[Varnish] #589: Round robin director not using healthy backend

[Varnish]

#589: Round robin director not using healthy backend
----------------------+-----------------------------------------------------
 Reporter:  jrieger   |       Owner:  phk  
     Type:  defect    |      Status:  new  
 Priority:  normal    |   Milestone:       
Component:  varnishd  |     Version:  trunk
 Severity:  normal    |    Keywords:       
----------------------+-----------------------------------------------------
 I have configured varnish to use two backends.
 If i turn off the first one (idefix_gallia), I get HTTP status 503.
 varnishlog correctly reports that the first backend is sick and the second
 one is healthy, but varnish doesn't use that backend.
 If i turn off the second one (miraculix_gallia), the first one is used and
 I get HTTP status 200 as expected.

 This is my VCL:

 {{{
 backend idefix_gallia {
         .host = "192.168.0.199";
         .port = "http";
         .probe = {
                 .url = "/";
                 .interval = 5s;
                 .timeout = 1s;
                 .window = 5;
                 .threshold = 3;
         }
 }

 backend miraculix_gallia {
         .host = "192.168.0.200";
         .port = "http";
         .probe = {
                 .url = "/";
                 .interval = 5s;
                 .timeout = 1s;
                 .window = 5;
                 .threshold = 3;
         }
 }

 director gallia round-robin {
         {
                 .backend = idefix_gallia;
         }
         {
                 .backend = miraculix_gallia;
         }
 }

 sub vcl_recv {
         if (req.http.host ~ "^(www.)\.example\.com$") {
                 set req.backend = gallia;
         }
 }
 }}}

 This is what varnishlog reports:

 {{{
     0 Backend_health - idefix_gallia Still sick ------- 0 3 5 0.000000
 0.000319
     0 Backend_health - miraculix_gallia Still healthy 4--X-RH 5 3 5
 0.000436 0.000473 HTTP/1.1 200 OK
 }}}

 This problem is reproducible in Varnish 2.0.4, 2.0.5 and trunk on Gentoo
 Linux.

-- 
Ticket URL: <http://varnish.projects.linpro.no/ticket/589>
Varnish <http://varnish.projects.linpro.no/>
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