php - Nginx/PHP-CGI - 502 错误网关

Question

当我四处浏览时（只需单击此处和此处的链接），我的网站似乎出现问题，并且我的系统将返回随机的 502 Bad Gateway 错误。我可以点击刷新按钮，它看起来工作正常。

错误信息：

2012/08/16 11:17:54 [error] 26777#0: *1049 recv() failed 
    (104: Connection reset by peer) while reading response header from upstream, 
    client: 66.162.194.10, server: SITE, 
    request: "GET /wp-admin/admin-ajax.php?action=dashboard-widgets&widget=dashboard_secondary HTTP/1.1", 
    upstream: "fastcgi://unix:/tmp/php.socket:", host: "SITE", referrer: "SITE/wp-admin/index.php"

2012/08/16 11:17:54 [error] 26777#0: *1049 connect() failed 
    (111: Connection refused) while connecting to upstream, 
    client: 66.162.194.10, server: SITE, 
    request: "GET /wp-admin/admin-ajax.php?action=dashboard-widgets&widget=dashboard_secondary HTTP/1.1", 
    upstream: "http://127.0.0.1:9000/wp-admin/admin-ajax.php?action=dashboard-widgets&widget=dashboard_secondary", 
    host: "SITE", referrer: "http://SITE/wp-admin/index.php"

/etc/nginx/nginx.conf:
user www-data;
worker_processes 8;