sock error

[Maxim Dounin]

Hello!

On Wed, May 27, 2015 at 05:55:23PM -0400, birimblongas wrote:

> Hi, i have a rails app using unicorn + nginx.
> Last month my app started to get really slow and giving me error 502.
> Unicorn log doesn't show nothing, either my rails app log.
> But looking at nginx error log, i get numerous: 
> 
>  [error] 1837#0: *263157 connect() to unix:/tmp/.app.sock failed (11:
> Resource temporarily unavailable) while connecting to upstream,
> 
> 
> What could it be? What causes this?
> 
> If I change from socket to tcp connection, my tcp connection doesn't give
> this error, but gets time out.

Both the error and timeouts indicate that your backend is 
overloaded and can't cope with load, so it's listening socket 
queue overflows and it starts rejecting connections.

-- 
Maxim Dounin
http://nginx.org/