Apache Server Configuration Full Introduction (i)

apache| Server | Introduction Author: Wangbo

The Apache server settings file is located in the/usr/local/apache/conf/directory and traditionally uses three profiles httpd.conf,access.conf and srm.conf to configure the Apache server's behavior.

HTTPD.CONF provides the most basic server configuration, the technical description of how the daemon httpd to run, srm.conf is the server's resource mapping file, tells the server the MIME types of the various files, and how to support these files; access.conf to configure access rights for the server, control different User and computer access restrictions; These three profiles control the characteristics of each aspect of the server, so the three files need to be set up to run the server properly.

In addition to these three settings files, Apache uses the Mime.types file to identify different files

The corresponding MIME type, the Magic file sets some special identities for different MIME type files, so that the Apache server can judge the MIME type of the document by using these special tags in the contents of the file when it cannot determine the MIME type of the file from the document suffix.

bash-2.02$ ls-l/usr/local/apache/conf

Total 100

-rw-r--r--1 root wheel 348 APR 16:01 access.conf

-rw-r--r--1 root wheel 348 Feb 13:33 Access.conf.default

-rw-r--r--1 root wheel 30331 may 08:55 httpd.conf

-rw-r--r--1 root wheel 29953 Feb 13:33 httpd.conf.default

-rw-r--r--1 root wheel 12441 Apr 15:42 Magic

-rw-r--r--1 root wheel 12441 Feb 13:33 magic.default

-rw-r--r--1 root wheel 7334 Feb 13:33 mime.types

-rw-r--r--1 root wheel 383 17:01 srm.conf

-rw-r--r--1 root Wheel 357 Feb 13:33 Srm.conf.default

In fact, the current version of Apache will originally httpd.conf, All of the configuration parameters in srm.conf and access.conf are placed in a single profile httpd.conf, only three profiles are used for reasons compatible with previous versions (from NCSA-HTTPD in the same way that the three settings files were used). There are no specific settings in the access.conf and srm.conf files provided.

Because in the new version of Apache, all of the settings are placed in the httpd.conf, so you just need to adjust the settings in this file. The following uses the default provided httpd.conf as an example to explain the various settings options for the Apache server. However, you do not have to worry because it provides too many parameters to set, basically these parameters are very clear, you can run the Apache server without changes. However, if you need to adjust the performance of the Apache server and increase support for an attribute, you need to understand what these settings parameters mean.

On the performance of the Apache server, there is a lot of controversy over the internet, basically using Apache users almost do not doubt its excellent performance, Apache also supported many well-known high load of the site, but in the business evaluation, Apache often scored low. Many people point out that in these reviews, commercial Web servers and their operating systems are often performed by engineers of their professional firms, while free operating systems and Web servers often use their default configurations or make only minor changes. It should be noted that, in addition to operating system performance tuning, the Apache server itself's default configuration is not optimized and most efficient, but to adapt to almost all kinds of operating systems, all kinds of hardware settings, multi-platform software is not possible for specific platforms and specific hardware to provide the most optimized default configuration. So when you want to use Apache, performance tuning is essential.

Another fact that has been overlooked in the business evaluation is that the metrics tend to compare different kinds of functions, such as using Apache's standard CGI performance compared to server-side APIs such as ISAPI,NSAPI, in fact the Apache server is Modperl with this comparable functionality, FastCGI, similar to ASP functionality for PHP, and so on, but because of the Apache open mode, these functions are independent development Group, as a stand-alone module to achieve. But in the evaluation, the tester did not add the corresponding module to evaluate its performance.

Operating parameters of the HTTP daemon

Httpd.conf first defines some of the parameters that the httpd daemon needs to run in order to determine its operating mode and operating environment.

ServerType Standalone

ServerType defines how the server is started, the default is independent STANDALONE,HTTPD

The server is started by itself and resides in the host to monitor connection requests. The Web server is automatically started in the startup file/etc/rc.d/rc.local/init.d/apache under Linux, which is the recommended setting.

Another way to start the Apache server is to inet, use the Super server inetd to monitor connection requests and start the server. When you need to use the inetd startup method, you need to change to this setting, mask the/etc/rc.d/rc.local/init.d/apache file, and change the/etc/ Inetd.conf and inetd, then Apache can be launched from the inetd.

The difference between the two approaches is that the server itself manages its own startup process. This allows multiple copies of the server to be started immediately at boot time, with each replica residing in memory, and a connection request that does not require a child process to be processed immediately, responding faster and with higher performance to the client's browser request. The inetd way to start the HTTP server by inetd found that there is a connection request, because inetd to listen to too many ports, so the response is slower, less efficient, but save the connection request when the Web server occupies resources. Therefore, the inetd method is only used on servers that are occasionally accessed and do not require access speed. In fact, the inetd mode is not suitable for the HTTP burst and multiple connection characteristics, because a page may contain multiple images, and each image will cause a connection request, even though the number of visitors to teach less, but a few moments of connection requests, which is limited by inetd performance, It can even affect other server programs that are started by inetd.

ServerRoot "/usr/local"

ServerRoot is used to specify the running directory of the daemon httpd, httpd will automatically change the current directory of the process to this directory after it is started, so if the file or directory specified in the settings file is a relative path, the True path is located under the ServerRoot defined path.

Because the httpd will often do concurrent file operations, you need to use a lock to ensure that the file operation does not conflict, because NFS file system in the file lock ability is limited, so this directory should be a local disk file system, and should not use NFS file system.

#LockFile/var/run/httpd.lock

The Lockfile parameter specifies the lock file for the httpd daemon, which generally does not need to be set, and the Apache server automatically operates in the path below ServerRoot. However, if ServerRoot is an NFS file system, you need to use this parameter to specify the path in the local file system.

Pidfile/var/run/httpd.pid

Pidfile the specified file will record the process number of the httpd daemon, because httpd can automatically replicate itself, so there are multiple httpd processes in the system, but only one process is the first initiated process, it is the parent process for the other process, and sending a signal to the process affects all httpd processes. The process number of the httpd parent process is recorded in the file defined by the Pidfile.

Scoreboardfile/var/run/httpd.scoreboard

HTTPD uses Scoreboardfile to maintain the internal data of the process, so there is usually no need to change this parameter unless the administrator wants to run several Apache servers on a single computer, and each Apache server requires a separate setup file htt Pd.conf, and use a different scoreboardfile.

#ResourceConfig conf/srm.conf

#AccessConfig conf/access.conf

These two parameters, ResourceConfig and AccessConfig, are compatible with the old version of Apache that uses srm.conf and access.conf settings files. If there is no compatible need, the corresponding settings file can be specified as/dev/null, which means that no other settings file exists, and that only one file is used httpd.conf to save all of the setup options.

Timeout 300

Timeout defines a time-out interval for client and server connections that will disconnect the client after this interval (in seconds).

KeepAlive on

In HTTP 1.0, a connection can only transmit one HTTP request at a time, and the keepalive parameter is used to support a single connection, multiple transfer features of the HTTP 1.1 version, so that multiple HTTP requests can be delivered in a single connection. Although only newer browsers support this feature, it is still open to use this option.

Maxkeepaliverequests 100

Maxkeepaliverequests the maximum number of requests for HTTP requests that can be made for a single connection. Setting its value to 0 will support an unlimited transmission request within a single connection. In fact, no client program requests too many pages in a single connection, and usually does not reach the upper limit to complete the connection.

KeepAliveTimeout 15

KeepAliveTimeout tests the time between multiple request transfers in a connection, and if the server has completed a request but has not received the next request from the client, the server disconnects after the interval exceeds the value set by this parameter.