I'm having a trouble connecting to a signalR server. My initial setting on nginx was
location /notificationHub/ {
rewrite ^/notificationHub/?(.*) /notificationHub/$1 break;
proxy_pass http://api_beta_server;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection $http_connection;
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;
}