Need to identify blocked requests vs other requests

[Maxim Dounin]

Hello!

On Tue, May 15, 2012 at 09:09:11PM -0300, Guzmán Brasó wrote:

> Hello there,
> 
> As limit_req returns 503 as well other 503 (service unavailable) native
> errors I need a way to differentiate them in the access log.
> 
> One easy way would be to be able to set the status limit_req returns, would
> be that possible?
> 
> The main reason I'm asking this it's because we analyze our logs in real
> time to alert on certain values, until limit_req I used to  hsend alerts if
> more than X 503 status were seen in a time range. However, now I've
> limit_req legitimate 503 which have nothing to do with the 503 of Service
> unavailable which indeed need to take action.

The only cases when nginx generates 503 by itself is limit_req and 
limit_conn.  Hence simple solution would be to log $upstream_status. 

Maxim Dounin