Error handling of "Connection refused" conditions

[Dustin Wenz]

This is how an affected service is configured. We have our proxy_read_timeout set high, because some requests can legitimately take that long to return. Any other timeouts would be the default; presumably 60 seconds.

	upstream pool012 {
	    server 172.16.1.223:80;
	    server 172.16.1.224:80;
	    server 172.16.1.225:80;
	    server 172.16.1.226:80;
	    server 172.16.1.227:80;
	 }

	keepalive_timeout  65;

	server {
	    listen       172.16.6.103:80;
	    server_name  application012.domain.com;

	    error_log       logs/application012.error.log ;

	    location / {
	        proxy_pass  http://pool012;
	        proxy_next_upstream error timeout invalid_header http_500 http_502 http_503;
	        proxy_redirect     off;
		proxy_read_timeout 930s;
	    }
	}


Is it considered good practice to reduce proxy_connect_timeout to some small value if responsiveness during an outage is desired?

	- .Dustin

On Jun 20, 2012, at 2:04 PM, Reinis Rozitis wrote:

>> I am using nginx to distribute http load across three upstream application servers. It actually works really well in normal usage, but when we restart one of the upstream servers for maintenance (such as for an OS update), nginx tends to hang incoming requests for some time (30 seconds or more). When a node is brought offline, the nginx error logs show a few messages like this:
> 
> 
> You should probably post the relevant parts of your configuration since there are quite few parameters to tune nginx for a better responsiveness.
> 
> To name a few: proxy_connect_timeout, proxy_read_timeout, proxy_send_timeout which by default are 60 seconds (what could explain your "hanging" requests), lowering those allows 'proxy_next_upstream' (by default - timeout and error) kick in sooner so the backend changes/restarts are seemless and don't really affect the end-users so much.
> 
> rr 
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