Anand, Check that vcl_recv is actually setting a backend. It might be that there's a route through the VCL that doesn't cause a backend to be specified.
Rob On 22 Dec 2010, at 08:39, Anand Shah wrote: > I immediately fired a test call using CURL which indicated me a > tcp_miss and i also got the response from origin. > > So backend was working and in healthy state. > > > > [r...@mymachine ~]# curl --head --header host:imads.mydomain.com > "http://localhost//0/OasDefault/IIPM_CPL_Nov10_B3_MW/iipm_winter02_300x600_10dec_03.gif"; > HTTP/1.1 200 OK > Last-Modified: Thu, 02 Dec 2010 12:19:14 GMT > P3P: CP="NON NID PSAa PSDa OUR IND UNI COM NAV STA",policyref="/w3c/p3p.xml" > Content-Type: image/gif > cache-control: max-age=604800 > Content-Length: 4150 > Date: Wed, 22 Dec 2010 06:39:26 GMT > Connection: keep-alive > H-Served-By: mymachine > Server: mydomain/2.0.6 > X-Cache: TCP_MISS > > [r...@mymachine ~]# curl --head --header host:imads.mydomain.com > "http://localhost//0/OasDefault/IIPM_CPL_Nov10_B3_MW/iipm_winter02_300x600_10dec_03.gif"; > HTTP/1.1 200 OK > Last-Modified: Thu, 02 Dec 2010 12:19:14 GMT > P3P: CP="NON NID PSAa PSDa OUR IND UNI COM NAV STA",policyref="/w3c/p3p.xml" > Content-Type: image/gif > cache-control: max-age=604800 > Content-Length: 4150 > Date: Wed, 22 Dec 2010 06:39:33 GMT > Connection: keep-alive > H-Served-By: mymachine > Server: mydomain/2.0.6 > X-Cache: TCP_HIT > > > > > Regards, > Anand > > On Wed, Dec 22, 2010 at 12:42:24PM +0530, Anand Shah wrote: >> I am running varnish on 64 bit Centos. Getting too many 503 errors >> recently and i tried debugging it with some help from Forums on >> mailinglist. > >> VARNISHLOGS: >> >> 180 VCL_call c miss fetch >> 180 FetchError c no backend connection >> 180 VCL_call c error deliver > > In my experience, "no backend connection" indicates that whatever > backend was selected to handle this request was unavailable due to the > health check/probe returning an error. > > What was the backend health at the time? You can use the 'debug.health' > command in the CLI to view health information, or > > varnishlog -i Backend_health > > to see the results of the health checks as they occur. If a backend is > marked as 'sick' then Varnish won't send any requests to it, since > it's unlikely to help the situation. > > _______________________________________________ > varnish-misc mailing list > [email protected] > http://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc > > _______________________________________________ > varnish-misc mailing list > [email protected] > http://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc _______________________________________________ varnish-misc mailing list [email protected] http://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
![http://localhost//0/OasDefault/IIPM_CPL_Nov10_B3_MW/iipm_winter02_300x600_10dec_03.gif"](http://localhost//0/OasDefault/IIPM_CPL_Nov10_B3_MW/iipm_winter02_300x600_10dec_03.gif"){kind=link}