Using Nginx to host multiple Node.js applications

server {
    listen 80;

    server_name greatwallprojects.com;

    location / {
        proxy_pass http://127.0.0.1:8080;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
    }

    location /pingtest/  {
            proxy_pass http://127.0.0.1:8081;
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection 'upgrade';
            proxy_set_header Host $host;
            proxy_cache_bypass $http_upgrade;
        }
    }

The second application pingtest is not displayed. My application folders lie in home/user/

You can check the problem by visiting http://greatwallprojects.com/pingtest/ a blank page is displayed.