Re: Random “http first read error: EOF” errors

Andrei lagged at gmail.com
Sat Apr 1 20:44:09 CEST 2017


If it's during peak hours are you sure there aren't any rate limits being
reached? Perhaps net.ipv4.ip_local_port_range might need a bump? Are Apache
or syslog logging anything around those times? No silly periodic
(Apache) graceful restarts? Just a few thoughts :)

On Sat, Apr 1, 2017 at 2:14 PM, Hazar Güney <hazarguney at gmail.com> wrote:

> We see this error a few times in a day on a highly busy production
> environment. Unfortunately there is too much traffic on the server to keep
> tcpdump/ngrep running and we cannot re-produce it on test environment :(
>
> I have started tcpdump on a test environment of another implementation and
> will let you as soon as the issue gets triggerred again.
>
> On Fri, Mar 31, 2017 at 4:17 PM, Andrei <lagged at gmail.com> wrote:
>
>> Can you provide a tcpdump/ngrep of the requests between
>> Client/Varnish/Apache along with the varnishlog entry to see if that
>> uncovers anything?
>>
>> On Fri, Mar 31, 2017 at 7:25 AM, Hazar Güney <hazarguney at gmail.com>
>> wrote:
>>
>>> Any idea?
>>>
>>> On Thu, Mar 30, 2017 at 3:41 PM, Hazar Güney <hazarguney at gmail.com>
>>> wrote:
>>>
>>>> It did not work either:
>>>>
>>>>     *   << BeReq    >> 127418176
>>>>     -   Begin          bereq 127418175 fetch
>>>>     -   Timestamp      Start: 1490877149.450124 0.000000 0.000000
>>>>     -   BereqMethod    GET
>>>>     -   BereqURL       XXXX
>>>>     -   BereqProtocol  HTTP/1.1
>>>>     -   BereqHeader    Accept: text/css,*/*;q=0.1
>>>>     -   BereqHeader    User-Agent: Mozilla/5.0 (iPhone; CPU iPhone OS
>>>> 10_2 like Mac OS X) AppleWebKit/602.3.12 (KHTML, like Gecko) Version/10.0
>>>> Mobile/14C92 Safari/602.1
>>>>     -   BereqHeader    Accept-Language: tr-tr
>>>>     -   BereqHeader    Referer: XXXX
>>>>     -   BereqHeader    Host: XXXX
>>>>     -   BereqHeader    RIP: XXXX
>>>>     -   BereqHeader    X-Forwarded-For: XXXX
>>>>     -   BereqHeader    Accept-Encoding: gzip
>>>>     -   BereqHeader    X-Varnish: 127418176
>>>>     -   VCL_call       BACKEND_FETCH
>>>>     -   BereqHeader    connection: Close
>>>>     -   VCL_return     fetch
>>>>     -   BackendOpen    25 reload_2017-03-30T14:53:46.st2 10.35.78.11 80
>>>> 172.17.0.2 59152
>>>>     -   BackendStart   10.35.78.11 80
>>>>     -   Timestamp      Bereq: 1490877149.450594 0.000470 0.000470
>>>>     -   FetchError     http first read error: EOF
>>>>     -   BackendClose   25 reload_2017-03-30T14:53:46.st2
>>>>     -   Timestamp      Beresp: 1490877149.451184 0.001060 0.000590
>>>>     -   Timestamp      Error: 1490877149.451189 0.001065 0.000005
>>>>     -   BerespProtocol HTTP/1.1
>>>>     -   BerespStatus   503
>>>>     -   BerespReason   Service Unavailable
>>>>     -   BerespReason   Backend fetch failed
>>>>     -   BerespHeader   Date: Thu, 30 Mar 2017 12:32:29 GMT
>>>>     -   BerespHeader   Server: Varnish
>>>>     -   VCL_call       BACKEND_ERROR
>>>>     -   BereqHeader    X-Varnish-Backend-5xx: 1
>>>>     -   VCL_return     retry
>>>>     -   Timestamp      Retry: 1490877149.451205 0.001081 0.000016
>>>>     -   Link           bereq 127298071 retry
>>>>     -   End
>>>>
>>>> On Thu, Mar 30, 2017 at 2:34 PM, Guillaume Quintard <
>>>> guillaume at varnish-software.com> wrote:
>>>>
>>>>> It does, I'm suspecting that the connection reuse is creating some
>>>>> issues, probably because Apache is doing some non-standard stuff (protip:
>>>>> always blame Apache).
>>>>>
>>>>> --
>>>>> Guillaume Quintard
>>>>>
>>>>> On Thu, Mar 30, 2017 at 1:17 PM, Hazar Güney <hazarguney at gmail.com>
>>>>> wrote:
>>>>>
>>>>>> "Connection: close" supersedes keep-alive behavior, is that correct?
>>>>>>
>>>>>> On Thu, Mar 30, 2017 at 2:08 PM, Guillaume Quintard <
>>>>>> guillaume at varnish-software.com> wrote:
>>>>>>
>>>>>>> Can you try something: add 'set bereq.http.connection = "Close"; '
>>>>>>> at the beginning of vcl_backend_fetch and see if that helps?
>>>>>>>
>>>>>>> --
>>>>>>> Guillaume Quintard
>>>>>>>
>>>>>>> On Thu, Mar 30, 2017 at 1:04 PM, Hazar Güney <hazarguney at gmail.com>
>>>>>>> wrote:
>>>>>>>
>>>>>>>> MaxKeepAliveRequests 20
>>>>>>>> KeepAliveTimeout 2
>>>>>>>>
>>>>>>>> Version is "4.1.3 revision 5e3b6d2". We have also seen "straight
>>>>>>>> insufficient bytes" error with POST requests to a specific php script
>>>>>>>> hosted by another backend and fixed it by using "pipe" instead of "pass"
>>>>>>>> but this specific backend gives "http first read error: EOF" error. Another
>>>>>>>> example from today:
>>>>>>>>
>>>>>>>> *   << BeReq    >> 126635444
>>>>>>>> -   Begin          bereq 126635443 fetch
>>>>>>>> -   Timestamp      Start: 1490870598.921499 0.000000 0.000000
>>>>>>>> -   BereqMethod    GET
>>>>>>>> -   BereqURL       XXXX
>>>>>>>> -   BereqProtocol  HTTP/1.1
>>>>>>>> -   BereqHeader    Host: XXXX
>>>>>>>> -   BereqHeader    User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64;
>>>>>>>> x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87
>>>>>>>> Safari/537.36
>>>>>>>> -   BereqHeader    Accept: image/webp,image/*,*/*;q=0.8
>>>>>>>> -   BereqHeader    Referer: XXXX
>>>>>>>> -   BereqHeader    Accept-Language: tr-TR,tr;q=0.8,en-US;q=0.6,en;
>>>>>>>> q=0.4
>>>>>>>> -   BereqHeader    RIP: XXXX
>>>>>>>> -   BereqHeader    X-Forwarded-For: XXXX
>>>>>>>> -   BereqHeader    Accept-Encoding: gzip
>>>>>>>> -   BereqHeader    X-Varnish: 126635444
>>>>>>>> -   VCL_call       BACKEND_FETCH
>>>>>>>> -   VCL_return     fetch
>>>>>>>> -   BackendOpen    35 reload_2017-03-20T11:32:44.st2 10.35.78.11 80
>>>>>>>> 172.17.0.2 48896
>>>>>>>> -   BackendStart   10.35.78.11 80
>>>>>>>> -   Timestamp      Bereq: 1490870598.922050 0.000552 0.000552
>>>>>>>> *-   FetchError     http first read error: EOF*
>>>>>>>> -   BackendClose   35 reload_2017-03-20T11:32:44.st2
>>>>>>>> -   Timestamp      Beresp: 1490870598.922622 0.001124 0.000572
>>>>>>>> -   Timestamp      Error: 1490870598.922627 0.001129 0.000005
>>>>>>>> -   BerespProtocol HTTP/1.1
>>>>>>>> -   BerespStatus   503
>>>>>>>> -   BerespReason   Service Unavailable
>>>>>>>> -   BerespReason   Backend fetch failed
>>>>>>>> -   BerespHeader   Date: Thu, 30 Mar 2017 10:43:18 GMT
>>>>>>>> -   BerespHeader   Server: Varnish
>>>>>>>> -   VCL_call       BACKEND_ERROR
>>>>>>>> -   BereqHeader    X-Varnish-Backend-5xx: 1
>>>>>>>> -   VCL_return     retry
>>>>>>>> -   Timestamp      Retry: 1490870598.922657 0.001159 0.000030
>>>>>>>> -   Link           bereq 126832283 retry
>>>>>>>> -   End
>>>>>>>>
>>>>>>>> On Wed, Mar 29, 2017 at 12:03 PM, Mattias Geniar <
>>>>>>>> mattias at nucleus.be> wrote:
>>>>>>>>
>>>>>>>>> > Backend is Apache.
>>>>>>>>>
>>>>>>>>> In older Varnish versions, you could sometimes see a similar error;
>>>>>>>>>
>>>>>>>>> >   11 FetchError   c straight insufficient bytes
>>>>>>>>>
>>>>>>>>> The error message you’re seeing might be related, as it mentions
>>>>>>>>> the EOF.
>>>>>>>>>
>>>>>>>>> This happens when the backend sends a Content-Length header that
>>>>>>>>> doesn’t match the _actual_ content length it’s sending. In Apache, this was
>>>>>>>>> commonly caused by a mod_deflate misconfiguration.
>>>>>>>>>
>>>>>>>>> For testing, could you try disabling Gzip either in your backend
>>>>>>>>> or strip the Accept-Encoding header in Varnish to force a plain text
>>>>>>>>> response?
>>>>>>>>>
>>>>>>>>> Mattias
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>> _______________________________________________
>>> varnish-misc mailing list
>>> varnish-misc at varnish-cache.org
>>> https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
>>>
>>
>>
>
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