Allowoverride all 500 error

My Project is working fine in Blue host shared hosting and as well in my XAMPP localhost.

For testing we moved the files to a local ubuntu server. But .htaccess not working in this ubuntu server.
Which means the files accesible with .php extention but 404 error when accesed without .php extention.

http://172.31.0.55/project/contact.php works, but
http://172.31.0.55/project/contact shows 404 error

This is the htaccess code I use.

Options +FollowSymLinks -MultiViews
# Turn mod_rewrite on
RewriteEngine On
RewriteBase /project/

## hide .php extension
# To externally redirect /dir/foo.php to /dir/foo
RewriteCond %{THE_REQUEST} ^[A-Z]{3,}s([^.]+).php[s?] [NC]
RewriteRule ^ %1 [R=301,L]

# To internally forward /dir/foo to /dir/foo.php
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{DOCUMENT_ROOT}/project/$1.php -f
RewriteRule ^(.+?)/?$ /project/$1.php [L]
Options All -Indexes
RewriteCond %{HTTP_REFERER} !^http://(www.)?172.31.0.55/project/ [NC] 
RewriteCond %{HTTP_REFERER} !^http://(www.)?172.31.0.55/project/.*$ [NC]


ErrorDocument 403 http://172.31.0.55/project/403-error
ErrorDocument 404 http://172.31.0.55/project/404-error

After some research I changed lines in /etc/apache2/apache2.conf

<Directory /var/www/>
    Options Indexes FollowSymLinks
    AllowOverride none
    Require all granted
</Directory>

to

<Directory /var/www/>
    Options Indexes FollowSymLinks
    AllowOverride All
    Require all granted
</Directory>

But now its showing 500 Internal server error when tried to access http://172.31.0.55/project/

Server version is Apache/2.4.18 (Ubuntu)
Its a PHP Website

I can see following codes in http://172.31.0.55/ Apache default page

The configuration layout for an Apache2 web server installation on Ubuntu systems is as follows:

/etc/apache2/
|-- apache2.conf
|       `--  ports.conf
|-- mods-enabled
|       |-- *.load
|       `-- *.conf
|-- conf-enabled
|       `-- *.conf
|-- sites-enabled
|       `-- *.conf

I tried changing from ip address to localhost in htaccess. But not working

I checked for File permission its rwx rwx r-x

I made these changes referring https://askubuntu.com/questions/421233/enabling-htaccess-file-to-rewrite-path-not-working

I have set up a server on my Mac (OSX 10.9) but it’s returning a 500 error with the following message in the error log…

[alert] [client ::1] /Users/user/Sites/mysite/.htaccess: AllowOverride not allowed here

Here’s the code in my .htaccess file

Options +FollowSymLinks -MultiViews
AllowOverride All

# Turn mod_rewrite on
RewriteEngine On
RewriteBase /

RewriteMap lc int:toLower
RewriteCond %{REQUEST_URI} [A-Z]
RewriteRule (.*) ${lc:$1} [R=301,L]

RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^i/(.*)/(.*)-(.*)$ /items/?id=$1&range=$2&type=$3 [L,QSA,NC]

RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^c/(.*)$ /category/?menu=$1 [L,QSA,NC]

And here’s the relevant httpd.conf code (let me know if there’s anything else that would help)

DocumentRoot "/Users/user/Sites/mysite"

<Directory />
    Options FollowSymLinks
    AllowOverride All
    Order deny,allow
    Deny from all
</Directory>

<Directory "/Users/user/Sites/mysite">
    Options Indexes FollowSymLinks MultiViews
    AllowOverride All
    Order allow,deny
    Allow from all
</Directory>

Any ideas?

Internal server error after chaning the Allow override in Apache.conf (Ubuntu)

I am facing a error after changing the AllowOveride to ALL and then i get internal server Error.

Can someone please Help me out from this Situation. I have .htaccess file in the /var/www/html/projecroot folder and having issue with Internal Navgation of project.

4 Answers 4

i have solved my error and i had issue with my .htaccess file and the Mod Filter Provider syntax has changed in the Apache version2.4 and my .htaccess file had the Filter provider from apache version 2.2.

• change the Filter provider for apache 2.4 in .htaccess

enable the rewrite mode apache and then restart the apache 2 .

The AllowOverride All directive enable .htaccess

So that mean you got an syntax error in your .htaccess, when AllowOverride is not activated the error is not triggered as .htaccess is not read.

I was having the same problem, I tried serveral solutions but no hope. Till I found that I need to enable apache header, here is the command I used

This fixed my issue.

In my case, the problem appears to be on .htaccess file, wich was trying to use GZIP, but it seams my server didin’t had it.

So there was no place saying my httpd.conf was missing GZIP library (that line was commented). I just remove the coment and we were ready to go.

To people who pass through same situation, full explanation here

Источник

500 Внутренняя ошибка сервера после изменения AllowOverride на All в Ubuntu

Мой проект работает нормально на хостинге Blue host, а также на моем локальном хосте XAMPP.

Для тестирования мы переместили файлы на локальный сервер Ubuntu. Но .htaccess не работает на этом сервере Ubuntu.
Это означает, что файлы доступны с расширением .php, но с ошибкой 404 при приеме без расширения .php.

http://172.31.0.55/project/contact.php работает, но
http://172.31.0.55/project/contact показывает ошибку 404

Это код htaccess, который я использую.

После некоторых исследований я изменил строки в /etc/apache2/apache2.conf

Но теперь он показывает 500 Внутренняя ошибка сервера при попытке доступа http://172.31.0.55/project/

Версия сервера Apache/2.4.18 (Ubuntu)
Это сайт PHP

Я могу видеть следующие коды в http://172.31.0.55/ Страница по умолчанию Apache

The configuration layout for an Apache2 web server installation on Ubuntu systems is as follows:

Я попытался изменить с IP-адреса на локальный хост в htaccess. Но не работает

Я проверил для разрешения файла его rwx rwx r-x

Решение

По умолчанию Apache запрещает использование файла .htaccess для применения правил перезаписи, поэтому сначала необходимо разрешить изменения в файле. Откройте файл конфигурации Apache по умолчанию, используя nano или ваш любимый текстовый редактор по этому пути /etc/apache2/sites-available/000-default.conf

$ sudo nano /etc/apache2/sites-available/000-default.conf

Внутри этого файла вы найдете блок начинается с первой строки. Внутри этого блока добавьте следующий новый блок, чтобы ваш файл конфигурации выглядел следующим образом. Убедитесь, что все блоки имеют правильные отступы.

Сохраните и закройте файл. Чтобы эти изменения вступили в силу, перезапустите Apache.

Я следовал за этими шагами, и моя проблема решена.

Источник

dimayakovlev.ru

Если сразу после установки или переноса GetSimple CMS на сервер c установленным, настроенным и работающим Apache, вместо страниц веб-сайта вы получаете ошибку 500 Internal Server Error, то после проверки корректности установленных прав доступа, а также, убедившись в присутствии всех файлов GetSimple CMS в файловой системе веб-сервера, не стоит поддаваться панике и обвинять в происходящем систему управления контентом.

Вместо этого следует попытаться разобраться в причине возникающей ошибки, которая является внутренней ошибкой сервера. В определении причин ошибки 500 поможет изучение логов сервера. Однако если к ним нет доступа, то можно попытаться устранить ошибку, основываясь на том, что чаще всего она возникает в следствие неверного синтаксиса файла .htaccess или наличия в нём неподдерживаемых директив.

Если вы самостоятельно не вносили изменения в корневой файл .htaccess и уверены в его соответствии первоначальному варианту из установки GetSimple CMS, то предположение о неверном синтаксисе может быть сразу отброшено. В качестве наиболее вероятной причины возникновения ошибки 500 следует рассмотреть использование в корневом файле .htaccess директив, устанавливающих настройки веб-сервера Apache для данного каталога.

Если вы обладаете доступом к настройкам Apache, то в файле httpd.conf следует проверить настройку назначения привилегий директивы AllowOverride, определяющей, использование каких директив допустимо в файлах .htaccess . В этом случае возникновение ошибки 500 решается изменением текущих настроек Apache на настройки, позволяющие использовать директивы, указанные в корневом файле .htaccess GetSimple CMS.

Если ваш доступ к настройкам Apache ограничен, следует попытаться установить, какая именно из директив в корневом файле .htaccess приводит к возникновению ошибки сервера. Для этого необходимо последовательно закомментировать каждую из директив, проверяя работу веб-сайта. В качестве рекомендации я могу посоветовать начать исследование с отключения директивы Options +FollowSymLinks , так как именно она часто бывает запрещена к использованию в файлах .htaccess на виртуальном хостинге.

В том случае, если закомментирование директив корневого файла .htaccess не привело к устранению ошибки 500 и причина её возникновения до сих пор не установлена, следует обратиться за помощью к администратору веб-сервера.

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dimayakovlev.ru © 2023 — Личная территория внутри всемирной паутины

Сайт создан и поддерживается мною с целью сохранения и распространения в свободном доступе опубликованных на нём материалов. Авторство разработок, текстов и изображений, принадлежит мне, если иное не указано отдельно.

При копировании материалов с сайта, не забывайте о важности обратных ссылок.

Размещение обратной индексируемой ссылки показывает интерес к содержанию сайта, что мотивирует к работе над новыми материалами.

Источник

Apache Core Features

Description:	Core Apache HTTP Server features that are always available
Status:	Core

Directives

Bugfix checklist

See also

AcceptFilter Directive

Description:	Configures optimizations for a Protocol’s Listener Sockets
Syntax:	AcceptFilter protocol accept_filter
Context:	server config
Status:	Core
Module:	core

This directive enables operating system specific optimizations for a listening socket by the Protocol type. The basic premise is for the kernel to not send a socket to the server process until either data is received or an entire HTTP Request is buffered. Only FreeBSD’s Accept Filters, Linux’s more primitive TCP_DEFER_ACCEPT , and Windows’ optimized AcceptEx() are currently supported.

Using none for an argument will disable any accept filters for that protocol. This is useful for protocols that require a server send data first, such as ftp: or nntp :

The default protocol names are https for port 443 and http for all other ports. To specify that another protocol is being used with a listening port, add the protocol argument to the Listen directive.

The default values on FreeBSD are:

The httpready accept filter buffers entire HTTP requests at the kernel level. Once an entire request is received, the kernel then sends it to the server. See the accf_http(9) man page for more details. Since HTTPS requests are encrypted, only the accf_data(9) filter is used.

The default values on Linux are:

Linux’s TCP_DEFER_ACCEPT does not support buffering http requests. Any value besides none will enable TCP_DEFER_ACCEPT on that listener. For more details see the Linux tcp(7) man page.

The default values on Windows are:

Window’s mpm_winnt interprets the AcceptFilter to toggle the AcceptEx() API, and does not support http protocol buffering. connect will use the AcceptEx() API, also retrieve the network endpoint addresses, but like none the connect option does not wait for the initial data transmission.

On Windows, none uses accept() rather than AcceptEx() and will not recycle sockets between connections. This is useful for network adapters with broken driver support, as well as some virtual network providers such as vpn drivers, or spam, virus or spyware filters.

The data AcceptFilter (Windows)

For versions 2.4.23 and prior, the Windows data accept filter waited until data had been transmitted and the initial data buffer and network endpoint addresses had been retrieved from the single AcceptEx() invocation. This implementation was subject to a denial of service attack and has been disabled.

Current releases of httpd default to the connect filter on Windows, and will fall back to connect if data is specified. Users of prior releases are encouraged to add an explicit setting of connect for their AcceptFilter, as shown above.

See also

AcceptPathInfo Directive

Description:	Resources accept trailing pathname information
Syntax:	AcceptPathInfo On|Off|Default
Default:	AcceptPathInfo Default
Context:	server config, virtual host, directory, .htaccess
Override:	FileInfo
Status:	Core
Module:	core

This directive controls whether requests that contain trailing pathname information that follows an actual filename (or non-existent file in an existing directory) will be accepted or rejected. The trailing pathname information can be made available to scripts in the PATH_INFO environment variable.

For example, assume the location /test/ points to a directory that contains only the single file here.html . Then requests for /test/here.html/more and /test/nothere.html/more both collect /more as PATH_INFO .

The three possible arguments for the AcceptPathInfo directive are:

Off A request will only be accepted if it maps to a literal path that exists. Therefore a request with trailing pathname information after the true filename such as /test/here.html/more in the above example will return a 404 NOT FOUND error. On A request will be accepted if a leading path component maps to a file that exists. The above example /test/here.html/more will be accepted if /test/here.html maps to a valid file. Default The treatment of requests with trailing pathname information is determined by the handler responsible for the request. The core handler for normal files defaults to rejecting PATH_INFO requests. Handlers that serve scripts, such as cgi-script and isapi-handler, generally accept PATH_INFO by default.

The primary purpose of the AcceptPathInfo directive is to allow you to override the handler’s choice of accepting or rejecting PATH_INFO . This override is required, for example, when you use a filter, such as INCLUDES, to generate content based on PATH_INFO . The core handler would usually reject the request, so you can use the following configuration to enable such a script:

AccessFileName Directive

Description:	Name of the distributed configuration file
Syntax:	AccessFileName filename [ filename ] .
Default:	AccessFileName .htaccess
Context:	server config, virtual host
Status:	Core
Module:	core

While processing a request, the server looks for the first existing configuration file from this list of names in every directory of the path to the document, if distributed configuration files are enabled for that directory. For example:

Before returning the document /usr/local/web/index.html , the server will read /.acl , /usr/.acl , /usr/local/.acl and /usr/local/web/.acl for directives unless they have been disabled with:

See also

AddDefaultCharset Directive

Description:	Default charset parameter to be added when a response content-type is text/plain or text/html
Syntax:	AddDefaultCharset On|Off| charset
Default:	AddDefaultCharset Off
Context:	server config, virtual host, directory, .htaccess
Override:	FileInfo
Status:	Core
Module:	core

This directive specifies a default value for the media type charset parameter (the name of a character encoding) to be added to a response if and only if the response’s content-type is either text/plain or text/html . This should override any charset specified in the body of the response via a META element, though the exact behavior is often dependent on the user’s client configuration. A setting of AddDefaultCharset Off disables this functionality. AddDefaultCharset On enables a default charset of iso-8859-1 . Any other value is assumed to be the charset to be used, which should be one of the IANA registered charset values for use in Internet media types (MIME types). For example:

AddDefaultCharset should only be used when all of the text resources to which it applies are known to be in that character encoding and it is too inconvenient to label their charset individually. One such example is to add the charset parameter to resources containing generated content, such as legacy CGI scripts, that might be vulnerable to cross-site scripting attacks due to user-provided data being included in the output. Note, however, that a better solution is to just fix (or delete) those scripts, since setting a default charset does not protect users that have enabled the «auto-detect character encoding» feature on their browser.

See also

AllowEncodedSlashes Directive

Description:	Determines whether encoded path separators in URLs are allowed to be passed through
Syntax:	AllowEncodedSlashes On|Off|NoDecode
Default:	AllowEncodedSlashes Off
Context:	server config, virtual host
Status:	Core
Module:	core
Compatibility:	NoDecode option available in 2.3.12 and later.

The AllowEncodedSlashes directive allows URLs which contain encoded path separators ( %2F for / and additionally %5C for on accordant systems) to be used in the path info.

With the default value, Off , such URLs are refused with a 404 (Not found) error.

With the value On , such URLs are accepted, and encoded slashes are decoded like all other encoded characters.

With the value NoDecode , such URLs are accepted, but encoded slashes are not decoded but left in their encoded state.

Turning AllowEncodedSlashes On is mostly useful when used in conjunction with PATH_INFO .

If encoded slashes are needed in path info, use of NoDecode is strongly recommended as a security measure. Allowing slashes to be decoded could potentially allow unsafe paths.

See also

AllowOverride Directive

Description:	Types of directives that are allowed in .htaccess files
Syntax:	AllowOverride All|None| directive-type [ directive-type ] .
Default:	AllowOverride None (2.3.9 and later), AllowOverride All (2.3.8 and earlier)
Context:	directory
Status:	Core
Module:	core

When the server finds an .htaccess file (as specified by AccessFileName ), it needs to know which directives declared in that file can override earlier configuration directives.

Only available in sections

When this directive is set to None and AllowOverrideList is set to None , .htaccess files are completely ignored. In this case, the server will not even attempt to read .htaccess files in the filesystem.

When this directive is set to All , then any directive which has the .htaccess Context is allowed in .htaccess files.

The directive-type can be one of the following groupings of directives. (See the override class index for an up-to-date listing of which directives are enabled by each directive-type .)

AuthConfig Allow use of the authorization directives ( AuthDBMGroupFile , AuthDBMUserFile , AuthGroupFile , AuthName , AuthType , AuthUserFile , Require , etc.). FileInfo Allow use of the directives controlling document types ( ErrorDocument , ForceType , LanguagePriority , SetHandler , SetInputFilter , SetOutputFilter , and mod_mime Add* and Remove* directives), document meta data ( Header , RequestHeader , SetEnvIf , SetEnvIfNoCase , BrowserMatch , CookieExpires , CookieDomain , CookieStyle , CookieTracking , CookieName ), mod_rewrite directives ( RewriteEngine , RewriteOptions , RewriteBase , RewriteCond , RewriteRule ), mod_alias directives ( Redirect , RedirectTemp , RedirectPermanent , RedirectMatch ), and Action from mod_actions . Indexes Allow use of the directives controlling directory indexing ( AddDescription , AddIcon , AddIconByEncoding , AddIconByType , DefaultIcon , DirectoryIndex , FancyIndexing , HeaderName , IndexIgnore , IndexOptions , ReadmeName , etc.). Limit Allow use of the directives controlling host access ( Allow , Deny and Order ). Nonfatal=[Override|Unknown|All] Allow use of AllowOverride option to treat syntax errors in .htaccess as nonfatal. Instead of causing an Internal Server Error, disallowed or unrecognised directives will be ignored and a warning logged:

• Nonfatal=Override treats directives forbidden by AllowOverride as nonfatal.
• Nonfatal=Unknown treats unknown directives as nonfatal. This covers typos and directives implemented by a module that’s not present.
• Nonfatal=All treats both the above as nonfatal.

Note that a syntax error in a valid directive will still cause an internal server error.

Security

Implicit disabling of Options

Even though the list of options that may be used in .htaccess files can be limited with this directive, as long as any Options directive is allowed any other inherited option can be disabled by using the non-relative syntax. In other words, this mechanism cannot force a specific option to remain set while allowing any others to be set.

In the example above, all directives that are neither in the group AuthConfig nor Indexes cause an internal server error.

For security and performance reasons, do not set AllowOverride to anything other than None in your block. Instead, find (or create) the block that refers to the directory where you’re actually planning to place a .htaccess file.

See also

AllowOverrideList Directive

Description:	Individual directives that are allowed in .htaccess files
Syntax:	AllowOverrideList None| directive [ directive-type ] .
Default:	AllowOverrideList None
Context:	directory
Status:	Core
Module:	core

When the server finds an .htaccess file (as specified by AccessFileName ), it needs to know which directives declared in that file can override earlier configuration directives.

Only available in sections

When this directive is set to None and AllowOverride is set to None , then .htaccess files are completely ignored. In this case, the server will not even attempt to read .htaccess files in the filesystem.

In the example above, only the Redirect and RedirectMatch directives are allowed. All others will cause an internal server error.

In the example above, AllowOverride grants permission to the AuthConfig directive grouping and AllowOverrideList grants permission to only two directives from the FileInfo directive grouping. All others will cause an internal server error.

See also

CGIMapExtension Directive

Description:	Technique for locating the interpreter for CGI scripts
Syntax:	CGIMapExtension cgi-path .extension
Context:	directory, .htaccess
Override:	FileInfo
Status:	Core
Module:	core
Compatibility:	NetWare only

This directive is used to control how Apache httpd finds the interpreter used to run CGI scripts. For example, setting CGIMapExtension sys:foo.nlm .foo will cause all CGI script files with a .foo extension to be passed to the FOO interpreter.

CGIPassAuth Directive

Description:	Enables passing HTTP authorization headers to scripts as CGI variables
Syntax:	CGIPassAuth On|Off
Default:	CGIPassAuth Off
Context:	directory, .htaccess
Override:	AuthConfig
Status:	Core
Module:	core
Compatibility:	Available in Apache HTTP Server 2.4.13 and later

CGIPassAuth allows scripts access to HTTP authorization headers such as Authorization , which is required for scripts that implement HTTP Basic authentication. Normally these HTTP headers are hidden from scripts. This is to disallow scripts from seeing user ids and passwords used to access the server when HTTP Basic authentication is enabled in the web server. This directive should be used when scripts are allowed to implement HTTP Basic authentication.

This directive can be used instead of the compile-time setting SECURITY_HOLE_PASS_AUTHORIZATION which has been available in previous versions of Apache HTTP Server.

The setting is respected by any modules which use ap_add_common_vars() , such as mod_cgi , mod_cgid , mod_proxy_fcgi , mod_proxy_scgi , and so on. Notably, it affects modules which don’t handle the request in the usual sense but still use this API; examples of this are mod_include and mod_ext_filter . Third-party modules that don’t use ap_add_common_vars() may choose to respect the setting as well.

CGIVar Directive

Description:	Controls how some CGI variables are set
Syntax:	CGIVar variable rule
Context:	directory, .htaccess
Override:	FileInfo
Status:	Core
Module:	core
Compatibility:	Available in Apache HTTP Server 2.4.21 and later

This directive controls how some CGI variables are set.

REQUEST_URI rules:

original-uri (default) The value is taken from the original request line, and will not reflect internal redirects or subrequests which change the requested resource. current-uri The value reflects the resource currently being processed, which may be different than the original request from the client due to internal redirects or subrequests.

ContentDigest Directive

Description:	Enables the generation of Content-MD5 HTTP Response headers
Syntax:	ContentDigest On|Off
Default:	ContentDigest Off
Context:	server config, virtual host, directory, .htaccess
Override:	Options
Status:	Core
Module:	core

This directive enables the generation of Content-MD5 headers as defined in RFC1864 respectively RFC2616.

MD5 is an algorithm for computing a «message digest» (sometimes called «fingerprint») of arbitrary-length data, with a high degree of confidence that any alterations in the data will be reflected in alterations in the message digest.

The Content-MD5 header provides an end-to-end message integrity check (MIC) of the entity-body. A proxy or client may check this header for detecting accidental modification of the entity-body in transit. Example header:

Note that this can cause performance problems on your server since the message digest is computed on every request (the values are not cached).

Content-MD5 is only sent for documents served by the core , and not by any module. For example, SSI documents, output from CGI scripts, and byte range responses do not have this header.

DefaultRuntimeDir Directive

Description:	Base directory for the server run-time files
Syntax:	DefaultRuntimeDir directory-path
Default:	DefaultRuntimeDir DEFAULT_REL_RUNTIMEDIR (logs/)
Context:	server config
Status:	Core
Module:	core
Compatibility:	Available in Apache 2.4.2 and later

The DefaultRuntimeDir directive sets the directory in which the server will create various run-time files (shared memory, locks, etc.). If set as a relative path, the full path will be relative to ServerRoot .

Example

The default location of DefaultRuntimeDir may be modified by changing the DEFAULT_REL_RUNTIMEDIR #define at build time.

Note: ServerRoot should be specified before this directive is used. Otherwise, the default value of ServerRoot would be used to set the base directory.

See also

• the security tips for information on how to properly set permissions on the ServerRoot

DefaultType Directive

Description:	This directive has no effect other than to emit warnings if the value is not none . In prior versions, DefaultType would specify a default media type to assign to response content for which no other media type configuration could be found.
Syntax:	DefaultType media-type|none
Default:	DefaultType none
Context:	server config, virtual host, directory, .htaccess
Override:	FileInfo
Status:	Core
Module:	core
Compatibility:	The argument none is available in Apache httpd 2.2.7 and later. All other choices are DISABLED for 2.3.x and later.

This directive has been disabled. For backwards compatibility of configuration files, it may be specified with the value none , meaning no default media type. For example:

DefaultType None is only available in httpd-2.2.7 and later.

Use the mime.types configuration file and the AddType to configure media type assignments via file extensions, or the ForceType directive to configure the media type for specific resources. Otherwise, the server will send the response without a Content-Type header field and the recipient may attempt to guess the media type.

Define Directive

Description:	Define a variable
Syntax:	Define parameter-name [ parameter-value ]
Context:	server config, virtual host, directory
Status:	Core
Module:	core

In its one parameter form, Define is equivalent to passing the -D argument to httpd . It can be used to toggle the use of sections without needing to alter -D arguments in any startup scripts.

In addition to that, if the second parameter is given, a config variable is set to this value. The variable can be used in the configuration using the $ syntax. The variable is always globally defined and not limited to the scope of the surrounding config section.

Variable names may not contain colon «:» characters, to avoid clashes with RewriteMap ‘s syntax.

Virtual Host scope and pitfalls

While this directive is supported in virtual host context, the changes it makes are visible to any later configuration directives, beyond any enclosing virtual host.

See also

Directive

Description:	Enclose a group of directives that apply only to the named file-system directory, sub-directories, and their contents.
Syntax:	directory-path > .
Context:	server config, virtual host
Status:	Core
Module:	core

and are used to enclose a group of directives that will apply only to the named directory, sub-directories of that directory, and the files within the respective directories. Any directive that is allowed in a directory context may be used. Directory-path is either the full path to a directory, or a wild-card string using Unix shell-style matching. In a wild-card string, ? matches any single character, and * matches any sequences of characters. You may also use [] character ranges. None of the wildcards match a `/’ character, so will not match /home/user/public_html , but will match. Example:

Directory paths may be quoted, if you like, however, it must be quoted if the path contains spaces. This is because a space would otherwise indicate the end of an argument.

Be careful with the directory-path arguments: They have to literally match the filesystem path which Apache httpd uses to access the files. Directives applied to a particular will not apply to files accessed from that same directory via a different path, such as via different symbolic links.

Regular expressions can also be used, with the addition of the

character. For example:

would match directories in /www/ that consisted of three numbers.

If multiple (non-regular expression) sections match the directory (or one of its parents) containing a document, then the directives are applied in the order of shortest match first, interspersed with the directives from the .htaccess files. For example, with

for access to the document /home/web/dir/doc.html the steps are:

• Apply directive AllowOverride None (disabling .htaccess files).
• Apply directive AllowOverride FileInfo (for directory /home ).
• Apply any FileInfo directives in /home/.htaccess , /home/web/.htaccess and /home/web/dir/.htaccess in that order.

Regular expressions are not considered until after all of the normal sections have been applied. Then all of the regular expressions are tested in the order they appeared in the configuration file. For example, with

the regular expression section won’t be considered until after all normal s and .htaccess files have been applied. Then the regular expression will match on /home/abc/public_html/abc and the corresponding will be applied.

Note that the default access for is to permit all access. This means that Apache httpd will serve any file mapped from an URL. It is recommended that you change this with a block such as

and then override this for directories you want accessible. See the Security Tips page for more details.

The directory sections occur in the httpd.conf file. directives cannot nest, and cannot appear in a or section.

See also

• How , and sections work for an explanation of how these different sections are combined when a request is received

Directive

Description:	Enclose directives that apply to the contents of file-system directories matching a regular expression.
Syntax:	regex > .
Context:	server config, virtual host
Status:	Core
Module:	core

and are used to enclose a group of directives which will apply only to the named directory (and the files within), the same as . However, it takes as an argument a regular expression. For example:

matches directories in /www/ (or any subdirectory thereof) that consist of three numbers.

Compatibility

Trailing Slash

From 2.4.8 onwards, named groups and backreferences are captured and written to the environment with the corresponding name prefixed with «MATCH_» and in upper case. This allows elements of paths to be referenced from within expressions and modules like mod_rewrite . In order to prevent confusion, numbered (unnamed) backreferences are ignored. Use named groups instead.

See also

• for a description of how regular expressions are mixed in with normal s
• How , and sections work for an explanation of how these different sections are combined when a request is received

DocumentRoot Directive

Description:	Directory that forms the main document tree visible from the web
Syntax:	DocumentRoot directory-path
Default:	DocumentRoot «/usr/local/apache/htdocs»
Context:	server config, virtual host
Status:	Core
Module:	core

This directive sets the directory from which httpd will serve files. Unless matched by a directive like Alias , the server appends the path from the requested URL to the document root to make the path to the document. Example:

then an access to http://my.example.com/index.html refers to /usr/web/index.html . If the directory-path is not absolute then it is assumed to be relative to the ServerRoot .

The DocumentRoot should be specified without a trailing slash.

See also

Directive

Description:	Contains directives that apply only if the condition of a previous or section is not satisfied by a request at runtime
Syntax:	.
Context:	server config, virtual host, directory, .htaccess
Override:	All
Status:	Core
Module:	core
Compatibility:	Nested conditions are evaluated in 2.4.26 and later

The applies the enclosed directives if and only if the most recent or section in the same scope has not been applied. For example: In

The would match HTTP/1.0 requests without a Host: header and the would match requests with a Host: header.

See also

• How , , sections work for an explanation of how these different sections are combined when a request is received. , , and are applied last.

Directive

Description:	Contains directives that apply only if a condition is satisfied by a request at runtime while the condition of a previous or section is not satisfied
Syntax:	expression > .
Context:	server config, virtual host, directory, .htaccess
Override:	All
Status:	Core
Module:	core
Compatibility:	Nested conditions are evaluated in 2.4.26 and later

The applies the enclosed directives if and only if both the given condition evaluates to true and the most recent or section in the same scope has not been applied. For example: In

The would match if the remote address of a request belongs to the subnet 10.0.0.0/8 but not to the subnet 10.1.0.0/16.

See also

• Expressions in Apache HTTP Server, for a complete reference and more examples.
• How , , sections work for an explanation of how these different sections are combined when a request is received. , , and are applied last.

EnableMMAP Directive

Description:	Use memory-mapping to read files during delivery
Syntax:	EnableMMAP On|Off
Default:	EnableMMAP On
Context:	server config, virtual host, directory, .htaccess
Override:	FileInfo
Status:	Core
Module:	core

This directive controls whether the httpd may use memory-mapping if it needs to read the contents of a file during delivery. By default, when the handling of a request requires access to the data within a file — for example, when delivering a server-parsed file using mod_include — Apache httpd memory-maps the file if the OS supports it.

This memory-mapping sometimes yields a performance improvement. But in some environments, it is better to disable the memory-mapping to prevent operational problems:

• On some multiprocessor systems, memory-mapping can reduce the performance of the httpd .
• Deleting or truncating a file while httpd has it memory-mapped can cause httpd to crash with a segmentation fault.

For server configurations that are vulnerable to these problems, you should disable memory-mapping of delivered files by specifying:

For NFS mounted files, this feature may be disabled explicitly for the offending files by specifying:

EnableSendfile Directive

Description:	Use the kernel sendfile support to deliver files to the client
Syntax:	EnableSendfile On|Off
Default:	EnableSendfile Off
Context:	server config, virtual host, directory, .htaccess
Override:	FileInfo
Status:	Core
Module:	core
Compatibility:	Default changed to Off in version 2.3.9.

This directive controls whether httpd may use the sendfile support from the kernel to transmit file contents to the client. By default, when the handling of a request requires no access to the data within a file — for example, when delivering a static file — Apache httpd uses sendfile to deliver the file contents without ever reading the file if the OS supports it.

This sendfile mechanism avoids separate read and send operations, and buffer allocations. But on some platforms or within some filesystems, it is better to disable this feature to avoid operational problems:

• Some platforms may have broken sendfile support that the build system did not detect, especially if the binaries were built on another box and moved to such a machine with broken sendfile support.
• On Linux the use of sendfile triggers TCP-checksum offloading bugs on certain networking cards when using IPv6.
• On Linux on Itanium, sendfile may be unable to handle files over 2GB in size.
• With a network-mounted DocumentRoot (e.g., NFS, SMB, CIFS, FUSE), the kernel may be unable to serve the network file through its own cache.

For server configurations that are not vulnerable to these problems, you may enable this feature by specifying:

For network mounted files, this feature may be disabled explicitly for the offending files by specifying:

Please note that the per-directory and .htaccess configuration of EnableSendfile is not supported by mod_cache_disk . Only global definition of EnableSendfile is taken into account by the module.

Error Directive

Description:	Abort configuration parsing with a custom error message
Syntax:	Error message
Context:	server config, virtual host, directory, .htaccess
Status:	Core
Module:	core
Compatibility:	2.3.9 and later

If an error can be detected within the configuration, this directive can be used to generate a custom error message, and halt configuration parsing. The typical use is for reporting required modules which are missing from the configuration.

This directive is evaluated and configuration processing time, not at runtime. As a result, this directive cannot be conditonally evaluated by enclosing it in an section.

ErrorDocument Directive

Description:	What the server will return to the client in case of an error
Syntax:	ErrorDocument error-code document
Context:	server config, virtual host, directory, .htaccess
Override:	FileInfo
Status:	Core
Module:	core

In the event of a problem or error, Apache httpd can be configured to do one of four things,

1. output a simple hardcoded error message
2. output a customized message
3. internally redirect to a local URL-path to handle the problem/error
4. redirect to an external URL to handle the problem/error

The first option is the default, while options 2-4 are configured using the ErrorDocument directive, which is followed by the HTTP response code and a URL or a message. Apache httpd will sometimes offer additional information regarding the problem/error.

From 2.4.13, expression syntax can be used inside the directive to produce dynamic strings and URLs.

URLs can begin with a slash (/) for local web-paths (relative to the DocumentRoot ), or be a full URL which the client can resolve. Alternatively, a message can be provided to be displayed by the browser. Note that deciding whether the parameter is an URL, a path or a message is performed before any expression is parsed. Examples:

Additionally, the special value default can be used to specify Apache httpd’s simple hardcoded message. While not required under normal circumstances, default will restore Apache httpd’s simple hardcoded message for configurations that would otherwise inherit an existing ErrorDocument .

Note that when you specify an ErrorDocument that points to a remote URL (ie. anything with a method such as http in front of it), Apache HTTP Server will send a redirect to the client to tell it where to find the document, even if the document ends up being on the same server. This has several implications, the most important being that the client will not receive the original error status code, but instead will receive a redirect status code. This in turn can confuse web robots and other clients which try to determine if a URL is valid using the status code. In addition, if you use a remote URL in an ErrorDocument 401 , the client will not know to prompt the user for a password since it will not receive the 401 status code. Therefore, if you use an ErrorDocument 401 directive, then it must refer to a local document.

Microsoft Internet Explorer (MSIE) will by default ignore server-generated error messages when they are «too small» and substitute its own «friendly» error messages. The size threshold varies depending on the type of error, but in general, if you make your error document greater than 512 bytes, then MSIE will show the server-generated error rather than masking it. More information is available in Microsoft Knowledge Base article Q294807.

Although most error messages can be overridden, there are certain circumstances where the internal messages are used regardless of the setting of ErrorDocument . In particular, if a malformed request is detected, normal request processing will be immediately halted and the internal error message returned. This is necessary to guard against security problems caused by bad requests.

If you are using mod_proxy, you may wish to enable ProxyErrorOverride so that you can provide custom error messages on behalf of your Origin servers. If you don’t enable ProxyErrorOverride, Apache httpd will not generate custom error documents for proxied content.

See also

ErrorLog Directive

Description:	Location where the server will log errors
Syntax:	ErrorLog file-path |syslog[:[ facility ][: tag ]]
Default:	ErrorLog logs/error_log (Unix) ErrorLog logs/error.log (Windows and OS/2)
Context:	server config, virtual host
Status:	Core
Module:	core

The ErrorLog directive sets the name of the file to which the server will log any errors it encounters. If the file-path is not absolute then it is assumed to be relative to the ServerRoot .

If the file-path begins with a pipe character » | » then it is assumed to be a command to spawn to handle the error log.

See the notes on piped logs for more information.

Using syslog instead of a filename enables logging via syslogd(8) if the system supports it. The default is to use syslog facility local7 , but you can override this by using the syslog: facility syntax where facility can be one of the names usually documented in syslog(1). The facility is effectively global, and if it is changed in individual virtual hosts, the final facility specified affects the entire server. Same rules apply for the syslog tag, which by default uses the Apache binary name, httpd in most cases. You can also override this by using the syslog:: tag syntax.

SECURITY: See the security tips document for details on why your security could be compromised if the directory where log files are stored is writable by anyone other than the user that starts the server.

When entering a file path on non-Unix platforms, care should be taken to make sure that only forward slashes are used even though the platform may allow the use of back slashes. In general it is a good idea to always use forward slashes throughout the configuration files.

See also

ErrorLogFormat Directive

Description:	Format specification for error log entries
Syntax:	ErrorLogFormat [connection|request] format
Context:	server config, virtual host
Status:	Core
Module:	core

ErrorLogFormat allows to specify what supplementary information is logged in the error log in addition to the actual log message.

Specifying connection or request as first parameter allows to specify additional formats, causing additional information to be logged when the first message is logged for a specific connection or request, respectively. This additional information is only logged once per connection/request. If a connection or request is processed without causing any log message, the additional information is not logged either.

It can happen that some format string items do not produce output. For example, the Referer header is only present if the log message is associated to a request and the log message happens at a time when the Referer header has already been read from the client. If no output is produced, the default behavior is to delete everything from the preceding space character to the next space character. This means the log line is implicitly divided into fields on non-whitespace to whitespace transitions. If a format string item does not produce output, the whole field is omitted. For example, if the remote address %a in the log format [%t] [%l] [%a] %M is not available, the surrounding brackets are not logged either. Space characters can be escaped with a backslash to prevent them from delimiting a field. The combination ‘% ‘ (percent space) is a zero-width field delimiter that does not produce any output.

The above behavior can be changed by adding modifiers to the format string item. A — (minus) modifier causes a minus to be logged if the respective item does not produce any output. In once-per-connection/request formats, it is also possible to use the + (plus) modifier. If an item with the plus modifier does not produce any output, the whole line is omitted.

A number as modifier can be used to assign a log severity level to a format item. The item will only be logged if the severity of the log message is not higher than the specified log severity level. The number can range from 1 (alert) over 4 (warn) and 7 (debug) to 15 (trace8).

For example, here’s what would happen if you added modifiers to the %i token, which logs the Referer request header.

Modified Token	Meaning
%-i	Logs a — if Referer is not set.
%+i	Omits the entire line if Referer is not set.
%4i	Logs the Referer only if the log message severity is higher than 4.

Some format string items accept additional parameters in braces.

Format String	Description
%%	The percent sign
%a	Client IP address and port of the request
%a	Underlying peer IP address and port of the connection (see the mod_remoteip module)
%A	Local IP-address and port
%<name>e	Request environment variable name
%E	APR/OS error status code and string
%F	Source file name and line number of the log call
%<name>i	Request header name
%k	Number of keep-alive requests on this connection
%l	Loglevel of the message
%L	Log ID of the request
%L	Log ID of the connection
%L	Log ID of the connection if used in connection scope, empty otherwise
%m	Name of the module logging the message
%M	The actual log message
%<name>n	Request note name
%P	Process ID of current process
%T	Thread ID of current thread
%T	System unique thread ID of current thread (the same ID as displayed by e.g. top ; currently Linux only)
%t	The current time
%t	The current time including micro-seconds
%t	The current time in compact ISO 8601 format, including micro-seconds
%v	The canonical ServerName of the current server.
%V	The server name of the server serving the request according to the UseCanonicalName setting.
(backslash space)	Non-field delimiting space
% (percent space)	Field delimiter (no output)

The log ID format %L produces a unique id for a connection or request. This can be used to correlate which log lines belong to the same connection or request, which request happens on which connection. A %L format string is also available in mod_log_config to allow to correlate access log entries with error log lines. If mod_unique_id is loaded, its unique id will be used as log ID for requests.

This would result in error messages such as:

[Thu May 12 08:28:57.652118 2011] [core:error] [pid 8777:tid 4326490112] [client ::1:58619] File does not exist: /usr/local/apache2/htdocs/favicon.ico

Notice that, as discussed above, some fields are omitted entirely because they are not defined.

See also

ExtendedStatus Directive

Description:	Keep track of extended status information for each request
Syntax:	ExtendedStatus On|Off
Default:	ExtendedStatus Off[*]
Context:	server config
Status:	Core
Module:	core

This option tracks additional data per worker about the currently executing request and creates a utilization summary. You can see these variables during runtime by configuring mod_status . Note that other modules may rely on this scoreboard.

This setting applies to the entire server and cannot be enabled or disabled on a virtualhost-by-virtualhost basis. The collection of extended status information can slow down the server. Also note that this setting cannot be changed during a graceful restart.

Note that loading mod_status will change the default behavior to ExtendedStatus On, while other third party modules may do the same. Such modules rely on collecting detailed information about the state of all workers. The default is changed by mod_status beginning with version 2.3.6. The previous default was always Off.

FileETag Directive

Description:	File attributes used to create the ETag HTTP response header for static files
Syntax:	FileETag component .
Default:	FileETag MTime Size
Context:	server config, virtual host, directory, .htaccess
Override:	FileInfo
Status:	Core
Module:	core
Compatibility:	The default used to be «INode MTime Size» in 2.3.14 and earlier.

The FileETag directive configures the file attributes that are used to create the ETag (entity tag) response header field when the document is based on a static file. (The ETag value is used in cache management to save network bandwidth.) The FileETag directive allows you to choose which of these — if any — should be used. The recognized keywords are:

INode The file’s i-node number will be included in the calculation MTime The date and time the file was last modified will be included Size The number of bytes in the file will be included All All available fields will be used. This is equivalent to: Digest If a document is file-based, the ETag field will be calculated by taking the digest over the file. None If a document is file-based, no ETag field will be included in the response

The INode , MTime , Size and Digest keywords may be prefixed with either + or — , which allow changes to be made to the default setting inherited from a broader scope. Any keyword appearing without such a prefix immediately and completely cancels the inherited setting.

If a directory’s configuration includes FileETag INode MTime Size , and a subdirectory’s includes FileETag -INode , the setting for that subdirectory (which will be inherited by any sub-subdirectories that don’t override it) will be equivalent to FileETag MTime Size .

Server Side Includes

Directive

Description:	Contains directives that apply to matched filenames
Syntax:	filename > .
Context:	server config, virtual host, directory, .htaccess
Override:	All
Status:	Core
Module:	core

The directive limits the scope of the enclosed directives by filename. It is comparable to the and directives. It should be matched with a directive. The directives given within this section will be applied to any object with a basename (last component of filename) matching the specified filename. sections are processed in the order they appear in the configuration file, after the sections and .htaccess files are read, but before sections. Note that can be nested inside sections to restrict the portion of the filesystem they apply to.

The filename argument should include a filename, or a wild-card string, where ? matches any single character, and * matches any sequences of characters.

Regular expressions can also be used, with the addition of the

character. For example:

would match most common Internet graphics formats. is preferred, however.

Note that unlike and sections, sections can be used inside .htaccess files. This allows users to control access to their own files, at a file-by-file level.

See also

• How , and sections work for an explanation of how these different sections are combined when a request is received

Directive

Description:	Contains directives that apply to regular-expression matched filenames
Syntax:	regex > .
Context:	server config, virtual host, directory, .htaccess
Override:	All
Status:	Core
Module:	core

The directive limits the scope of the enclosed directives by filename, just as the directive does. However, it accepts a regular expression. For example:

would match most common Internet graphics formats.

From 2.4.8 onwards, named groups and backreferences are captured and written to the environment with the corresponding name prefixed with «MATCH_» and in upper case. This allows elements of files to be referenced from within expressions and modules like mod_rewrite . In order to prevent confusion, numbered (unnamed) backreferences are ignored. Use named groups instead.

See also

• How , and sections work for an explanation of how these different sections are combined when a request is received

FlushMaxPipelined Directive

Description:	Maximum number of pipelined responses above which they are flushed to the network
Syntax:	FlushMaxPipelined number
Default:	FlushMaxPipelined 5
Context:	server config, virtual host
Status:	Core
Module:	core
Compatibility:	2.4.47 and later

This directive allows to configure the maximum number of pipelined responses, which remain pending so long as pipelined request are received. When the limit is reached, responses are forcibly flushed to the network in blocking mode, until passing under the limit again.

FlushMaxPipelined helps constraining memory usage. When set to 0 pipelining is disabled, when set to -1 there is no limit ( FlushMaxThreshold still applies).

FlushMaxThreshold Directive

Description:	Threshold above which pending data are flushed to the network
Syntax:	FlushMaxThreshold number-of-bytes
Default:	FlushMaxThreshold 65536
Context:	server config, virtual host
Status:	Core
Module:	core
Compatibility:	2.4.47 and later

This directive allows to configure the threshold for pending output data (in bytes). When the limit is reached, data are forcibly flushed to the network in blocking mode, until passing under the limit again.

FlushMaxThreshold helps constraining memory usage. When set to 0 or a too small value there are actually no pending data, but for threaded MPMs there can be more threads busy waiting for the network thus less ones available to handle the other simultaneous connections.

ForceType Directive

Description:	Forces all matching files to be served with the specified media type in the HTTP Content-Type header field
Syntax:	ForceType media-type |None
Context:	directory, .htaccess
Override:	FileInfo
Status:	Core
Module:	core

When placed into an .htaccess file or a , or or section, this directive forces all matching files to be served with the content type identification given by media-type . For example, if you had a directory full of GIF files, but did not want to label them all with .gif , you might want to use:

Note that this directive overrides other indirect media type associations defined in mime.types or via the AddType .

You can also override more general ForceType settings by using the value of None :

This directive primarily overrides the content types generated for static files served out of the filesystem. For resources other than static files, where the generator of the response typically specifies a Content-Type, this directive has no effect.

When explicit directives such as SetHandler or AddHandler do not apply to the current request, the internal handler name normally set by those directives is set to match the content type specified by this directive. This is a historical behavior that some third-party modules (such as mod_php) may use «magic» content types used only to signal the module to take responsibility for the matching request. Configurations that rely on such «magic» types should be avoided by the use of SetHandler or AddHandler .

GprofDir Directive

Description:	Directory to write gmon.out profiling data to.
Syntax:	GprofDir /tmp/gprof/ | /tmp/gprof/ %
Context:	server config, virtual host
Status:	Core
Module:	core

When the server has been compiled with gprof profiling support, GprofDir causes gmon.out files to be written to the specified directory when the process exits. If the argument ends with a percent symbol (‘%’), subdirectories are created for each process id.

This directive currently only works with the prefork MPM.

HostnameLookups Directive

Description:	Enables DNS lookups on client IP addresses
Syntax:	HostnameLookups On|Off|Double
Default:	HostnameLookups Off
Context:	server config, virtual host, directory
Status:	Core
Module:	core

This directive enables DNS lookups so that host names can be logged (and passed to CGIs/SSIs in REMOTE_HOST ). The value Double refers to doing double-reverse DNS lookup. That is, after a reverse lookup is performed, a forward lookup is then performed on that result. At least one of the IP addresses in the forward lookup must match the original address. (In «tcpwrappers» terminology this is called PARANOID .)

Regardless of the setting, when mod_authz_host is used for controlling access by hostname, a double reverse lookup will be performed. This is necessary for security. Note that the result of this double-reverse isn’t generally available unless you set HostnameLookups Double . For example, if only HostnameLookups On and a request is made to an object that is protected by hostname restrictions, regardless of whether the double-reverse fails or not, CGIs will still be passed the single-reverse result in REMOTE_HOST .

The default is Off in order to save the network traffic for those sites that don’t truly need the reverse lookups done. It is also better for the end users because they don’t have to suffer the extra latency that a lookup entails. Heavily loaded sites should leave this directive Off , since DNS lookups can take considerable amounts of time. The utility logresolve , compiled by default to the bin subdirectory of your installation directory, can be used to look up host names from logged IP addresses offline.

Finally, if you have hostname-based Require directives, a hostname lookup will be performed regardless of the setting of HostnameLookups .

HttpProtocolOptions Directive

Description:	Modify restrictions on HTTP Request Messages
Syntax:	HttpProtocolOptions [Strict|Unsafe] [RegisteredMethods|LenientMethods] [Allow0.9|Require1.0]
Default:	HttpProtocolOptions Strict LenientMethods Allow0.9
Context:	server config, virtual host
Status:	Core
Module:	core
Compatibility:	2.2.32 or 2.4.24 and later

This directive changes the rules applied to the HTTP Request Line (RFC 7230 В§3.1.1) and the HTTP Request Header Fields (RFC 7230 В§3.2), which are now applied by default or using the Strict option. Due to legacy modules, applications or custom user-agents which must be deprecated the Unsafe option has been added to revert to the legacy behaviors.

These rules are applied prior to request processing, so must be configured at the global or default (first) matching virtual host section, by IP/port interface (and not by name) to be honored.

The directive accepts three parameters from the following list of choices, applying the default to the ones not specified:

Prior to the introduction of this directive, the Apache HTTP Server request message parsers were tolerant of a number of forms of input which did not conform to the protocol. RFC 7230 В§9.4 Request Splitting and В§9.5 Response Smuggling call out only two of the potential risks of accepting non-conformant request messages, while RFC 7230 В§3.5 «Message Parsing Robustness» identify the risks of accepting obscure whitespace and request message formatting. As of the introduction of this directive, all grammar rules of the specification are enforced in the default Strict operating mode, and the strict whitespace suggested by section 3.5 is enforced and cannot be relaxed.

Security risks of Unsafe

Users are strongly cautioned against toggling the Unsafe mode of operation, particularly on outward-facing, publicly accessible server deployments. If an interface is required for faulty monitoring or other custom service consumers running on an intranet, users should toggle the Unsafe option only on a specific virtual host configured to service their internal private network.

Example of a request leading to HTTP 400 with Strict mode

# Missing CRLF
GET / HTTP/1.0nn

Command line tools and CRLF

Some tools need to be forced to use CRLF, otherwise httpd will return a HTTP 400 response like described in the above use case. For example, the OpenSSL s_client needs the -crlf parameter to work properly.

The DumpIOInput directive can help while reviewing the HTTP request to identify issues like the absence of CRLF.

RFC 7231 В§4.1 «Request Methods» «Overview» requires that origin servers shall respond with a HTTP 501 status code when an unsupported method is encountered in the request line. This already happens when the LenientMethods option is used, but administrators may wish to toggle the RegisteredMethods option and register any non-standard methods using the RegisterHttpMethod directive, particularly if the Unsafe option has been toggled.

Forward Proxy compatibility

The RegisteredMethods option should not be toggled for forward proxy hosts, as the methods supported by the origin servers are unknown to the proxy server.

Example of a request leading to HTTP 501 with LenientMethods mode

# Unknown HTTP method
WOW / HTTP/1.0rnrn

# Lowercase HTTP method
get / HTTP/1.0rnrn

RFC 2616 В§19.6 «Compatibility With Previous Versions» had encouraged HTTP servers to support legacy HTTP/0.9 requests. RFC 7230 supersedes this with «The expectation to support HTTP/0.9 requests has been removed» and offers additional comments in RFC 7230 Appendix A. The Require1.0 option allows the user to remove support of the default Allow0.9 option’s behavior.

Example of a request leading to HTTP 400 with Require1.0 mode

# Unsupported HTTP version
GET /rnrn

Reviewing the messages logged to the ErrorLog , configured with LogLevel debug level, can help identify such faulty requests along with their origin. Users should pay particular attention to the 400 responses in the access log for invalid requests which were unexpectedly rejected.

Directive

Description:	Contains directives that apply only if a condition is satisfied by a request at runtime
Syntax:	expression > .
Context:	server config, virtual host, directory, .htaccess
Override:	All
Status:	Core
Module:	core
Compatibility:	Nested conditions are evaluated in 2.4.26 and later

The directive evaluates an expression at runtime, and applies the enclosed directives if and only if the expression evaluates to true. For example:

would match HTTP/1.0 requests without a Host: header. Expressions may contain various shell-like operators for string comparison ( == , != , , . ), integer comparison ( -eq , -ne , . ), and others ( -n , -z , -f , . ). It is also possible to use regular expressions,

shell-like pattern matches and many other operations. These operations can be done on request headers ( req ), environment variables ( env ), and a large number of other properties. The full documentation is available in Expressions in Apache HTTP Server.

Only directives that support the directory context can be used within this configuration section.

See also

• Expressions in Apache HTTP Server, for a complete reference and more examples.
• How , , sections work for an explanation of how these different sections are combined when a request is received. , , and are applied last.

Directive

Description:	Encloses directives that will be processed only if a test is true at startup
Syntax:	parameter-name > .
Context:	server config, virtual host, directory, .htaccess
Override:	All
Status:	Core
Module:	core

The test >. section is used to mark directives that are conditional. The directives within an section are only processed if the test is true. If test is false, everything between the start and end markers is ignored.

The test in the section directive can be one of two forms:

In the former case, the directives between the start and end markers are only processed if the parameter named parameter-name is defined. The second format reverses the test, and only processes the directives if parameter-name is not defined.

The parameter-name argument is a define as given on the httpd command line via -D parameter at the time the server was started or by the Define directive.

sections are nest-able, which can be used to implement simple multiple-parameter tests. Example:

httpd -DReverseProxy -DUseCache -DMemCache .

Directive

Description:	Encloses directives that are processed conditional on the presence or absence of a specific directive
Syntax:	directive-name > .
Context:	server config, virtual host, directory, .htaccess
Override:	All
Status:	Core
Module:	core
Compatibility:	Available in 2.4.34 and later.

The test >. section is used to mark directives that are conditional on the presence of a specific directive. The directives within an section are only processed if the test is true. If test is false, everything between the start and end markers is ignored.

The test in the section can be one of two forms:

In the former case, the directives between the start and end markers are only processed if a directive of the given name is available at the time of processing. The second format reverses the test, and only processes the directives if directive-name is not available.

See also

Directive

Description:	Encloses directives that will be processed only if file exists at startup
Syntax:	filename > .
Context:	server config, virtual host, directory, .htaccess
Override:	All
Status:	Core
Module:	core
Compatibility:	Available in 2.4.34 and later.

The filename >. section is used to mark directives that are conditional on the existence of a file on disk. The directives within an section are only processed if filename exists. If filename doesn’t exist, everything between the start and end markers is ignored. filename can be an absolute path or a path relative to the server root.

The filename in the section directive can take the same forms as the test variable in the section, i.e. the test can be negated if the ! character is placed directly before filename .

If a relative filename is supplied, the check is ServerRoot relative. In the case where this directive occurs before the ServerRoot , the path will be checked relative to the compiled-in server root or the server root passed in on the command line via the -d parameter.

Warning

Directive

Description:	Encloses directives that are processed conditional on the presence or absence of a specific module
Syntax:	module-file | module-identifier > .
Context:	server config, virtual host, directory, .htaccess
Override:	All
Status:	Core
Module:	core
Compatibility:	Module identifiers are available in version 2.1 and later.

The test >. section is used to mark directives that are conditional on the presence of a specific module. The directives within an section are only processed if the test is true. If test is false, everything between the start and end markers is ignored.

The test in the section directive can be one of two forms:

In the former case, the directives between the start and end markers are only processed if the module named module is included in Apache httpd — either compiled in or dynamically loaded using LoadModule . The second format reverses the test, and only processes the directives if module is not included.

The module argument can be either the module identifier or the file name of the module, at the time it was compiled. For example, rewrite_module is the identifier and mod_rewrite.c is the file name. If a module consists of several source files, use the name of the file containing the string STANDARD20_MODULE_STUFF .

sections are nest-able, which can be used to implement simple multiple-module tests.

Directive

Description:	Encloses directives that are processed conditional on the presence or absence of a specific section directive
Syntax:	section-name > .
Context:	server config, virtual host, directory, .htaccess
Override:	All
Status:	Core
Module:	core
Compatibility:	Available in 2.4.34 and later.

The test >. section is used to mark directives that are conditional on the presence of a specific section directive. A section directive is any directive such as which encloses other directives, and has a directive name with a leading » section are only processed if the test is true. If test is false, everything between the start and end markers is ignored.

The section-name must be specified without either the leading » «. The test in the section can be one of two forms:

In the former case, the directives between the start and end markers are only processed if a section directive of the given name is available at the time of processing. The second format reverses the test, and only processes the directives if section-name is not an available section directive.

See also

Include Directive

Description:	Includes other configuration files from within the server configuration files
Syntax:	Include file-path | directory-path | wildcard
Context:	server config, virtual host, directory
Status:	Core
Module:	core
Compatibility:	Directory wildcard matching available in 2.3.6 and later

This directive allows inclusion of other configuration files from within the server configuration files.

Shell-style ( fnmatch() ) wildcard characters can be used in the filename or directory parts of the path to include several files at once, in alphabetical order. In addition, if Include points to a directory, rather than a file, Apache httpd will read all files in that directory and any subdirectory. However, including entire directories is not recommended, because it is easy to accidentally leave temporary files in a directory that can cause httpd to fail. Instead, we encourage you to use the wildcard syntax shown below, to include files that match a particular pattern, such as *.conf, for example.

The Include directive will fail with an error if a wildcard expression does not match any file. The IncludeOptional directive can be used if non-matching wildcards should be ignored.

The file path specified may be an absolute path, or may be relative to the ServerRoot directory.

Or, providing paths relative to your ServerRoot directory:

Wildcards may be included in the directory or file portion of the path. This example will fail if there is no subdirectory in conf/vhosts that contains at least one *.conf file:

Alternatively, the following command will just be ignored in case of missing files or directories:

See also

IncludeOptional Directive

Description:	Includes other configuration files from within the server configuration files
Syntax:	IncludeOptional file-path | directory-path | wildcard
Context:	server config, virtual host, directory
Status:	Core
Module:	core
Compatibility:	Available in 2.3.6 and later. Not existent file paths without wildcards do not cause SyntaxError after 2.4.30

This directive allows inclusion of other configuration files from within the server configuration files. It works identically to the Include directive, but it will be silently ignored (instead of causing an error) if wildcards are used and they do not match any file or directory or if a file path does not exist on the file system.

See also

KeepAlive Directive

Description:	Enables HTTP persistent connections
Syntax:	KeepAlive On|Off
Default:	KeepAlive On
Context:	server config, virtual host
Status:	Core
Module:	core

The Keep-Alive extension to HTTP/1.0 and the persistent connection feature of HTTP/1.1 provide long-lived HTTP sessions which allow multiple requests to be sent over the same TCP connection. In some cases this has been shown to result in an almost 50% speedup in latency times for HTML documents with many images. To enable Keep-Alive connections, set KeepAlive On .

For HTTP/1.0 clients, Keep-Alive connections will only be used if they are specifically requested by a client. In addition, a Keep-Alive connection with an HTTP/1.0 client can only be used when the length of the content is known in advance. This implies that dynamic content such as CGI output, SSI pages, and server-generated directory listings will generally not use Keep-Alive connections to HTTP/1.0 clients. For HTTP/1.1 clients, persistent connections are the default unless otherwise specified. If the client requests it, chunked encoding will be used in order to send content of unknown length over persistent connections.

When a client uses a Keep-Alive connection, it will be counted as a single «request» for the MaxConnectionsPerChild directive, regardless of how many requests are sent using the connection.

See also

KeepAliveTimeout Directive

Description:	Amount of time the server will wait for subsequent requests on a persistent connection
Syntax:	KeepAliveTimeout num [ms]
Default:	KeepAliveTimeout 5
Context:	server config, virtual host
Status:	Core
Module:	core

The number of seconds Apache httpd will wait for a subsequent request before closing the connection. By adding a postfix of ms the timeout can be also set in milliseconds. Once a request has been received, the timeout value specified by the Timeout directive applies.

Setting KeepAliveTimeout to a high value may cause performance problems in heavily loaded servers. The higher the timeout, the more server processes will be kept occupied waiting on connections with idle clients.

If KeepAliveTimeout is not set for a name-based virtual host, the value of the first defined virtual host best matching the local IP and port will be used.

Directive

Description:	Restrict enclosed access controls to only certain HTTP methods
Syntax:	method [ method ] . > .
Context:	directory, .htaccess
Override:	AuthConfig, Limit
Status:	Core
Module:	core

Access controls are normally effective for all access methods, and this is the usual desired behavior. In the general case, access control directives should not be placed within a
section.

The purpose of the

directive is to restrict the effect of the access controls to the nominated HTTP methods. For all other methods, the access restrictions that are enclosed in the

bracket will have no effect. The following example applies the access control only to the methods POST , PUT , and DELETE , leaving all other methods unprotected:

The method names listed can be one or more of: GET , POST , PUT , DELETE , CONNECT , OPTIONS , PATCH , PROPFIND , PROPPATCH , MKCOL , COPY , MOVE , LOCK , and UNLOCK . The method name is case-sensitive. If GET is used, it will also restrict HEAD requests. The TRACE method cannot be limited (see TraceEnable ).

For example, given the following configuration, all users will be authorized for POST requests, and the Require group editors directive will be ignored in all cases:

Directive

Description:	Restrict access controls to all HTTP methods except the named ones
Syntax:	method [ method ] . > .
Context:	directory, .htaccess
Override:	AuthConfig, Limit
Status:	Core
Module:	core

and are used to enclose a group of access control directives which will then apply to any HTTP access method not listed in the arguments; i.e., it is the opposite of a section and can be used to control both standard and nonstandard/unrecognized methods. See the documentation for for more details.

LimitInternalRecursion Directive

Description:	Determine maximum number of internal redirects and nested subrequests
Syntax:	LimitInternalRecursion number [ number ]
Default:	LimitInternalRecursion 10
Context:	server config, virtual host
Status:	Core
Module:	core

An internal redirect happens, for example, when using the Action directive, which internally redirects the original request to a CGI script. A subrequest is Apache httpd’s mechanism to find out what would happen for some URI if it were requested. For example, mod_dir uses subrequests to look for the files listed in the DirectoryIndex directive.

LimitInternalRecursion prevents the server from crashing when entering an infinite loop of internal redirects or subrequests. Such loops are usually caused by misconfigurations.

The directive stores two different limits, which are evaluated on per-request basis. The first number is the maximum number of internal redirects that may follow each other. The second number determines how deeply subrequests may be nested. If you specify only one number , it will be assigned to both limits.

LimitRequestBody Directive

Description:	Restricts the total size of the HTTP request body sent from the client
Syntax:	LimitRequestBody bytes
Default:	LimitRequestBody 1073741824
Context:	server config, virtual host, directory, .htaccess
Override:	All
Status:	Core
Module:	core
Compatibility:	In Apache HTTP Server 2.4.53 and earlier, the default value was 0 (unlimited)

This directive specifies the number of bytes that are allowed in a request body. A value of 0 means unlimited.

The LimitRequestBody directive allows the user to set a limit on the allowed size of an HTTP request message body within the context in which the directive is given (server, per-directory, per-file or per-location). If the client request exceeds that limit, the server will return an error response instead of servicing the request. The size of a normal request message body will vary greatly depending on the nature of the resource and the methods allowed on that resource. CGI scripts typically use the message body for retrieving form information. Implementations of the PUT method will require a value at least as large as any representation that the server wishes to accept for that resource.

This directive gives the server administrator greater control over abnormal client request behavior, which may be useful for avoiding some forms of denial-of-service attacks.

If, for example, you are permitting file upload to a particular location and wish to limit the size of the uploaded file to 100K, you might use the following directive:

LimitRequestFields Directive

Description:	Limits the number of HTTP request header fields that will be accepted from the client
Syntax:	LimitRequestFields number
Default:	LimitRequestFields 100
Context:	server config, virtual host
Status:	Core
Module:	core

Setting number at 0 means unlimited. The default value is defined by the compile-time constant DEFAULT_LIMIT_REQUEST_FIELDS (100 as distributed).

The LimitRequestFields directive allows the server administrator to modify the limit on the number of request header fields allowed in an HTTP request. A server needs this value to be larger than the number of fields that a normal client request might include. The number of request header fields used by a client rarely exceeds 20, but this may vary among different client implementations, often depending upon the extent to which a user has configured their browser to support detailed content negotiation. Optional HTTP extensions are often expressed using request header fields.

This directive gives the server administrator greater control over abnormal client request behavior, which may be useful for avoiding some forms of denial-of-service attacks. The value should be increased if normal clients see an error response from the server that indicates too many fields were sent in the request.

Warning

When name-based virtual hosting is used, the value for this directive is taken from the default (first-listed) virtual host for the local IP and port combination.

LimitRequestFieldSize Directive

Description:	Limits the size of the HTTP request header allowed from the client
Syntax:	LimitRequestFieldSize bytes
Default:	LimitRequestFieldSize 8190
Context:	server config, virtual host
Status:	Core
Module:	core

This directive specifies the number of bytes that will be allowed in an HTTP request header.

The LimitRequestFieldSize directive allows the server administrator to set the limit on the allowed size of an HTTP request header field. A server needs this value to be large enough to hold any one header field from a normal client request. The size of a normal request header field will vary greatly among different client implementations, often depending upon the extent to which a user has configured their browser to support detailed content negotiation. SPNEGO authentication headers can be up to 12392 bytes.

This directive gives the server administrator greater control over abnormal client request behavior, which may be useful for avoiding some forms of denial-of-service attacks.

Warning

When name-based virtual hosting is used, the value for this directive is taken from the default (first-listed) virtual host best matching the current IP address and port combination.

LimitRequestLine Directive

Description:	Limit the size of the HTTP request line that will be accepted from the client
Syntax:	LimitRequestLine bytes
Default:	LimitRequestLine 8190
Context:	server config, virtual host
Status:	Core
Module:	core

This directive sets the number of bytes that will be allowed on the HTTP request-line.

The LimitRequestLine directive allows the server administrator to set the limit on the allowed size of a client’s HTTP request-line. Since the request-line consists of the HTTP method, URI, and protocol version, the LimitRequestLine directive places a restriction on the length of a request-URI allowed for a request on the server. A server needs this value to be large enough to hold any of its resource names, including any information that might be passed in the query part of a GET request.

This directive gives the server administrator greater control over abnormal client request behavior, which may be useful for avoiding some forms of denial-of-service attacks.

Warning

When name-based virtual hosting is used, the value for this directive is taken from the default (first-listed) virtual host best matching the current IP address and port combination.

LimitXMLRequestBody Directive

Description:	Limits the size of an XML-based request body
Syntax:	LimitXMLRequestBody bytes
Default:	LimitXMLRequestBody 1000000
Context:	server config, virtual host, directory, .htaccess
Override:	All
Status:	Core
Module:	core

Limit (in bytes) on the maximum size of an XML-based request body. A value of 0 will apply a hard limit (depending on 32bit vs 64bit system) allowing for XML escaping within the bounds of the system addressable memory, but it exists for compatibility only and is not recommended since it does not account for memory consumed elsewhere or concurrent requests, which might result in an overall system out-of-memory.

Directive

Description:	Applies the enclosed directives only to matching URLs
Syntax:	URL-path | URL > .
Context:	server config, virtual host
Status:	Core
Module:	core

The directive limits the scope of the enclosed directives by URL. It is similar to the directive, and starts a subsection which is terminated with a directive. sections are processed in the order they appear in the configuration file, after the sections and .htaccess files are read, and after the sections.

sections operate completely outside the filesystem. This has several consequences. Most importantly, directives should not be used to control access to filesystem locations. Since several different URLs may map to the same filesystem location, such access controls may by circumvented.

The enclosed directives will be applied to the request if the path component of the URL meets any of the following criteria:

• The specified location matches exactly the path component of the URL.
• The specified location, which ends in a forward slash, is a prefix of the path component of the URL (treated as a context root).
• The specified location, with the addition of a trailing slash, is a prefix of the path component of the URL (also treated as a context root).

In the example below, where no trailing slash is used, requests to /private1, /private1/ and /private1/file.txt will have the enclosed directives applied, but /private1other would not.

In the example below, where a trailing slash is used, requests to /private2/ and /private2/file.txt will have the enclosed directives applied, but /private2 and /private2other would not.

When to use

Use to apply directives to content that lives outside the filesystem. For content that lives in the filesystem, use and . An exception is , which is an easy way to apply a configuration to the entire server.

For all origin (non-proxy) requests, the URL to be matched is a URL-path of the form /path/ . No scheme, hostname, port, or query string may be included. For proxy requests, the URL to be matched is of the form scheme://servername/path , and you must include the prefix.

The URL may use wildcards. In a wild-card string, ? matches any single character, and * matches any sequences of characters. Neither wildcard character matches a / in the URL-path.

Regular expressions can also be used, with the addition of the

character. For example:

would match URLs that contained the substring /extra/data or /special/data . The directive behaves identical to the regex version of , and is preferred, for the simple reason that

is hard to distinguish from — in many fonts.

The functionality is especially useful when combined with the SetHandler directive. For example, to enable status requests but allow them only from browsers at example.com , you might use:

Note about / (slash)

The slash character has special meaning depending on where in a URL it appears. People may be used to its behavior in the filesystem where multiple adjacent slashes are frequently collapsed to a single slash (i.e., /home///foo is the same as /home/foo ). In URL-space this is not necessarily true if directive MergeSlashes has been set to «OFF». The directive and the regex version of require you to explicitly specify multiple slashes if the slashes are not being merged.

For example, would match the request URL /abc but not the request URL //abc . The (non-regex) directive behaves similarly when used for proxy requests. But when (non-regex) is used for non-proxy requests it will implicitly match multiple slashes with a single slash. For example, if you specify and the request is to /abc//def then it will match.

See also

• How , and sections work for an explanation of how these different sections are combined when a request is received.
• LocationMatch

Directive

Description:	Applies the enclosed directives only to regular-expression matching URLs
Syntax:	regex > .
Context:	server config, virtual host
Status:	Core
Module:	core

The directive limits the scope of the enclosed directives by URL, in an identical manner to . However, it takes a regular expression as an argument instead of a simple string. For example:

would match URLs that contained the substring /extra/data or /special/data .

If the intent is that a URL starts with /extra/data , rather than merely contains /extra/data , prefix the regular expression with a ^ to require this.

From 2.4.8 onwards, named groups and backreferences are captured and written to the environment with the corresponding name prefixed with «MATCH_» and in upper case. This allows elements of URLs to be referenced from within expressions and modules like mod_rewrite . In order to prevent confusion, numbered (unnamed) backreferences are ignored. Use named groups instead.

Note about / (slash)

The slash character has special meaning depending on where in a URL it appears. People may be used to its behavior in the filesystem where multiple adjacent slashes are frequently collapsed to a single slash (i.e., /home///foo is the same as /home/foo ). In URL-space this is not necessarily true if directive MergeSlashes has been set to «OFF». The directive and the regex version of require you to explicitly specify multiple slashes if the slashes are not being merged.

For example, would match the request URL /abc but not the request URL //abc . The (non-regex) directive behaves similarly when used for proxy requests. But when (non-regex) is used for non-proxy requests it will implicitly match multiple slashes with a single slash. For example, if you specify and the request is to /abc//def then it will match.

See also

• How , and sections work for an explanation of how these different sections are combined when a request is received

LogLevel Directive

Description:	Controls the verbosity of the ErrorLog
Syntax:	LogLevel [ module :] level [ module : level ] .
Default:	LogLevel warn
Context:	server config, virtual host, directory
Status:	Core
Module:	core
Compatibility:	Per-module and per-directory configuration is available in Apache HTTP Server 2.3.6 and later

LogLevel adjusts the verbosity of the messages recorded in the error logs (see ErrorLog directive). The following level s are available, in order of decreasing significance:

Level	Description	Example
emerg	Emergencies — system is unusable.	«Child cannot open lock file. Exiting»
alert	Action must be taken immediately.	«getpwuid: couldn’t determine user name from uid»
crit	Critical Conditions.	«socket: Failed to get a socket, exiting child»
error	Error conditions.	«Premature end of script headers»
warn	Warning conditions.	«child process 1234 did not exit, sending another SIGHUP»
notice	Normal but significant condition.	«httpd: caught SIGBUS, attempting to dump core in . «
info	Informational.	«Server seems busy, (you may need to increase StartServers, or Min/MaxSpareServers). «
debug	Debug-level messages	«Opening config file . «
trace1	Trace messages	«proxy: FTP: control connection complete»
trace2	Trace messages	«proxy: CONNECT: sending the CONNECT request to the remote proxy»
trace3	Trace messages	«openssl: Handshake: start»
trace4	Trace messages	«read from buffered SSL brigade, mode 0, 17 bytes»
trace5	Trace messages	«map lookup FAILED: map=rewritemap key=keyname»
trace6	Trace messages	«cache lookup FAILED, forcing new map lookup»
trace7	Trace messages, dumping large amounts of data	«| 0000: 02 23 44 30 13 40 ac 34 df 3d bf 9a 19 49 39 15 |»
trace8	Trace messages, dumping large amounts of data	«| 0000: 02 23 44 30 13 40 ac 34 df 3d bf 9a 19 49 39 15 |»

When a particular level is specified, messages from all other levels of higher significance will be reported as well. E.g., when LogLevel info is specified, then messages with log levels of notice and warn will also be posted.

Using a level of at least crit is recommended.

When logging to a regular file, messages of the level notice cannot be suppressed and thus are always logged. However, this doesn’t apply when logging is done using syslog .

Specifying a level without a module name will reset the level for all modules to that level. Specifying a level with a module name will set the level for that module only. It is possible to use the module source file name, the module identifier, or the module identifier with the trailing _module omitted as module specification. This means the following three specifications are equivalent:

It is also possible to change the level per directory:

See also

MaxKeepAliveRequests Directive

Description:	Number of requests allowed on a persistent connection
Syntax:	MaxKeepAliveRequests number
Default:	MaxKeepAliveRequests 100
Context:	server config, virtual host
Status:	Core
Module:	core

The MaxKeepAliveRequests directive limits the number of requests allowed per connection when KeepAlive is on. If it is set to 0 , unlimited requests will be allowed. We recommend that this setting be kept to a high value for maximum server performance.

MaxRangeOverlaps Directive

Description:	Number of overlapping ranges (eg: 100-200,150-300 ) allowed before returning the complete resource
Syntax:	MaxRangeOverlaps default | unlimited | none | number-of-ranges
Default:	MaxRangeOverlaps 20
Context:	server config, virtual host, directory
Status:	Core
Module:	core
Compatibility:	Available in Apache HTTP Server 2.3.15 and later

The MaxRangeOverlaps directive limits the number of overlapping HTTP ranges the server is willing to return to the client. If more overlapping ranges than permitted are requested, the complete resource is returned instead.

default Limits the number of overlapping ranges to a compile-time default of 20. none No overlapping Range headers are allowed. unlimited The server does not limit the number of overlapping ranges it is willing to satisfy. number-of-ranges A positive number representing the maximum number of overlapping ranges the server is willing to satisfy.

MaxRangeReversals Directive

Description:	Number of range reversals (eg: 100-200,50-70 ) allowed before returning the complete resource
Syntax:	MaxRangeReversals default | unlimited | none | number-of-ranges
Default:	MaxRangeReversals 20
Context:	server config, virtual host, directory
Status:	Core
Module:	core
Compatibility:	Available in Apache HTTP Server 2.3.15 and later

The MaxRangeReversals directive limits the number of HTTP Range reversals the server is willing to return to the client. If more ranges reversals than permitted are requested, the complete resource is returned instead.

default Limits the number of range reversals to a compile-time default of 20. none No Range reversals headers are allowed. unlimited The server does not limit the number of range reversals it is willing to satisfy. number-of-ranges A positive number representing the maximum number of range reversals the server is willing to satisfy.

MaxRanges Directive

Description:	Number of ranges allowed before returning the complete resource
Syntax:	MaxRanges default | unlimited | none | number-of-ranges
Default:	MaxRanges 200
Context:	server config, virtual host, directory
Status:	Core
Module:	core
Compatibility:	Available in Apache HTTP Server 2.3.15 and later

The MaxRanges directive limits the number of HTTP ranges the server is willing to return to the client. If more ranges than permitted are requested, the complete resource is returned instead.

default Limits the number of ranges to a compile-time default of 200. none Range headers are ignored. unlimited The server does not limit the number of ranges it is willing to satisfy. number-of-ranges A positive number representing the maximum number of ranges the server is willing to satisfy.

MergeSlashes Directive

Description:	Controls whether the server merges consecutive slashes in URLs.
Syntax:	MergeSlashes ON|OFF
Default:	MergeSlashes ON
Context:	server config, virtual host
Status:	Core
Module:	core
Compatibility:	Added in 2.4.39

By default, the server merges (or collapses) multiple consecutive slash (‘/’) characters in the path component of the request URL.

When mapping URL’s to the filesystem, these multiple slashes are not significant. However, URL’s handled other ways, such as by CGI or proxy, might prefer to retain the significance of multiple consecutive slashes. In these cases MergeSlashes can be set to OFF to retain the multiple consecutive slashes, which is the legacy behavior.

When set to «OFF», regular expressions used in the configuration file that match the path component of the URL ( LocationMatch , RewriteRule , . ) need to take into account multiple consecutive slashes. Non regular expression based Location always operate against a URL with merged slashes and cannot differentiate between multiple slashes.

MergeTrailers Directive

Description:	Determines whether trailers are merged into headers
Syntax:	MergeTrailers [on|off]
Default:	MergeTrailers off
Context:	server config, virtual host
Status:	Core
Module:	core
Compatibility:	2.4.11 and later

This directive controls whether HTTP trailers are copied into the internal representation of HTTP headers. This merging occurs when the request body has been completely consumed, long after most header processing would have a chance to examine or modify request headers.

This option is provided for compatibility with releases prior to 2.4.11, where trailers were always merged.

Mutex Directive

Description:	Configures mutex mechanism and lock file directory for all or specified mutexes
Syntax:	Mutex mechanism [default| mutex-name ] . [OmitPID]
Default:	Mutex default
Context:	server config
Status:	Core
Module:	core
Compatibility:	Available in Apache HTTP Server 2.3.4 and later

The Mutex directive sets the mechanism, and optionally the lock file location, that httpd and modules use to serialize access to resources. Specify default as the second argument to change the settings for all mutexes; specify a mutex name (see table below) as the second argument to override defaults only for that mutex.

The Mutex directive is typically used in the following exceptional situations:

• change the mutex mechanism when the default mechanism selected by APR has a functional or performance problem
• change the directory used by file-based mutexes when the default directory does not support locking

Supported modules

This directive only configures mutexes which have been registered with the core server using the ap_mutex_register() API. All modules bundled with httpd support the Mutex directive, but third-party modules may not. Consult the documentation of the third-party module, which must indicate the mutex name(s) which can be configured if this directive is supported.

The following mutex mechanisms are available:

This selects the default locking implementation, as determined by APR. The default locking implementation can be displayed by running httpd with the -V option.

This effectively disables the mutex, and is only allowed for a mutex if the module indicates that it is a valid choice. Consult the module documentation for more information.

This is a mutex variant based on a Posix semaphore.

Warning

The semaphore ownership is not recovered if a thread in the process holding the mutex segfaults, resulting in a hang of the web server.

This is a mutex variant based on a SystemV IPC semaphore.

Warning

It is possible to «leak» SysV semaphores if processes crash before the semaphore is removed.

Security

The semaphore API allows for a denial of service attack by any CGIs running under the same uid as the webserver (i.e., all CGIs, unless you use something like suexec or cgiwrapper ).

This selects the «best» available semaphore implementation, choosing between Posix and SystemV IPC semaphores, in that order.

This is a mutex variant based on cross-process Posix thread mutexes.

Warning

On most systems, if a child process terminates abnormally while holding a mutex that uses this implementation, the server will deadlock and stop responding to requests. When this occurs, the server will require a manual restart to recover.

Solaris and Linux are notable exceptions as they provide a mechanism which usually allows the mutex to be recovered after a child process terminates abnormally while holding a mutex.

If your system is POSIX compliant or if it implements the pthread_mutexattr_setrobust_np() function, you may be able to use the pthread option safely.

This is a mutex variant where a physical (lock-)file and the fcntl() function are used as the mutex.

Warning

When multiple mutexes based on this mechanism are used within multi-threaded, multi-process environments, deadlock errors (EDEADLK) can be reported for valid mutex operations if fcntl() is not thread-aware, such as on Solaris.

This is similar to the fcntl:/path/to/mutex method with the exception that the flock() function is used to provide file locking.

This selects the «best» available file locking implementation, choosing between fcntl and flock , in that order.

Most mechanisms are only available on selected platforms, where the underlying platform and APR support it. Mechanisms which aren’t available on all platforms are posixsem, sysvsem, sem, pthread, fcntl, flock, and file.

With the file-based mechanisms fcntl and flock, the path, if provided, is a directory where the lock file will be created. The default directory is httpd’s run-time file directory relative to ServerRoot . Always use a local disk filesystem for /path/to/mutex and never a directory residing on a NFS- or AFS-filesystem. The basename of the file will be the mutex type, an optional instance string provided by the module, and unless the OmitPID keyword is specified, the process id of the httpd parent process will be appended to make the file name unique, avoiding conflicts when multiple httpd instances share a lock file directory. For example, if the mutex name is mpm-accept and the lock file directory is /var/httpd/locks , the lock file name for the httpd instance with parent process id 12345 would be /var/httpd/locks/mpm-accept.12345 .

Security

It is best to avoid putting mutex files in a world-writable directory such as /var/tmp because someone could create a denial of service attack and prevent the server from starting by creating a lockfile with the same name as the one the server will try to create.

The following table documents the names of mutexes used by httpd and bundled modules.

Mutex name	Module(s)	Protected resource
mpm-accept	prefork and worker MPMs	incoming connections, to avoid the thundering herd problem; for more information, refer to the performance tuning documentation
authdigest-client	mod_auth_digest	client list in shared memory
authdigest-opaque	mod_auth_digest	counter in shared memory
ldap-cache	mod_ldap	LDAP result cache
rewrite-map	mod_rewrite	communication with external mapping programs, to avoid intermixed I/O from multiple requests
ssl-cache	mod_ssl	SSL session cache
ssl-stapling	mod_ssl	OCSP stapling response cache
watchdog-callback	mod_watchdog	callback function of a particular client module

The OmitPID keyword suppresses the addition of the httpd parent process id from the lock file name.

In the following example, the mutex mechanism for the MPM accept mutex will be changed from the compiled-in default to fcntl , with the associated lock file created in directory /var/httpd/locks . The mutex mechanism for all other mutexes will be changed from the compiled-in default to sysvsem .

NameVirtualHost Directive

Description:	DEPRECATED: Designates an IP address for name-virtual hosting
Syntax:	NameVirtualHost addr [: port ]
Context:	server config
Status:	Core
Module:	core

Prior to 2.3.11, NameVirtualHost was required to instruct the server that a particular IP address and port combination was usable as a name-based virtual host. In 2.3.11 and later, any time an IP address and port combination is used in multiple virtual hosts, name-based virtual hosting is automatically enabled for that address.

This directive currently has no effect.

See also

Options Directive

Description:	Configures what features are available in a particular directory
Syntax:	Options [+|-] option [[+|-] option ] .
Default:	Options FollowSymlinks
Context:	server config, virtual host, directory, .htaccess
Override:	Options
Status:	Core
Module:	core
Compatibility:	The default was changed from All to FollowSymlinks in 2.3.11

The Options directive controls which server features are available in a particular directory.

option can be set to None , in which case none of the extra features are enabled, or one or more of the following:

All All options except for MultiViews . ExecCGI Execution of CGI scripts using mod_cgi is permitted. FollowSymLinks The server will follow symbolic links in this directory. This is the default setting.

Even though the server follows the symlink it does not change the pathname used to match against sections.

The FollowSymLinks and SymLinksIfOwnerMatch Options work only in sections or .htaccess files.

Omitting this option should not be considered a security restriction, since symlink testing is subject to race conditions that make it circumventable.

This option gets ignored if set anywhere other than , as mod_negotiation needs real resources to compare against and evaluate from.

The FollowSymLinks and SymLinksIfOwnerMatch Options work only in sections or .htaccess files.

This option should not be considered a security restriction, since symlink testing is subject to race conditions that make it circumventable.

Normally, if multiple Options could apply to a directory, then the most specific one is used and others are ignored; the options are not merged. (See how sections are merged.) However if all the options on the Options directive are preceded by a + or — symbol, the options are merged. Any options preceded by a + are added to the options currently in force, and any options preceded by a — are removed from the options currently in force.

Mixing Options with a + or — with those without is not valid syntax and will be rejected during server startup by the syntax check with an abort.

For example, without any + and — symbols:

then only Includes will be set for the /web/docs/spec directory. However if the second Options directive uses the + and — symbols:

then the options FollowSymLinks and Includes are set for the /web/docs/spec directory.

Using -IncludesNOEXEC or -Includes disables server-side includes completely regardless of the previous setting.

The default in the absence of any other settings is FollowSymlinks .

Protocol Directive

Description:	Protocol for a listening socket
Syntax:	Protocol protocol
Context:	server config, virtual host
Status:	Core
Module:	core
Compatibility:	Available in Apache 2.1.5 and later. On Windows, from Apache 2.3.3 and later.

This directive specifies the protocol used for a specific listening socket. The protocol is used to determine which module should handle a request and to apply protocol specific optimizations with the AcceptFilter directive.

This directive not required for most configurations. If not specified, https is the default for port 443 and http the default for all other ports. The protocol is used to determine which module should handle a request, and to apply protocol specific optimizations with the AcceptFilter directive.

For example, if you are running https on a non-standard port, specify the protocol explicitly:

You can also specify the protocol using the Listen directive.

See also

Protocols Directive

Description:	Protocols available for a server/virtual host
Syntax:	Protocols protocol .
Default:	Protocols http/1.1
Context:	server config, virtual host
Status:	Core
Module:	core
Compatibility:	Only available from Apache 2.4.17 and later.

This directive specifies the list of protocols supported for a server/virtual host. The list determines the allowed protocols a client may negotiate for this server/host.

You need to set protocols if you want to extend the available protocols for a server/host. By default, only the http/1.1 protocol (which includes the compatibility with 1.0 and 0.9 clients) is allowed.

For example, if you want to support HTTP/2 for a server with TLS, specify:

Valid protocols are http/1.1 for http and https connections, h2 on https connections and h2c for http connections. Modules may enable more protocols.

It is safe to specify protocols that are unavailable/disabled. Such protocol names will simply be ignored.

Protocols specified in base servers are inherited for virtual hosts only if the virtual host has no own Protocols directive. Or, the other way around, Protocols directives in virtual hosts replace any such directive in the base server.

See also

ProtocolsHonorOrder Directive

Description:	Determines if order of Protocols determines precedence during negotiation
Syntax:	ProtocolsHonorOrder On|Off
Default:	ProtocolsHonorOrder On
Context:	server config, virtual host
Status:	Core
Module:	core
Compatibility:	Only available from Apache 2.4.17 and later.

This directive specifies if the server should honor the order in which the Protocols directive lists protocols.

If configured Off, the client supplied list order of protocols has precedence over the order in the server configuration.

With ProtocolsHonorOrder set to on (default), the client ordering does not matter and only the ordering in the server settings influences the outcome of the protocol negotiation.

See also

QualifyRedirectURL Directive

Description:	Controls whether the REDIRECT_URL environment variable is fully qualified
Syntax:	QualifyRedirectURL On|Off
Default:	QualifyRedirectURL Off
Context:	server config, virtual host, directory
Override:	FileInfo
Status:	Core
Module:	core
Compatibility:	Directive supported in 2.4.18 and later. 2.4.17 acted as if ‘QualifyRedirectURL On’ was configured.

This directive controls whether the server will ensure that the REDIRECT_URL environment variable is fully qualified. By default, the variable contains the verbatim URL requested by the client, such as «/index.html». With QualifyRedirectURL On , the same request would result in a value such as «http://www.example.com/index.html».

Even without this directive set, when a request is issued against a fully qualified URL, REDIRECT_URL will remain fully qualified.

ReadBufferSize Directive

Description:	Size of the buffers used to read data
Syntax:	ReadBufferSize bytes
Default:	ReadBufferSize 8192
Context:	server config, virtual host, directory
Status:	Core
Module:	core
Compatibility:	2.4.27 and later

This directive allows to configure the size (in bytes) of the memory buffer used to read data from the network or files.

A larger buffer can increase peformances with larger data, but consumes more memory per connection. The minimum configurable size is 1024 .

RegexDefaultOptions Directive

Description:	Allow to configure global/default options for regexes
Syntax:	RegexDefaultOptions [none] [+|-] option [[+|-] option ] .
Default:	RegexDefaultOptions DOTALL DOLLAR_ENDONLY
Context:	server config
Status:	Core
Module:	core
Compatibility:	Only available from Apache 2.4.30 and later.

This directive adds some default behavior to ANY regular expression used afterwards.

Any option preceded by a ‘+’ is added to the already set options.
Any option preceded by a ‘-‘ is removed from the already set options.
Any option without a ‘+’ or a ‘-‘ will be set, removing any other already set option.
The none keyword resets any already set options.

ICASE Use a case-insensitive match. EXTENDED Perl’s /x flag, ignore (unescaped-)spaces and comments in the pattern. DOTALL Perl’s /s flag, ‘.’ matches newline characters. DOLLAR_ENDONLY ‘$’ matches at end of subject string only.

RegisterHttpMethod Directive

Description:	Register non-standard HTTP methods
Syntax:	RegisterHttpMethod method [ method [. ]]
Context:	server config
Status:	Core
Module:	core
Compatibility:	Available in Apache HTTP Server 2.4.24 and later

This directive may be used to register additional HTTP methods. This is necessary if non-standard methods need to be used with directives that accept method names as parameters, or to allow particular non-standard methods to be used via proxy or CGI script when the server has been configured to only pass recognized methods to modules.

See also

RLimitCPU Directive

Description:	Limits the CPU consumption of processes launched by Apache httpd children
Syntax:	RLimitCPU seconds |max [ seconds |max]
Default:	Unset; uses operating system defaults
Context:	server config, virtual host, directory, .htaccess
Override:	All
Status:	Core
Module:	core

Takes 1 or 2 parameters. The first parameter sets the soft resource limit for all processes and the second parameter sets the maximum resource limit. Either parameter can be a number, or max to indicate to the server that the limit should be set to the maximum allowed by the operating system configuration. Raising the maximum resource limit requires that the server is running as root or in the initial startup phase.

This applies to processes forked from Apache httpd children servicing requests, not the Apache httpd children themselves. This includes CGI scripts and SSI exec commands, but not any processes forked from the Apache httpd parent, such as piped logs.

CPU resource limits are expressed in seconds per process.

See also

RLimitMEM Directive

Description:	Limits the memory consumption of processes launched by Apache httpd children
Syntax:	RLimitMEM bytes |max [ bytes |max]
Default:	Unset; uses operating system defaults
Context:	server config, virtual host, directory, .htaccess
Override:	All
Status:	Core
Module:	core

Takes 1 or 2 parameters. The first parameter sets the soft resource limit for all processes and the second parameter sets the maximum resource limit. Either parameter can be a number, or max to indicate to the server that the limit should be set to the maximum allowed by the operating system configuration. Raising the maximum resource limit requires that the server is running as root or in the initial startup phase.

This applies to processes forked from Apache httpd children servicing requests, not the Apache httpd children themselves. This includes CGI scripts and SSI exec commands, but not any processes forked from the Apache httpd parent, such as piped logs.

Memory resource limits are expressed in bytes per process.

See also

RLimitNPROC Directive

Description:	Limits the number of processes that can be launched by processes launched by Apache httpd children
Syntax:	RLimitNPROC number |max [ number |max]
Default:	Unset; uses operating system defaults
Context:	server config, virtual host, directory, .htaccess
Override:	All
Status:	Core
Module:	core

Takes 1 or 2 parameters. The first parameter sets the soft resource limit for all processes, and the second parameter sets the maximum resource limit. Either parameter can be a number, or max to indicate to the server that the limit should be set to the maximum allowed by the operating system configuration. Raising the maximum resource limit requires that the server is running as root or in the initial startup phase.

This applies to processes forked from Apache httpd children servicing requests, not the Apache httpd children themselves. This includes CGI scripts and SSI exec commands, but not any processes forked from the Apache httpd parent, such as piped logs.

Process limits control the number of processes per user.

If CGI processes are not running under user ids other than the web server user id, this directive will limit the number of processes that the server itself can create. Evidence of this situation will be indicated by cannot fork messages in the error_log .

See also

ScriptInterpreterSource Directive

Description:	Technique for locating the interpreter for CGI scripts
Syntax:	ScriptInterpreterSource Registry|Registry-Strict|Script
Default:	ScriptInterpreterSource Script
Context:	server config, virtual host, directory, .htaccess
Override:	FileInfo
Status:	Core
Module:	core
Compatibility:	Win32 only.

This directive is used to control how Apache httpd finds the interpreter used to run CGI scripts. The default setting is Script . This causes Apache httpd to use the interpreter pointed to by the shebang line (first line, starting with #! ) in the script. On Win32 systems this line usually looks like:

or, if perl is in the PATH , simply:

Setting ScriptInterpreterSource Registry will cause the Windows Registry tree HKEY_CLASSES_ROOT to be searched using the script file extension (e.g., .pl ) as a search key. The command defined by the registry subkey ShellExecCGICommand or, if it does not exist, by the subkey ShellOpenCommand is used to open the script file. If the registry keys cannot be found, Apache httpd falls back to the behavior of the Script option.

Security

Be careful when using ScriptInterpreterSource Registry with ScriptAlias ‘ed directories, because Apache httpd will try to execute every file within this directory. The Registry setting may cause undesired program calls on files which are typically not executed. For example, the default open command on .htm files on most Windows systems will execute Microsoft Internet Explorer, so any HTTP request for an .htm file existing within the script directory would start the browser in the background on the server. This is a good way to crash your system within a minute or so.

The option Registry-Strict does the same thing as Registry but uses only the subkey ShellExecCGICommand . The ExecCGI key is not a common one. It must be configured manually in the windows registry and hence prevents accidental program calls on your system.

SeeRequestTail Directive

Description:	Determine if mod_status displays the first 63 characters of a request or the last 63, assuming the request itself is greater than 63 chars.
Syntax:	SeeRequestTail On|Off
Default:	SeeRequestTail Off
Context:	server config
Status:	Core
Module:	core
Compatibility:	Available in Apache httpd 2.2.7 and later.

mod_status with ExtendedStatus On displays the actual request being handled. For historical purposes, only 63 characters of the request are actually stored for display purposes. This directive controls whether the first 63 characters are stored (the previous behavior and the default) or if the last 63 characters are. This is only applicable, of course, if the length of the request is 64 characters or greater.

If Apache httpd is handling GET /disk1/storage/apache/htdocs/images/imagestore1/food/apples.jpg HTTP/1.1 mod_status displays as follows:

Off (default)	GET /disk1/storage/apache/htdocs/images/imagestore1/food/apples
On	orage/apache/htdocs/images/imagestore1/food/apples.jpg HTTP/1.1

ServerAdmin Directive

Description:	Email address that the server includes in error messages sent to the client
Syntax:	ServerAdmin email-address | URL
Context:	server config, virtual host
Status:	Core
Module:	core

The ServerAdmin sets the contact address that the server includes in any error messages it returns to the client. If the httpd doesn’t recognize the supplied argument as an URL, it assumes, that it’s an email-address and prepends it with mailto: in hyperlink targets. However, it’s recommended to actually use an email address, since there are a lot of CGI scripts that make that assumption. If you want to use an URL, it should point to another server under your control. Otherwise users may not be able to contact you in case of errors.

It may be worth setting up a dedicated address for this, e.g.

as users do not always mention that they are talking about the server!

ServerAlias Directive

Description:	Alternate names for a host used when matching requests to name-virtual hosts
Syntax:	ServerAlias hostname [ hostname ] .
Context:	virtual host
Status:	Core
Module:	core

The ServerAlias directive sets the alternate names for a host, for use with name-based virtual hosts. The ServerAlias may include wildcards, if appropriate.

Name-based virtual hosts for the best-matching set of s are processed in the order they appear in the configuration. The first matching ServerName or ServerAlias is used, with no different precedence for wildcards (nor for ServerName vs. ServerAlias).

The complete list of names in the directive are treated just like a (non wildcard) ServerAlias .

See also

ServerName Directive

Description:	Hostname and port that the server uses to identify itself
Syntax:	ServerName [ scheme ://] domain-name | ip-address [: port ]
Context:	server config, virtual host
Status:	Core
Module:	core

The ServerName directive sets the request scheme, hostname and port that the server uses to identify itself.

ServerName is used (possibly in conjunction with ServerAlias ) to uniquely identify a virtual host, when using name-based virtual hosts.

Additionally, this is used when creating self-referential redirection URLs when UseCanonicalName is set to a non-default value.

For example, if the name of the machine hosting the web server is simple.example.com , but the machine also has the DNS alias www.example.com and you wish the web server to be so identified, the following directive should be used:

The ServerName directive may appear anywhere within the definition of a server. However, each appearance overrides the previous appearance (within that server).

If no ServerName is specified, the server attempts to deduce the client visible hostname by first asking the operating system for the system hostname, and if that fails, performing a reverse lookup on an IP address present on the system.

If no port is specified in the ServerName , then the server will use the port from the incoming request. For optimal reliability and predictability, you should specify an explicit hostname and port using the ServerName directive.

If you are using name-based virtual hosts, the ServerName inside a section specifies what hostname must appear in the request’s Host: header to match this virtual host.

Sometimes, the server runs behind a device that processes SSL, such as a reverse proxy, load balancer or SSL offload appliance. When this is the case, specify the https:// scheme and the port number to which the clients connect in the ServerName directive to make sure that the server generates the correct self-referential URLs.

See the description of the UseCanonicalName and UseCanonicalPhysicalPort directives for settings which determine whether self-referential URLs (e.g., by the mod_dir module) will refer to the specified port, or to the port number given in the client’s request.

Failure to set ServerName to a name that your server can resolve to an IP address will result in a startup warning. httpd will then use whatever hostname it can determine, using the system’s hostname command. This will almost never be the hostname you actually want.

Источник

1.Refresh the Page

The first thing to do when you encounter this error is wait a moment and then refresh the page. Sometimes this error is caused when a service restarts, and you happen to catch it at exactly the wrong time. If the problem persists after you refresh the page, continue troubleshooting.

2.Check Your Server Logs

• Your first stop should be your website’s error logs. On a Linux server, the default location for the main website error log is /var/log/httpd/error_log.
• If you have multiple websites hosted on your server, they will likely have their own error logs. The location of these log files will be specified in the site’s Apache configurations. Typically these are located in the website’s /logs/ directory.
• If the error log is large, it can be difficult to find the correct line. If you know that a particular script is causing the error, you can search the file for this script name by using the command:
  • more /var/log/httpd/error_log | grep [file name]
    This will return any lines which have the file name in them.
• If you are not sure what is causing the error, you can follow the error log in one window and watch it being generated. First, in your SSH session, use the command:
  • tail -f /var/log/httpd/error_log
    Without closing the SSH session, go to a web browser and refresh the page to generate the 500 error again. You should see the error appear in the log file.
• You can also view the last 10 lines in the error log with the command:
  • tail -20 /var/log/httpd/error_log
    Once you find the error, copying and pasting it into Google will often yield helpful results.

3.Check Permissions

An HTTP 500 error can be caused by a permissions problem with your website’s files or folders. Check the permissions on all of your main folders and scripts. Most Perl and CGI files need to have their permissions set to 755.

To check the permissions of files on a Linux system, connect via SSH to your server and go to the directory where the files are kept. Use the ll command to list all files and file details.

The first block of letters lists the file’s permissions. There are three permission levels:

Read (r)
Write (w)
Execute (x)
The permissions are shown in groups of three:

Group 1: Owner
Group 2: Group
Group 3: World (everyone)

4.Changing Permissions

To change the permissions for a file, you need to use the chmod command, along with the numerical value of the permissions level you want to set. The most common permissions levels are:

7: Read, write, and execute (rwx)
5: Read and execute (r-x)
0: None (—)
Most scripts will require read/write/execute permissions for the owner, and read/execute permissions for group and world. To set this on a file, use the command:

chmod 755 [filename]
If you are still receiving an error when you run your script, try setting it to global read/write/execute permissions for testing purposes. To set this on a file, use the command:

chmod 777 [filename]
This permissions level can be risky, because it allows anyone to rewrite your file. Once you have finished troubleshooting, be sure to set the file back to the correct permissions.

5.Examine Your Scripts

If your website relies on scripts (such as Perl or CGI files), there are a number of things that can go wrong. Always check the file permissions first. If those are correct, examine the scripts themselves.

Are they in the right place, and named correctly? Verify that the scripts have not been moved, deleted, or renamed by accident.

Are the file paths correct? Many scripts will require other files and programs in order to run. For example, if you have a Perl script, it will start with the path to Perl. You can use the which command to find the path to Perl (or any other programming language or command) with the command:

which perl

Do the scripts have permission to run in the folder where they are located? You may want to find a simple test script to check this.

Be sure your test script is in the same language as the one you are troubleshooting, and uses the same file extension. For example, if you are having trouble with a Python script named myfile.py, search for a Python test script, and give the file a .py file extension. Using a Perl test script, or a Python test script that ends in .cgi won’t be effective as a test.

Was the script recently edited in a word processing program like Microsoft Word or Wordpad? CGI programs and other scripts should only be edited with a text editor like Notepad. To fix this problem, find a fresh copy of the script, and use a text editor like Notepad (for Windows) or BBEdit (for Mac).

6.Check the Apache Files

An HTTP 500 error can be caused by a problem with your Apache configurations. If you have scripts or CGI programs which are generating a 500 error, check to make sure they have permission to run in the directory where they are located.

Apache will not allow programs to execute by default. Permission must be given in either an .htaccess file in the directory where the program runs, or in the website’s main Apache configuration file.

7.Granting Permissions With an .htaccess File

You can grant executable permissions on a directory-by-directory basis using an .htaccess file.

Note: because the file name begins with a period, the file will be hidden from a basic ls search from the command line. To list the files in the directory including any which begin with a period, use the command:

ls -la
Either edit the existing file, or create one in the directory, if none exists. You can also create this file in Notepad on your desktop computer, and upload it to your website with FTP.

The file will need to have this line:

Options +ExecCGI
You will also need a line that will tell Apache how to run scripts written in Python, PHP, Perl, etc. Customize this line to add the extension your files are using (.py, .php, .pl, etc.).

AddHandler cgi-script .cgi .py .php .pl

8.Is the .htaccess File Being Read?

If you have an .htaccess file which is set up correctly, but you are still getting an HTTP 500 error, the problem might be that the .htaccess file is being ignored.

In order for the .htaccess file to work, Apache will need to be configured to allow it to run.

Check the website’s main Apache configuration file. For the main domain on a server, this will typically be:

Ubuntu and Debian: /etc/apache2/apache2.conf
CentOS 7: /etc/httpd/conf/httpd.conf

For other domains being hosted on the server, the location and name of the file will vary depending on how the domain was set up.

Edit this main configuration file and find the block which pertains to the directory where you are adding an .htaccess file. For example, the default document root for the main directory will probably be:

<directory “=”” var=”” www=”” html”=””>

Inside this block, look for the AllowOverride configuration. Set this to:

AllowOverride All

After making changes to the main Apache configuration file, restart Apache for the changes to take effect:

Ubuntu and Debian: use the command service apache2 restart.
CentOS 7: use the command systemctl restart httpd.

9.Timeout Errors

If you have scripts which call external networks or resources, an HTTP 500 error can be caused when those connections time out, usually because the resource is unreachable. Check your external resources to be sure they are accessible.

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