Nginx proxy with keepalive connection

vhost.conf

upstream service-keepalive {
 server loadbalancer.aws.com:443 max_fails=0 fail_timeout=30s;
 keepalive 1024;
}

server {
 listen   8443;
 server_name  service.proxy.example.net;

 location / {
   proxy_http_version 1.1;
   proxy_set_header Connection "";
   proxy_set_header Host "service.myapp.com";
   proxy_pass https://service-keepalive;
 }
}