varnish not generating 304 in case multiple etags are used.
Mark Nottingham
mnot at yahoo-inc.com
Tue Apr 26 02:31:04 CEST 2011
An ETag header can only contain one ETag. See:
http://tools.ietf.org/html/draft-ietf-httpbis-p4-conditional-14#section-2.2
Cheers,
On 23/04/2011, at 10:28 PM, Harm Verhagen wrote:
> Hi,
>
> I'm having a problem with the handling of http responses that contain multiple etag headers. I think varnish does not handle this case as effecient as it can. (And therefor I suspect a bug in varnish).
> What do you think?
>
>
> steps to reproduce
> ==============
> See request/response below. Force a reload of a cached item in browser: Cache-Control: max-age=0
>
> result
> ====
> HTTP 200 is returned, varnish serves file content, varnish does NOT contact backend.
>
> expected result
> ============
> HTTP 304 is returned, varnish does not server file content, varnish does NOT contact backend.
>
> NOTE
> =====
> This does work correct, in case the reply contains a SINGLE etag header. -> all works as expected, I get a nice 304 instead of a 200.
> As soon as the reply contains TWO etag headers, it seems varnish never returns a 304. Which I think is incorrect. No ?
>
> Note; This is not related to the vlc, as single etag headers are working fine. (I'm doing NOTHING with headers, etag or others in my vlc).
>
> request (anonimised)
> =======
> GET /dam/asset/download/uuid/121a8df4-4fe8-11e0-bd65-56167b3dc56d/variant/103/ HTTP/1.1
> Host: X.X.X
> User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:2.0) Gecko/20100101 Firefox/4.0
> Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
> Accept-Language: nl,en-us;q=0.7,en;q=0.3
> Accept-Encoding: gzip, deflate
> Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
> Keep-Alive: 115
> Connection: keep-alive
> Cookie: __utma=1.1741069999.1296235686.1303504321.1303507491.8; <snipped rest of cookie>
> If-Modified-Since: Fri, 22 Apr 2011 13:00:00 GMT
> If-None-Match: "d41d8cd98f00b204e9800998ecf8427e", "4a00e1-3ddf-4a1816f7a9400"
> Cache-Control: max-age=0
>
>
> reply
> HTTP/1.1 200 OK
> Server: Apache/2.2.14 (Ubuntu)
> Content-Disposition: inline; filename="Seminar Speakers.jpg"
> Expires: Sat, 23 Apr 2011 13:00:00 GMT
> Etag: "d41d8cd98f00b204e9800998ecf8427e", "4a00e1-3ddf-4a1816f7a9400"
> Cache-Control: max-age=86400
> P3P: CP="IDC DSP COR ADM DEVi TAIi PSA PSD IVAi IVDi CONi HIS OUR IND CNT"
> Last-Modified: Fri, 22 Apr 2011 13:00:00 GMT
> Content-Type: image/jpeg;charset=utf-8
> Content-Length: 15839
> Date: Sat, 23 Apr 2011 12:07:39 GMT
> X-Varnish: 2113947582 2113947501
> Age: 58
> Via: 1.1 varnish
> Connection: keep-alive
>
>
>
>
> version
> ======
> varnish 2.1.5
>
>
>
> Log transcript of a single request+response (varnishlog)
> =================================
> 11 SessionOpen c X.X.X.220 50540 :80
> 11 ReqStart c X.X.X.220 50540 2113947582
> 11 RxRequest c GET
> 11 RxURL c /dam/asset/download/uuid/121a8df4-4fe8-11e0-bd65-56167b3dc56d/variant/103/
> 11 RxProtocol c HTTP/1.1
> 11 RxHeader c Host: X.X.X
> 11 RxHeader c User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:2.0) Gecko/20100101 Firefox/4.0
> 11 RxHeader c Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
> 11 RxHeader c Accept-Language: nl,en-us;q=0.7,en;q=0.3
> 11 RxHeader c Accept-Encoding: gzip, deflate
> 11 RxHeader c Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
> 11 RxHeader c Keep-Alive: 115
> 11 RxHeader c Connection: keep-alive
> 11 RxHeader c Cookie: __utma=1.1741069999.1296235686.1303504321.1303507491.8; __utmz=1.1303507491.8.8.utmcsr=senzio.com|utmccn=(referral)|utmcmd=referral|utmcct=/; __utma=142895841.963436971.1296236932.1302872710.1303499754.14; __utmz=142895841.1296236932.1.1.utmcsr=(d
> 11 RxHeader c If-Modified-Since: Fri, 22 Apr 2011 13:00:00 GMT
> 11 RxHeader c If-None-Match: "d41d8cd98f00b204e9800998ecf8427e", "4a00e1-3ddf-4a1816f7a9400"
> 11 RxHeader c Cache-Control: max-age=0
> 11 VCL_call c recv
> 11 VCL_return c lookup
> 11 VCL_call c hash
> 11 VCL_return c hash
> 11 Hit c 2113947501
> 11 VCL_call c hit
> 11 LostHeader c X-Cache:
> 11 VCL_return c deliver
> 11 VCL_call c deliver
> 11 VCL_return c deliver
> 11 TxProtocol c HTTP/1.1
> 11 TxStatus c 200
> 11 TxResponse c OK
> 11 TxHeader c Server: Apache/2.2.14 (Ubuntu)
> 11 TxHeader c Content-Disposition: inline; filename="Seminar Speakers.jpg"
> 11 TxHeader c Expires: Sat, 23 Apr 2011 13:00:00 GMT
> 11 TxHeader c ETag: "d41d8cd98f00b204e9800998ecf8427e"
> 11 TxHeader c Cache-Control: max-age=86400
> 11 TxHeader c P3P: CP="IDC DSP COR ADM DEVi TAIi PSA PSD IVAi IVDi CONi HIS OUR IND CNT"
> 11 TxHeader c Last-Modified: Fri, 22 Apr 2011 13:00:00 GMT
> 11 TxHeader c ETag: "4a00e1-3ddf-4a1816f7a9400"
> 11 TxHeader c Content-Type: image/jpeg;charset=utf-8
> 11 TxHeader c Content-Length: 15839
> 11 TxHeader c Date: Sat, 23 Apr 2011 12:07:39 GMT
> 11 TxHeader c X-Varnish: 2113947582 2113947501
> 11 TxHeader c Age: 58
> 11 TxHeader c Via: 1.1 varnish
> 11 TxHeader c Connection: keep-alive
> 11 Length c 15839
> 11 ReqEnd c 2113947582 1303560459.219877005 1303560459.317925930 0.000497818 0.000181675 0.097867250
> 11 Debug c "herding"
> 0 ExpKill - 2113947483 -30
> 0 CLI - Rd ping
> 0 CLI - Wr 200 19 PONG 1303560459 1.0
>
>
> Regards,
> Harm Verhagen
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--
Mark Nottingham mnot at yahoo-inc.com
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