Blank pages with HTTP/1.0

[Fredrik Nygren]

Hi,
I have a couple of servers with Varnish 1.1.2-5 installed. Some  
visitors has reported a blank page when they are visiting us. What I  
can se from our logs the problem seems to be related to the visitors  
HTTP protocol version. Requests with HTTP/1.0 gets a blank page but  
HTTP/1.1 not. Our Apache logs shows this:

[28/Feb/2008:10:32:14 +0100] "GET /index.jsp HTTP/1.1" 200 145883 "-"  
"Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 1.1.4322)"
[28/Feb/2008:10:39:53 +0100] "GET /index.jsp HTTP/1.1" 200 145863 "-"  
"Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 1.1.4322)"
[28/Feb/2008:10:44:18 +0100] "GET /index.jsp HTTP/1.1" 200 145886 "-"  
"Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1)"
[28/Feb/2008:10:44:32 +0100] "GET /index.jsp HTTP/1.0" 200 17491 "-"  
"Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1)"
[28/Feb/2008:10:44:43 +0100] "GET /index.jsp HTTP/1.0" 200 17491 "-"  
"Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1)"
[28/Feb/2008:10:44:44 +0100] "GET /index.jsp HTTP/1.0" 200 17491 "-"  
"Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1)"
[28/Feb/2008:10:44:45 +0100] "GET /index.jsp HTTP/1.0" 200 17491 "-"  
"Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1)"
[28/Feb/2008:10:44:47 +0100] "GET /index.jsp HTTP/1.0" 200 17491 "-"  
"Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1)"
[28/Feb/2008:10:45:04 +0100] "GET /index.jsp HTTP/1.0" 200 17491 "-"  
"Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1)"
[28/Feb/2008:11:21:09 +0100] "GET /index.jsp HTTP/1.1" 200 146633 "-"  
"Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1)"
[28/Feb/2008:12:31:46 +0100] "GET /index.jsp HTTP/1.1" 200 146205 "-"  
"Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1)"

Responses with 17491 bytes in return are blank page views.
 From our varnishlog I read the following:

134 SessionOpen  c 134.25.0.133 14373
   134 ReqStart     c 134.25.0.133 14373 2174456149
   134 RxRequest    c GET
   134 RxURL        c /
   134 RxProtocol   c HTTP/1.0
   134 RxHeader     c Accept: image/gif, image/x-xbitmap, image/jpeg,  
image/pjpeg, application/x-shockwave-flash, application/vnd.ms-excel,  
application/vnd.ms-powerpoint, application/msword, */*
   134 RxHeader     c Accept-Language: sv
   134 RxHeader     c UA-CPU: x86
   134 RxHeader     c User-Agent: Mozilla/4.0 (compatible; MSIE 7.0;  
Windows NT 5.1; .NET CLR 1.1.4322)
   134 RxHeader     c Host: www.smp.se
   134 RxHeader     c Cookie:  
__utma=147067189.81457932.1204189951.1204189951.1204189951.1;  
__utmb=147067189; __utmz=147067189.1204189951.1.1.utmccn=(direct)| 
utmcsr=(direct)|utmcmd=(none); InsightXE022004=216172787026292393
   134 RxHeader     c X-NovINet: v1.2
   134 RxHeader     c Via: 1.0 portos.sr.se:8080 (squid/2.6.STABLE18)
   134 RxHeader     c Cache-Control: max-age=259200
   134 VCL_call     c recv lookup
   134 VCL_call     c hash hash
   134 HitPass      c 2174455371
   134 VCL_call     c pass pass
   134 Backend      c 123 smp
   134 ObjProtocol  c HTTP/1.1
   134 ObjStatus    c 200
   134 ObjResponse  c OK
   134 ObjHeader    c Date: Thu, 28 Feb 2008 09:22:29 GMT
   134 ObjHeader    c Server: Apache-Coyote/1.1
   134 ObjHeader    c Content-Type: text/html;charset=ISO-8859-1
   134 ObjHeader    c Content-Language: sv-SE
   134 ObjHeader    c Set-Cookie:  
JSESSIONID=4CF19E800052C32EC682743E8D6B8920.sehan9078gota8009; Path=/
   134 TTL          c 2174456149 RFC 120 1204190549 1204190549 0 0 0
   134 VCL_call     c fetch pass
   134 Length       c 0
   134 VCL_call     c deliver deliver
   134 TxProtocol   c HTTP/1.1
   134 TxStatus     c 200
   134 TxResponse   c OK
   134 TxHeader     c Server: Apache-Coyote/1.1
   134 TxHeader     c Content-Type: text/html;charset=ISO-8859-1
   134 TxHeader     c Content-Language: sv-SE
   134 TxHeader     c Set-Cookie:  
JSESSIONID=4CF19E800052C32EC682743E8D6B8920.sehan9078gota8009; Path=/
   134 TxHeader     c Date: Thu, 28 Feb 2008 09:22:29 GMT
   134 TxHeader     c X-Varnish: 2174456149
   134 TxHeader     c Age: 0
   134 TxHeader     c Via: 1.1 varnish
   134 TxHeader     c Connection: close
   134 ReqEnd       c 2174456149 1204190549.767153978  
1204190549.773138046 0.000030041 0.005959034 0.000025034

I have searched the mailinglist and found this thread which seems to  
look like our problem but I'm not sure it's the same problem:
http://projects.linpro.no/pipermail/varnish-misc/2008-February/001349.html

Is there a known problem with the HTTP/1.0 protocol and Varnish?

Regards
<fredrik />