Re: General question on Serf

Branko Čibej <brane_at_wandisco.com> writes:

> This is how the cache /should/ work, according to any number of HTTP
> specs. Unfortunately, most proxies that I know about don't attempt
> anything as "advanced" as that.

If the cache ignores X-SVN-VR-Base and simply caches the response that
will break 1.8 clients. Looking at the response:

HTTP/1.1 200 OK
Date: Wed, 26 Sep 2012 16:20:33 GMT
Server: Apache/2.2.16 (Debian) mod_ssl/2.2.16 OpenSSL/0.9.8o DAV/2 SVN/1.8.0-dev
Last-Modified: Wed, 26 Sep 2012 16:20:19 GMT
ETag: "2//f"
Cache-Control: max-age=604800
Accept-Ranges: bytes
Transfer-Encoding: chunked
Content-Type: application/vnd.svn-svndiff

I don't see a header that allows the client to confirm that that delta
is based on the requested revision. I suppose the client just assumes
that the server used the right base revision so if a cache returns the
wrong delta the client will get a checksum mismatch when constructing
the full-text.

Perhaps the server should send the X-SVN-VR-Base header back?

I suppose the server admin might be able to use mod_headers to send
  Cache-Control: no-cache
if a dodgy cache is known to be affecting clients, although a dodgy
cache might ignore that.

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