# 499s and repeated requests

**URL:** <https://www.ruby-forum.com/t/499s-and-repeated-requests/237342>\
**Category:** NGINX\
**Created:** [November 7, 2013, 4:36am UTC](https://www.ruby-forum.com/t/499s-and-repeated-requests/237342 "2013-11-07T04:36:25Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![musicdenotation](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/ea666f/32.png) [@musicdenotation](https://www.ruby-forum.com/u/musicdenotation)\
**Post date:** [November 7, 2013, 4:36am UTC](https://www.ruby-forum.com/t/499s-and-repeated-requests/237342/1 "2013-11-07T04:36:25Z")

</div>

So, I’m running a rather standard nginx → unicorn → rails application,  
all  
over HTTPS. Recently, I started looking into some strange load bursts  
(which  
have been going on for a while but are getting more important), and saw  
repeated requests (both GET and POST) in my access logs, all getting a  
499  
status code and reporting 0 bytes sent. I know the browser isn’t seeing  
these 499s, but that they’re closing the connection before getting data.  
These aren’t long-running requests; I can find them in my Rails logs and  
they’re returning in 50-100ms.

I’ve seen in other threads that “the user clicked save twice really  
fast” is  
the most likely cause – but we had one client make 6500 requests over  
the  
course of a few minutes the other day, so, um, it’s probably not that.  
I’m  
rather sure this isn’t some kind of denial-of-service attack, either;  
they  
appear to be legit requests repeated by… the browser…? insanely  
quickly.  
I can’t, alas, find any way to replicate this locally.

I know there are application-level things we can do to mitigate the  
effects  
of something like this (duplicate records being created and such), but I  
want to check at this end: is there some kind of configuration error I  
could  
have made that would cause this?

In case it matters, we appear to still be running nginx 1.1.19.

Thanks!  
-Nate

Posted at Nginx Forum:

> **[499s and repeated requests](https://forum.nginx.org/read.php?2,244509,244509#msg-244509)**
>
> So, I'm running a rather standard nginx -\> unicorn -\> rails application, all over HTTPS. Recently, I started looking into some strange load bursts (which have been going on for a while but are getting more important), and saw repeated requests...

---

<div class="post-metadata">

**Author:** ![njvack](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/85f322/32.png) [@njvack](https://www.ruby-forum.com/u/njvack)\
**Post date:** [November 7, 2013, 11:27am UTC](https://www.ruby-forum.com/t/499s-and-repeated-requests/237342/2 "2013-11-07T11:27:37Z")

</div>

On 07.11.2013 04:35, njvack wrote:

> they appear to be legit requests repeated by… the browser…? insanely  
> quickly.

I experienced that kind of issue in either Firefox or Chrome (i think it  
was Firefox) myself. The only difference is that the status code was  
444. After the closing of the connection by nginx Firefox would try to  
repeat the request, instead of showing an error message, until I closed  
the browser window or nginx served a valid page.

The nginx I was running at that time was an nginx 1.4.3 built by dotdeb.

Tim