我在apache有一个虚拟主机。我在ubuntu10.04上使用LAMP。

<VirtualHost *:80>
DocumentRoot /home/username/websites/site_folder
ServerName www.site_folder.com
ServerAlias site_folder.com
    <Directory /home/username/websites/site_folder/>
        Options Indexes FollowSymLinks MultiViews
        AllowOverride All
        Order allow,deny
        allow from all
    </Directory>
</VirtualHost>

我在/etc/hosts中添加了以下行：

127.0.0.1 site_folder.com

在vhost的文件夹中，我添加了一个名为one.php的php脚本，代码如下：

<?php
$today = getdate();
$handle = fopen("logs/logs.txt", "a");
fwrite($handle, $today['mday'].'/'.$today['mon'].'/'.$today['year']." this is a log post"." \n");
fclose($handle);
?>

当我从浏览器http://localhost/one.php或site_folder.com/one.php运行脚本时，logs.txt记录了3次相同的消息：

12/4/2011 this is a log post 
12/4/2011 this is a log post 
12/4/2011 this is a log post

使用netbeans调试器，我看到脚本实际上重复了3次（到达脚本末尾后，它从同一脚本的开头继续-〉one.php）文件夹中不存在.htaccess。
我注意到$_SERVER ['REQUEST_URI']在每次执行/重复时都会发生一些变化：

1)$_SERVER['REQUEST_URI'] => /one.php?XDEBUG_SESSION_START=netbeans-xdebug
2)$_SERVER['REQUEST_URI'] => /one.php
3)$_SERVER['REQUEST_URI'] => /one.php

我只需要记录我的消息一次。
我添加了apache2.conf中未注解的指令：

ServerRoot "/etc/apache2"
LockFile /var/lock/apache2/accept.lock
PidFile ${APACHE_PID_FILE}
Timeout 300
KeepAlive On
MaxKeepAliveRequests 100
KeepAliveTimeout 15
<IfModule mpm_prefork_module>
    StartServers          5
    MinSpareServers       5
    MaxSpareServers      10
    MaxClients          150
    MaxRequestsPerChild   0
</IfModule>
<IfModule mpm_worker_module>
    StartServers          2
    MinSpareThreads      25
    MaxSpareThreads      75 
    ThreadLimit          64
    ThreadsPerChild      25
    MaxClients          150
    MaxRequestsPerChild   0
</IfModule>
<IfModule mpm_event_module>
    StartServers          2
    MaxClients          150
    MinSpareThreads      25
    MaxSpareThreads      75 
    ThreadLimit          64
    ThreadsPerChild      25
    MaxRequestsPerChild   0
</IfModule>
User ${APACHE_RUN_USER}
Group ${APACHE_RUN_GROUP}
AccessFileName .htaccess
<Files ~ "^\.ht">
    Order allow,deny
    Deny from all
    Satisfy all
</Files>
DefaultType text/plain
HostnameLookups Off
ErrorLog /var/log/apache2/error.log
LogLevel warn
Include /etc/apache2/mods-enabled/*.load
Include /etc/apache2/mods-enabled/*.conf
Include /etc/apache2/httpd.conf
Include /etc/apache2/ports.conf
LogFormat "%v:%p %h %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\"" vhost_combined
LogFormat "%h %l %u %t \"%r\" %>s %O \"%{Referer}i\" \"%{User-Agent}i\"" combined
LogFormat "%h %l %u %t \"%r\" %>s %O" common
LogFormat "%{Referer}i -> %U" referer
LogFormat "%{User-agent}i" agent
CustomLog /var/log/apache2/other_vhosts_access.log vhost_combined
Include /etc/apache2/conf.d/
Include /etc/apache2/sites-enabled/