502 errors with nginx and php5-fpm

Mon Sep 15 10:51:30 UTC 2014

Hello!

On Thu, Sep 11, 2014 at 04:42:51PM -0400, nfn wrote:

> Hi,
> 
> Here is the debug log: http://pastebin.com/raw.php?i=w8Bwj4pS
> 
> Can you help me understand why I have these random 502 error?

As previously suggested, there is an error logged at "error" level:

2014/09/09 23:55:59 [error] 31744#0: *35461 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 0.0.0.0, server: www.example.com, request: "POST /index.php?app=members&module=messaging&section=send&do=sendReply&topicID=54192 HTTP/1.1", upstream: "fastcgi://unix:/var/run/php5-fpm.sock:", host: "www.example.com", referrer: "http://www.example.com/index.php?app=members&module=messaging&section=view&do=showConversation&topicID=54192&st=200"

As others already explained, the message suggestes there is 
something wrong with your backend, most likely it dies for some 
reason.

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