Restoring cookies on a miss

[Ken Brownfield]

If you sometimes see the proper cookies being passed to the back-end, I would think this would be a client problem?  The VCL logic in question should either always work or never work.

I just did a test of this, and I see the proper header hitting the back-end.  Maybe you're seeing unexpectedly cookie-less requests?
-- 
Ken

On Jan 25, 2010, at 1:03 PM, John Norman wrote:

> Folks,
> 
> I've been trying to implement a technique posted here to restore
> cookies on a cache miss.
> 
> The original question is here:
> 
>    http://projects.linpro.no/pipermail/varnish-misc/2010-January/003505.html
> 
> and an interesting answer is here:
> 
>    http://projects.linpro.no/pipermail/varnish-misc/2010-January/003506.html
> 
> Below is my .vcl file.
> 
> And again, here's the use case:
> 
> We have certain pages that should never be cached. The user comes in
> with cookies set: "session=foo" or some such.
> 
> We strip the cookie and do a lookup.
> 
> If there's a hit, return what is in the cache.
> 
> If there's a miss, we'd like to fetch with the cookie.
> 
> Then, in fetch, pass for pages set for no-cache, and deliver for those
> that are public.
> 
> It can be assumed that these pages are never hit first by non-cookied users.
> 
> But -- I am seeing a lot of requests that have no cookies on the backend.
> 
> John
> 
> Here's the VCL:
> 
> backend reviews0 {
>  .host = "127.0.0.1";
>  .port = "7000";
> }
> 
> backend reviews1 {
>  .host = "127.0.0.1";
>  .port = "7001";
> }
> 
> director reviews round-robin {
>    { .backend = reviews0; }
>    { .backend = reviews1; }
> }
> 
> sub vcl_recv {
> 
> 	unset req.http.user-agent;
> 
> 	set req.backend = reviews;
> 
>  if (req.request != "GET" && req.request != "HEAD") {
>    pass;
>  }
> 
>  set req.http.OLD-Cookie = req.http.Cookie;
>  unset req.http.cookie;
> 
> 	lookup;
> }
> 
> sub vcl_miss {
>  if (req.http.OLD-Cookie) {
>    set bereq.http.Cookie = req.http.OLD-Cookie;
>    unset req.http.OLD-Cookie;
>  }
>  fetch;
> }
> 
> sub vcl_fetch {
> 
>  unset obj.http.user-agent;
> 
> 	if (obj.http.Pragma ~ "no-cache" ||
> 	  obj.http.Cache-Control ~ "no-cache" ||
> 	  obj.http.Cache-Control ~ "private") {
> 	    pass;
> 	}
> 
> 	if (obj.http.Cache-Control ~ "public") {
>    unset obj.http.Set-Cookie;
> 		deliver;
> 	}
> 	pass;
> }
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