Re: Ignore reload for some time ?

From: Tony Demark <>
Date: Wed, 23 Sep 1998 10:21:41 -0400

Well, we were in the same situation except we basically never wanted the
cached object to expire automatically. Setting expires was out because the
web database we were using to get to the database couldn't handle it (and
Netscape Server didn't seem to wanna help out either).

I solved this by:

(a) Hacking squid to always ignore "no-cache".

    In icp.c:

        if (Config.Options.reload_into_ims)
        BIT_SET(request->flags, REQ_NOCACHE_SPECIAL);
        BIT_SET(request->flags, REQ_NOCACHE);

    By adding the first and last lines of this snippet to the program, then
no-cache will be ignored unless "ALLOW_NOCACHE" is defined in the Makefile.

(b) Wrote a program that, given parameters of the URL, parse through the cache
log and delete those files from the cache that match the parameters.

Our site is completely database driven and dynamic, yet we get a cached page
view ratio of about 80%. Although they are not included in that total, almost
all images are cached (which, if counted, would drive the cache ratio up over
95%). Any pages that either shouldn't be cached, or need to be cleared from
cache at certain points during the day are handled by stoplists and a cron job
that deletes the files directly from the cache.

The other solution we tried for a little while was hacking the squid code to
look for 'ih-cache' instead of 'no-cache' and then make the same modification
to several browser binaries. It basically let only us "clear" the cache by
hitting "reload" on our hacked browsers.

- Tony
Received on Wed Sep 23 1998 - 07:24:51 MDT

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