Dealing with "http format error"

Jay Luker lbjay at
Wed Sep 15 20:14:58 CEST 2010

I have a backend that I do not control that is causing an error in
varnish due (I think) to a lack of http headers in the response. The
URL in question is (shortened). If you look
you'll see that the http response consists of "HTTP/1.0 200 OK" and
that's all. No content-type, content-length, etc. This results in the
following varnishlog output:

   11 FetchError   c http format error
   12 BackendClose b ned
   11 VCL_call     c error

My question is, since I don't have any control of this backend, is
there some VCL magic I can use to fudge whatever missing headers are
causing varnish to spit the bit on the response? I have already
unsuccessfully tried the only obvious thing I could think of, which
was to add to vcl_fetch:

    set obj.http.Content-Type = "text/plain; charset=ascii";
    set obj.http.Content-Length = "100000";
    set obj.http.Content-Encoding = "none";

I'm using v2.06.


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