upstream max_fails disable

[Richard Kearsley]

Hi
I'm using the upstream module - with sole purpose to enable keepalives 
to my backend
I don't want to use any of the other features, I only have 1 server in 
the upstream {}
Does that mean max_fails is still being used? (defaults to 1?) and 
fail_timeout etc..? they both have default values
What happens if they are "all" marked as down?

If the 10.100.0.11 is down, I would like it to just keep using it and 
just return 502 if it's down

upstream test
{
     server 10.100.0.11;
     keepalive 100;
}

Thanks