Apache Reference Manual (8)

MaxRequestsPerChild directive
Syntax: MaxRequestsPerChild number
Default: MaxRequestsPerChild 0
Context: server config
Status: core
The MaxRequestsPerChild directive sets the limit on the number of requests that an individual child server process will handle. After MaxRequestsPerChild requests, the child process will die. If MaxRequestsPerChild is 0, then the process will never expire.
Setting MaxRequestsPerChild to a non-zero limit has two beneficial effects:
it limits the amount of memory that process can consume by (accidental) memory leakage;
by giving processes a finite lifetime, it helps reduce the number of processes when the server load reduces.
This directive has no effect on Win32.
NOTE: For KeepAlive requests, only the first request is counted towards this limit. In effect, it changes the behavior to limit the number of connections per child.
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MaxSpareServers directive
Syntax: MaxSpareServers number
Default: MaxSpareServers 10
Context: server config
Status: core
The MaxSpareServers directive sets the desired maximum number of idle child server processes. An idle process is one which is not handling a request. If there are more than MaxSpareServers idle, then the parent process will kill off the excess processes.
Tuning of this parameter should only be necessary on very busy sites. Setting this parameter to a large number is almost always a bad idea.
This directive has no effect when used with the Apache Web server on a Microsoft Windows platform.
See also MinSpareServers and StartServers.
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MinSpareServers directive
Syntax: MinSpareServers number
Default: MinSpareServers 5
Context: server config
Status: core
The MinSpareServers directive sets the desired minimum number of idle child server processes. An idle process is one which is not handling a request. If there are fewer than MinSpareServers idle, then the parent process creates new children at a maximum rate of 1 per second.
<FilesMatch>
Syntax: <FilesMatch regex> ... </FilesMatch>
Context: server config, virtual host, .htaccess
Status: core
Compatibility: only available in Apache 1.3 and above.
The <FilesMatch> directive provides for access control by filename, just as the <Files> directive does. However, it accepts a regular expression. For example:
     <FilesMatch ".(gif|jpe?g|png)$">
would match most common Internet graphics formats.
See also: How Directory, Location and Files sections work for an explanation of how these different sections are combined when a request is received
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Group directive
Syntax: Group unix-group
Default: Group #-1
Context: server config, virtual host
Status: core
The Group directive sets the group under which the server will answer requests. In order to use this directive, the stand-alone server must be run initially as root. Unix-group is one of:
A group name
Refers to the given group by name.
# followed by a group number.
Refers to a group by its number.
It is recommended that you set up a new group specifically for running the server. Some admins use user nobody, but this is not always possible or desirable.
Note: if you start the server as a non-root user, it will fail to change to the specified group, and will instead continue to run as the group of the original user.
Special note: Use of this directive in <VirtualHost> requires a properly configured suEXEC wrapper. When used inside a <VirtualHost> in this manner, only the group that CGIs are run as is affected. Non-CGI requests are still processed as the group specified in the main Group directive.
SECURITY: See User for a discussion of the security considerations.
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php: PHP Version 5.0.0b4
apache: Apache/2.0.49 (Win32)
1，做为cgi来运行
2，做为module来运行
1,做为apache2的cgi运行
ScriptAlias /php/ "c:/php/"
AddType application/x-httpd-php .php
Action application/x-httpd-php "/php/php-cgi.exe"
上面的代码添加到httpd.conf
2,做为apache的模块运行
LoadModule php5_module "c:/php/sapi/php5apache2.dll"
AddType application/x-httpd-php .php
上面的代码添加到httpd.conf
有时候,我们需要在WINDOWS服务器中安装多个不同版本的PHP环境,或采用不同的php.ini配置,例如在使用中国E商务网的IONCUBE系统对PHP程序进行加密后,要在php.ini中设置加载选项目，但这个选项和zend加密程序解释器不能同时存在，如果在服务器中有另外程序采用ZEND加密的话，就非常可惜。
    如果能在WINDOWS服务器中装多套PHP，使用不同的PHP.INI就可以解决这样的问题。但是如果采用正规的方法要重新编译PHP，比较麻烦。我们最近已经研究成功，采用另一种方式来安装多个PHP：
    首先安装一套PHP，采用默认方式，装在c:php ，安装后，php.ini一般自动复制到c:winnt下。
    将winnt下的php.ini用Ctrl+c和 Ctrl+V方式复制到c:php下，这时候你可以用PHPINFO()查看php.ini的路径，已经自动变成c:/php/php.ini 了。
    接着，就可以安装第二套PHP，最好换个磁盘，安装在d:php，安装时，PHP又会把php.ini拷贝在c:winnt下，只要如法炮制将其拷贝到d:php下就可以了。
    然后，在IIS -> 主目录->配置中，可以为不同站点指定不同的PHP运行文件就可以了。
     采用此方法安装两套PHP后，对系统资源并没有特别的影响，经测试，系统运行正常。

运行PHP软件包的安装程序，在弹出的欢迎窗口中单击“Next”按钮，接着在“许可协议”窗口中单击“I Agree”按钮，然后在安装类型(Installation Type)窗口中选择“标准(Standard)”安装，点击“Next”按钮后，指定PHP的安装目录，建议使用默认安装目录。接着“Mail configuration”窗口中设置邮件地址和指定SMTP服务器，在“服务类型(Server Type)”窗口中选择你使用的Web服务器的类型(如图2)，因为我们使用Windows XP系统自带的IIS5.1，选择“Microsoft iis4 or higher”单选项，点击“下一步”后开始安装，最后在“IIS Scriptmap Node selection”窗口中选中所有的站点(如图3)，点击“OK”按钮，就完成了PHP的安装和配置。
图3选中所有站点
    检查PHP调试环境配置
　　进入到“控制面板→管理工具”，运行Internet信息服务程序，右键点击“默认网站”在弹出的菜单中选择“属性”，接着在弹出的属性对话框中切换到“主目录”标签页，点击应用程序设置栏中的“配置”按钮，弹出“应用程序配置”对话框，在“映射”标签页中，查看应用程序映射列表框中是否有扩展名为“.php”的选项(如图4)，如果存在则表示PHP安装配置成功。
图4查看程序映射
    如果没有找到该选项，也可以手工添加。在应用程序配置对话框中点击“添加”按钮，弹出“添加/编辑应用程序扩展名映射”对话框(如图5)，在“可执行文件”栏中输入“php.exe”程序路径，“扩展名”中输入“.PHP”，其它选项使用默认设置，最后点击“确定”按钮即可。
图5手工添加映射
    这样就完成了PHP调试环境的配置，以后就可以在IIS中调试PHP文件了。