查看日志，发现太多的这条记录了：（

::1 - - [05/Feb/2007:16:05:27 +0800] "GET / HTTP/1.0" 200 263 "-" "Apache/2.2.3 (Unix) DAV/2 PHP/5.1.6 (internal dummy connection)"


搜索一下，应该是Apache2.2以上版本才有此问题。

It's defined in /server/mpm_common.c:

| This function connects to the server, then immediately closes the
| connection.
| This permits the MPM to skip the poll when there is only one listening
| socket, because it provides a alternate way to unblock an accept()
| when the pod is used.

pod=pipe of death.

| The pipe of death is used to tell all child processes that it is time
| to die gracefully.

So if you use the worker MPM which doesn't use a pod, there are no
internal dummy connections anymore.

--
Robert

来源：http://www.gossamer-threads.com/lists/apache/users/309026

查了近半个小时，终于找到解决方法。
原来是配置的时候，要采用-with-mpm=worker方式。

参考：Apache 2.0性能优化—MPM的选择与配置