Unable to coect NGINX to Tomcat Server

I have Nginx Server ruing on port 80 and and Tomcat Service is ruing on port 8080. I followed some of the tutorials for setting Nginx as proxy server but getting 502 Bad Gateway. i have created a /etc/nginx/conf.d/tomcat.conf.

upstream myapp {
server 127.0.0.1:8080;
keepalive 8;

}

server {
listen 0.0.0.0:80;
server_name my_domain.com;
access_log /var/log/nginx/my_domain.com.log;

location / {
  proxy_set_header X-Real-IP $remote_addr;
  proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
  proxy_set_header Host $http_host;
  proxy_set_header X-NginX-Proxy true;

  proxy_pass http://myapp/;
  proxy_redirect off;
}

}