public class Startup
    {
        // This method gets called by the runtime. Use this method to add services to the container.
        // For more information on how to configure your application,visit https://go.microsoft.com/fwlink/?LinkID=398940
        public void ConfigureServices(IServiceCollection services)
        {
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app,IHostingEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            app.Run(async (context) =>
            {
                //await context.Response.WriteAsync("this is first web application");
                await context.Response.WriteAsync("this is second web application");
            });
        }
    }

upstream cluster.com{ server 192.168.254.140 weight=1; server 192.168.254.141 weight=1; }       

server {
        listen 80 default_server;
        # listen [::]:80 default_server deferred;
        # SSL configuration
        #
        # listen 443 ssl default_server;
        # listen [::]:443 ssl default_server;
        #
        # Note: You should disable gzip for SSL traffic.
        # See: https://bugs.debian.org/773332
        #
        # Read up on ssl_ciphers to ensure a secure configuration.
        # See: https://bugs.debian.org/765782
        #
        # Self signed certs generated by the ssl-cert package
        # Don‘t use them in a production server!
        #
        # include snippets/snakeoil.conf;

        root /var/www/html;

        # Add index.PHP to the list if you are using PHP
        index index.html index.htm index.Nginx-debian.html;

        server_name _example.com *.example.com;

        location / {
                proxy_pass http://cluster.com;
                proxy_http_version 1.1;
                proxy_set_header   Upgrade $http_upgrade;
                proxy_set_header   Connection keep-alive;
                proxy_set_header   Host $host;
                proxy_cache_bypass $http_upgrade;
                proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
                proxy_set_header   X-Forwarded-Proto $scheme;
                # First attempt to serve request as file,then
                # as directory,then fall back to displaying a 404.
                try_files $uri $uri/ =404;
        }

        # pass PHP scripts to FastCGI server
        #
        #location ~ \.PHP$ {
        #       include snippets/fastcgi-PHP.conf;
        #
        #       # With PHP-fpm (or other unix sockets):
        #       fastcgi_pass unix:/var/run/PHP/PHP7.0-fpm.sock;
        #       # With PHP-cgi (or other tcp sockets):
        #       fastcgi_pass 127.0.0.1:9000;
        #}

        # deny access to .htaccess files,if Apache‘s document root
        # concurs with Nginx‘s one
        #
        #location ~ /\.ht {
        #       deny all;
        #}
}

    class Program
    {
        static void Main(string[] args)
        {
            HttpClient httpClient = new HttpClient();
            for (int i = 0; i < 1000; i++)
            {
                string result = httpClient.GetStringAsync("http://192.168.254.139").Result;
                Console.WriteLine(result);
            }
            Console.ReadKey();
        }
    }