Using Apache with Microsoft Windows

Requirements

Apache 2.0 is designed to run on Windows NT 4.0 and Windows 2000. The binary installer will only work with the x86 family of processors, such as Intel's. Apache may also run on Windows 9x, but it is not tested, and is never recommended for production servers. In all cases TCP/IP networking must be installed.

If running on Windows 95, the "Winsock2" upgrade MUST BE INSTALLED. "Winsock2" for Windows 95 is available here.

If running on NT 4.0, installing Service Pack 6 is recommended, as Service Pack 4 created known issues with TCP/IP and WinSock integrity that were resolved in later Service Packs.

Downloading Apache for Windows

Information on the latest version of Apache can be found on the Apache web server at http://httpd.apache.org/. This will list the current release, any more recent alpha or beta-test releases, together with details of mirror web and anonymous ftp sites.

You should download the version of Apache for Windows with the .msi extension. This is a single Microsoft Installer file containing Apache, ready to install and run. There is a seperate .zip file containing only the source code, to compile Apache yourself with the Microsoft Visual C++ (Visual Studio) tools.

Installing Apache for Windows

Run the Apache .msi file you downloaded above. This will ask for:

• the directory to install Apache into (the default is \Program Files\Apache Group\Apache although you can change this to any other directory)
• the start menu name (default is "Apache Web Server")
• the installation type. The "Typical" option installs everything except the source code. The "Minimum" option does not install the manuals or source code. Choose the "Custom" install if you want to install the source code.

During the installation, Apache will configure the files in the conf directory for your chosen installation directory. However if any of the files in this directory already exist they will not be overwritten. Instead the new copy of the corresponding file will be left with the extension .default. So, for example, if conf\httpd.conf already exists it will not be altered, but the version which would have been installed will be left in conf\httpd.conf.default. After the installation has finished you should manually check to see what is in new in the .default file, and if necessary update your existing configuration files.

Also, if you already have a file called htdocs\index.html then it will not be overwritten (no index.html.default file will be installed either). This should mean it a safe to install Apache over an existing installation (but you will have to stop the existing server running before doing the installation, then start the new one after the installation is finished).

After installing Apache, you should edit the configuration files in the conf directory as required. These files will be configured during the install ready for Apache to be run from the directory where it was installed, with the documents served from the subdirectory htdocs. There are lots of other options which should be set before you start really using Apache. However to get started quickly the files should work as installed.

Running Apache for Windows

There are two ways you can run Apache:

• As a "service" (available on Windows NT, or a pseudo-service on Windows 9x). This is the best option if you want Apache to automatically start when you machine boots, and to keep Apache running when you log-off.

• From a console window. This MUST be used by any administrator to test before attempting to run as a service.

To run Apache from a console window, select the "Start Apache as console app" option from the Start menu (in Apache 1.3.4 and earlier, this option was called "Apache Server"). This will open a console window and start Apache running inside it. The window will remain active until you stop Apache. To stop Apache running, either select the "Shutdown Apache console app" icon option from the Start menu (this is not available in Apache 1.3.4 or earlier), or see Signalling Console Apache when Running for how to control Apache from the command line.

If the Apache console window closes immediately (or unexpectedly), run the "Command Prompt" from the Start Menu - Programs list. Change to the folder to which you installed Apache, type the command apache, and read the error message. Then change to the logs folder, and review the error.log file for configuration mistakes. If you accepted the defaults when you installed Apache, the commands would be:

Complete the steps above before you proceed to attempt to start Apache as a Windows NT service!

To start Apache as a service, you first need to install it as a service. Multiple Apache services can be installed, each with a different name and configuration. To install the default Apache service named "Apache", run the "Install Apache as Service (NT only)" option from the Start menu. Once this is done you can start the "Apache" service by opening the Services window (in the Control Panel), selecting Apache, then clicking on Start. Apache will now be running in the background. You can later stop Apache by clicking on Stop. As an alternative to using the Services window, you can start and stop the "Apache" service from the control line with:

See Signalling Service Apache when Running for more information on installing and controlling Apache services.

After starting Apache running (either in a console window or as a service) it will be listening on port 80 (unless you changed the Listen directive in the configuration files). To connect to the server and access the default page, launch a browser and enter this URL:

This should respond with a welcome page, and a link to the Apache manual. If nothing happens or you get an error, look in the error_log file in the logs directory. If your host isn't connected to the net, you may have to use this URL:

Once your basic installation is working, you should configure it properly by editing the files in the conf directory. Again, if you change the configuration of the Windows NT service for Apache, first attempt to start it from the command line to assure that the service starts with no errors.

Because Apache CANNOT share the same port with another TCP/IP application, you may need to stop or uninstall certain services first. These include (but are not limited to) other web servers, and firewall products such as BlackIce. If you can only start Apache with these services disabled, reconfigure either Apache or the other product so that they do not listen on the same TCP/IP ports.

Configuring Apache for Windows

Apache is configured by files in the conf directory. These are the same as files used to configure the Unix version, but there are a few different directives for Apache on Windows. See the Apache documentation for all the available directives.

The main differences in Apache for Windows are:

• Because Apache for Windows is multithreaded, it does not use a separate process for each request, as Apache does with Unix. Instead there are usually only two Apache processes running: a parent process, and a child which handles the requests. Within the child each request is handled by a separate thread.

  So the "process"-management directives are different:

  MaxRequestsPerChild - Like the Unix directive, this controls how many requests a process will serve before exiting. However, unlike Unix, a process serves all the requests at once, not just one, so if this is set, it is recommended that a very high number is used. The recommended default, MaxRequestsPerChild 0, does not cause the process to ever exit.

  Warning: The server configuration file is reread when the new child process is started. If you have modified httpd.conf, the new child may not start or you may receive unexpected results.

  ThreadsPerChild - This directive is new, and tells the server how many threads it should use. This is the maximum number of connections the server can handle at once; be sure and set this number high enough for your site if you get a lot of hits. The recommended default is ThreadsPerChild 50.

• The directives that accept filenames as arguments now must use Windows filenames instead of Unix ones. However, because Apache uses Unix-style names internally, you must use forward slashes, not backslashes. Drive letters can be used; if omitted, the drive with the Apache executable will be assumed.

• Apache for Windows contains the ability to load modules at runtime, without recompiling the server. If Apache is compiled normally, it will install a number of optional modules in the \Apache\modules directory. To activate these, or other modules, the new LoadModule directive must be used. For example, to active the status module, use the following (in addition to the status-activating directives in access.conf):

  LoadModule status_module modules/mod_status.so

  Information on creating loadable modules is also available.

• Apache can also load ISAPI Extensions (i.e., Internet Server Applications), such as those used by Microsoft's IIS, and other Windows servers. More information is available. Note that Apache CANNOT load ISAPI Filters.

• When running CGI scripts, the method Apache uses to find the interpreter for the script is configurable using the ScriptInterpreterSource directive.

• Since it is often difficult to manage files with names like .htaccess under windows, you may find it useful to change the name of this configuration file using the AccessFilename directive.

Running Apache for Windows as a Service

You can install Apache as a Windows NT service as follows:

To install a service to use a particular configuration, specify the configuration file when the service is installed:

To remove an Apache service, use

The default "service name", if one is not specified, is "Apache".

Once a service is installed, you can use the -n option, in conjunction with other options, to refer to a service's configuration file. For example:

To test a service's configuration file:

To start a console Apache using a service's configuration file:

Important Note on service dependencies:

Prior to Apache release 1.3.13, the dependencies required to successfully start an installed service were not configured. After installing a service using earlier versions of Apache, you must follow these steps:

If you are using COM or DCOM components from a third party module, ISAPI, or other add-in scripting technologies such as ActiveState Perl, you may also need to add the entry Rpcss to the DependOnService list. To avoid exposing the TCP port 135 when it is unnecessary, Apache does not create that entry upon installation. Follow the directions above to find or create the DependOnService value, double click that value if it already exists, and add the Rpcss entry to the list.

Running Apache for Windows from the Command Line

The Start menu icons and the Windows Service manager can provide a simple interface for administering Apache. But in some cases it is easier to work from the command line.

When working with Apache it is important to know how it will find the configuration files. You can specify a configuration file on the command line in two ways:

• -f specifies a path to a particular configuration file

• -n specifies the configuration file of an installed Apache service (Apache 1.3.7 and later)

In these cases, the proper ServerRoot should be set in the configuration file.

If you don't specify a configuration file name with -f or -n, Apache will use the file name compiled into the server, usually "conf/httpd.conf". Invoking Apache with the -V switch will display this value labeled as SERVER_CONFIG_FILE. Apache will then determine its ServerRoot by trying the following, in this order:

• A ServerRoot directive via a -C switch.
• The -d switch on the command line.
• Current working directory
• A registry entry, created if you did a binary install.
• The server root compiled into the server.

The server root compiled into the server is usually "/apache". invoking apache with the -V switch will display this value labeled as HTTPD_ROOT.

When invoked from the start menu, Apache is usually passed no arguments, so using the registry entry is the preferred technique for console Apache.

During a binary installation, a version-specific registry key is created in the Windows registry:

This key is compiled into the server and can enable you to test new versions without affecting the current version. Of course you must take care not to install the new version on top of the old version in the file system.

If you did not do a binary install then Apache will in some scenarios complain that about the missing registry key. This warning can be ignored if it otherwise was able to find its configuration files.

The value of this key is the ServerRoot directory, containing the conf directory. When Apache starts it will read the httpd.conf file from this directory. If this file contains a ServerRoot directive which is different from the directory obtained from the registry key above, Apache will forget the registry key and use the directory from the configuration file. If you copy the Apache directory or configuration files to a new location it is vital that you update the ServerRoot directory in the httpd.conf file to the new location.

To run Apache from the command line as a console application, use the following command:

Apache will execute, and will remain running until it is stopped by pressing control-C.

Signalling Apache when running as a Service

On Windows NT, multiple instances of Apache can be run as services. Signal an Apache service to start, restart, or shutdown as follows:

In addition, when running on Windows NT, you can use the native NET command to start and stop Apache services as follows:

Signalling Apache when running as a console application

On Windows 9x, Apache runs as a console application. You can tell a running Apache to stop by opening another console window and typing:

This should be used instead of pressing Control-C in the running Apache console window, because it lets Apache end any current transactions and cleanup gracefully.

You can also tell Apache to restart. This makes it re-read the configuration files. Any transactions in progress are allowed to complete without interruption. To restart Apache, run