Talk me through the upstream process

Server NGINX
1

So far I am loving nginx; its doing what lighhtpd was doing but no where
near consuming the CPU. Result.

I would like to understand how it manages the pool of backend machines.
Say for example I have:

upstream backends {
server 10.0.0.150:80 weight=2;
server 10.0.0.153:80;
server 10.0.0.154:80;
}

Now, assume one of them goes off line, the others one will pick up the
load, but when will nginx decide to put it back into the pool of
available workers? Does every new connection coming in, trigger an
attempt to the offline servers?

Maybe there is some docs i am missing that explains this already, but
any pointers would be appreciated.

a

2

On Tue, Jun 24, 2008 at 11:44:18AM +0100, Alan W. wrote:

}

Now, assume one of them goes off line, the others one will pick up the
load, but when will nginx decide to put it back into the pool of
available workers? Does every new connection coming in, trigger an
attempt to the offline servers?

Maybe there is some docs i am missing that explains this already, but
any pointers would be appreciated.

If some backend goes off, then nginx passes failed request to another
one.
It will not pass new request until fail_timeout (by default 30s) will
expire.
You may change fail_timeout:

server  10.0.0.153 fail_timeout=2m;