[squid-users] Caching Content from Dynamic URLs (very hacky solution)

Greetings everyone,

Like many others, we have the need to cache data from URLs that are dynamic, even if the data is the same. I know about the storeurl_rewrite command, but that's only available in squid 2.x, and for some reason, that version didn't play well with our proprietary tools.

I wanted to share my solution (which is a super ugly hack) since it seems to be working for us, in case anyone else needs to make a similar change in the future. All changes were done to a 3.1.9 release. The changes take about 5 minutes total.

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1. In src/protos.h, add the following declaration:

        SQUIDCEXTERN char *getRelativePathFromUrl(char *);

2. In src/store_key_md5.cc (or in any file, really), add the following:

char*
getRelativePathFromUrl(char *url)
{
        char *relativePath = ...
        return relativePath;
}

This function should map a dynamic path to a relative one. The structure of all our URLs is http://********/foo/<GUID>/path/to/file.txt, so this function, for us, would return path/to/file.txt
I'm not pasting the body of this function, since it's VERY specific to our tools, but you can hack in whatever URL translation you need here.

3. In src/store_key_md5.cc, add the following line:

        char *relativeUrl = getRelativePathFromUrl((char *)url);

To the following functions:

        storeKeyPrivate
        storeKeyPublic
        storeKeyPublicByRequestMethod

Then, replace all references to the const char *url with relativeUrl.

4. In src/StoreMetaUrl.cc, add the following lines:

    char *relativeUrl = getRelativePathFromUrl(e->mem_obj->url);
    char *relativeValue = getRelativePathFromUrl((char *)value);

Replace all references to e->mem_obj->url with relativeUrl
Replace all references to (char *)value with relativeValue

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That's all I did, and the caching seems to be working. If I deploy two sets of the exact same files, with different GUIDs, the second set is all TCP_HITs.

I know this solution is not a good one, just wanted to share in case anyone else was in a similar bind like me.

Thanks for your time,

-Adam
Received on Tue Dec 14 2010 - 22:11:06 MST