Re: nginx reverse proxy getting ECONNRESET

[Eric Wong <e@80x24.org>]

Michael Fischer <mfischer@zendesk.com> wrote:
> We have an nginx 1.6.2 proxy in front of a Unicorn 4.8.3 server that
> is frequently reporting the following error:
> 
> 2015/03/24 01:46:01 [error] 11217#0: *872231 readv() failed (104:
> Connection reset by peer) while reading upstream
> 
> The interesting things are:
> 
> 1) The upstream is a Unix domain socket (to which Unicorn is bound)
> 2) Unicorn isn't reporting that a child died in the error log (and I
> verified their lifetimes with ps(1))
> 
> Any hints as to what we should look for?

What changed recently with your setup?

Which OS/kernel version + vendor version?

Since you've been around a while, I take it this is only a recent issue?

Can you setup a test instance on a different nginx port/unicorn socket
and with a config.ru such as:

------------------------- 8< ----------------------
run(lambda do |env|
  $stderr.write("#$$ starting at #{Time.now}\n")
  # be sure to configure your unicorn timeout
  sleep
  # should not return, wait for unicorn to kill
end)
----------------------------------------------------

And hitting nginx with a single test request to reproduce the issue.

And see if it happens on the same/different hosts where you notice the
problem.