMF/Plone interact with Zope. Once I get this =
all working I plan on polishing it up and adding it as a HowTo to =
Zope.org's literary collection.<BR>
<BR>
<BR>
Thanks in advance for any help you can furnish.<BR>
<BR>
<BR>
Matt Hardy<BR>
mphardy@umich.edu</FONT>
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