How to keep alive when upstream 2 internal server nginx

Server NGINX
1

This is my config and
how i can keep alive request from port *:83 and port *:7082
http{
upstream download_redirect {
server 127.0.0.1:80 weight=1;
keepalive 20;
}

 server {
     listen       7082;
     server_name  localhost;

     location ~ ^/x-keam/service/v0.5/videos/stream(.*)$ {
          if ( $args ) {
             return 307

http://111.30.211.144:8000/x-keam/service/v1.0/videos/stream$1?$args;
}
return 307
http://111.30.211.144:8000/x-keam/service/v1.0/videos/stream$1;
}
}

server {
    listen          83;
    server_name     localhost;
    location ~ ^/x-keam/service/v0.5/videos/stream(.*)$ {
            proxy_pass http://download_redirect;
            proxy_http_version 1.1;
           proxy_set_header Connection "";
    }
}

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