用drupal做了一個網站，在本機開發和測試都沒出現這個警告，發佈到萬網的阿里雲服務器上後，出現瞭如題的錯誤。google+drupal官網，說是因爲安全原因引起的，服務器提供商沒有開啓一個叫要stream_socket_client()的函數，去萬網的控制面板查看php函數設置，沒有這個函數，倒是看到一個fsockopen的函數默認被禁用了。
試着打開這個函數，然後刷新網站，警告消失了。
官網上看到的一段話，記一下
Notice:
Undefined variable: errno in drupal_http_request() (line 829 of /foobar.com/includes/common.inc).
Notice: Undefined variable: errstr in drupal_http_request() (line 830 of /foobar.com/includes/common.inc).In my case (as it turns out), my hosting provider had disabled a whole basket of php functions (41 in total) for security reasons. One of the disabled functions was stream_socket_client().
My host provider was kind enough to enable this function (after I told them it was now part of Drupal 7 core) but they offered the opinion that this was a security compromise.