map $ssl_preread_server_name $name {
backend.example.com backend;
default backend2;
}
upstream backend {
server 192.168.0.1:12345;
server 192.168.0.2:12345;
}
upstream backend2 {
server 192.168.0.3:12345;
server 192.168.0.4:12345;
}
server {
listen 12346;
proxy_pass $name;
ssl_preread on;
}