Node.js nginx和同一域下的Nodejs应用程序

我试图在同一个域下为两个nodejs应用程序提供服务，我像这样配置nginx

server {   
    listen 80;     

    location /client {
        proxy_pass         http://127.0.0.1:3000;
        proxy_redirect     off;
        proxy_set_header   Host             $host;
        proxy_set_header   X-Real-IP        $remote_addr;
        proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for;
    }

    location / {
        proxy_pass         http://127.0.0.1:3001;
        proxy_redirect     off;
        proxy_set_header   Host             $host;
        proxy_set_header   X-Real-IP        $remote_addr;
        proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for;
    }

}

我可以连接到第二个应用程序，即端口3001上的应用程序，但我无法连接到端口3000（App1）上的应用程序，我得到了502坏网关

App1正在express 4.x上运行，是否还有其他配置

server {
listen 80;
root /var/www;
server_name your-domain.com;

location /app1 {
    proxy_pass http://localhost:{YOUR_PORT};
    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 /app2 {
    proxy_pass http://localhost:{YOUR_PORT};
    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;
}
}

尝试与上面类似的配置