<div dir="ltr">Hi, I'm occasionally seeing this error " http first read error: EOF" in varnishlog for content that exist, and not exceeding "first_byte_timeout" TTL<div>I was considering issuing a restart < 4 on 503's with a URL condition match since this is happening pretty rarely, I'm seeing the error just 2-3 times while also getting a 200 for the same html asset 3,000+ times within a couple of mins of logging. </div><div><br></div><div><div><br></div><div>







<p class="">varnish-4.0.3</p><p class=""><br></p><p class=""># varnishadm "param.show first_byte_timeout"</p><p class="">first_byte_timeout</p><p class="">        Value is: 60.000 [seconds] (default)</p><p class="">        Default is: 60.000</p><p class="">        Minimum is: 0.000</p><p class=""># varnishadm "param.show thread_pool_timeout"<br></p><p class="">thread_pool_timeout</p><p class="">        Value is: 120.000 [seconds]</p><p class="">        Default is: 300.000</p><p class="">        Minimum is: 10.000<br></p><p class=""><br></p><p class="">VCL code used to define and use backend where 503 errors are being generated..<br></p><p class="">backend wwwdot {<br></p><p class="">        .host = "<a href="http://web-prod-ssf.domain.ly">web-prod-ssf.domain.ly</a>";</p><p class="">        .port = "80";</p><p class="">        }</p><p class=""><br></p><p class="">if (req.http.host ~ "^(origin-www|www)") {</p><p class="">        set req.backend_hint = wwwdot;</p><p class="">        return(pass);</p><p class="">




























</p><p class="">}</p><p class=""><< BeReq    >> 575646365</p><p class="">-   Begin          bereq 575646364 pass</p><p class="">-   Timestamp      Start: 1453229310.040839 0.000000 0.000000</p><p class="">-   BereqMethod    GET</p><p class="">-   BereqURL       /toprail-domain.html</p><p class="">-   BereqProtocol  HTTP/1.1</p><p class="">-   BereqHeader    DNT: 1</p><p class="">-   BereqHeader    Cookie: bknx_fa=1453197478872; bknx_ss=1453229297581; CPN_crispkey=; CPN_geo=eyJpcF9hZGRyZXNzIjoiNzAuMTk2LjEzMi4yMyIsImlwX3R5cGUiOiJNYXBwZWQiLCJOZXR3b3JrIjp7ImNvbm5lY3Rpb25fdHlwZSI6Im1vYmlsZSB3aXJlbGVzcyIsImxpbmVfc3BlZWQiOiJsb3ciLCJpcF9yb3V0aW5nX3R5cGUiO</p><p class="">-   BereqHeader    Accept: */*</p><p class="">-   BereqHeader    User-Agent: Mozilla/5.0 (iPhone; CPU iPhone OS 9_2 like Mac OS X) AppleWebKit/601.1.46 (KHTML, like Gecko) Version/9.0 Mobile/13C75 Safari/601.1</p><p class="">-   BereqHeader    Accept-Language: en-us</p><p class="">-   BereqHeader    Referer: <a href="http://www.domain.com/outdoors/index.ssf/2014/02/wild_boar_attacks_slidell_man.html">http://www.domain.com/outdoors/index.ssf/2014/02/wild_boar_attacks_slidell_man.html</a></p><p class="">-   BereqHeader    X-Client-Dest-Addr: 69.164.6.110</p><p class="">-   BereqHeader    True-Client-IP: 70.196.132.44</p><p class="">-   BereqHeader    X-Via: 1.1 <a href="http://sw.cds943.dal.llnw.net:8000">sw.cds943.dal.llnw.net:8000</a> (EdgePrism/<a href="http://4.3.1.0">4.3.1.0</a>), 1.1 <a href="http://cds1158.dal.llnw.net:80">cds1158.dal.llnw.net:80</a> (EdgePrism/<a href="http://4.3.1.0">4.3.1.0</a>), 1.1 <a href="http://cds1079.lga.llnw.net:80">cds1079.lga.llnw.net:80</a> (EdgePrism/<a href="http://4.3.1.0">4.3.1.0</a>)</p><p class="">-   BereqHeader    Host: <a href="http://www.domain.com">www.domain.com</a></p><p class="">-   BereqHeader    Accept-Encoding: identity</p><p class="">-   BereqHeader    X-Forwarded-For: 70.196.132.44, 69.164.7.89, 69.164.43.169, 69.164.48.181, 10.51.13.254</p><p class="">-   BereqHeader    X-Varnish: 575646365</p><p class="">-   VCL_call       BACKEND_FETCH</p><p class="">-   VCL_return     fetch</p><p class="">-   BackendOpen    86 wwwdot(69.4.99.100,,80) 10.51.13.97 56085</p><p class="">-   Backend        86 wwwdot wwwdot(69.2.99.10,,80)</p><p class="">-   Timestamp      Bereq: 1453229310.041475 0.000635 0.000635</p><p class="">-   FetchError     http first read error: EOF</p><p class="">-   BackendClose   86 wwwdot(69.4.99.100,,80)</p><p class="">-   Timestamp      Beresp: 1453229310.041717 0.000877 0.000242</p><p class="">-   Timestamp      Error: 1453229310.041720 0.000881 0.000003</p><p class="">-   BerespProtocol HTTP/1.1</p><p class="">-   BerespStatus   503</p><p class="">-   BerespReason   Service Unavailable</p><p class="">-   BerespReason   Backend fetch failed</p><p class="">-   BerespHeader   Date: Tue, 19 Jan 2016 18:48:30 GMT</p><p class="">-   BerespHeader   Server: Varnish</p><p class="">-   VCL_call       BACKEND_ERROR</p><p class="">-   BerespHeader   Content-Type: text/html; charset=utf-8</p><p class="">-   BerespHeader   Retry-After: 5</p><p class="">-   VCL_return     deliver</p><p class="">-   Storage        malloc Transient</p><p class="">-   ObjProtocol    HTTP/1.1</p><p class="">-   ObjStatus      503</p><p class="">-   ObjReason      Backend fetch failed</p><p class="">-   ObjHeader      Date: Tue, 19 Jan 2016 18:48:30 GMT</p><p class="">-   ObjHeader      Server: Varnish</p><p class="">-   ObjHeader      Content-Type: text/html; charset=utf-8</p><p class="">-   ObjHeader      Retry-After: 5</p><p class="">-   Length         286</p><p class="">-   BereqAcct      5960 0 5960 0 0 0</p><p class="">























































</p><p class="">-   End</p><p class=""><br></p><p class="">any suggestions and or ideas on solving this issue would be much appreciated.   <br></p><div><br></div><p class="">Thanks <br></p><p class="">-LC<br><br></p></div></div></div>