What is the scope of the upstream member liveness: is it per upstream group, or per vhost ?

If the question is unclear, consider I have 3 nginx - one balancer and two backends, and the following config part on the nginx balancer:


upstream backends {
server 192.168.0.1;
server 192.168.0.2;
}

And on both 192.168.0.1 and 192.168.0.2 the following configs:

server {
server_name A;

root /foo/bar1;

location / {
fastcgi_pass 127.0.0.1:9000;
}
}

server {
server_name B;

root /foo/bar1;

location / {
fastcgi_pass 127.0.0.1:9000;
}
}


server 192.168.0.1 returns 500 for vhost A, will it be considered dead for vhost B (and I supposed it will be) ?

Thanks.