Description:	HTTP/1.1 proxy/gateway server
Status:	Extension
Source File:	mod_proxy.c

Description:	Ports that are allowed to CONNECT through -the proxy
Syntax:	`AllowCONNECT port [port] ...`
Default:	`AllowCONNECT 443 563`
Context:	server config, virtual host
Description:	Add a member to a load balancing group
Syntax:	`BalancerMember [balancerurl] url [key=value [key=value ...]]`
Context:	directory
Status:	Extension
Module:	mod_proxy
Compatibility:	BalancerMember is only available in Apache 2.2 + and later.

The AllowCONNECT directive specifies a list -of port numbers to which the proxy CONNECT method may -connect. Today's browsers use this method when a https -connection is requested and proxy tunneling over http is in -effect.
By default, only the default https port (443) and the -default snews port (563) are enabled. Use the -AllowCONNECT directive to overrride this default and -allow connections to the listed ports only.

+

This directive adds a member to a load balancing group. It could be used + within a <Proxy balancer://...> container + directive, and can take any of the key value pair parameters available to + ProxyPass directives.

+

One additional parameter is available only to BalancerMember directives: + loadfactor. This is the member load factor - a number between 1 + (default) and 100, which defines the weighted load to be applied to the + member in question.

+

The balancerurl is only needed when not in <Proxy balancer://...> + container directive. It corresponds to the url of a balancer defined in + ProxyPass directive.

NoProxy Directive

- - + +

Description:	Hosts, domains, or networks that will be connected -to directly
Syntax:	`NoProxy host [host] ...`
Description:	Hosts, domains, or networks that will be connected to +directly
Syntax:	`NoProxy host [host] ...`
Context:	server config, virtual host
Status:	Extension
Module:	mod_proxy

-

This directive is only useful for Apache proxy servers within -intranets. The NoProxy directive specifies a -list of subnets, IP addresses, hosts and/or domains, separated by -spaces. A request to a host which matches one or more of these is -always served directly, without forwarding to the configured -ProxyRemote proxy server(s).

- -

Example

- ProxyRemote * http://firewall.mycompany.com:81 - NoProxy .mycompany.com 192.168.112.0/21 -

- -

The host arguments to the NoProxy directive are one of the -following type list:

-

Hostname: +
A Hostname is a fully qualified DNS domain name which can + be resolved to one or more IPAddrs via the + DNS domain name service. It represents a logical host (in contrast to + Domains, see above) and must be resolvable + to at least one IPAddr (or often to a list + of hosts with different IPAddrs).
+ +
Examples
+ prep.ai.example.com + www.apache.org +
+ +
Note
+
In many situations, it is more effective to specify an IPAddr in place of a Hostname since a + DNS lookup can be avoided. Name resolution in Apache can take a remarkable + deal of time when the connection to the name server uses a slow PPP + link.
+
Hostname comparisons are done without regard to the case, + and Hostnames are always assumed to be anchored in the root + of the DNS tree, therefore two hosts WWW.ExAmple.com + and www.example.com. (note the trailing period) are + considered equal.
+

<Proxy> Directive

- - + +

Description:	Container for directives applied to proxied -resources
Syntax:	`<Proxy wildcard-url> ...</Proxy>`
Description:	Container for directives applied to proxied resources
Syntax:	`<Proxy wildcard-url> ...</Proxy>`
Context:	server config, virtual host
Status:	Extension
Module:	mod_proxy

-

Directives placed in <Proxy> -sections apply only to matching proxied content. Shell-style -wildcards are allowed.

- -

For example, the following will allow only hosts in -yournetwork.example.com to access content via your -proxy server:

- -

-<Proxy *> - Order Deny,Allow - Deny from all - Allow from yournetwork.example.com -</Proxy> -

- -

The following example will process all files in the -foo directory of example.com through the -INCLUDES filter when they are sent through the proxy -server:

-

-<Proxy http://example.com/foo/*> - SetOutputFilter INCLUDES -</Proxy> -

+

Directives placed in <Proxy> + sections apply only to matching proxied content. Shell-style wildcards are + allowed.

+ +

For example, the following will allow only hosts in + yournetwork.example.com to access content via your proxy + server:

+ +

+ <Proxy *> + + Order Deny,Allow + Deny from all + Allow from yournetwork.example.com + + </Proxy> +

+ +

The following example will process all files in the foo + directory of example.com through the INCLUDES + filter when they are sent through the proxy server:

+ +

+ <Proxy http://example.com/foo/*> + + SetOutputFilter INCLUDES + + </Proxy> +

+ +

ProxyBadHeader Directive

@@ -475,24 +528,26 @@ response Context:server config, virtual host Status:Extension Module:mod_proxy -Compatibility:available in Apache 2.0.44 and later +Compatibility:Available in Apache 2.0.44 and later -

The ProxyBadHeader directive determines the behaviour -of mod_proxy if it receives syntactically invalid header lines -(i.e. containing no colon). The following arguments are possible:

-

IsError: Abort the request and end up with a 502 (Bad Gateway) response. This is the -default behaviour.
Ignore: Treat bad header lines as if they weren't sent.
StartBody: When receiving the first bad header line, finish reading the headers and -treat the remainder as body. This helps to work around buggy backend servers -which forget to insert an empty line between the headers and the body.

+

The ProxyBadHeader directive determines the + behaviour of mod_proxy if it receives syntactically invalid + header lines (i.e. containing no colon). The following arguments + are possible:

+ +

IsError: Abort the request and end up with a 502 (Bad Gateway) response. This is + the default behaviour.
Ignore: Treat bad header lines as if they weren't sent.
StartBody: When receiving the first bad header line, finish reading the headers and + treat the remainder as body. This helps to work around buggy backend servers + which forget to insert an empty line between the headers and the body.

Description:	Words, hosts, or domains that are banned from being proxied
Syntax:	`ProxyBlock *\|word\|host\|domain -[word\|host\|domain] ...`
Syntax:	`ProxyBlock *\|word\|host\|domain +[word\|host\|domain] ...`
Context:	server config, virtual host
Status:	Extension
Module:	mod_proxy

The ProxyBlock directive specifies a list of -words, hosts and/or domains, separated by spaces. HTTP, HTTPS, and -FTP document requests to sites whose names contain matched words, -hosts or domains are blocked by the proxy server. The proxy -module will also attempt to determine IP addresses of list items which -may be hostnames during startup, and cache them for match test as -well. Example:

- ProxyBlock joes-garage.com some-host.co.uk rocky.wotsamattau.edu -

The ProxyBlock directive specifies a list of + words, hosts and/or domains, separated by spaces. HTTP, HTTPS, and + FTP document requests to sites whose names contain matched words, + hosts or domains are blocked by the proxy server. The proxy + module will also attempt to determine IP addresses of list items which + may be hostnames during startup, and cache them for match test as + well. That may slow down the startup time of the server.

'rocky.wotsamattau.edu' would also be matched if referenced by IP -address.

Example

+ ProxyBlock joes-garage.com some-host.co.uk rocky.wotsamattau.edu +

Note that 'wotsamattau' would also be sufficient to match -'wotsamattau.edu'.

rocky.wotsamattau.edu would also be matched if referenced by + IP address.

Note also that

Note that wotsamattau would also be sufficient to match + wotsamattau.edu.

-ProxyBlock * -

Note also that

blocks connections to all sites.

+ ProxyBlock * +

blocks connections to all sites.

ProxyDomain Directive

- +

Description:	Default domain name for proxied requests
Syntax:	`ProxyDomain Domain`
Syntax:	`ProxyDomain Domain`
Context:	server config, virtual host
Status:	Extension
Module:	mod_proxy

-

This directive is only useful for Apache proxy servers within -intranets. The ProxyDomain directive specifies -the default domain which the apache proxy server will belong to. If a -request to a host without a domain name is encountered, a redirection -response to the same host with the configured Domain appended -will be generated.

- -

Example

- ProxyRemote * http://firewall.mycompany.com:81 - NoProxy .mycompany.com 192.168.112.0/21 - ProxyDomain .mycompany.com -

+

This directive is only useful for Apache proxy servers within + intranets. The ProxyDomain directive specifies + the default domain which the apache proxy server will belong to. If a + request to a host without a domain name is encountered, a redirection + response to the same host with the configured Domain appended + will be generated.

+ +

Example

+ ProxyRemote * http://firewall.example.com:81 + NoProxy .example.com 192.168.112.0/21 + ProxyDomain .example.com +

@@ -568,25 +622,42 @@ will be generated.

Module:mod_proxy Compatibility:Available in version 2.0 and later -

This directive is useful for reverse-proxy setups, where you want to -have a common look and feel on the error pages seen by the end user. -This also allows for included files (via mod_include's SSI) to get -the error code and act accordingly (default behavior would display -the error page of the proxied server, turning this on shows the SSI -Error message).

+

This directive is useful for reverse-proxy setups, where you want to + have a common look and feel on the error pages seen by the end user. + This also allows for included files (via + mod_include's SSI) to get + the error code and act accordingly (default behavior would display + the error page of the proxied server, turning this on shows the SSI + Error message).

+ +

This directive does not affect the processing of informational (1xx), + normal success (2xx), or redirect (3xx) responses.

ProxyIOBufferSize Directive

- - + + +

Description:	IO buffer size for outgoing HTTP and FTP -connections
Syntax:	`ProxyIOBufferSize bytes`
Description:	Determine size of internal data throughput buffer
Syntax:	`ProxyIOBufferSize bytes`
Default:	`ProxyIOBufferSize 8192`
Context:	server config, virtual host
Status:	Extension
Module:	mod_proxy

- +

The ProxyIOBufferSize directive adjusts the size + of the internal buffer, which is used as a scratchpad for the data between + input and output. The size must be at least 512.

+ +

In almost every case there's no reason to change that value.

+

If used with AJP this directive sets the maximum AJP packet size in + bytes. If you change it from the default, you must also change the + packetSize attribute of your AJP connector on the + Tomcat side! The attribute packetSize is only available + in Tomcat 5.5.20+ and 6.0.2+

+

Normally it is not necessary to change the maximum packet size. + Problems with the default value have been reported when sending + certificates or certificate chains.

+

Description:	Container for directives applied to regular-expression-matched proxied resources
Syntax:	`<ProxyMatch regex> ...</ProxyMatch>`
Syntax:	`<ProxyMatch regex> ...</ProxyMatch>`
Context:	server config, virtual host
Status:	Extension
Module:	mod_proxy

ProxyMaxForwards Directive

- - + + - +

Description:	Maximium number of proxies that a request can be forwarded through
Syntax:	`ProxyMaxForwards number`
Default:	`ProxyMaxForwards 10`
Syntax:	`ProxyMaxForwards number`
Default:	`ProxyMaxForwards -1`
Context:	server config, virtual host
Status:	Extension
Module:	mod_proxy
Compatibility:	Available in Apache 2.0 and later
Compatibility:	Available in Apache 2.0 and later; + default behaviour changed in 2.2.7/2.3

-

The ProxyMaxForwards directive specifies the -maximum number of proxies through which a request may pass. This is -set to prevent infinite proxy loops, or a DoS attack.

- -

Example

- ProxyMaxForwards 10 -

+

The ProxyMaxForwards directive specifies the + maximum number of proxies through which a request may pass, if there's no + Max-Forwards header supplied with the request. This may + be set to prevent infinite proxy loops, or a DoS attack.

+ +

Example

+ ProxyMaxForwards 15 +

+ +

Note that setting ProxyMaxForwards is a + violation of the HTTP/1.1 protocol (RFC2616), which forbids a Proxy + setting Max-Forwards if the Client didn't set it. + Earlier Apache versions would always set it. A negative + ProxyMaxForwards value, including the + default -1, gives you protocol-compliant behaviour, but may + leave you open to loops.

ProxyPass Directive

- - - + + +

Description:	Maps remote servers into the local server -URL-space
Syntax:	`ProxyPass [path] !\|url`
Context:	server config, virtual host
Description:	Maps remote servers into the local server URL-space
Syntax:	`ProxyPass [path] !\|url [key=value + [key=value ...]] [nocanon] [interpolate]`
Context:	server config, virtual host, directory
Status:	Extension
Module:	mod_proxy

-

This directive allows remote servers to be mapped into the space of -the local server; the local server does not act as a proxy in the -conventional sense, but appears to be a mirror of the remote -server. path is the name of a local virtual path; -url is a partial URL for the remote server and cannot -include a query string.

- -

Suppose the local server has address http://wibble.org/; -then

-

- ProxyPass /mirror/foo/ http://foo.com/ -

-

will cause a local request for the -<http://wibble.org/mirror/foo/bar> to be -internally converted into a proxy request to -<http://foo.com/bar>.

-

-The ! directive is useful in situations where you don't want to reverse-proxy -a subdirectory. eg.

-

- ProxyPass /mirror/foo/i ! - ProxyPass /mirror/foo http://foo.com -

-

will proxy all requests to /mirror/foo to foo.com EXCEPT requests made to /mirror/foo/i

- -

NB: order is important. you need to put the exclusions BEFORE the general proxypass directive

- -

When used inside a <Location> section, the first argument is -ommitted and the local directory is obtained from the <Location>.

- -

If you require a more flexible reverse-proxy configuration, see -the RewriteRule directive -with the [P] flag.

+

This directive allows remote servers to be mapped into the + space of the local server; the local server does not act as a + proxy in the conventional sense, but appears to be a mirror of the + remote server. The local server is often called a reverse + proxy or gateway. The path is the name of + a local virtual path; url is a partial URL for the + remote server and cannot include a query string.

+ +

The ProxyRequests directive should + usually be set off when using + ProxyPass.

+ +

Suppose the local server has address http://example.com/; + then

+ +

+ ProxyPass /mirror/foo/ http://backend.example.com/ +

+ +

will cause a local request for + http://example.com/mirror/foo/bar to be internally converted + into a proxy request to http://backend.example.com/bar.

+ +

+

If the first argument ends with a trailing /, the second + argument should also end with a trailing / and vice + versa. Otherwise the resulting requests to the backend may miss some + needed slashes and do not deliver the expected results. +

+

+ +

The ! directive is useful in situations where you don't want + to reverse-proxy a subdirectory, e.g.

+ +

+ ProxyPass /mirror/foo/i ! + ProxyPass /mirror/foo http://backend.example.com +

+ +

will proxy all requests to /mirror/foo to + backend.example.com except requests made to + /mirror/foo/i.

+ +

Note

+

Order is important: exclusions must come before the + general ProxyPass directive.

+

+ +

As of Apache 2.1, the ability to use pooled connections to a backend + server is available. Using the key=value parameters it is + possible to tune this connection pooling. The default for a Hard + Maximum for the number of connections is the number of threads per + process in the active MPM. In the Prefork MPM, this is always 1, while with + the Worker MPM it is controlled by the + ThreadsPerChild.

+ +

Setting min will determine how many connections will always + be open to the backend server. Upto the Soft Maximum or smax + number of connections will be created on demand. Any connections above + smax are subject to a time to live or ttl. Apache + will never create more than the Hard Maximum or max connections + to the backend server.

+ +

+ ProxyPass /example http://backend.example.com smax=5 max=20 ttl=120 retry=300 +

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

Parameter	Default	Description
min	0	Minimum number of connections that will always + be open to the backend server.
max	1...n	Hard Maximum number of connections that will be + allowed to the backend server. The default for a Hard Maximum + for the number of connections is the number of threads per process in the + active MPM. In the Prefork MPM, this is always 1, while with the Worker MPM + it is controlled by the `ThreadsPerChild`. + Apache will never create more than the Hard Maximum connections + to the backend server.
smax	max	Upto the Soft Maximum + number of connections will be created on demand. Any connections above + `smax` are subject to a time to live or `ttl`. +
acquire	-	If set this will be the maximum time to wait for a free + connection in the connection pool, in milliseconds. If there are no free + connections in the pool the Apache will return `SERVER_BUSY` + status to the client. +
connectiontimeout	timeout	Connect timeout in seconds. + The number of seconds Apache waits for the creation of a connection to + the backend to complete. By adding a postfix of ms the timeout can be + also set in milliseconds. +
disablereuse	Off	This parameter should be used when you want to force mod_proxy + to immediately close a connection to the backend after being used, and + thus, disable its persistent connection and pool for that backend. + This helps in various situations where a firewall between Apache and + the backend server (regardless of protocol) tends to silently + drop connections or when backends themselves may be under round- + robin DNS. To disable connection pooling reuse, + set this property value to `On`. +
flushpackets	off	Determines whether the proxy module will auto-flush the output + brigade after each "chunk" of data. 'off' means that it will flush + only when needed, 'on' means after each chunk is sent and + 'auto' means poll/wait for a period of time and flush if + no input has been received for 'flushwait' milliseconds. + Currently this is in effect only for AJP. +
flushwait	10	The time to wait for additional input, in milliseconds, before + flushing the output brigade if 'flushpackets' is 'auto'. +
iobuffersize	8192	Adjusts the size of the internal scratchpad IO buffer. This allows you + to override the `ProxyIOBufferSize` for a specific worker. + This must be at least 512 or set to 0 for the system default of 8192. +
keepalive	Off	This parameter should be used when you have a firewall between your + Apache and the backend server, who tend to drop inactive connections. + This flag will tell the Operating System to send `KEEP_ALIVE` + messages on inactive connections (interval depends on global OS settings, + generally 120ms), and thus prevent the firewall to drop the connection. + To enable keepalive set this property value to `On`. +
lbset	0	Sets the load balancer cluster set that the worker is a member + of. The load balancer will try all members of a lower numbered + lbset before trying higher numbered ones. +
ping	0	Ping property tells webserver to send a `CPING` + request on ajp13 connection before forwarding a request. + The parameter is the delay in seconds to wait for the + `CPONG` reply. + This features has been added to avoid problem with hung and + busy Tomcat's and require ajp13 ping/pong support which has + been implemented on Tomcat 3.3.2+, 4.1.28+ and 5.0.13+. + This will increase the network traffic during the normal operation + which could be an issue, but it will lower the + traffic in case some of the cluster nodes are down or busy. + Currently this has an effect only for AJP. + By adding a postfix of ms the delay can be also set in + milliseconds. +
receivebuffersize	0	Adjusts the size of the explicit (TCP/IP) network buffer size for + proxied connections. This allows you to override the + `ProxyReceiveBufferSize` for a specific worker. + This must be at least 512 or set to 0 for the system default. +
redirect	-	Redirection Route of the worker. This value is usually + set dynamically to enable safe removal of the node from + the cluster. If set all requests without session id will be + redirected to the BalancerMember that has route parametar + equal as this value. +
retry	60	Connection pool worker retry timeout in seconds. + If the connection pool worker to the backend server is in the error state, + Apache will not forward any requests to that server until the timeout + expires. This enables to shut down the backend server for maintenance, + and bring it back online later. A value of 0 means always retry workers + in an error state with no timeout. +
route	-	Route of the worker when used inside load balancer. + The route is a value appended to session id. +
status	-	Single letter value defining the initial status of + this worker: 'D' is disabled, 'S' is stopped, 'I' is ignore-errors, + 'H' is hot-standby and 'E' is in an error state. Status + can be set (which is the default) by prepending with '+' or + cleared by prepending with '-'. + Thus, a setting of 'S-E' sets this worker to Stopped and + clears the in-error flag. +
timeout	`ProxyTimeout`	Connection timeout in seconds. + The number of seconds Apache waits for data sent by / to the backend. +
ttl	-	Time To Live for the inactive connections above the + `smax` connections in seconds. Apache will close all + connections that has not been used inside that time period. +

+ +

If the Proxy directive scheme starts with the + balancer:// (eg: balancer://cluster/, + any path information is ignored) then a virtual worker that does not really + communicate with the backend server will be created. Instead it is responsible + for the management of several "real" workers. In that case the special set of + parameters can be add to this virtual worker. See mod_proxy_balancer + for more information about how the balancer works. +

+ + + + + + + + + + + + + + + + + + + + + + + +

Parameter	Default	Description
lbmethod	byrequests	Balancer load-balance method. Select the load-balancing scheduler + method to use. Either `byrequests`, to perform weighted + request counting, `bytraffic`, to perform weighted + traffic byte count balancing, or `bybusyness`, to perform + pending request balancing. Default is `byrequests`. +
maxattempts	1	Maximum number of failover attempts before giving up. +
nofailover	Off	If set to `On` the session will break if the worker is in + error state or disabled. Set this value to On if backend servers do not + support session replication. +
stickysession	-	Balancer sticky session name. The value is usually set to something + like `JSESSIONID` or `PHPSESSIONID`, + and it depends on the backend application server that support sessions. + If the backend application server uses different name for cookies + and url encoded id (like servlet containers) use \| to to separate them. + The first part is for the cookie the second for the path. +
scolonpathdelim	Off	If set to `On` the semi-colon character ';' will be + used as an additional sticky session path deliminator/separator. This + is mainly used to emulate mod_jk's behavior when dealing with paths such + as `JSESSIONID=6736bcf34;foo=aabfa` +
timeout	0	Balancer timeout in seconds. If set this will be the maximum time + to wait for a free worker. Default is not to wait. +

+

A sample balancer setup

+

+ ProxyPass /special-area http://special.example.com smax=5 max=10 + ProxyPass / balancer://mycluster/ stickysession=JSESSIONID|jsessionid nofailover=On + <Proxy balancer://mycluster> + + BalancerMember http://1.2.3.4:8009 + BalancerMember http://1.2.3.5:8009 smax=10 + # Less powerful server, don't send as many requests there + BalancerMember http://1.2.3.6:8009 smax=1 loadfactor=20 + + </Proxy> +

+ +

Setting up a hot-standby, that will only be used if no other + members are available

+

+ ProxyPass / balancer://hotcluster/ + <Proxy balancer://hotcluster> + + BalancerMember http://1.2.3.4:8009 loadfactor=1 + BalancerMember http://1.2.3.5:8009 loadfactor=2 + # The below is the hot standby + BalancerMember http://1.2.3.6:8009 status=+H + ProxySet lbmethod=bytraffic + + </Proxy> +

+ +

Normally, mod_proxy will canonicalise ProxyPassed URLs. + But this may be incompatible with some backends, particularly those + that make use of PATH_INFO. The optional nocanon + keyword suppresses this, and passes the URL path "raw" to the + backend. Note that may affect the security of your backend, as it + removes the normal limited protection against URL-based attacks + provided by the proxy.

+ +

The optional interpolate keyword (available in + httpd 2.2.9 and later), in combination with + ProxyPassInterpolateEnv causes the ProxyPass + to interpolate environment variables, using the syntax + ${VARNAME}. Note that many of the standard CGI-derived + environment variables will not exist when this interpolation happens, + so you may still have to resort to mod_rewrite + for complex rules.

+ +

When used inside a <Location> section, the first argument is omitted and the local + directory is obtained from the <Location>.

+ +

If you require a more flexible reverse-proxy configuration, see the + RewriteRule directive with the + [P] flag.

+

ProxyPassInterpolateEnv Directive

+ + + + + + + + +

Description:	Enable Environment Variable interpolation in Reverse Proxy configurations
Syntax:	`ProxyPassInterpolateEnv On\|Off`
Default:	`ProxyPassInterpolateEnv Off`
Context:	server config, virtual host, directory
Status:	Extension
Module:	mod_proxy
Compatibility:	Available in httpd 2.2.9 and later

+

This directive, together with the interpolate argument to + ProxyPass, ProxyPassReverse, + ProxyPassReverseCookieDomain and + ProxyPassReverseCookiePath + enables reverse proxies to be dynamically + configured using environment variables, which may be set by + another module such as mod_rewrite. + It affects the ProxyPass, + ProxyPassReverse, + ProxyPassReverseCookieDomain, and + ProxyPassReverseCookiePath directives, + and causes them to substitute the value of an environment + variable varname for the string ${varname} + in configuration directives.

+

Keep this turned off (for server performance) unless you need it!

+ +

ProxyPassMatch Directive

+ + + + + + +

Description:	Maps remote servers into the local server URL-space using regular expressions
Syntax:	`ProxyPassMatch [regex] !\|url [key=value + [key=value ...]]`
Context:	server config, virtual host, directory
Status:	Extension
Module:	mod_proxy

+

This directive is equivalent to ProxyPass, + but makes use of regular expressions, instead of simple prefix matching. The + supplied regular expression is matched against the url, and if it + matches, the server will substitute any parenthesized matches into the given + string and use it as a new url.

+ +

Suppose the local server has address http://example.com/; + then

+ +

+ ProxyPassMatch ^(/.*\.gif)$ http://backend.example.com$1 +

+ +

will cause a local request for + http://example.com/foo/bar.gif to be internally converted + into a proxy request to http://backend.example.com/foo/bar.gif.

+

Note

+

The URL argument must be parsable as a URL before regexp + substitutions (as well as after). This limits the matches you can use. + For instance, if we had used

+

+ ProxyPassMatch ^(/.*\.gif)$ http://backend.example.com:8000$1 +

+

in our previous example, it would fail with a syntax error + at server startup. This is a bug (PR 46665 in the ASF bugzilla), + and the workaround is to reformulate the match:

+

+ ProxyPassMatch ^/(.*\.gif)$ http://backend.example.com:8000/$1 +

+

The ! directive is useful in situations where you don't want + to reverse-proxy a subdirectory.

ProxyPassReverse Directive

- - - + + +

Description:	Adjusts the URL in HTTP response headers sent from -a reverse proxied server
Syntax:	`ProxyPassReverse [path] url`
Context:	server config, virtual host
Description:	Adjusts the URL in HTTP response headers sent from a reverse +proxied server
Syntax:	`ProxyPassReverse [path] url +[interpolate]`
Context:	server config, virtual host, directory
Status:	Extension
Module:	mod_proxy

-

This directive lets Apache adjust the URL in the Location, -Content-Location and URI headers on -HTTP redirect responses. This is essential when Apache is used as -a reverse proxy to avoid by-passing the reverse proxy because of HTTP -redirects on the backend servers which stay behind the reverse proxy.

- -

path is the name of a local virtual path.
-url is a partial URL for the remote server - the same way they are -used for the ProxyPass directive.

- -

-Example:
-Suppose the local server has address http://wibble.org/; then

-

- ProxyPass /mirror/foo/ http://foo.com/ - ProxyPassReverse /mirror/foo/ http://foo.com/ -

-

will not only cause a local request for the -<http://wibble.org/mirror/foo/bar> to be internally -converted into a proxy request to <http://foo.com/bar> (the -functionality ProxyPass provides here). It also takes care of -redirects the server foo.com sends: when http://foo.com/bar is -redirected by him to http://foo.com/quux Apache adjusts this to -http://wibble.org/mirror/foo/quux before forwarding the HTTP -redirect response to the client. Note that the hostname used for -constructing the URL is chosen in respect to the setting of the -UseCanonicalName directive.

-

-Note that this ProxyPassReverse directive can -also be used in conjunction with the proxy pass-through feature -("RewriteRule ... [P]") from -mod_rewrite because its doesn't depend on a -corresponding ProxyPass -directive.

- -

When used inside a <Location> section, the first argument is -ommitted and the local directory is obtained from the <Location>.

+

This directive lets Apache adjust the URL in the Location, + Content-Location and URI headers on HTTP + redirect responses. This is essential when Apache is used as a + reverse proxy (or gateway) to avoid by-passing the reverse proxy + because of HTTP redirects on the backend servers which stay behind + the reverse proxy.

+ +

Only the HTTP response headers specifically mentioned above + will be rewritten. Apache will not rewrite other response + headers, nor will it rewrite URL references inside HTML pages. + This means that if the proxied content contains absolute URL + references, they will by-pass the proxy. A third-party module + that will look inside the HTML and rewrite URL references is Nick + Kew's mod_proxy_html.

+ +

path is the name of a local virtual path. url is a + partial URL for the remote server - the same way they are used for the + ProxyPass directive.

+ +

For example, suppose the local server has address + http://example.com/; then

+ +

+ ProxyPass /mirror/foo/ http://backend.example.com/ + ProxyPassReverse /mirror/foo/ http://backend.example.com/ + ProxyPassReverseCookieDomain backend.example.com public.example.com + ProxyPassReverseCookiePath / /mirror/foo/ +

+ +

will not only cause a local request for the + http://example.com/mirror/foo/bar to be internally converted + into a proxy request to http://backend.example.com/bar + (the functionality ProxyPass provides here). It also takes care + of redirects the server backend.example.com sends: when + http://backend.example.com/bar is redirected by him to + http://backend.example.com/quux Apache adjusts this to + http://example.com/mirror/foo/quux before forwarding the HTTP + redirect response to the client. Note that the hostname used for + constructing the URL is chosen in respect to the setting of the UseCanonicalName directive.

+ +

Note that this ProxyPassReverse directive can + also be used in conjunction with the proxy pass-through feature + (RewriteRule ... [P]) from mod_rewrite + because it doesn't depend on a corresponding ProxyPass directive.

+ +

The optional interpolate keyword (available in + httpd 2.2.9 and later), used together with + ProxyPassInterpolateEnv, enables interpolation + of environment variables specified using the format ${VARNAME}. +

+ +

When used inside a <Location> section, the first argument is omitted and the local + directory is obtained from the <Location>.

+

ProxyPassReverseCookieDomain Directive

+ + + + + + +

Description:	Adjusts the Domain string in Set-Cookie headers from a reverse- +proxied server
Syntax:	`ProxyPassReverseCookieDomain internal-domain +public-domain [interpolate]`
Context:	server config, virtual host, directory
Status:	Extension
Module:	mod_proxy

+

Usage is basically similar to +ProxyPassReverse, but instead of +rewriting headers that are a URL, this rewrites the domain +string in Set-Cookie headers.

+ +

ProxyPassReverseCookiePath Directive

+ + + + + + +

Description:	Adjusts the Path string in Set-Cookie headers from a reverse- +proxied server
Syntax:	`ProxyPassReverseCookiePath internal-path +public-path [interpolate]`
Context:	server config, virtual host, directory
Status:	Extension
Module:	mod_proxy

+

Usage is basically similar to +ProxyPassReverse, but instead of +rewriting headers that are a URL, this rewrites the path +string in Set-Cookie headers.

ProxyPreserveHost Directive

- - + + - + - +

Description:	Use incoming Host HTTP request header for -proxy request
Syntax:	`ProxyPreserveHost on\|off`
Description:	Use incoming Host HTTP request header for proxy +request
Syntax:	`ProxyPreserveHost On\|Off`
Default:	`ProxyPreserveHost Off`
Context:	server config, virtual host
Context:	server config, virtual host, directory
Status:	Extension
Module:	mod_proxy
Compatibility:	Available in -Apache 2.0.31 and later.
Compatibility:	Available in Apache 2.0.31 and later.

-

When enabled, this option will pass the Host: line from the -incoming request to the proxied host, instead of the hostname -specified in the proxypass line. -

-

This option should normally be turned 'off'.

+

When enabled, this option will pass the Host: line from the incoming + request to the proxied host, instead of the hostname specified in the + ProxyPass line.

+ +

This option should normally be turned Off. It is mostly + useful in special configurations like proxied mass name-based virtual + hosting, where the original Host header needs to be evaluated by the + backend server.

ProxyReceiveBufferSize Directive

- - + +

Description:	Network buffer size for outgoing HTTP and FTP +
Description:	Network buffer size for proxied HTTP and FTP connections
Syntax:	`ProxyReceiveBufferSize bytes`
Syntax:	`ProxyReceiveBufferSize bytes`
Default:	`ProxyReceiveBufferSize 0`
Context:	server config, virtual host
Status:	Extension
Module:	mod_proxy

-

The ProxyReceiveBufferSize directive -specifies an explicit network buffer size for outgoing HTTP and FTP -connections, for increased throughput. It has to be greater than 512 -or set to 0 to indicate that the system's default buffer size should -be used.

-

Example

- ProxyReceiveBufferSize 2048 -

+

The ProxyReceiveBufferSize directive specifies an + explicit (TCP/IP) network buffer size for proxied HTTP and FTP connections, + for increased throughput. It has to be greater than 512 or set + to 0 to indicate that the system's default buffer size should + be used.

+ +

Example

+ ProxyReceiveBufferSize 2048 +

ProxyRemote Directive

- +

Description:	Remote proxy used to handle certain requests
Syntax:	`ProxyRemote match remote-server`
Syntax:	`ProxyRemote match remote-server`
Context:	server config, virtual host
Status:	Extension
Module:	mod_proxy

-

This defines remote proxies to this proxy. match is either the -name of a URL-scheme that the remote server supports, or a partial URL -for which the remote server should be used, or '*' to indicate the -server should be contacted for all requests. remote-server is a -partial URL for the remote server. Syntax:

- -

-  remote-server = protocol://hostname[:port]
-

- -

protocol is the protocol that should be used to communicate -with the remote server; only "http" is supported by this module.

- -

-Example:

-

- ProxyRemote http://goodguys.com/ http://mirrorguys.com:8000 - ProxyRemote * http://cleversite.com - ProxyRemote ftp http://ftpproxy.mydomain.com:8080 -

- -

In the last example, the proxy will forward FTP requests, encapsulated -as yet another HTTP proxy request, to another proxy which can handle -them.

- -

This option also supports reverse proxy configuration - a backend -webserver can be embedded within a virtualhost URL space even if that -server is hidden by another forward proxy.

+

This defines remote proxies to this proxy. match is either the + name of a URL-scheme that the remote server supports, or a partial URL + for which the remote server should be used, or * to indicate + the server should be contacted for all requests. remote-server is + a partial URL for the remote server. Syntax:

+ +

+ remote-server = + scheme://hostname[:port] +

+ +

scheme is effectively the protocol that should be used to + communicate with the remote server; only http and https + are supported by this module. When using https, the requests + are forwarded through the remote proxy using the HTTP CONNECT method.

+ +

Example

+ ProxyRemote http://goodguys.example.com/ http://mirrorguys.example.com:8000 + ProxyRemote * http://cleverproxy.localdomain + ProxyRemote ftp http://ftpproxy.mydomain:8080 +

+ +

In the last example, the proxy will forward FTP requests, encapsulated + as yet another HTTP proxy request, to another proxy which can handle + them.

+ +

This option also supports reverse proxy configuration - a backend + webserver can be embedded within a virtualhost URL space even if that + server is hidden by another forward proxy.

ProxyRemoteMatch Directive

- - + +

Description:	Remote proxy used to handle requests -matched by regular expressions
Syntax:	`ProxyRemoteMatch regex remote-server`
Description:	Remote proxy used to handle requests matched by regular +expressions
Syntax:	`ProxyRemoteMatch regex remote-server`
Context:	server config, virtual host
Status:	Extension
Module:	mod_proxy

-

The ProxyRemoteMatch is identical -to the ProxyRemote -directive, except the first argument is a regular expression -match against the requested URL.

+

The ProxyRemoteMatch is identical to the + ProxyRemote directive, except the + first argument is a regular expression + match against the requested URL.

ProxyRequests Directive

- +

Description:	Enables forward (standard) proxy requests
Syntax:	`ProxyRequests on\|off`
Syntax:	`ProxyRequests On\|Off`
Default:	`ProxyRequests Off`
Context:	server config, virtual host
Status:	Extension
Module:	mod_proxy

-

This allows or prevents Apache from functioning as a forward proxy -server. (Setting ProxyRequests to 'off' does not disable use of the -ProxyPass directive.)

+

This allows or prevents Apache from functioning as a forward proxy + server. (Setting ProxyRequests to Off does not disable use of + the ProxyPass directive.)

+ +

In a typical reverse proxy or gateway configuration, this + option should be set to + Off.

+ +

In order to get the functionality of proxying HTTP or FTP sites, you + need also mod_proxy_http or mod_proxy_ftp + (or both) present in the server.

-

In a typical reverse proxy configuration, this option should be set to -'off'.

+

Warning

+

Do not enable proxying with ProxyRequests until you have secured your server. Open proxy servers are dangerous + both to your network and to the Internet at large.

+

-

Do not enable proxying with ProxyRequests until you have -secured your server. Open proxy servers are -dangerous both to your network and to the Internet at large.

+

ProxySet Directive

+ + + + + + + +

Description:	Set various Proxy balancer or member parameters
Syntax:	`ProxySet url key=value [key=value ...]`
Context:	directory
Status:	Extension
Module:	mod_proxy
Compatibility:	ProxySet is only available in Apache 2.2 + and later.

+

This directive is used as an alternate method of setting any of the + parameters available to Proxy balancers and workers normally done via the + ProxyPass directive. If used + within a <Proxy balancer url|worker url> + container directive, the url argument is not required. As a side + effect the respective balancer or worker gets created. This can be useful + when doing reverse proxying via a + RewriteRule instead of a + ProxyPass directive.

+ +

+ <Proxy balancer://hotcluster> + + BalancerMember http://www2.example.com:8009 loadfactor=1 + BalancerMember http://www3.example.com:8009 loadfactor=2 + ProxySet lbmethod=bytraffic + + </Proxy> +

+ +

+ <Proxy http://backend> + + ProxySet keepalive=On + + </Proxy> +

+ +

+ ProxySet balancer://foo lbmethod=bytraffic timeout=15 +

+ +

+ ProxySet ajp://backend:7001 timeout=15 +

+ +

Warning

+

Keep in mind that the same parameter key can have a different meaning + depending whether it is applied to a balancer or a worker as shown by the two + examples above regarding timeout.

+

+ + +

ProxyStatus Directive

+ + + + + + + + +

Description:	Show Proxy LoadBalancer status in mod_status
Syntax:	`ProxyStatus Off\|On\|Full`
Default:	`ProxyStatus Off`
Context:	server config, virtual host
Status:	Extension
Module:	mod_proxy
Compatibility:	Available in version 2.2 and later

+

This directive determines whether or not proxy + loadbalancer status data is displayed via the mod_status + server-status page.

+

Note

+

Full is synonymous with On

+

ProxyTimeout Directive

- - + + - +

Description:	Network timeout for proxied requests
Syntax:	`ProxyTimeout seconds`
Default:	`ProxyTimeout 300`
Syntax:	`ProxyTimeout seconds`
Default:	`Value of Timeout`
Context:	server config, virtual host
Status:	Extension
Module:	mod_proxy
Compatibility:	Available in -Apache 2.0.31 and later
Compatibility:	Available in Apache 2.0.31 and later

-

This directive allows a user to specifiy a timeout on proxy requests. -This is usefull when you have a slow/buggy appserver which hangs, -and you would rather just return a timeout and fail gracefully instead -of waiting however long it takes the server to return -

+

This directive allows a user to specifiy a timeout on proxy requests. + This is useful when you have a slow/buggy appserver which hangs, and you + would rather just return a timeout and fail gracefully instead of waiting + however long it takes the server to return.

ProxyVia Directive

- - - + +

Description:	Information provided in the Via HTTP response +
Description:	Information provided in the `Via` HTTP response header for proxied requests
Syntax:	`ProxyVia on\|off\|full\|block`
Default:	`ProxyVia off`
Syntax:	`ProxyVia On\|Off\|Full\|Block`
Default:	`ProxyVia Off`
Context:	server config, virtual host
Status:	Extension
Module:	mod_proxy

-

This directive controls the use of the Via: HTTP -header by the proxy. Its intended use is to control the flow of of -proxy requests along a chain of proxy servers. See RFC2068 (HTTP/1.1) -for an explanation of Via: header lines.

- -

If set -to off, which is the default, no special processing is -performed. If a request or reply contains a Via: header, -it is passed through unchanged.
If set to on, each -request and reply will get a Via: header line added for -the current host.
If set to full, each generated Via: header -line will additionally have the Apache server version shown as a -Via: comment field.
If set to block, every -proxy request will have all its Via: header lines -removed. No new Via: header will be generated.

+

This directive controls the use of the Via: HTTP + header by the proxy. Its intended use is to control the flow of + proxy requests along a chain of proxy servers. See RFC 2616 (HTTP/1.1), section + 14.45 for an explanation of Via: header lines.

+ +

If set to Off, which is the default, no special processing + is performed. If a request or reply contains a Via: header, + it is passed through unchanged.
If set to On, each request and reply will get a + Via: header line added for the current host.
If set to Full, each generated Via: header + line will additionally have the Apache server version shown as a + Via: comment field.
If set to Block, every proxy request will have all its + Via: header lines removed. No new Via: header will + be generated.

Apache Module mod_proxy

Summary

Warning

Warning

Directives

Topics

See also

Note

Forward Proxy

Reverse Proxy

Example

Example

Examples

Note

Example

Note

Examples

Note

See also

See also

Example

Example

Example

See also

Example

Example

Note

Note

Example

Example

Example

Warning

See also

Warning

Note