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
![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}