this might be helpful -
http://stackoverflow.com/questions/12315832/how-to-fix-nginx-throws-400-bad-request-headers-on-any-header-testing-tools/17289826#comment16555393_12315832

On Wed, Apr 19, 2017 at 7:53 PM, Jeff Dyke <jeff.dyke@gmail.com> wrote:

> untested, but if you set error_log to the correct level, it should log
> there as it likely received a > 300 response from the backends. I don't
> think you want these in your access logs, but i am suprised you don't get
> some sort of non < 400 response in those logs. But it's been a long day....
>
> On Wed, Apr 19, 2017 at 7:06 PM, Alex Samad <alex@samad.com.au> wrote:
>
>> Will it not be logged as a timeout either in access or error/log ?
>>
>> On 20 April 2017 at 03:46, aT <atif.ali@gmail.com> wrote:
>>
>>> HI ,
>>>
>>> Is there a way to log all incoming requests on Nginx .
>>>
>>> Regardless of them being served or not .
>>>
>>> For example, In case of surge of crawler hits , if the upstream backend
>>> cannot perform and requests hang , nginx will not log any such failed
>>> request .
>>>
>>> How can we log them to have more detail on the surges of requests.
>>>
>>> Thanks
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> nginx mailing list
>>> nginx@nginx.org
>>> http://mailman.nginx.org/mailman/listinfo/nginx
>>>
>>
>>
>> _______________________________________________
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>>
>
>
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