# placed in /etc/nginx/conf.d/upstream.conf

upstream rails_app {
    server unix:/var/www/rails_app/shared/sockets/rails_app.socket weight=10 max_fails=3 fail_timeout=30s;
    server unix:/var/www/rails_app2/shared/sockets/rails_app.socket weight=10 max_fails=3 fail_timeout=30s;
}