Versión 2.4 del Servidor HTTP Apache
Descripción: | Funcionalides básicas del Servidor HTTP Apache que siempre están presentes. |
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Estado: | Core |
Descripción: | Configura mejoras para un Protocolo de Escucha de Sockets |
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Sintaxis: | AcceptFilter protocol accept_filter |
Contexto: | server config |
Estado: | Core |
Módulo: | core |
Compatibilidad: | Disponible en Apache httpd 2.1.5 y posteriores. En Windows desde Apache httpd 2.3.3 y posteriores. |
Esta directiva hace posible mejoras específicas a nivel de sistema operativo
y a través del tipo de Protocolo para un socket que escucha.
La premisa básica es que el kernel no envíe un socket al servidor
hasta que o bien los datos se hayan recibido o bien se haya almacenado
en el buffer una Respuesta HTTP completa.
Actualmente sólo están soportados
Accept Filters sobre FreeBSD, TCP_DEFER_ACCEPT
sobre Linux,
y AcceptEx() sobre Windows.
El uso de none
para un argumento desactiva cualquier filtro
aceptado para ese protocolo. Esto es útil para protocolos que requieren que un
servidor envíe datos primeros, tales como ftp:
o nntp
:
AcceptFilter nntp none
Los nombres de protocolo por defecto son https
para el puerto 443
y http
para todos los demás puertos. Para especificar que se está
utilizando otro protocolo con un puerto escuchando, añade el argumento protocol
a la directiva Listen
.
Sobre FreeBDS los valores por defecto:
AcceptFilter http httpready
AcceptFilter https dataready
El filtro httpready
almacena en el buffer peticiones HTTP completas
a nivel de kernel. Una vez que la petición es recibida, el kernel la envía al servidor.
Consulta la página man de
accf_http(9) para más detalles. Puesto que las peticiones HTTPS
están encriptadas, sólo se utiliza el filtro
accf_data(9).
Sobre Linux los valores por defecto son:
AcceptFilter http data
AcceptFilter https data
En Linux, TCP_DEFER_ACCEPT
no soporta el buffering en peticiones http.
Cualquier valor además de none
habilitará
TCP_DEFER_ACCEPT
en ese socket. Para más detalles
ver la página man de Linux
tcp(7).
Sobre Windows los valores por defecto son:
AcceptFilter http data
AcceptFilter https data
Sobre Windows mpm_winnt interpreta el argumento AcceptFilter para conmutar la API
AcceptEx(), y no soporta el buffering sobre el protocolo http. Hay dos valores
que utilizan la API Windows AcceptEx() y que recuperan sockets de red
entre conexciones. data
espera hasta que los datos han sido
transmitidos como se comentaba anteriormente, y el buffer inicial de datos y las
direcciones de red son recuperadas a partir de una única llamada AcceptEx().
connect
utiliza la API AcceptEx() API, y recupera también
las direccciones de red, pero a diferencia de none
la opción connect
no espera a la transmisión inicial de los datos.
Sobre Windows, none
prefiere accept() antes que AcceptEx()
y no recuperará sockets entre las conexiones. Lo que es útil para los adaptadores de
red con un soporte precario de drivers, así como para algunos proveedores de red
tales como drivers vpn, o filtros de spam, de virus o de spyware.
Protocol
Descripción: | Los recursos aceptan información sobre su ruta |
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Sintaxis: | AcceptPathInfo On|Off|Default |
Valor por defecto: | AcceptPathInfo Default |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | FileInfo |
Estado: | Core |
Módulo: | core |
Compatibilidad: | Disponible en Apache httpd 2.0.30 y posteriores |
Esta directiva controla si las peticiones que contienen información sobre la ruta
que sigue un fichero que existe (o un fichero que no existe pero en un directorio que
sí existe) serán aceptadas o denegadas. La información de ruta puede estar disponible
para los scripts en la variable de entorno PATH_INFO
.
Por ejemplo, asumamos que la ubicación /test/
apunta a
un directorio que contiene únicamente el fichero
here.html
. Entonces, las peticiones tanto para
/test/here.html/more
como para
/test/nothere.html/more
recogen
/more
como PATH_INFO
.
Los tres posibles argumentos para la directiva
AcceptPathInfo
son los siguientes:
Off
/test/here.html/more
en el ejemplo anterior devolverá
un error 404 NOT FOUND.On
/test/here.html/more
será aceptado si
/test/here.html
corresponde a un fichero válido.Default
PATH_INFO
. Los controladores que sirven scripts, tales como cgi-script e isapi-handler, normalmente aceptan
PATH_INFO
por defecto.El objetivo principal de la directiva AcceptPathInfo
es permitirte sobreescribir la opción del controlador
de aceptar or rechazar PATH_INFO
. Este tipo de sobreescritura se necesita,
por ejemplo, cuando utilizas un filtro, tal como
INCLUDES, para generar contenido
basado en PATH_INFO
. El controlador principal normalmente rechazaría
la petición, de modo que puedes utilizar la siguiente configuración para habilitarla
como script:
<Files "mypaths.shtml">
Options +Includes
SetOutputFilter INCLUDES
AcceptPathInfo On
</Files>
Descripción: | Nombre del fichero distribuido de configuración |
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Sintaxis: | AccessFileName filename [filename] ... |
Valor por defecto: | AccessFileName .htaccess |
Contexto: | server config, virtual host |
Estado: | Core |
Módulo: | core |
Mientras que procesa una petición el servidor busca el primer fichero de configuración existente dentro de un listado de nombres en cada directorio de la ruta del documento, si los ficheros distribuidos de configuración están habilitados para ese directorio. Por ejemplo:
AccessFileName .acl
antes de servir el documento
/usr/local/web/index.html
, el servidor leerá
/.acl
, /usr/.acl
,
/usr/local/.acl
and /usr/local/web/.acl
para las directivas, salvo que estén deshabilitadas with
<Directory />
AllowOverride None
</Directory>
Descripción: | Default charset parameter to be added when a response
content-type is text/plain or text/html |
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Sintaxis: | AddDefaultCharset On|Off|charset |
Valor por defecto: | AddDefaultCharset Off |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | FileInfo |
Estado: | Core |
Módulo: | 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 utf-8
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.
Descripción: | Determines whether encoded path separators in URLs are allowed to be passed through |
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Sintaxis: | AllowEncodedSlashes On|Off |
Valor por defecto: | AllowEncodedSlashes Off |
Contexto: | server config, virtual host |
Estado: | Core |
Módulo: | core |
Compatibilidad: | Available in Apache httpd 2.0.46 and later |
The AllowEncodedSlashes
directive allows URLs
which contain encoded path separators (%2F
for /
and additionally %5C
for \
on according systems)
to be used. Normally such URLs are refused with a 404 (Not found) error.
Turning AllowEncodedSlashes
On
is
mostly useful when used in conjunction with PATH_INFO
.
Allowing encoded slashes does not imply decoding.
Occurrences of %2F
or %5C
(only on
according systems) will be left as such in the otherwise decoded URL
string.
Descripción: | Types of directives that are allowed in
.htaccess files |
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Sintaxis: | AllowOverride All|None|directive-type
[directive-type] ... |
Valor por defecto: | AllowOverride None (2.3.9 and later), AllowOverride All (2.3.8 and earlier) |
Contexto: | directory |
Estado: | Core |
Módulo: | 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.
AllowOverride
is valid only in
<Directory>
sections specified without regular expressions, not in <Location>
, <DirectoryMatch>
or
<Files>
sections.
When this directive 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.
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.
AuthDBMGroupFile
,
AuthDBMUserFile
,
AuthGroupFile
,
AuthName
,
AuthType
, AuthUserFile
, Require
, etc.).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
) and
Action
from
mod_actions
.
AddDescription
,
AddIcon
, AddIconByEncoding
,
AddIconByType
,
DefaultIcon
, DirectoryIndex
, FancyIndexing
, HeaderName
, IndexIgnore
, IndexOptions
, ReadmeName
,
etc.).Allow
, Deny
and Order
).Options
and
XBitHack
).
An equal sign may be given followed by a comma (but no spaces)
separated lists of options that may be set using the Options
command.Example:
AllowOverride AuthConfig Indexes
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 <Directory />
block. Instead, find (or
create) the <Directory>
block that refers to the
directory where you're actually planning to place a
.htaccess
file.
Descripción: | Individual directives that are allowed in
.htaccess files |
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Sintaxis: | AllowOverrideList None|directive
[directive-type] ... |
Valor por defecto: | AllowOverrideList None |
Contexto: | directory |
Estado: | Core |
Módulo: | core |
The documentation for this directive has not been translated yet. Please have a look at the English version.
Descripción: | Technique for locating the interpreter for CGI scripts |
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Sintaxis: | CGIMapExtension cgi-path .extension |
Contexto: | directory, .htaccess |
Prevalece sobre: | FileInfo |
Estado: | Core |
Módulo: | core |
Compatibilidad: | 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.
Descripción: | Enables the generation of Content-MD5 HTTP Response
headers |
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Sintaxis: | ContentDigest On|Off |
Valor por defecto: | ContentDigest Off |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | Options |
Estado: | Core |
Módulo: | 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:
Content-MD5: AuLb7Dp1rqtRtxz2m9kRpA==
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.
Descripción: | Base directory for the server run-time files |
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Sintaxis: | DefaultRuntimeDir directory-path |
Valor por defecto: | DefaultRuntimeDir DEFAULT_REL_RUNTIMEDIR (logs/) |
Contexto: | server config |
Estado: | Core |
Módulo: | core |
The documentation for this directive has not been translated yet. Please have a look at the English version.
ServerRoot
Descripción: | 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.
|
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Sintaxis: | DefaultType media-type|none |
Valor por defecto: | DefaultType none |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | FileInfo |
Estado: | Core |
Módulo: | core |
Compatibilidad: | 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
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.
Descripción: | Define the existence of a variable |
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Sintaxis: | Define parameter-name |
Contexto: | server config |
Estado: | Core |
Módulo: | core |
Equivalent to passing the -D
argument to httpd
.
This directive can be used to toggle the use of <IfDefine>
sections without needing to alter
-D
arguments in any startup scripts.
Descripción: | Enclose a group of directives that apply only to the named file-system directory, sub-directories, and their contents. |
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Sintaxis: | <Directory directory-path>
... </Directory> |
Contexto: | server config, virtual host |
Estado: | Core |
Módulo: | core |
<Directory>
and
</Directory>
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 <Directory
/*/public_html>
will not match
/home/user/public_html
, but <Directory
/home/*/public_html>
will match. Example:
<Directory /usr/local/httpd/htdocs>
Options Indexes FollowSymLinks
</Directory>
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
<Directory>
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:
<Directory ~ "^/www/.*/[0-9]{3}">
would match directories in /www/
that consisted of
three numbers.
If multiple (non-regular expression) <Directory>
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
<Directory />
AllowOverride None
</Directory>
<Directory /home/>
AllowOverride FileInfo
</Directory>
for access to the document /home/web/dir/doc.html
the steps are:
AllowOverride None
(disabling .htaccess
files).AllowOverride FileInfo
(for
directory /home
).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
<Directory ~ abc$>
# ... directives here ...
</Directory>
the regular expression section won't be considered until after
all normal <Directory>
s and
.htaccess
files have been applied. Then the regular
expression will match on /home/abc/public_html/abc
and
the corresponding <Directory>
will
be applied.
Note that the default access for
<Directory />
is Allow from All
.
This means that Apache httpd will serve any file mapped from an URL. It is
recommended that you change this with a block such
as
<Directory />
Order Deny,Allow
Deny from All
</Directory>
and then override this for directories you want accessible. See the Security Tips page for more details.
The directory sections occur in the httpd.conf
file.
<Directory>
directives
cannot nest, and cannot appear in a <Limit>
or <LimitExcept>
section.
Descripción: | Enclose directives that apply to the contents of file-system directories matching a regular expression. |
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Sintaxis: | <DirectoryMatch regex>
... </DirectoryMatch> |
Contexto: | server config, virtual host |
Estado: | Core |
Módulo: | core |
<DirectoryMatch>
and
</DirectoryMatch>
are used to enclose a group
of directives which will apply only to the named directory (and the files within),
the same as <Directory>
.
However, it takes as an argument a
regular expression. For example:
<DirectoryMatch "^/www/(.+/)?[0-9]{3}">
would match directories in /www/
that consisted of three
numbers.
<Directory>
) and
could not match the end of line symbol ($). In 2.3.9 and later,
only directories that match the expression are affected by the enclosed
directives.
<Directory>
for
a description of how regular expressions are mixed in with normal
<Directory>
sDescripción: | Directory that forms the main document tree visible from the web |
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Sintaxis: | DocumentRoot directory-path |
Valor por defecto: | DocumentRoot /usr/local/apache/htdocs |
Contexto: | server config, virtual host |
Estado: | Core |
Módulo: | 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:
DocumentRoot /usr/web
then an access to
http://www.my.host.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.
Descripción: | Contains directives that apply only if the condition of a
previous <If> or
<ElseIf> section is not
satisfied by a request at runtime |
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Sintaxis: | <Else> ... </Else> |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | All |
Estado: | Core |
Módulo: | core |
The documentation for this directive has not been translated yet. Please have a look at the English version.
<If>
<ElseIf>
<If>
,
<ElseIf>
, and
<Else>
are applied last.Descripción: | Contains directives that apply only if a condition is satisfied
by a request at runtime while the condition of a previous
<If> or
<ElseIf> section is not
satisfied |
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Sintaxis: | <ElseIf expression> ... </ElseIf> |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | All |
Estado: | Core |
Módulo: | core |
The documentation for this directive has not been translated yet. Please have a look at the English version.
<If>
<Else>
<If>
,
<ElseIf>
, and
<Else>
are applied last.Descripción: | Use memory-mapping to read files during delivery |
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Sintaxis: | EnableMMAP On|Off |
Valor por defecto: | EnableMMAP On |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | FileInfo |
Estado: | Core |
Módulo: | 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:
httpd
.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:
EnableMMAP Off
For NFS mounted files, this feature may be disabled explicitly for the offending files by specifying:
<Directory "/path-to-nfs-files">
EnableMMAP Off
</Directory>
Descripción: | Use the kernel sendfile support to deliver files to the client |
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Sintaxis: | EnableSendfile On|Off |
Valor por defecto: | EnableSendfile Off |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | FileInfo |
Estado: | Core |
Módulo: | core |
Compatibilidad: | Available in version 2.0.44 and later. 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:
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:
EnableSendfile On
For network mounted files, this feature may be disabled explicitly for the offending files by specifying:
<Directory "/path-to-nfs-files">
EnableSendfile Off
</Directory>
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.
Descripción: | Abort configuration parsing with a custom error message |
---|---|
Sintaxis: | Error message |
Contexto: | server config, virtual host, directory, .htaccess |
Estado: | Core |
Módulo: | core |
Compatibilidad: | 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.
# ensure that mod_include is loaded
<IfModule !include_module>
Error mod_include is required by mod_foo. Load it with LoadModule.
</IfModule>
# ensure that exactly one of SSL,NOSSL is defined
<IfDefine SSL>
<IfDefine NOSSL>
Error Both SSL and NOSSL are defined. Define only one of them.
</IfDefine>
</IfDefine>
<IfDefine !SSL>
<IfDefine !NOSSL>
Error Either SSL or NOSSL must be defined.
</IfDefine>
</IfDefine>
Descripción: | What the server will return to the client in case of an error |
---|---|
Sintaxis: | ErrorDocument error-code document |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | FileInfo |
Estado: | Core |
Módulo: | core |
In the event of a problem or error, Apache httpd can be configured to do one of four things,
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.
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. Examples:
ErrorDocument 500 http://foo.example.com/cgi-bin/tester
ErrorDocument 404 /cgi-bin/bad_urls.pl
ErrorDocument 401 /subscription_info.html
ErrorDocument 403 "Sorry can't allow you access today"
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
.
ErrorDocument 404 /cgi-bin/bad_urls.pl
<Directory /web/docs>
ErrorDocument 404 default
</Directory>
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 overriden, 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.
Descripción: | Location where the server will log errors |
---|---|
Sintaxis: | ErrorLog file-path|syslog[:facility] |
Valor por defecto: | ErrorLog logs/error_log (Unix) ErrorLog logs/error.log (Windows and OS/2) |
Contexto: | server config, virtual host |
Estado: | Core |
Módulo: | 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
.
ErrorLog /var/log/httpd/error_log
If the file-path
begins with a pipe character "|
" then it is assumed to be a
command to spawn to handle the error log.
ErrorLog "|/usr/local/bin/httpd_errors"
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.
ErrorLog syslog:user
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 slashed 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.
Descripción: | Format specification for error log entries |
---|---|
Sintaxis: | ErrorLog [connection|request] format |
Contexto: | server config, virtual host |
Estado: | Core |
Módulo: | core |
Compatibilidad: | Available in Apache httpd 2.3.9 and later |
ErrorLogFormat
allows to specify what
supplementary information is logged in the error log in addition to the
actual log message.
ErrorLogFormat "[%t] [%l] [pid %P] %F: %E: [client %a] %M"
Specifying connection
or request
as first
paramter allows to specify additional formats, causing additional
information to be logged when the first message is logged for a specific
connection or request, respectivly. 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 behaviour is to delete everything from the preceeding
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
ommitted. 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-witdh field delimiter that does not produce any
output.
The above behaviour 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
ommitted.
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).
Some format string items accept additional parameters in braces.
Format String | Description |
---|---|
%% |
The percent sign |
%...a |
Remote IP-address and port |
%...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 |
%...{c}L |
Log ID of the connection |
%...{C}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 |
The current time |
%...{u}t |
The current time including micro-seconds |
%...{cu}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.
ErrorLogFormat "[%{u}t] [%-m:%l] [pid %P] %7F: %E: [client\ %a]
%M% ,\ referer\ %{Referer}i"
ErrorLogFormat "[%t] [%l] %7F: %E: [client\ %a]
%M% ,\ referer\ %{Referer}i"
ErrorLogFormat "[%{uc}t] [%-m:%-l] [R:%L] [C:%{C}L] %7F: %E: %M"
ErrorLogFormat request "[%{uc}t] [R:%L] Request %k on C:%{c}L pid:%P tid:%T"
ErrorLogFormat request "[%{uc}t] [R:%L] UA:'%+{User-Agent}i'"
ErrorLogFormat request "[%{uc}t] [R:%L] Referer:'%+{Referer}i'"
ErrorLogFormat connection "[%{uc}t] [C:%{c}L] local\ %a remote\ %A"
Descripción: | Keep track of extended status information for each request |
---|---|
Sintaxis: | ExtendedStatus On|Off |
Valor por defecto: | ExtendedStatus Off[*] |
Contexto: | server config |
Estado: | Core |
Módulo: | core |
This option tracks additional data per worker about the
currently executing request, and 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.
Descripción: | File attributes used to create the ETag HTTP response header for static files |
---|---|
Sintaxis: | FileETag component ... |
Valor por defecto: | FileETag INode MTime Size |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | FileInfo |
Estado: | Core |
Módulo: | core |
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:
FileETag INode MTime Size
ETag
field will be
included in the responseThe INode
, MTime
, and Size
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
.
mod_dav_fs
as a storage provider.
mod_dav_fs
uses INode MTime Size
as a fixed format for ETag
comparisons on conditional requests.
These conditional requests will break if the ETag
format is
changed via FileETag
.
mod_include
,
since the response entity can change without a change of the INode, MTime, or Size
of the static file with embedded SSI directives.
Descripción: | Contains directives that apply to matched filenames |
---|---|
Sintaxis: | <Files filename> ... </Files> |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | All |
Estado: | Core |
Módulo: | core |
The <Files>
directive
limits the scope of the enclosed directives by filename. It is comparable
to the <Directory>
and <Location>
directives. It should be matched with a </Files>
directive. The directives given within this section will be applied to
any object with a basename (last component of filename) matching the
specified filename. <Files>
sections are processed in the order they appear in the
configuration file, after the <Directory>
sections and
.htaccess
files are read, but before <Location>
sections. Note
that <Files>
can be nested
inside <Directory>
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:
<Files ~ "\.(gif|jpe?g|png)$">
would match most common Internet graphics formats. <FilesMatch>
is preferred,
however.
Note that unlike <Directory>
and <Location>
sections, <Files>
sections can be used inside
.htaccess
files. This allows users to control access to
their own files, at a file-by-file level.
Descripción: | Contains directives that apply to regular-expression matched filenames |
---|---|
Sintaxis: | <FilesMatch regex> ... </FilesMatch> |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | All |
Estado: | Core |
Módulo: | core |
The <FilesMatch>
directive
limits the scope of the enclosed directives by filename, just as the
<Files>
directive
does. However, it accepts a regular
expression. For example:
<FilesMatch "\.(gif|jpe?g|png)$">
would match most common Internet graphics formats.
Descripción: | Forces all matching files to be served with the specified media type in the HTTP Content-Type header field |
---|---|
Sintaxis: | ForceType media-type|None |
Contexto: | directory, .htaccess |
Prevalece sobre: | FileInfo |
Estado: | Core |
Módulo: | core |
Compatibilidad: | Moved to the core in Apache httpd 2.0 |
When placed into an .htaccess
file or a
<Directory>
, or
<Location>
or
<Files>
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:
ForceType image/gif
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
:
# force all files to be image/gif:
<Location /images>
ForceType image/gif
</Location>
# but normal mime-type associations here:
<Location /images/mixed>
ForceType None
</Location>
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.
Descripción: | Directory to write gmon.out profiling data to. |
---|---|
Sintaxis: | GprofDir /tmp/gprof/|/tmp/gprof/% |
Contexto: | server config, virtual host |
Estado: | Core |
Módulo: | core |
When the server has been compiled with gprof profiling suppport,
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.
Descripción: | Enables DNS lookups on client IP addresses |
---|---|
Sintaxis: | HostnameLookups On|Off|Double |
Valor por defecto: | HostnameLookups Off |
Contexto: | server config, virtual host, directory |
Estado: | Core |
Módulo: | 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.
Descripción: | Contains directives that apply only if a condition is satisfied by a request at runtime |
---|---|
Sintaxis: | <If expression> ... </If> |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | All |
Estado: | Core |
Módulo: | core |
The <If>
directive
evaluates an expression at runtime, and applies the enclosed
directives if and only if the expression evaluates to true.
For example:
<If "$req{Host} = ''">
would match HTTP/1.0 requests without a Host: header.
You may compare the value of any variable in the request headers ($req), response headers ($resp) or environment ($env) in your expression.
Apart from =
, If
can use the IN
operator to compare if the expression is in a given range:
<If %{REQUEST_METHOD} IN GET,HEAD,OPTIONS>
<If>
has the same precedence
and usage as <Files>
Descripción: | Encloses directives that will be processed only if a test is true at startup |
---|---|
Sintaxis: | <IfDefine [!]parameter-name> ...
</IfDefine> |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | All |
Estado: | Core |
Módulo: | core |
The <IfDefine test>...</IfDefine>
section is used to mark directives that are conditional. The
directives within an <IfDefine>
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 <IfDefine>
section directive can be one of two forms:
!
parameter-nameIn 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 -Dparameter
at the time the server was started or by the Define
directive.
<IfDefine>
sections are
nest-able, which can be used to implement simple
multiple-parameter tests. Example:
httpd -DReverseProxy -DUseCache -DMemCache ...
# httpd.conf
<IfDefine ReverseProxy>
LoadModule proxy_module modules/mod_proxy.so
LoadModule proxy_http_module modules/mod_proxy_http.so
<IfDefine UseCache>
LoadModule cache_module modules/mod_cache.so
<IfDefine MemCache>
LoadModule mem_cache_module modules/mod_mem_cache.so
</IfDefine>
<IfDefine !MemCache>
LoadModule cache_disk_module modules/mod_cache_disk.so
</IfDefine>
</IfDefine>
</IfDefine>
Descripción: | Encloses directives that are processed conditional on the presence or absence of a specific module |
---|---|
Sintaxis: | <IfModule [!]module-file|module-identifier> ...
</IfModule> |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | All |
Estado: | Core |
Módulo: | core |
Compatibilidad: | Module identifiers are available in version 2.1 and later. |
The <IfModule test>...</IfModule>
section is used to mark directives that are conditional on the presence of
a specific module. The directives within an <IfModule>
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 <IfModule>
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
.
<IfModule>
sections are
nest-able, which can be used to implement simple multiple-module
tests.
<IfModule>
sections.Descripción: | Includes other configuration files from within the server configuration files |
---|---|
Sintaxis: | Include [optional|strict] file-path|directory-path|wildcard |
Contexto: | server config, virtual host, directory |
Estado: | Core |
Módulo: | core |
Compatibilidad: | Wildcard matching available in 2.0.41 and later, 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.
When a wildcard is specified for a file component of
the path, and no file matches the wildcard, the
Include
directive will be silently ignored. When a wildcard is
specified for a directory component of the path, and
no directory matches the wildcard, the
Include
directive will
fail with an error saying the directory cannot be found.
For further control over the behaviour of the server when no files or directories match, prefix the path with the modifiers optional or strict. If optional is specified, any wildcard file or directory that does not match will be silently ignored. If strict is specified, any wildcard file or directory that does not match at least one file will cause server startup to fail.
When a directory or file component of the path is
specified exactly, and that directory or file does not exist,
Include
directive will fail with an
error saying the file or directory cannot be found.
The file path specified may be an absolute path, or may be relative
to the ServerRoot
directory.
Examples:
Include /usr/local/apache2/conf/ssl.conf
Include /usr/local/apache2/conf/vhosts/*.conf
Or, providing paths relative to your ServerRoot
directory:
Include conf/ssl.conf
Include conf/vhosts/*.conf
Wildcards may be included in the directory or file portion of the path. In the following example, the server will fail to load if no directories match conf/vhosts/*, but will load successfully if no files match *.conf.
Include conf/vhosts/*/vhost.conf
Include conf/vhosts/*/*.conf
In this example, the server will fail to load if either conf/vhosts/* matches no directories, or if *.conf matches no files:
Include strict conf/vhosts/*/*.conf
In this example, the server load successfully if either conf/vhosts/* matches no directories, or if *.conf matches no files:
Include optional conf/vhosts/*/*.conf
Descripción: | Includes other configuration files from within the server configuration files |
---|---|
Sintaxis: | IncludeOptional file-path|directory-path|wildcard |
Contexto: | server config, virtual host, directory |
Estado: | Core |
Módulo: | core |
Compatibilidad: | Available in 2.3.6 and later |
The documentation for this directive has not been translated yet. Please have a look at the English version.
Descripción: | Enables HTTP persistent connections |
---|---|
Sintaxis: | KeepAlive On|Off |
Valor por defecto: | KeepAlive On |
Contexto: | server config, virtual host |
Estado: | Core |
Módulo: | 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.
Descripción: | Amount of time the server will wait for subsequent requests on a persistent connection |
---|---|
Sintaxis: | KeepAliveTimeout num[ms] |
Valor por defecto: | KeepAliveTimeout 5 |
Contexto: | server config, virtual host |
Estado: | Core |
Módulo: | core |
Compatibilidad: | Specifying a value in milliseconds is available in Apache httpd 2.3.2 and later |
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.
In a name-based virtual host context, the value of the first
defined virtual host (the default host) in a set of NameVirtualHost
will be used.
The other values will be ignored.
Descripción: | Restrict enclosed access controls to only certain HTTP methods |
---|---|
Sintaxis: | <Limit method [method] ... > ...
</Limit> |
Contexto: | directory, .htaccess |
Prevalece sobre: | AuthConfig, Limit |
Estado: | Core |
Módulo: | 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
<Limit>
section.
The purpose of the <Limit>
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 <Limit>
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:
<Limit POST PUT DELETE>
Require valid-user
</Limit>
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
).
<LimitExcept>
section should always be
used in preference to a <Limit>
section when restricting access, since a <LimitExcept>
section provides protection
against arbitrary methods.The <Limit>
and
<LimitExcept>
directives may be nested. In this case, each successive level of
<Limit>
or <LimitExcept>
directives must
further restrict the set of methods to which access controls apply.
<Limit>
or
<LimitExcept>
directives with
the Require
directive,
note that the first Require
to succeed authorizes the request, regardless of the presence of other
Require
directives.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:
<LimitExcept GET>
Require valid-user
</LimitExcept>
<Limit POST>
Require group editors
</Limit>
Descripción: | Restrict access controls to all HTTP methods except the named ones |
---|---|
Sintaxis: | <LimitExcept method [method] ... > ...
</LimitExcept> |
Contexto: | directory, .htaccess |
Prevalece sobre: | AuthConfig, Limit |
Estado: | Core |
Módulo: | core |
<LimitExcept>
and
</LimitExcept>
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 <Limit>
section and can be used to control
both standard and nonstandard/unrecognized methods. See the
documentation for <Limit>
for more details.
For example:
<LimitExcept POST GET>
Require valid-user
</LimitExcept>
Descripción: | Determine maximum number of internal redirects and nested subrequests |
---|---|
Sintaxis: | LimitInternalRecursion number [number] |
Valor por defecto: | LimitInternalRecursion 10 |
Contexto: | server config, virtual host |
Estado: | Core |
Módulo: | core |
Compatibilidad: | Available in Apache httpd 2.0.47 and later |
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 deep subrequests may be nested. If you specify only one number, it will be assigned to both limits.
LimitInternalRecursion 5
Descripción: | Restricts the total size of the HTTP request body sent from the client |
---|---|
Sintaxis: | LimitRequestBody bytes |
Valor por defecto: | LimitRequestBody 0 |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | All |
Estado: | Core |
Módulo: | core |
This directive specifies the number of bytes from 0 (meaning unlimited) to 2147483647 (2GB) that are allowed in a request body. See the note below for the limited applicability to proxy requests.
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:
LimitRequestBody 102400
For a full description of how this directive is interpreted by
proxy requests, see the mod_proxy
documentation.
Descripción: | Limits the number of HTTP request header fields that will be accepted from the client |
---|---|
Sintaxis: | LimitRequestFields number |
Valor por defecto: | LimitRequestFields 100 |
Contexto: | server config, virtual host |
Estado: | Core |
Módulo: | core |
Number is an integer from 0 (meaning unlimited) to
32767. 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.
For example:
LimitRequestFields 50
When name-based virtual hosting is used, the value for this
directive is taken from the default (first-listed) virtual host for the
NameVirtualHost
the connection was mapped to.
Descripción: | Limits the size of the HTTP request header allowed from the client |
---|---|
Sintaxis: | LimitRequestFieldSize bytes |
Valor por defecto: | LimitRequestFieldSize 8190 |
Contexto: | server config, virtual host |
Estado: | Core |
Módulo: | 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 reduce or increase 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.
For example:
LimitRequestFieldSize 4094
When name-based virtual hosting is used, the value for this
directive is taken from the default (first-listed) virtual host for the
NameVirtualHost
the connection was mapped to.
Descripción: | Limit the size of the HTTP request line that will be accepted from the client |
---|---|
Sintaxis: | LimitRequestLine bytes |
Valor por defecto: | LimitRequestLine 8190 |
Contexto: | server config, virtual host |
Estado: | Core |
Módulo: | 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 reduce or increase 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.
For example:
LimitRequestLine 4094
When name-based virtual hosting is used, the value for this
directive is taken from the default (first-listed) virtual host for the
NameVirtualHost
the connection was mapped to.
Descripción: | Limits the size of an XML-based request body |
---|---|
Sintaxis: | LimitXMLRequestBody bytes |
Valor por defecto: | LimitXMLRequestBody 1000000 |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | All |
Estado: | Core |
Módulo: | core |
Limit (in bytes) on maximum size of an XML-based request
body. A value of 0
will disable any checking.
Example:
LimitXMLRequestBody 0
Descripción: | Applies the enclosed directives only to matching URLs |
---|---|
Sintaxis: | <Location
URL-path|URL> ... </Location> |
Contexto: | server config, virtual host |
Estado: | Core |
Módulo: | core |
The <Location>
directive
limits the scope of the enclosed directives by URL. It is similar to the
<Directory>
directive, and starts a subsection which is terminated with a
</Location>
directive. <Location>
sections are processed in the
order they appear in the configuration file, after the <Directory>
sections and
.htaccess
files are read, and after the <Files>
sections.
<Location>
sections operate
completely outside the filesystem. This has several consequences.
Most importantly, <Location>
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:
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.
<Location /private1>
...
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.
<Location /private2/>
...
<Location>
Use <Location>
to apply
directives to content that lives outside the filesystem. For
content that lives in the filesystem, use <Directory>
and <Files>
. An exception is
<Location />
, 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:
<Location ~ "/(extra|special)/data">
would match URLs that contained the substring /extra/data
or /special/data
. The directive <LocationMatch>
behaves
identical to the regex version of <Location>
, and is preferred, for the
simple reason that ~
is hard to distinguish from
-
in many fonts.
The <Location>
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:
<Location /status>
SetHandler server-status
Require host example.com
</Location>
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.
The <LocationMatch>
directive and the regex version of <Location>
require you to explicitly specify multiple
slashes if that is your intention.
For example, <LocationMatch ^/abc>
would match
the request URL /abc
but not the request URL
//abc
. The (non-regex) <Location>
directive behaves similarly when used for
proxy requests. But when (non-regex) <Location>
is used for non-proxy requests it will
implicitly match multiple slashes with a single slash. For example,
if you specify <Location /abc/def>
and the
request is to /abc//def
then it will match.
LocationMatch
Descripción: | Applies the enclosed directives only to regular-expression matching URLs |
---|---|
Sintaxis: | <LocationMatch
regex> ... </LocationMatch> |
Contexto: | server config, virtual host |
Estado: | Core |
Módulo: | core |
The <LocationMatch>
directive
limits the scope of the enclosed directives by URL, in an identical manner
to <Location>
. However,
it takes a regular expression
as an argument instead of a simple string. For example:
<LocationMatch "/(extra|special)/data">
would match URLs that contained the substring /extra/data
or /special/data
.
Descripción: | Controls the verbosity of the ErrorLog |
---|---|
Sintaxis: | LogLevel [module:]level
[module:level] ...
|
Valor por defecto: | LogLevel warn |
Contexto: | server config, virtual host, directory |
Estado: | Core |
Módulo: | core |
Compatibilidad: | 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
levels 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.
For example:
LogLevel notice
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:
LogLevel info ssl:warn
LogLevel info mod_ssl.c:warn
LogLevel info ssl_module:warn
It is also possible to change the level per directory:
LogLevel info
<Directory /usr/local/apache/htdocs/app>
LogLevel debug
</Files>
Descripción: | Number of requests allowed on a persistent connection |
---|---|
Sintaxis: | MaxKeepAliveRequests number |
Valor por defecto: | MaxKeepAliveRequests 100 |
Contexto: | server config, virtual host |
Estado: | Core |
Módulo: | 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.
For example:
MaxKeepAliveRequests 500
Descripción: | Number of overlapping ranges (eg: 100-200,150-300 ) allowed before returning the complete
resource |
---|---|
Sintaxis: | MaxRangeOverlaps default | unlimited | none | number-of-ranges |
Valor por defecto: | MaxRangeOverlaps 20 |
Contexto: | server config, virtual host, directory |
Estado: | Core |
Módulo: | core |
Compatibilidad: | Available in Apache HTTP Server 2.3.15 and later |
The documentation for this directive has not been translated yet. Please have a look at the English version.
Descripción: | Number of range reversals (eg: 100-200,50-70 ) allowed before returning the complete
resource |
---|---|
Sintaxis: | MaxRangeReversals default | unlimited | none | number-of-ranges |
Valor por defecto: | MaxRangeReversals 20 |
Contexto: | server config, virtual host, directory |
Estado: | Core |
Módulo: | core |
Compatibilidad: | Available in Apache HTTP Server 2.3.15 and later |
The documentation for this directive has not been translated yet. Please have a look at the English version.
Descripción: | Number of ranges allowed before returning the complete resource |
---|---|
Sintaxis: | MaxRanges default | unlimited | none | number-of-ranges |
Valor por defecto: | MaxRanges 200 |
Contexto: | server config, virtual host, directory |
Estado: | Core |
Módulo: | core |
Compatibilidad: | Available in Apache HTTP Server 2.3.15 and later |
The documentation for this directive has not been translated yet. Please have a look at the English version.
Descripción: | Configures mutex mechanism and lock file directory for all or specified mutexes |
---|---|
Sintaxis: | Mutex mechanism [default|mutex-name] ... [OmitPID] |
Valor por defecto: | Mutex default |
Contexto: | server config |
Estado: | Core |
Módulo: | core |
Compatibilidad: | 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 first argument to change the settings for all mutexes; specify
a mutex name (see table below) as the first argument to override
defaults only for that mutex.
The Mutex
directive is typically used in
the following exceptional situations:
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:
default | yes
This selects the default locking implementation, as determined by
APR. The default locking implementation can
be displayed by running httpd
with the
-V
option.
none | no
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.
posixsem
This is a mutex variant based on a Posix semaphore.
The semaphore ownership is not recovered if a thread in the process holding the mutex segfaults, resulting in a hang of the web server.
sysvsem
This is a mutex variant based on a SystemV IPC semaphore.
It is possible to "leak" SysV semaphores if processes crash before the semaphore is removed.
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
).
sem
This selects the "best" available semaphore implementation, choosing between Posix and SystemV IPC semaphores, in that order.
pthread
This is a mutex variant based on cross-process Posix thread mutexes.
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 is a notable exception as it provides a mechanism which usually allows the mutex to be recovered after a child process terminates abnormally while holding a mutex.
If your system implements the
pthread_mutexattr_setrobust_np()
function, you may be able
to use the pthread
option safely.
fcntl:/path/to/mutex
This is a mutex variant where a physical (lock-)file and the
fcntl()
function are used as the mutex.
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.
flock:/path/to/mutex
This is similar to the fcntl:/path/to/mutex
method
with the exception that the flock()
function is used to
provide file locking.
file:/path/to/mutex
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 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
.
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
.
Mutex default sysvsem
Mutex mpm-accept fcntl:/var/httpd/locks
Descripción: | Designates an IP address for name-virtual hosting |
---|---|
Sintaxis: | NameVirtualHost addr[:port] |
Contexto: | server config |
Estado: | Core |
Módulo: | core |
A single NameVirtualHost
directive
identifies a set of identical virtual hosts on which the server will
further select from on the basis of the hostname
requested by the client. The NameVirtualHost
directive is a required directive if you want to configure
name-based virtual hosts.
This directive, and the corresponding VirtualHost
,
must be qualified with a port number if the server supports both HTTP
and HTTPS connections.
Although addr can be a hostname, it is recommended that you always use an IP address or a wildcard. A wildcard NameVirtualHost matches only virtualhosts that also have a literal wildcard as their argument.
In cases where a firewall or other proxy receives the requests and forwards them on a different IP address to the server, you must specify the IP address of the physical interface on the machine which will be servicing the requests.
In the example below, requests received on interface 192.0.2.1 and port 80 will only select among the first two virtual hosts. Requests received on port 80 on any other interface will only select among the third and fourth virtual hosts. In the common case where the interface isn't important to the mapping, only the "*:80" NameVirtualHost and VirtualHost directives are necessary.
NameVirtualHost 192.0.2.1:80
NameVirtualHost *:80
<VirtualHost 192.0.2.1:80>
ServerName namebased-a.example.com
</VirtualHost>
<VirtualHost 192.0.2.1:80>
Servername namebased-b.example.com
</VirtualHost>
<VirtualHost *:80>
ServerName namebased-c.example.com
</VirtualHost>
<VirtualHost *:80>
ServerName namebased-d.example.com
</VirtualHost>
If no matching virtual host is found, then the first listed virtual host that matches the IP address and port will be used.
IPv6 addresses must be enclosed in square brackets, as shown in the following example:
NameVirtualHost [2001:db8::a00:20ff:fea7:ccea]:8080
<VirtualHost>
directiveNote that the argument to the <VirtualHost>
directive must
exactly match the argument to the NameVirtualHost
directive.
NameVirtualHost 192.0.2.2:80
<VirtualHost 192.0.2.2:80>
# ...
</VirtualHost>
Descripción: | Configures what features are available in a particular directory |
---|---|
Sintaxis: | Options
[+|-]option [[+|-]option] ... |
Valor por defecto: | Options All |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | Options |
Estado: | Core |
Módulo: | core |
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
MultiViews
. This is the default
setting.ExecCGI
mod_cgi
is permitted.FollowSymLinks
Even though the server follows the symlink it does not
change the pathname used to match against <Directory>
sections.
Note also, that this option gets ignored if set
inside a <Location>
section.
Omitting this option should not be considered a security restriction, since symlink testing is subject to race conditions that make it circumventable.
Includes
mod_include
are permitted.IncludesNOEXEC
#exec
cmd
and #exec cgi
are disabled. It is still
possible to #include virtual
CGI scripts from
ScriptAlias
ed
directories.Indexes
DirectoryIndex
(e.g., index.html
) in that directory, then
mod_autoindex
will return a formatted listing
of the directory.MultiViews
mod_negotiation
.
This option gets ignored if set
anywhere other than <Directory>
, as mod_negotiation
needs real resources to compare against and evaluate from.
SymLinksIfOwnerMatch
This option gets ignored if
set inside a <Location>
section.
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 is likely
to cause unexpected results.
For example, without any +
and -
symbols:
<Directory /web/docs>
Options Indexes FollowSymLinks
</Directory>
<Directory /web/docs/spec>
Options Includes
</Directory>
then only Includes
will be set for the
/web/docs/spec
directory. However if the second
Options
directive uses the +
and
-
symbols:
<Directory /web/docs>
Options Indexes FollowSymLinks
</Directory>
<Directory /web/docs/spec>
Options +Includes -Indexes
</Directory>
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
All
.
Descripción: | Protocol for a listening socket |
---|---|
Sintaxis: | Protocol protocol |
Contexto: | server config, virtual host |
Estado: | Core |
Módulo: | core |
Compatibilidad: | 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.
You only need to set the protocol if you are running on non-standard ports, otherwise http
is assumed for port 80 and https
for port 443.
For example, if you are running https
on a non-standard port, specify the protocol explicitly:
Protocol https
You can also specify the protocol using the Listen
directive.
AcceptFilter
Listen
Descripción: | Limits the CPU consumption of processes launched by Apache httpd children |
---|---|
Sintaxis: | RLimitCPU seconds|max [seconds|max] |
Valor por defecto: | Unset; uses operating system defaults |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | All |
Estado: | Core |
Módulo: | 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 off 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 off from the Apache httpd parent such as piped logs.
CPU resource limits are expressed in seconds per process.
Descripción: | Limits the memory consumption of processes launched by Apache httpd children |
---|---|
Sintaxis: | RLimitMEM bytes|max [bytes|max] |
Valor por defecto: | Unset; uses operating system defaults |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | All |
Estado: | Core |
Módulo: | 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 off 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 off from the Apache httpd parent such as piped logs.
Memory resource limits are expressed in bytes per process.
Descripción: | Limits the number of processes that can be launched by processes launched by Apache httpd children |
---|---|
Sintaxis: | RLimitNPROC number|max [number|max] |
Valor por defecto: | Unset; uses operating system defaults |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | All |
Estado: | Core |
Módulo: | 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 off 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 off 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
.
Descripción: | Technique for locating the interpreter for CGI scripts |
---|---|
Sintaxis: | ScriptInterpreterSource Registry|Registry-Strict|Script |
Valor por defecto: | ScriptInterpreterSource Script |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | FileInfo |
Estado: | Core |
Módulo: | core |
Compatibilidad: | Win32 only;
option Registry-Strict is available in Apache HTTP Server 2.0 and
later |
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:
#!C:/Perl/bin/perl.exe
or, if perl
is in the PATH
, simply:
#!perl
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
Shell\ExecCGI\Command
or, if it does not exist, by the subkey
Shell\Open\Command
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.
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
which is new in Apache HTTP Server
2.0 does the same thing as Registry
but uses only the
subkey Shell\ExecCGI\Command
. 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.
Descripción: | 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. |
---|---|
Sintaxis: | SeeRequestTail On|Off |
Valor por defecto: | SeeRequestTail Off |
Contexto: | server config |
Estado: | Core |
Módulo: | core |
Compatibilidad: | 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 1st 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 |
Descripción: | Email address that the server includes in error messages sent to the client |
---|---|
Sintaxis: | ServerAdmin email-address|URL |
Contexto: | server config, virtual host |
Estado: | Core |
Módulo: | 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.
ServerAdmin www-admin@foo.example.com
as users do not always mention that they are talking about the server!
Descripción: | Alternate names for a host used when matching requests to name-virtual hosts |
---|---|
Sintaxis: | ServerAlias hostname [hostname] ... |
Contexto: | virtual host |
Estado: | Core |
Módulo: | 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.
<VirtualHost *:80>
ServerName server.domain.com
ServerAlias server server2.domain.com server2
ServerAlias *.example.com
UseCanonicalName Off
# ...
</VirtualHost>
Descripción: | Hostname and port that the server uses to identify itself |
---|---|
Sintaxis: | ServerName [scheme://]fully-qualified-domain-name[:port] |
Contexto: | server config, virtual host |
Estado: | Core |
Módulo: | core |
The ServerName
directive sets the
request scheme, hostname and
port that the server uses to identify itself. This is used when
creating redirection URLs.
Additionally, ServerName
is used (possibly
in conjunction with ServerAlias
) to uniquely
identify a virtual host, when using name-based virtual hosts.
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:
ServerName www.example.com:80
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, then the
server attempts to deduce the hostname by performing a reverse
lookup on the IP address. 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
<VirtualHost>
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.
httpd: Could not reliably determine the server's fully qualified domain name, using rocinante.local for ServerName
Descripción: | Legacy URL pathname for a name-based virtual host that is accessed by an incompatible browser |
---|---|
Sintaxis: | ServerPath URL-path |
Contexto: | virtual host |
Estado: | Core |
Módulo: | core |
The ServerPath
directive sets the legacy
URL pathname for a host, for use with name-based virtual hosts.
Descripción: | Base directory for the server installation |
---|---|
Sintaxis: | ServerRoot directory-path |
Valor por defecto: | ServerRoot /usr/local/apache |
Contexto: | server config |
Estado: | Core |
Módulo: | core |
The ServerRoot
directive sets the
directory in which the server lives. Typically it will contain the
subdirectories conf/
and logs/
. Relative
paths in other configuration directives (such as Include
or LoadModule
, for example) are taken as
relative to this directory.
ServerRoot /home/httpd
-d
option to httpd
ServerRoot
Descripción: | Configures the footer on server-generated documents |
---|---|
Sintaxis: | ServerSignature On|Off|EMail |
Valor por defecto: | ServerSignature Off |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | All |
Estado: | Core |
Módulo: | core |
The ServerSignature
directive allows the
configuration of a trailing footer line under server-generated
documents (error messages, mod_proxy
ftp directory
listings, mod_info
output, ...). The reason why you
would want to enable such a footer line is that in a chain of proxies,
the user often has no possibility to tell which of the chained servers
actually produced a returned error message.
The Off
setting, which is the default, suppresses the footer line (and is
therefore compatible with the behavior of Apache-1.2 and
below). The On
setting simply adds a line with the
server version number and ServerName
of the serving virtual host,
and the EMail
setting additionally creates a
"mailto:" reference to the ServerAdmin
of the referenced
document.
After version 2.0.44, the details of the server version number
presented are controlled by the ServerTokens
directive.
Descripción: | Configures the Server HTTP response
header |
---|---|
Sintaxis: | ServerTokens Major|Minor|Min[imal]|Prod[uctOnly]|OS|Full |
Valor por defecto: | ServerTokens Full |
Contexto: | server config |
Estado: | Core |
Módulo: | core |
This directive controls whether Server
response
header field which is sent back to clients includes a
description of the generic OS-type of the server as well as
information about compiled-in modules.
ServerTokens Full
(or not specified)Server: Apache/2.4.1
(Unix) PHP/4.2.2 MyMod/1.2
ServerTokens Prod[uctOnly]
Server:
Apache
ServerTokens Major
Server:
Apache/2
ServerTokens Minor
Server:
Apache/2.4
ServerTokens Min[imal]
Server:
Apache/2.4.1
ServerTokens OS
Server: Apache/2.4.1
(Unix)
This setting applies to the entire server, and cannot be enabled or disabled on a virtualhost-by-virtualhost basis.
After version 2.0.44, this directive also controls the
information presented by the ServerSignature
directive.
ServerTokens
to less than
minimal
is not recommended because it makes it more
difficult to debug interoperational problems. Also note that
disabling the Server: header does nothing at all to make your
server more secure; the idea of "security through obscurity"
is a myth and leads to a false sense of safety.Descripción: | Forces all matching files to be processed by a handler |
---|---|
Sintaxis: | SetHandler handler-name|None |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | FileInfo |
Estado: | Core |
Módulo: | core |
Compatibilidad: | Moved into the core in Apache httpd 2.0 |
When placed into an .htaccess
file or a
<Directory>
or
<Location>
section, this directive forces all matching files to be parsed
through the handler given by
handler-name. For example, if you had a directory you
wanted to be parsed entirely as imagemap rule files, regardless
of extension, you might put the following into an
.htaccess
file in that directory:
SetHandler imap-file
Another example: if you wanted to have the server display a
status report whenever a URL of
http://servername/status
was called, you might put
the following into httpd.conf
:
<Location /status>
SetHandler server-status
</Location>
You can override an earlier defined SetHandler
directive by using the value None
.
Note: because SetHandler overrides default handlers, normal behaviour such as handling of URLs ending in a slash (/) as directories or index files is suppressed.
Descripción: | Sets the filters that will process client requests and POST input |
---|---|
Sintaxis: | SetInputFilter filter[;filter...] |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | FileInfo |
Estado: | Core |
Módulo: | core |
The SetInputFilter
directive sets the
filter or filters which will process client requests and POST
input when they are received by the server. This is in addition to
any filters defined elsewhere, including the
AddInputFilter
directive.
If more than one filter is specified, they must be separated by semicolons in the order in which they should process the content.
Descripción: | Sets the filters that will process responses from the server |
---|---|
Sintaxis: | SetOutputFilter filter[;filter...] |
Contexto: | server config, virtual host, directory, .htaccess |
Prevalece sobre: | FileInfo |
Estado: | Core |
Módulo: | core |
The SetOutputFilter
directive sets the filters
which will process responses from the server before they are
sent to the client. This is in addition to any filters defined
elsewhere, including the
AddOutputFilter
directive.
For example, the following configuration will process all files
in the /www/data/
directory for server-side
includes.
<Directory /www/data/>
SetOutputFilter INCLUDES
</Directory>
If more than one filter is specified, they must be separated by semicolons in the order in which they should process the content.
Descripción: | Amount of time the server will wait for certain events before failing a request |
---|---|
Sintaxis: | TimeOut seconds |
Valor por defecto: | TimeOut 60 |
Contexto: | server config, virtual host |
Estado: | Core |
Módulo: | core |
The TimeOut
directive defines the length
of time Apache httpd will wait for I/O in various circumstances:
mod_cgi
, the length of time to wait for
output from a CGI script.mod_ext_filter
, the length of time to
wait for output from a filtering process.mod_proxy
, the default timeout value if
ProxyTimeout
is not
configured.Descripción: | Determines the behaviour on TRACE requests |
---|---|
Sintaxis: | TraceEnable [on|off|extended] |
Valor por defecto: | TraceEnable on |
Contexto: | server config |
Estado: | Core |
Módulo: | core |
Compatibilidad: | Available in Apache HTTP Server 1.3.34, 2.0.55 and later |
This directive overrides the behavior of TRACE
for both
the core server and mod_proxy
. The default
TraceEnable on
permits TRACE
requests per
RFC 2616, which disallows any request body to accompany the request.
TraceEnable off
causes the core server and
mod_proxy
to return a 405
(Method not
allowed) error to the client.
Finally, for testing and diagnostic purposes only, request
bodies may be allowed using the non-compliant TraceEnable
extended
directive. The core (as an origin server) will
restrict the request body to 64k (plus 8k for chunk headers if
Transfer-Encoding: chunked
is used). The core will
reflect the full headers and all chunk headers with the response
body. As a proxy server, the request body is not restricted to 64k.
Descripción: | Undefine the existence of a variable |
---|---|
Sintaxis: | UnDefine parameter-name |
Contexto: | server config |
Estado: | Core |
Módulo: | core |
Undoes the effect of a Define
or
of passing a -D
argument to httpd
.
This directive can be used to toggle the use of <IfDefine>
sections without needing to alter
-D
arguments in any startup scripts.
Descripción: | Configures how the server determines its own name and port |
---|---|
Sintaxis: | UseCanonicalName On|Off|DNS |
Valor por defecto: | UseCanonicalName Off |
Contexto: | server config, virtual host, directory |
Estado: | Core |
Módulo: | core |
In many situations Apache httpd must construct a self-referential
URL -- that is, a URL that refers back to the same server. With
UseCanonicalName On
Apache httpd will use the hostname and port
specified in the ServerName
directive to construct the canonical name for the server. This name
is used in all self-referential URLs, and for the values of
SERVER_NAME
and SERVER_PORT
in CGIs.
With UseCanonicalName Off
Apache httpd will form
self-referential URLs using the hostname and port supplied by
the client if any are supplied (otherwise it will use the
canonical name, as defined above). These values are the same
that are used to implement name-based virtual hosts,
and are available with the same clients. The CGI variables
SERVER_NAME
and SERVER_PORT
will be
constructed from the client supplied values as well.
An example where this may be useful is on an intranet server
where you have users connecting to the machine using short
names such as www
. You'll notice that if the users
type a shortname, and a URL which is a directory, such as
http://www/splat
, without the trailing
slash then Apache httpd will redirect them to
http://www.domain.com/splat/
. If you have
authentication enabled, this will cause the user to have to
authenticate twice (once for www
and once again
for www.domain.com
-- see the
FAQ on this subject for more information). But if
UseCanonicalName
is set Off
, then
Apache httpd will redirect to http://www/splat/
.
There is a third option, UseCanonicalName DNS
,
which is intended for use with mass IP-based virtual hosting to
support ancient clients that do not provide a
Host:
header. With this option Apache httpd does a
reverse DNS lookup on the server IP address that the client
connected to in order to work out self-referential URLs.
If CGIs make assumptions about the values of SERVER_NAME
they may be broken by this option. The client is essentially free
to give whatever value they want as a hostname. But if the CGI is
only using SERVER_NAME
to construct self-referential URLs
then it should be just fine.
Descripción: | Configures how the server determines its own name and port |
---|---|
Sintaxis: | UseCanonicalPhysicalPort On|Off |
Valor por defecto: | UseCanonicalPhysicalPort Off |
Contexto: | server config, virtual host, directory |
Estado: | Core |
Módulo: | core |
In many situations Apache httpd must construct a self-referential
URL -- that is, a URL that refers back to the same server. With
UseCanonicalPhysicalPort On
Apache httpd will, when
constructing the canonical port for the server to honor
the UseCanonicalName
directive,
provide the actual physical port number being used by this request
as a potential port. With UseCanonicalPhysicalPort Off
Apache httpd will not ever use the actual physical port number, instead
relying on all configured information to construct a valid port number.
The ordering of when the physical port is used is as follows:
UseCanonicalName On
Servername
UseCanonicalName Off | DNS
Host:
headerServername
With UseCanonicalPhysicalPort Off
, the
physical ports are removed from the ordering.
Descripción: | Contains directives that apply only to a specific hostname or IP address |
---|---|
Sintaxis: | <VirtualHost
addr[:port] [addr[:port]]
...> ... </VirtualHost> |
Contexto: | server config |
Estado: | Core |
Módulo: | core |
<VirtualHost>
and
</VirtualHost>
are used to enclose a group of
directives that will apply only to a particular virtual host. Any
directive that is allowed in a virtual host context may be
used. When the server receives a request for a document on a
particular virtual host, it uses the configuration directives
enclosed in the <VirtualHost>
section. Addr can be:
*
, which is used only in combination with
NameVirtualHost *
to match all IP addresses; or_default_
, which is used only
with IP virtual hosting to catch unmatched IP addresses.
<VirtualHost 10.1.2.3>
ServerAdmin webmaster@host.example.com
DocumentRoot /www/docs/host.example.com
ServerName host.example.com
ErrorLog logs/host.example.com-error_log
TransferLog logs/host.example.com-access_log
</VirtualHost>
IPv6 addresses must be specified in square brackets because the optional port number could not be determined otherwise. An IPv6 example is shown below:
<VirtualHost [2001:db8::a00:20ff:fea7:ccea]>
ServerAdmin webmaster@host.example.com
DocumentRoot /www/docs/host.example.com
ServerName host.example.com
ErrorLog logs/host.example.com-error_log
TransferLog logs/host.example.com-access_log
</VirtualHost>
Each Virtual Host must correspond to a different IP address,
different port number or a different host name for the server,
in the former case the server machine must be configured to
accept IP packets for multiple addresses. (If the machine does
not have multiple network interfaces, then this can be
accomplished with the ifconfig alias
command -- if
your OS supports it).
The use of <VirtualHost>
does
not affect what addresses Apache httpd listens on. You
may need to ensure that Apache httpd is listening on the correct addresses
using Listen
.
When using IP-based virtual hosting, the special name
_default_
can be specified in
which case this virtual host will match any IP address that is
not explicitly listed in another virtual host. In the absence
of any _default_
virtual host the "main" server config,
consisting of all those definitions outside any VirtualHost
section, is used when no IP-match occurs.
You can specify a :port
to change the port that is
matched. If unspecified then it defaults to the same port as the
most recent Listen
statement of the main server. You may also specify :*
to match all ports on that address. (This is recommended when used
with _default_
.)
A ServerName
should be
specified inside each <VirtualHost>
block. If it is absent, the
ServerName
from the "main"
server configuration will be inherited.
If no matching virtual host is found, then the first listed virtual host that matches the IP address will be used. As a consequence, the first listed virtual host is the default virtual host.
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.