upstream tomcat_ server { 
        server localhost:8090;
    }

server {
     listen 80;
     server_ name localhost;
    charset utf-8;
    access_ log logs/ host.access.log main;

location / {
    proxy_ pass http://tomcat_ server
    proxy_ set_ header Host $http_ Host; / / to add a host header here, return the header information to the server
}