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16 <p class="apache">Apache HTTP Server Version 2.3</p>
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21 <div id="page-content">
22 <div id="preamble"><h1>Apache Module mod_proxy</h1>
24 <p><span>Available Languages: </span><a href="../en/mod/mod_proxy.html" title="English"> en </a> |
25 <a href="../fr/mod/mod_proxy.html" hreflang="fr" rel="alternate" title="Français"> fr </a> |
26 <a href="../ja/mod/mod_proxy.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a></p>
28 <table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>HTTP/1.1 proxy/gateway server</td></tr>
29 <tr><th><a href="module-dict.html#Status">Status:</a></th><td>Extension</td></tr>
30 <tr><th><a href="module-dict.html#ModuleIdentifier">Module Identifier:</a></th><td>proxy_module</td></tr>
31 <tr><th><a href="module-dict.html#SourceFile">Source File:</a></th><td>mod_proxy.c</td></tr></table>
34 <div class="warning"><h3>Warning</h3>
35 <p>Do not enable proxying with <code class="directive"><a href="#proxyrequests">ProxyRequests</a></code> until you have <a href="#access">secured your server</a>. Open proxy servers are dangerous both to your
36 network and to the Internet at large.</p>
39 <p>This module implements a proxy/gateway for Apache. It implements
40 proxying capability for <code>AJP13</code> (Apache JServe Protocol
41 version 1.3), <code>FTP</code>, <code>CONNECT</code> (for SSL),
42 <code>HTTP/0.9</code>, <code>HTTP/1.0</code>, and <code>HTTP/1.1</code>.
43 The module can be configured to connect to other proxy modules for these
44 and other protocols.</p>
46 <p>Apache's proxy features are divided into several modules in
47 addition to <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code>:
48 <code class="module"><a href="../mod/mod_proxy_http.html">mod_proxy_http</a></code>, <code class="module"><a href="../mod/mod_proxy_ftp.html">mod_proxy_ftp</a></code>,
49 <code class="module"><a href="../mod/mod_proxy_ajp.html">mod_proxy_ajp</a></code>, <code class="module"><a href="../mod/mod_proxy_balancer.html">mod_proxy_balancer</a></code>,
50 and <code class="module"><a href="../mod/mod_proxy_connect.html">mod_proxy_connect</a></code>. Thus, if you want to use
51 one or more of the particular proxy functions, load
52 <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> <em>and</em> the appropriate module(s)
53 into the server (either statically at compile-time or dynamically
54 via the <code class="directive"><a href="../mod/mod_so.html#loadmodule">LoadModule</a></code>
57 <p>In addition, extended features are provided by other modules.
58 Caching is provided by <code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code> and related
59 modules. The ability to contact remote servers using the SSL/TLS
60 protocol is provided by the <code>SSLProxy*</code> directives of
61 <code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code>. These additional modules will need
62 to be loaded and configured to take advantage of these features.</p>
64 <div id="quickview"><h3 class="directives">Directives</h3>
66 <li><img alt="" src="../images/down.gif" /> <a href="#allowconnect">AllowCONNECT</a></li>
67 <li><img alt="" src="../images/down.gif" /> <a href="#balancermember">BalancerMember</a></li>
68 <li><img alt="" src="../images/down.gif" /> <a href="#noproxy">NoProxy</a></li>
69 <li><img alt="" src="../images/down.gif" /> <a href="#proxy"><Proxy></a></li>
70 <li><img alt="" src="../images/down.gif" /> <a href="#proxybadheader">ProxyBadHeader</a></li>
71 <li><img alt="" src="../images/down.gif" /> <a href="#proxyblock">ProxyBlock</a></li>
72 <li><img alt="" src="../images/down.gif" /> <a href="#proxydomain">ProxyDomain</a></li>
73 <li><img alt="" src="../images/down.gif" /> <a href="#proxyerroroverride">ProxyErrorOverride</a></li>
74 <li><img alt="" src="../images/down.gif" /> <a href="#proxyftpdircharset">ProxyFtpDirCharset</a></li>
75 <li><img alt="" src="../images/down.gif" /> <a href="#proxyiobuffersize">ProxyIOBufferSize</a></li>
76 <li><img alt="" src="../images/down.gif" /> <a href="#proxymatch"><ProxyMatch></a></li>
77 <li><img alt="" src="../images/down.gif" /> <a href="#proxymaxforwards">ProxyMaxForwards</a></li>
78 <li><img alt="" src="../images/down.gif" /> <a href="#proxypass">ProxyPass</a></li>
79 <li><img alt="" src="../images/down.gif" /> <a href="#proxypassinterpolateenv">ProxyPassInterpolateEnv</a></li>
80 <li><img alt="" src="../images/down.gif" /> <a href="#proxypassmatch">ProxyPassMatch</a></li>
81 <li><img alt="" src="../images/down.gif" /> <a href="#proxypassreverse">ProxyPassReverse</a></li>
82 <li><img alt="" src="../images/down.gif" /> <a href="#proxypassreversecookiedomain">ProxyPassReverseCookieDomain</a></li>
83 <li><img alt="" src="../images/down.gif" /> <a href="#proxypassreversecookiepath">ProxyPassReverseCookiePath</a></li>
84 <li><img alt="" src="../images/down.gif" /> <a href="#proxypreservehost">ProxyPreserveHost</a></li>
85 <li><img alt="" src="../images/down.gif" /> <a href="#proxyreceivebuffersize">ProxyReceiveBufferSize</a></li>
86 <li><img alt="" src="../images/down.gif" /> <a href="#proxyremote">ProxyRemote</a></li>
87 <li><img alt="" src="../images/down.gif" /> <a href="#proxyremotematch">ProxyRemoteMatch</a></li>
88 <li><img alt="" src="../images/down.gif" /> <a href="#proxyrequests">ProxyRequests</a></li>
89 <li><img alt="" src="../images/down.gif" /> <a href="#proxyset">ProxySet</a></li>
90 <li><img alt="" src="../images/down.gif" /> <a href="#proxystatus">ProxyStatus</a></li>
91 <li><img alt="" src="../images/down.gif" /> <a href="#proxytimeout">ProxyTimeout</a></li>
92 <li><img alt="" src="../images/down.gif" /> <a href="#proxyvia">ProxyVia</a></li>
96 <li><img alt="" src="../images/down.gif" /> <a href="#forwardreverse">Forward Proxies and Reverse
97 Proxies/Gateways</a></li>
98 <li><img alt="" src="../images/down.gif" /> <a href="#examples">Basic Examples</a></li>
99 <li><img alt="" src="../images/down.gif" /> <a href="#access">Controlling access to your proxy</a></li>
100 <li><img alt="" src="../images/down.gif" /> <a href="#startup">Slow Startup</a></li>
101 <li><img alt="" src="../images/down.gif" /> <a href="#intranet">Intranet Proxy</a></li>
102 <li><img alt="" src="../images/down.gif" /> <a href="#envsettings">Protocol Adjustments</a></li>
103 <li><img alt="" src="../images/down.gif" /> <a href="#request-bodies">Request Bodies</a></li>
104 <li><img alt="" src="../images/down.gif" /> <a href="#x-headers">Reverse Proxy Request Headers</a></li>
105 </ul><h3>See also</h3>
107 <li><code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code></li>
108 <li><code class="module"><a href="../mod/mod_proxy_http.html">mod_proxy_http</a></code></li>
109 <li><code class="module"><a href="../mod/mod_proxy_ftp.html">mod_proxy_ftp</a></code></li>
110 <li><code class="module"><a href="../mod/mod_proxy_connect.html">mod_proxy_connect</a></code></li>
111 <li><code class="module"><a href="../mod/mod_proxy_balancer.html">mod_proxy_balancer</a></code></li>
112 <li><code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code></li>
114 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
115 <div class="section">
116 <h2><a name="forwardreverse" id="forwardreverse">Forward Proxies and Reverse
117 Proxies/Gateways</a></h2>
118 <p>Apache can be configured in both a <dfn>forward</dfn> and
119 <dfn>reverse</dfn> proxy (also known as <dfn>gateway</dfn>) mode.</p>
121 <p>An ordinary <dfn>forward proxy</dfn> is an intermediate
122 server that sits between the client and the <em>origin
123 server</em>. In order to get content from the origin server,
124 the client sends a request to the proxy naming the origin server
125 as the target and the proxy then requests the content from the
126 origin server and returns it to the client. The client must be
127 specially configured to use the forward proxy to access other
130 <p>A typical usage of a forward proxy is to provide Internet
131 access to internal clients that are otherwise restricted by a
132 firewall. The forward proxy can also use caching (as provided
133 by <code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code>) to reduce network usage.</p>
135 <p>The forward proxy is activated using the <code class="directive"><a href="#proxyrequests">ProxyRequests</a></code> directive. Because
136 forward proxies allow clients to access arbitrary sites through
137 your server and to hide their true origin, it is essential that
138 you <a href="#access">secure your server</a> so that only
139 authorized clients can access the proxy before activating a
142 <p>A <dfn>reverse proxy</dfn> (or <dfn>gateway</dfn>), by
143 contrast, appears to the client just like an ordinary web
144 server. No special configuration on the client is necessary.
145 The client makes ordinary requests for content in the name-space
146 of the reverse proxy. The reverse proxy then decides where to
147 send those requests, and returns the content as if it was itself
150 <p>A typical usage of a reverse proxy is to provide Internet
151 users access to a server that is behind a firewall. Reverse
152 proxies can also be used to balance load among several back-end
153 servers, or to provide caching for a slower back-end server.
154 In addition, reverse proxies can be used simply to bring
155 several servers into the same URL space.</p>
157 <p>A reverse proxy is activated using the <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive or the
158 <code>[P]</code> flag to the <code class="directive"><a href="../mod/mod_rewrite.html#rewriterule">RewriteRule</a></code> directive. It is
159 <strong>not</strong> necessary to turn <code class="directive"><a href="#proxyrequests">ProxyRequests</a></code> on in order to
160 configure a reverse proxy.</p>
161 </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
162 <div class="section">
163 <h2><a name="examples" id="examples">Basic Examples</a></h2>
165 <p>The examples below are only a very basic idea to help you
166 get started. Please read the documentation on the individual
169 <p>In addition, if you wish to have caching enabled, consult
170 the documentation from <code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code>.</p>
172 <div class="example"><h3>Forward Proxy</h3><p><code>
173 ProxyRequests On<br />
176 <Proxy *><br />
177 <span class="indent">
178 Order deny,allow<br />
180 Allow from internal.example.com<br />
185 <div class="example"><h3>Reverse Proxy</h3><p><code>
186 ProxyRequests Off<br />
188 <Proxy *><br />
189 <span class="indent">
190 Order deny,allow<br />
195 ProxyPass /foo http://foo.example.com/bar<br />
196 ProxyPassReverse /foo http://foo.example.com/bar
198 </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
199 <div class="section">
200 <h2><a name="access" id="access">Controlling access to your proxy</a></h2>
201 <p>You can control who can access your proxy via the <code class="directive"><a href="#proxy"><Proxy></a></code> control block as in
202 the following example:</p>
204 <div class="example"><p><code>
205 <Proxy *><br />
206 <span class="indent">
207 Order Deny,Allow<br />
209 Allow from 192.168.0<br />
214 <p>For more information on access control directives, see
215 <code class="module"><a href="../mod/mod_authz_host.html">mod_authz_host</a></code>.</p>
217 <p>Strictly limiting access is essential if you are using a
218 forward proxy (using the <code class="directive"><a href="#proxyrequests">ProxyRequests</a></code> directive).
219 Otherwise, your server can be used by any client to access
220 arbitrary hosts while hiding his or her true identity. This is
221 dangerous both for your network and for the Internet at large.
222 When using a reverse proxy (using the <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive with
223 <code>ProxyRequests Off</code>), access control is less
224 critical because clients can only contact the hosts that you
225 have specifically configured.</p>
227 <p><strong>See Also</strong> the <a href="mod_proxy_http.html#env">Proxy-Chain-Auth</a> environment variable.</p>
229 </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
230 <div class="section">
231 <h2><a name="startup" id="startup">Slow Startup</a></h2>
232 <p>If you're using the <code class="directive"><a href="#proxyblock">ProxyBlock</a></code> directive, hostnames' IP addresses are looked up
233 and cached during startup for later match test. This may take a few
234 seconds (or more) depending on the speed with which the hostname lookups
236 </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
237 <div class="section">
238 <h2><a name="intranet" id="intranet">Intranet Proxy</a></h2>
239 <p>An Apache proxy server situated in an intranet needs to forward
240 external requests through the company's firewall (for this, configure
241 the <code class="directive"><a href="#proxyremote">ProxyRemote</a></code> directive
242 to forward the respective <var>scheme</var> to the firewall proxy).
243 However, when it has to
244 access resources within the intranet, it can bypass the firewall when
245 accessing hosts. The <code class="directive"><a href="#noproxy">NoProxy</a></code>
246 directive is useful for specifying which hosts belong to the intranet and
247 should be accessed directly.</p>
249 <p>Users within an intranet tend to omit the local domain name from their
250 WWW requests, thus requesting "http://somehost/" instead of
251 <code>http://somehost.example.com/</code>. Some commercial proxy servers
252 let them get away with this and simply serve the request, implying a
253 configured local domain. When the <code class="directive"><a href="#proxydomain">ProxyDomain</a></code> directive is used and the server is <a href="#proxyrequests">configured for proxy service</a>, Apache can return
254 a redirect response and send the client to the correct, fully qualified,
255 server address. This is the preferred method since the user's bookmark
256 files will then contain fully qualified hosts.</p>
257 </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
258 <div class="section">
259 <h2><a name="envsettings" id="envsettings">Protocol Adjustments</a></h2>
260 <p>For circumstances where <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> is sending
261 requests to an origin server that doesn't properly implement
262 keepalives or HTTP/1.1, there are two <a href="../env.html">environment variables</a> that can force the
263 request to use HTTP/1.0 with no keepalive. These are set via the
264 <code class="directive"><a href="../mod/mod_env.html#setenv">SetEnv</a></code> directive.</p>
266 <p>These are the <code>force-proxy-request-1.0</code> and
267 <code>proxy-nokeepalive</code> notes.</p>
269 <div class="example"><p><code>
270 <Location /buggyappserver/><br />
271 <span class="indent">
272 ProxyPass http://buggyappserver:7001/foo/<br />
273 SetEnv force-proxy-request-1.0 1<br />
274 SetEnv proxy-nokeepalive 1<br />
279 </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
280 <div class="section">
281 <h2><a name="request-bodies" id="request-bodies">Request Bodies</a></h2>
283 <p>Some request methods such as POST include a request body.
284 The HTTP protocol requires that requests which include a body
285 either use chunked transfer encoding or send a
286 <code>Content-Length</code> request header. When passing these
287 requests on to the origin server, <code class="module"><a href="../mod/mod_proxy_http.html">mod_proxy_http</a></code>
288 will always attempt to send the <code>Content-Length</code>. But
289 if the body is large and the original request used chunked
290 encoding, then chunked encoding may also be used in the upstream
291 request. You can control this selection using <a href="../env.html">environment variables</a>. Setting
292 <code>proxy-sendcl</code> ensures maximum compatibility with
293 upstream servers by always sending the
294 <code>Content-Length</code>, while setting
295 <code>proxy-sendchunked</code> minimizes resource usage by using
296 chunked encoding.</p>
298 </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
299 <div class="section">
300 <h2><a name="x-headers" id="x-headers">Reverse Proxy Request Headers</a></h2>
302 <p>When acting in a reverse-proxy mode (using the <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive, for example),
303 <code class="module"><a href="../mod/mod_proxy_http.html">mod_proxy_http</a></code> adds several request headers in
304 order to pass information to the origin server. These headers
308 <dt><code>X-Forwarded-For</code></dt>
309 <dd>The IP address of the client.</dd>
310 <dt><code>X-Forwarded-Host</code></dt>
311 <dd>The original host requested by the client in the <code>Host</code>
312 HTTP request header.</dd>
313 <dt><code>X-Forwarded-Server</code></dt>
314 <dd>The hostname of the proxy server.</dd>
317 <p>Be careful when using these headers on the origin server, since
318 they will contain more than one (comma-separated) value if the
319 original request already contained one of these headers. For
320 example, you can use <code>%{X-Forwarded-For}i</code> in the log
321 format string of the origin server to log the original clients IP
322 address, but you may get more than one address if the request
323 passes through several proxies.</p>
325 <p>See also the <code class="directive"><a href="#proxypreservehost">ProxyPreserveHost</a></code> and <code class="directive"><a href="#proxyvia">ProxyVia</a></code> directives, which control
326 other request headers.</p>
329 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
330 <div class="directive-section"><h2><a name="AllowCONNECT" id="AllowCONNECT">AllowCONNECT</a> <a name="allowconnect" id="allowconnect">Directive</a></h2>
331 <table class="directive">
332 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Ports that are allowed to <code>CONNECT</code> through the
334 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AllowCONNECT <var>port</var> [<var>port</var>] ...</code></td></tr>
335 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AllowCONNECT 443 563</code></td></tr>
336 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
337 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
338 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
340 <p>The <code class="directive">AllowCONNECT</code> directive specifies a list
341 of port numbers to which the proxy <code>CONNECT</code> method may
342 connect. Today's browsers use this method when a <code>https</code>
343 connection is requested and proxy tunneling over HTTP is in effect.</p>
345 <p>By default, only the default https port (<code>443</code>) and the
346 default snews port (<code>563</code>) are enabled. Use the
347 <code class="directive">AllowCONNECT</code> directive to override this default and
348 allow connections to the listed ports only.</p>
350 <p>Note that you'll need to have <code class="module"><a href="../mod/mod_proxy_connect.html">mod_proxy_connect</a></code> present
351 in the server in order to get the support for the <code>CONNECT</code> at
355 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
356 <div class="directive-section"><h2><a name="BalancerMember" id="BalancerMember">BalancerMember</a> <a name="balancermember" id="balancermember">Directive</a></h2>
357 <table class="directive">
358 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Add a member to a load balancing group</td></tr>
359 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>BalancerMember [<var>balancerurl</var>] <var>url</var> [<var>key=value [key=value ...]]</var></code></td></tr>
360 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory</td></tr>
361 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
362 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
363 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>BalancerMember is only available in Apache 2.2
366 <p>This directive adds a member to a load balancing group. It could be used
367 within a <code><Proxy <var>balancer://</var>...></code> container
368 directive, and can take any of the key value pair parameters available to
369 <code class="directive"><a href="#proxypass">ProxyPass</a></code> directives.</p>
370 <p>One additional parameter is available only to <code class="directive"><a href="#balancermember">BalancerMember</a></code> directives:
371 <var>loadfactor</var>. This is the member load factor - a number between 1
372 (default) and 100, which defines the weighted load to be applied to the
373 member in question.</p>
374 <p>The balancerurl is only needed when not in <code><Proxy <var>balancer://</var>...></code>
375 container directive. It corresponds to the url of a balancer defined in
376 <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive.</p>
379 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
380 <div class="directive-section"><h2><a name="NoProxy" id="NoProxy">NoProxy</a> <a name="noproxy" id="noproxy">Directive</a></h2>
381 <table class="directive">
382 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Hosts, domains, or networks that will be connected to
384 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>NoProxy <var>host</var> [<var>host</var>] ...</code></td></tr>
385 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
386 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
387 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
389 <p>This directive is only useful for Apache proxy servers within
390 intranets. The <code class="directive">NoProxy</code> directive specifies a
391 list of subnets, IP addresses, hosts and/or domains, separated by
392 spaces. A request to a host which matches one or more of these is
393 always served directly, without forwarding to the configured
394 <code class="directive"><a href="#proxyremote">ProxyRemote</a></code> proxy server(s).</p>
396 <div class="example"><h3>Example</h3><p><code>
397 ProxyRemote * http://firewall.example.com:81<br />
398 NoProxy .example.com 192.168.112.0/21
401 <p>The <var>host</var> arguments to the <code class="directive">NoProxy</code>
402 directive are one of the following type list:</p>
406 <dt><var><a name="domain" id="domain">Domain</a></var></dt>
408 <p>A <dfn>Domain</dfn> is a partially qualified DNS domain name, preceded
409 by a period. It represents a list of hosts which logically belong to the
410 same DNS domain or zone (<em>i.e.</em>, the suffixes of the hostnames are
411 all ending in <var>Domain</var>).</p>
413 <div class="example"><h3>Examples</h3><p><code>
417 <p>To distinguish <var>Domain</var>s from <var><a href="#hostname">Hostname</a></var>s (both syntactically and semantically; a DNS domain can
418 have a DNS A record, too!), <var>Domain</var>s are always written with a
421 <div class="note"><h3>Note</h3>
422 <p>Domain name comparisons are done without regard to the case, and
423 <var>Domain</var>s are always assumed to be anchored in the root of the
424 DNS tree, therefore two domains <code>.ExAmple.com</code> and
425 <code>.example.com.</code> (note the trailing period) are considered
426 equal. Since a domain comparison does not involve a DNS lookup, it is much
427 more efficient than subnet comparison.</p>
431 <dt><var><a name="subnet" id="subnet">SubNet</a></var></dt>
433 <p>A <dfn>SubNet</dfn> is a partially qualified internet address in
434 numeric (dotted quad) form, optionally followed by a slash and the netmask,
435 specified as the number of significant bits in the <var>SubNet</var>. It is
436 used to represent a subnet of hosts which can be reached over a common
437 network interface. In the absence of the explicit net mask it is assumed
438 that omitted (or zero valued) trailing digits specify the mask. (In this
439 case, the netmask can only be multiples of 8 bits wide.) Examples:</p>
442 <dt><code>192.168</code> or <code>192.168.0.0</code></dt>
443 <dd>the subnet 192.168.0.0 with an implied netmask of 16 valid bits
444 (sometimes used in the netmask form <code>255.255.0.0</code>)</dd>
445 <dt><code>192.168.112.0/21</code></dt>
446 <dd>the subnet <code>192.168.112.0/21</code> with a netmask of 21
447 valid bits (also used in the form <code>255.255.248.0</code>)</dd>
450 <p>As a degenerate case, a <em>SubNet</em> with 32 valid bits is the
451 equivalent to an <var><a href="#ipadr">IPAddr</a></var>, while a <var>SubNet</var> with zero
452 valid bits (<em>e.g.</em>, 0.0.0.0/0) is the same as the constant
453 <var>_Default_</var>, matching any IP address.</p></dd>
456 <dt><var><a name="ipaddr" id="ipaddr">IPAddr</a></var></dt>
458 <p>A <dfn>IPAddr</dfn> represents a fully qualified internet address in
459 numeric (dotted quad) form. Usually, this address represents a host, but
460 there need not necessarily be a DNS domain name connected with the
462 <div class="example"><h3>Example</h3><p><code>
466 <div class="note"><h3>Note</h3>
467 <p>An <var>IPAddr</var> does not need to be resolved by the DNS system, so
468 it can result in more effective apache performance.</p>
472 <dt><var><a name="hostname" id="hostname">Hostname</a></var></dt>
474 <p>A <dfn>Hostname</dfn> is a fully qualified DNS domain name which can
475 be resolved to one or more <var><a href="#ipaddr">IPAddrs</a></var> via the
476 DNS domain name service. It represents a logical host (in contrast to
477 <var><a href="#domain">Domain</a></var>s, see above) and must be resolvable
478 to at least one <var><a href="#ipaddr">IPAddr</a></var> (or often to a list
479 of hosts with different <var><a href="#ipaddr">IPAddr</a></var>s).</p>
481 <div class="example"><h3>Examples</h3><p><code>
482 prep.ai.example.com<br />
486 <div class="note"><h3>Note</h3>
487 <p>In many situations, it is more effective to specify an <var><a href="#ipaddr">IPAddr</a></var> in place of a <var>Hostname</var> since a
488 DNS lookup can be avoided. Name resolution in Apache can take a remarkable
489 deal of time when the connection to the name server uses a slow PPP
491 <p><var>Hostname</var> comparisons are done without regard to the case,
492 and <var>Hostname</var>s are always assumed to be anchored in the root
493 of the DNS tree, therefore two hosts <code>WWW.ExAmple.com</code>
494 and <code>www.example.com.</code> (note the trailing period) are
495 considered equal.</p>
501 <li><a href="../dns-caveats.html">DNS Issues</a></li>
504 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
505 <div class="directive-section"><h2><a name="Proxy" id="Proxy"><Proxy></a> <a name="proxy" id="proxy">Directive</a></h2>
506 <table class="directive">
507 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Container for directives applied to proxied resources</td></tr>
508 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Proxy <var>wildcard-url</var>> ...</Proxy></code></td></tr>
509 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
510 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
511 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
513 <p>Directives placed in <code class="directive"><Proxy></code>
514 sections apply only to matching proxied content. Shell-style wildcards are
517 <p>For example, the following will allow only hosts in
518 <code>yournetwork.example.com</code> to access content via your proxy
521 <div class="example"><p><code>
522 <Proxy *><br />
523 <span class="indent">
524 Order Deny,Allow<br />
526 Allow from yournetwork.example.com<br />
531 <p>The following example will process all files in the <code>foo</code>
532 directory of <code>example.com</code> through the <code>INCLUDES</code>
533 filter when they are sent through the proxy server:</p>
535 <div class="example"><p><code>
536 <Proxy http://example.com/foo/*><br />
537 <span class="indent">
538 SetOutputFilter INCLUDES<br />
546 <li><code class="directive"><a href="#proxymatch"><ProxyMatch></a></code></li>
549 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
550 <div class="directive-section"><h2><a name="ProxyBadHeader" id="ProxyBadHeader">ProxyBadHeader</a> <a name="proxybadheader" id="proxybadheader">Directive</a></h2>
551 <table class="directive">
552 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determines how to handle bad header lines in a
554 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyBadHeader IsError|Ignore|StartBody</code></td></tr>
555 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyBadHeader IsError</code></td></tr>
556 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
557 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
558 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
559 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.44 and later</td></tr>
561 <p>The <code class="directive">ProxyBadHeader</code> directive determines the
562 behaviour of <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> if it receives syntactically invalid
563 header lines (<em>i.e.</em> containing no colon). The following arguments
567 <dt><code>IsError</code></dt>
568 <dd>Abort the request and end up with a 502 (Bad Gateway) response. This is
569 the default behaviour.</dd>
571 <dt><code>Ignore</code></dt>
572 <dd>Treat bad header lines as if they weren't sent.</dd>
574 <dt><code>StartBody</code></dt>
575 <dd>When receiving the first bad header line, finish reading the headers and
576 treat the remainder as body. This helps to work around buggy backend servers
577 which forget to insert an empty line between the headers and the body.</dd>
581 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
582 <div class="directive-section"><h2><a name="ProxyBlock" id="ProxyBlock">ProxyBlock</a> <a name="proxyblock" id="proxyblock">Directive</a></h2>
583 <table class="directive">
584 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Words, hosts, or domains that are banned from being
586 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyBlock *|<var>word</var>|<var>host</var>|<var>domain</var>
587 [<var>word</var>|<var>host</var>|<var>domain</var>] ...</code></td></tr>
588 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
589 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
590 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
592 <p>The <code class="directive">ProxyBlock</code> directive specifies a list of
593 words, hosts and/or domains, separated by spaces. HTTP, HTTPS, and
594 FTP document requests to sites whose names contain matched words,
595 hosts or domains are <em>blocked</em> by the proxy server. The proxy
596 module will also attempt to determine IP addresses of list items which
597 may be hostnames during startup, and cache them for match test as
598 well. That may slow down the startup time of the server.</p>
600 <div class="example"><h3>Example</h3><p><code>
601 ProxyBlock joes-garage.com some-host.co.uk rocky.wotsamattau.edu
604 <p><code>rocky.wotsamattau.edu</code> would also be matched if referenced by
607 <p>Note that <code>wotsamattau</code> would also be sufficient to match
608 <code>wotsamattau.edu</code>.</p>
610 <p>Note also that</p>
612 <div class="example"><p><code>
616 <p>blocks connections to all sites.</p>
619 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
620 <div class="directive-section"><h2><a name="ProxyDomain" id="ProxyDomain">ProxyDomain</a> <a name="proxydomain" id="proxydomain">Directive</a></h2>
621 <table class="directive">
622 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Default domain name for proxied requests</td></tr>
623 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyDomain <var>Domain</var></code></td></tr>
624 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
625 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
626 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
628 <p>This directive is only useful for Apache proxy servers within
629 intranets. The <code class="directive">ProxyDomain</code> directive specifies
630 the default domain which the apache proxy server will belong to. If a
631 request to a host without a domain name is encountered, a redirection
632 response to the same host with the configured <var>Domain</var> appended
633 will be generated.</p>
635 <div class="example"><h3>Example</h3><p><code>
636 ProxyRemote * http://firewall.example.com:81<br />
637 NoProxy .example.com 192.168.112.0/21<br />
638 ProxyDomain .example.com
642 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
643 <div class="directive-section"><h2><a name="ProxyErrorOverride" id="ProxyErrorOverride">ProxyErrorOverride</a> <a name="proxyerroroverride" id="proxyerroroverride">Directive</a></h2>
644 <table class="directive">
645 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Override error pages for proxied content</td></tr>
646 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyErrorOverride On|Off</code></td></tr>
647 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyErrorOverride Off</code></td></tr>
648 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
649 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
650 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
651 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in version 2.0 and later</td></tr>
653 <p>This directive is useful for reverse-proxy setups, where you want to
654 have a common look and feel on the error pages seen by the end user.
655 This also allows for included files (via
656 <code class="module"><a href="../mod/mod_include.html">mod_include</a></code>'s SSI) to get
657 the error code and act accordingly (default behavior would display
658 the error page of the proxied server, turning this on shows the SSI
661 <p>This directive does not affect the processing of informational (1xx),
662 normal success (2xx), or redirect (3xx) responses.</p>
665 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
666 <div class="directive-section"><h2><a name="ProxyFtpDirCharset" id="ProxyFtpDirCharset">ProxyFtpDirCharset</a> <a name="proxyftpdircharset" id="proxyftpdircharset">Directive</a></h2>
667 <table class="directive">
668 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Define the character set for proxied FTP listings</td></tr>
669 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyFtpDirCharset <var>character set</var></code></td></tr>
670 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyFtpDirCharset ISO-8859-1</code></td></tr>
671 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
672 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
673 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
674 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.2.7 and later</td></tr>
676 <p>The <code class="directive">ProxyFtpDirCharset</code> directive defines the
677 character set to be set for FTP directory listings in HTML generated by
678 <code class="module"><a href="../mod/mod_proxy_ftp.html">mod_proxy_ftp</a></code>.</p>
681 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
682 <div class="directive-section"><h2><a name="ProxyIOBufferSize" id="ProxyIOBufferSize">ProxyIOBufferSize</a> <a name="proxyiobuffersize" id="proxyiobuffersize">Directive</a></h2>
683 <table class="directive">
684 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determine size of internal data throughput buffer</td></tr>
685 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyIOBufferSize <var>bytes</var></code></td></tr>
686 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyIOBufferSize 8192</code></td></tr>
687 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
688 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
689 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
691 <p>The <code class="directive">ProxyIOBufferSize</code> directive adjusts the size
692 of the internal buffer, which is used as a scratchpad for the data between
693 input and output. The size must be at least <code>512</code>.</p>
695 <p>In almost every case there's no reason to change that value.</p>
696 <p>If used with AJP this directive sets the maximum AJP packet size in
697 bytes. If you change it from the default, you must also change the
698 <code>packetSize</code> attribute of your AJP connector on the
699 Tomcat side! The attribute <code>packetSize</code> is only available
700 in Tomcat <code>5.5.20+</code> and <code>6.0.2+</code></p>
701 <p>Normally it is not necessary to change the maximum packet size.
702 Problems with the default value have been reported when sending
703 certificates or certificate chains.</p>
707 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
708 <div class="directive-section"><h2><a name="ProxyMatch" id="ProxyMatch"><ProxyMatch></a> <a name="proxymatch" id="proxymatch">Directive</a></h2>
709 <table class="directive">
710 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Container for directives applied to regular-expression-matched
711 proxied resources</td></tr>
712 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><ProxyMatch <var>regex</var>> ...</ProxyMatch></code></td></tr>
713 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
714 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
715 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
717 <p>The <code class="directive"><ProxyMatch></code> directive is
718 identical to the <code class="directive"><a href="#proxy"><Proxy></a></code> directive, except it matches URLs
719 using <a class="glossarylink" href="../glossary.html#regex" title="see glossary">regular expressions</a>.</p>
723 <li><code class="directive"><a href="#proxy"><Proxy></a></code></li>
726 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
727 <div class="directive-section"><h2><a name="ProxyMaxForwards" id="ProxyMaxForwards">ProxyMaxForwards</a> <a name="proxymaxforwards" id="proxymaxforwards">Directive</a></h2>
728 <table class="directive">
729 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Maximium number of proxies that a request can be forwarded
731 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyMaxForwards <var>number</var></code></td></tr>
732 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyMaxForwards -1</code></td></tr>
733 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
734 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
735 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
736 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0 and later;
737 default behaviour changed in 2.2.7/2.3</td></tr>
739 <p>The <code class="directive">ProxyMaxForwards</code> directive specifies the
740 maximum number of proxies through which a request may pass, if there's no
741 <code>Max-Forwards</code> header supplied with the request. This may
742 be set to prevent infinite proxy loops, or a DoS attack.</p>
744 <div class="example"><h3>Example</h3><p><code>
748 <p>Note that setting <code class="directive">ProxyMaxForwards</code> is a
749 violation of the HTTP/1.1 protocol (RFC2616), which forbids a Proxy
750 setting <code>Max-Forwards</code> if the Client didn't set it.
751 Earlier Apache versions would always set it. A negative
752 <code class="directive">ProxyMaxForwards</code> value, including the
753 default -1, gives you protocol-compliant behaviour, but may
754 leave you open to loops.</p>
757 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
758 <div class="directive-section"><h2><a name="ProxyPass" id="ProxyPass">ProxyPass</a> <a name="proxypass" id="proxypass">Directive</a></h2>
759 <table class="directive">
760 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Maps remote servers into the local server URL-space</td></tr>
761 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyPass [<var>path</var>] !|<var>url</var> [<var>key=value</var>
762 <var>[key=value</var> ...]] [nocanon] [interpolate]</code></td></tr>
763 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
764 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
765 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
767 <p>This directive allows remote servers to be mapped into the
768 space of the local server; the local server does not act as a
769 proxy in the conventional sense, but appears to be a mirror of the
770 remote server. The local server is often called a <dfn>reverse
771 proxy</dfn> or <dfn>gateway</dfn>. The <var>path</var> is the name of
772 a local virtual path; <var>url</var> is a partial URL for the
773 remote server and cannot include a query string.</p>
775 <div class="warning">The <code class="directive"><a href="#proxyrequests">ProxyRequests</a></code> directive should
776 usually be set <strong>off</strong> when using
777 <code class="directive">ProxyPass</code>.</div>
779 <p>Suppose the local server has address <code>http://example.com/</code>;
782 <div class="example"><p><code>
783 ProxyPass /mirror/foo/ http://backend.example.com/
786 <p>will cause a local request for
787 <code>http://example.com/mirror/foo/bar</code> to be internally converted
788 into a proxy request to <code>http://backend.example.com/bar</code>.</p>
790 <div class="warning">
791 <p>If the first argument ends with a trailing <strong>/</strong>, the second
792 argument should also end with a trailing <strong>/</strong> and vice
793 versa. Otherwise the resulting requests to the backend may miss some
794 needed slashes and do not deliver the expected results.
798 <p>The <code>!</code> directive is useful in situations where you don't want
799 to reverse-proxy a subdirectory, <em>e.g.</em></p>
801 <div class="example"><p><code>
802 ProxyPass /mirror/foo/i !<br />
803 ProxyPass /mirror/foo http://backend.example.com
806 <p>will proxy all requests to <code>/mirror/foo</code> to
807 <code>backend.example.com</code> <em>except</em> requests made to
808 <code>/mirror/foo/i</code>.</p>
810 <div class="note"><h3>Note</h3>
811 <p>Order is important: exclusions must come <em>before</em> the
812 general <code class="directive">ProxyPass</code> directive.</p>
815 <p>As of Apache 2.1, the ability to use pooled connections to a backend
816 server is available. Using the <code>key=value</code> parameters it is
817 possible to tune this connection pooling. The default for a <code>Hard
818 Maximum</code> for the number of connections is the number of threads per
819 process in the active MPM. In the Prefork MPM, this is always 1, while with
820 the Worker MPM it is controlled by the
821 <code class="directive">ThreadsPerChild</code>.</p>
823 <p>Setting <code>min</code> will determine how many connections will always
824 be open to the backend server. Upto the Soft Maximum or <code>smax</code>
825 number of connections will be created on demand. Any connections above
826 <code>smax</code> are subject to a time to live or <code>ttl</code>. Apache
827 will never create more than the Hard Maximum or <code>max</code> connections
828 to the backend server.</p>
830 <div class="example"><p><code>
831 ProxyPass /example http://backend.example.com smax=5 max=20 ttl=120 retry=300
835 <tr><th>Parameter</th>
837 <th>Description</th></tr>
840 <td>Minimum number of connections that will always
841 be open to the backend server.</td></tr>
844 <td>Hard Maximum number of connections that will be
845 allowed to the backend server. The default for a Hard Maximum
846 for the number of connections is the number of threads per process in the
847 active MPM. In the Prefork MPM, this is always 1, while with the Worker MPM
848 it is controlled by the <code class="directive">ThreadsPerChild</code>.
849 Apache will never create more than the Hard Maximum connections
850 to the backend server.</td></tr>
853 <td>Upto the Soft Maximum
854 number of connections will be created on demand. Any connections above
855 <code>smax</code> are subject to a time to live or <code>ttl</code>.
859 <td>If set this will be the maximum time to wait for a free
860 connection in the connection pool, in milliseconds. If there are no free
861 connections in the pool the Apache will return <code>SERVER_BUSY</code>
862 status to the client.
864 <tr><td>connectiontimeout</td>
866 <td>Connect timeout in seconds.
867 The number of seconds Apache waits for the creation of a connection to
868 the backend to complete. By adding a postfix of ms the timeout can be
869 also set in milliseconds.
871 <tr><td>disablereuse</td>
873 <td>This parameter should be used when you want to force mod_proxy
874 to immediately close a connection to the backend after being used, and
875 thus, disable its persistent connection and pool for that backend.
876 This helps in various situations where a firewall between Apache and
877 the backend server (regardless of protocol) tends to silently
878 drop connections or when backends themselves may be under round-
879 robin DNS. To disable connection pooling reuse,
880 set this property value to <code>On</code>.
882 <tr><td>flushpackets</td>
884 <td>Determines whether the proxy module will auto-flush the output
885 brigade after each "chunk" of data. 'off' means that it will flush
886 only when needed, 'on' means after each chunk is sent and
887 'auto' means poll/wait for a period of time and flush if
888 no input has been received for 'flushwait' milliseconds.
889 Currently this is in effect only for AJP.
891 <tr><td>flushwait</td>
893 <td>The time to wait for additional input, in milliseconds, before
894 flushing the output brigade if 'flushpackets' is 'auto'.
896 <tr><td>iobuffersize</td>
898 <td>Adjusts the size of the internal scratchpad IO buffer. This allows you
899 to override the <code class="directive">ProxyIOBufferSize</code> for a specific worker.
900 This must be at least 512 or set to 0 for the system default of 8192.
902 <tr><td>keepalive</td>
904 <td>This parameter should be used when you have a firewall between your
905 Apache and the backend server, who tend to drop inactive connections.
906 This flag will tell the Operating System to send <code>KEEP_ALIVE</code>
907 messages on inactive connections (interval depends on global OS settings,
908 generally 120ms), and thus prevent the firewall to drop the connection.
909 To enable keepalive set this property value to <code>On</code>.
913 <td>Sets the load balancer cluster set that the worker is a member
914 of. The load balancer will try all members of a lower numbered
915 lbset before trying higher numbered ones.
919 <td>Ping property tells webserver to send a <code>CPING</code>
920 request on ajp13 connection before forwarding a request.
921 The parameter is the delay in seconds to wait for the
922 <code>CPONG</code> reply.
923 This features has been added to avoid problem with hung and
924 busy Tomcat's and require ajp13 ping/pong support which has
925 been implemented on Tomcat 3.3.2+, 4.1.28+ and 5.0.13+.
926 This will increase the network traffic during the normal operation
927 which could be an issue, but it will lower the
928 traffic in case some of the cluster nodes are down or busy.
929 Currently this has an effect only for AJP.
930 By adding a postfix of ms the delay can be also set in
933 <tr><td>receivebuffersize</td>
935 <td>Adjusts the size of the explicit (TCP/IP) network buffer size for
936 proxied connections. This allows you to override the
937 <code class="directive">ProxyReceiveBufferSize</code> for a specific worker.
938 This must be at least 512 or set to 0 for the system default.
940 <tr><td>redirect</td>
942 <td>Redirection Route of the worker. This value is usually
943 set dynamically to enable safe removal of the node from
944 the cluster. If set all requests without session id will be
945 redirected to the BalancerMember that has route parametar
950 <td>Connection pool worker retry timeout in seconds.
951 If the connection pool worker to the backend server is in the error state,
952 Apache will not forward any requests to that server until the timeout
953 expires. This enables to shut down the backend server for maintenance,
954 and bring it back online later. A value of 0 means always retry workers
955 in an error state with no timeout.
959 <td>Route of the worker when used inside load balancer.
960 The route is a value appended to session id.
964 <td>Single letter value defining the initial status of
965 this worker: 'D' is disabled, 'S' is stopped, 'I' is ignore-errors,
966 'H' is hot-standby and 'E' is in an error state. Status
967 can be set (which is the default) by prepending with '+' or
968 cleared by prepending with '-'.
969 Thus, a setting of 'S-E' sets this worker to Stopped and
970 clears the in-error flag.
973 <td><code class="directive"><a href="#proxytimeout">ProxyTimeout</a></code></td>
974 <td>Connection timeout in seconds.
975 The number of seconds Apache waits for data sent by / to the backend.
979 <td>Time To Live for the inactive connections above the
980 <code>smax</code> connections in seconds. Apache will close all
981 connections that has not been used inside that time period.
986 <p>If the Proxy directive scheme starts with the
987 <code>balancer://</code> (eg: <code>balancer://cluster/</code>,
988 any path information is ignored) then a virtual worker that does not really
989 communicate with the backend server will be created. Instead it is responsible
990 for the management of several "real" workers. In that case the special set of
991 parameters can be add to this virtual worker. See <code class="module"><a href="../mod/mod_proxy_balancer.html">mod_proxy_balancer</a></code>
992 for more information about how the balancer works.
995 <tr><th>Parameter</th>
997 <th>Description</th></tr>
998 <tr><td>lbmethod</td>
1000 <td>Balancer load-balance method. Select the load-balancing scheduler
1001 method to use. Either <code>byrequests</code>, to perform weighted
1002 request counting, <code>bytraffic</code>, to perform weighted
1003 traffic byte count balancing, or <code>bybusyness</code>, to perform
1004 pending request balancing. Default is <code>byrequests</code>.
1006 <tr><td>maxattempts</td>
1008 <td>Maximum number of failover attempts before giving up.
1010 <tr><td>nofailover</td>
1012 <td>If set to <code>On</code> the session will break if the worker is in
1013 error state or disabled. Set this value to On if backend servers do not
1014 support session replication.
1016 <tr><td>stickysession</td>
1018 <td>Balancer sticky session name. The value is usually set to something
1019 like <code>JSESSIONID</code> or <code>PHPSESSIONID</code>,
1020 and it depends on the backend application server that support sessions.
1021 If the backend application server uses different name for cookies
1022 and url encoded id (like servlet containers) use | to to separate them.
1023 The first part is for the cookie the second for the path.
1025 <tr><td>scolonpathdelim</td>
1027 <td>If set to <code>On</code> the semi-colon character ';' will be
1028 used as an additional sticky session path deliminator/separator. This
1029 is mainly used to emulate mod_jk's behavior when dealing with paths such
1030 as <code>JSESSIONID=6736bcf34;foo=aabfa</code>
1032 <tr><td>timeout</td>
1034 <td>Balancer timeout in seconds. If set this will be the maximum time
1035 to wait for a free worker. Default is not to wait.
1039 <p>A sample balancer setup</p>
1040 <div class="example"><p><code>
1041 ProxyPass /special-area http://special.example.com/ smax=5 max=10<br />
1042 ProxyPass / balancer://mycluster/ stickysession=JSESSIONID|jsessionid nofailover=On<br />
1043 <Proxy balancer://mycluster><br />
1044 <span class="indent">
1045 BalancerMember http://1.2.3.4:8009<br />
1046 BalancerMember http://1.2.3.5:8009 smax=10<br />
1047 # Less powerful server, don't send as many requests there<br />
1048 BalancerMember http://1.2.3.6:8009 smax=1 loadfactor=20<br />
1053 <p>Setting up a hot-standby, that will only be used if no other
1054 members are available</p>
1055 <div class="example"><p><code>
1056 ProxyPass / balancer://hotcluster/ <br />
1057 <Proxy balancer://hotcluster><br />
1058 <span class="indent">
1059 BalancerMember http://1.2.3.4:8009 loadfactor=1<br />
1060 BalancerMember http://1.2.3.5:8009 loadfactor=2<br />
1061 # The below is the hot standby<br />
1062 BalancerMember http://1.2.3.6:8009 status=+H<br />
1063 ProxySet lbmethod=bytraffic
1068 <p>Normally, mod_proxy will canonicalise ProxyPassed URLs.
1069 But this may be incompatible with some backends, particularly those
1070 that make use of <var>PATH_INFO</var>. The optional <var>nocanon</var>
1071 keyword suppresses this, and passes the URL path "raw" to the
1072 backend. Note that may affect the security of your backend, as it
1073 removes the normal limited protection against URL-based attacks
1074 provided by the proxy.</p>
1076 <p>The optional <var>interpolate</var> keyword (available in
1077 httpd 2.2.9 and later), in combination with
1078 <code class="directive">ProxyPassInterpolateEnv</code> causes the ProxyPass
1079 to interpolate environment variables, using the syntax
1080 <var>${VARNAME}</var>. Note that many of the standard CGI-derived
1081 environment variables will not exist when this interpolation happens,
1082 so you may still have to resort to <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code>
1083 for complex rules.</p>
1085 <p>When used inside a <code class="directive"><a href="../mod/core.html#location"><Location></a></code> section, the first argument is omitted and the local
1086 directory is obtained from the <code class="directive"><a href="../mod/core.html#location"><Location></a></code>.</p>
1088 <p>If you require a more flexible reverse-proxy configuration, see the
1089 <code class="directive"><a href="../mod/mod_rewrite.html#rewriterule">RewriteRule</a></code> directive with the
1090 <code>[P]</code> flag.</p>
1093 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1094 <div class="directive-section"><h2><a name="ProxyPassInterpolateEnv" id="ProxyPassInterpolateEnv">ProxyPassInterpolateEnv</a> <a name="proxypassinterpolateenv" id="proxypassinterpolateenv">Directive</a></h2>
1095 <table class="directive">
1096 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enable Environment Variable interpolation in Reverse Proxy configurations</td></tr>
1097 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyPassInterpolateEnv On|Off</code></td></tr>
1098 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyPassInterpolateEnv Off</code></td></tr>
1099 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
1100 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
1101 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
1102 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in httpd 2.2.9 and later</td></tr>
1104 <p>This directive, together with the <var>interpolate</var> argument to
1105 <code class="directive">ProxyPass</code>, <code class="directive">ProxyPassReverse</code>,
1106 <code class="directive">ProxyPassReverseCookieDomain</code> and
1107 <code class="directive">ProxyPassReverseCookiePath</code>
1108 enables reverse proxies to be dynamically
1109 configured using environment variables, which may be set by
1110 another module such as <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code>.
1111 It affects the <code class="directive">ProxyPass</code>,
1112 <code class="directive">ProxyPassReverse</code>,
1113 <code class="directive">ProxyPassReverseCookieDomain</code>, and
1114 <code class="directive">ProxyPassReverseCookiePath</code> directives,
1115 and causes them to substitute the value of an environment
1116 variable <code>varname</code> for the string <code>${varname}</code>
1117 in configuration directives.</p>
1118 <p>Keep this turned off (for server performance) unless you need it!</p>
1121 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1122 <div class="directive-section"><h2><a name="ProxyPassMatch" id="ProxyPassMatch">ProxyPassMatch</a> <a name="proxypassmatch" id="proxypassmatch">Directive</a></h2>
1123 <table class="directive">
1124 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Maps remote servers into the local server URL-space using regular expressions</td></tr>
1125 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyPassMatch [<var>regex</var>] !|<var>url</var> [<var>key=value</var>
1126 <var>[key=value</var> ...]]</code></td></tr>
1127 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
1128 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
1129 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
1131 <p>This directive is equivalent to <code class="directive"><a href="#proxypass">ProxyPass</a></code>,
1132 but makes use of regular expressions, instead of simple prefix matching. The
1133 supplied regular expression is matched against the <var>url</var>, and if it
1134 matches, the server will substitute any parenthesized matches into the given
1135 string and use it as a new <var>url</var>.</p>
1137 <p>Suppose the local server has address <code>http://example.com/</code>;
1140 <div class="example"><p><code>
1141 ProxyPassMatch ^(/.*\.gif)$ http://backend.example.com$1
1144 <p>will cause a local request for
1145 <code>http://example.com/foo/bar.gif</code> to be internally converted
1146 into a proxy request to <code>http://backend.example.com/foo/bar.gif</code>.</p>
1147 <div class="note"><h3>Note</h3>
1148 <p>The URL argument must be parsable as a URL <em>before</em> regexp
1149 substitutions (as well as after). This limits the matches you can use.
1150 For instance, if we had used</p>
1151 <div class="example"><p><code>
1152 ProxyPassMatch ^(/.*\.gif)$ http://backend.example.com:8000$1
1154 <p>in our previous example, it would fail with a syntax error
1155 at server startup. This is a bug (PR 46665 in the ASF bugzilla),
1156 and the workaround is to reformulate the match:</p>
1157 <div class="example"><p><code>
1158 ProxyPassMatch ^/(.*\.gif)$ http://backend.example.com:8000/$1
1161 <p>The <code>!</code> directive is useful in situations where you don't want
1162 to reverse-proxy a subdirectory.</p>
1165 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1166 <div class="directive-section"><h2><a name="ProxyPassReverse" id="ProxyPassReverse">ProxyPassReverse</a> <a name="proxypassreverse" id="proxypassreverse">Directive</a></h2>
1167 <table class="directive">
1168 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Adjusts the URL in HTTP response headers sent from a reverse
1169 proxied server</td></tr>
1170 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyPassReverse [<var>path</var>] <var>url</var>
1171 [<var>interpolate</var>]</code></td></tr>
1172 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
1173 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
1174 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
1176 <p>This directive lets Apache adjust the URL in the <code>Location</code>,
1177 <code>Content-Location</code> and <code>URI</code> headers on HTTP
1178 redirect responses. This is essential when Apache is used as a
1179 reverse proxy (or gateway) to avoid by-passing the reverse proxy
1180 because of HTTP redirects on the backend servers which stay behind
1181 the reverse proxy.</p>
1183 <p>Only the HTTP response headers specifically mentioned above
1184 will be rewritten. Apache will not rewrite other response
1185 headers, nor will it rewrite URL references inside HTML pages.
1186 This means that if the proxied content contains absolute URL
1187 references, they will by-pass the proxy. A third-party module
1188 that will look inside the HTML and rewrite URL references is Nick
1189 Kew's <a href="http://apache.webthing.com/mod_proxy_html/">mod_proxy_html</a>.</p>
1191 <p><var>path</var> is the name of a local virtual path. <var>url</var> is a
1192 partial URL for the remote server - the same way they are used for the
1193 <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive.</p>
1195 <p>For example, suppose the local server has address
1196 <code>http://example.com/</code>; then</p>
1198 <div class="example"><p><code>
1199 ProxyPass /mirror/foo/ http://backend.example.com/<br />
1200 ProxyPassReverse /mirror/foo/ http://backend.example.com/<br />
1201 ProxyPassReverseCookieDomain backend.example.com public.example.com<br />
1202 ProxyPassReverseCookiePath / /mirror/foo/
1205 <p>will not only cause a local request for the
1206 <code>http://example.com/mirror/foo/bar</code> to be internally converted
1207 into a proxy request to <code>http://backend.example.com/bar</code>
1208 (the functionality <code>ProxyPass</code> provides here). It also takes care
1209 of redirects the server <code>backend.example.com</code> sends: when
1210 <code>http://backend.example.com/bar</code> is redirected by him to
1211 <code>http://backend.example.com/quux</code> Apache adjusts this to
1212 <code>http://example.com/mirror/foo/quux</code> before forwarding the HTTP
1213 redirect response to the client. Note that the hostname used for
1214 constructing the URL is chosen in respect to the setting of the <code class="directive"><a href="../mod/core.html#usecanonicalname">UseCanonicalName</a></code> directive.</p>
1216 <p>Note that this <code class="directive">ProxyPassReverse</code> directive can
1217 also be used in conjunction with the proxy pass-through feature
1218 (<code>RewriteRule ... [P]</code>) from <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code>
1219 because it doesn't depend on a corresponding <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive.</p>
1221 <p>The optional <var>interpolate</var> keyword (available in
1222 httpd 2.2.9 and later), used together with
1223 <code class="directive">ProxyPassInterpolateEnv</code>, enables interpolation
1224 of environment variables specified using the format <var>${VARNAME}</var>.
1227 <p>When used inside a <code class="directive"><a href="../mod/core.html#location"><Location></a></code> section, the first argument is omitted and the local
1228 directory is obtained from the <code class="directive"><a href="../mod/core.html#location"><Location></a></code>.</p>
1231 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1232 <div class="directive-section"><h2><a name="ProxyPassReverseCookieDomain" id="ProxyPassReverseCookieDomain">ProxyPassReverseCookieDomain</a> <a name="proxypassreversecookiedomain" id="proxypassreversecookiedomain">Directive</a></h2>
1233 <table class="directive">
1234 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Adjusts the Domain string in Set-Cookie headers from a reverse-
1235 proxied server</td></tr>
1236 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyPassReverseCookieDomain <var>internal-domain</var>
1237 <var>public-domain</var> [<var>interpolate</var>]</code></td></tr>
1238 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
1239 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
1240 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
1242 <p>Usage is basically similar to
1243 <code class="directive"><a href="#proxypassreverse">ProxyPassReverse</a></code>, but instead of
1244 rewriting headers that are a URL, this rewrites the <code>domain</code>
1245 string in <code>Set-Cookie</code> headers.</p>
1248 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1249 <div class="directive-section"><h2><a name="ProxyPassReverseCookiePath" id="ProxyPassReverseCookiePath">ProxyPassReverseCookiePath</a> <a name="proxypassreversecookiepath" id="proxypassreversecookiepath">Directive</a></h2>
1250 <table class="directive">
1251 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Adjusts the Path string in Set-Cookie headers from a reverse-
1252 proxied server</td></tr>
1253 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyPassReverseCookiePath <var>internal-path</var>
1254 <var>public-path</var> [<var>interpolate</var>]</code></td></tr>
1255 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
1256 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
1257 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
1259 <p>Usage is basically similar to
1260 <code class="directive"><a href="#proxypassreverse">ProxyPassReverse</a></code>, but instead of
1261 rewriting headers that are a URL, this rewrites the <code>path</code>
1262 string in <code>Set-Cookie</code> headers.</p>
1265 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1266 <div class="directive-section"><h2><a name="ProxyPreserveHost" id="ProxyPreserveHost">ProxyPreserveHost</a> <a name="proxypreservehost" id="proxypreservehost">Directive</a></h2>
1267 <table class="directive">
1268 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Use incoming Host HTTP request header for proxy
1270 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyPreserveHost On|Off</code></td></tr>
1271 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyPreserveHost Off</code></td></tr>
1272 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
1273 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
1274 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
1275 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.31 and later.</td></tr>
1277 <p>When enabled, this option will pass the Host: line from the incoming
1278 request to the proxied host, instead of the hostname specified in the
1279 <code class="directive">ProxyPass</code> line.</p>
1281 <p>This option should normally be turned <code>Off</code>. It is mostly
1282 useful in special configurations like proxied mass name-based virtual
1283 hosting, where the original Host header needs to be evaluated by the
1287 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1288 <div class="directive-section"><h2><a name="ProxyReceiveBufferSize" id="ProxyReceiveBufferSize">ProxyReceiveBufferSize</a> <a name="proxyreceivebuffersize" id="proxyreceivebuffersize">Directive</a></h2>
1289 <table class="directive">
1290 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Network buffer size for proxied HTTP and FTP
1291 connections</td></tr>
1292 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyReceiveBufferSize <var>bytes</var></code></td></tr>
1293 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyReceiveBufferSize 0</code></td></tr>
1294 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1295 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
1296 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
1298 <p>The <code class="directive">ProxyReceiveBufferSize</code> directive specifies an
1299 explicit (TCP/IP) network buffer size for proxied HTTP and FTP connections,
1300 for increased throughput. It has to be greater than <code>512</code> or set
1301 to <code>0</code> to indicate that the system's default buffer size should
1304 <div class="example"><h3>Example</h3><p><code>
1305 ProxyReceiveBufferSize 2048
1309 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1310 <div class="directive-section"><h2><a name="ProxyRemote" id="ProxyRemote">ProxyRemote</a> <a name="proxyremote" id="proxyremote">Directive</a></h2>
1311 <table class="directive">
1312 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Remote proxy used to handle certain requests</td></tr>
1313 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyRemote <var>match</var> <var>remote-server</var></code></td></tr>
1314 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1315 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
1316 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
1318 <p>This defines remote proxies to this proxy. <var>match</var> is either the
1319 name of a URL-scheme that the remote server supports, or a partial URL
1320 for which the remote server should be used, or <code>*</code> to indicate
1321 the server should be contacted for all requests. <var>remote-server</var> is
1322 a partial URL for the remote server. Syntax:</p>
1324 <div class="example"><p><code>
1325 <dfn>remote-server</dfn> =
1326 <var>scheme</var>://<var>hostname</var>[:<var>port</var>]
1329 <p><var>scheme</var> is effectively the protocol that should be used to
1330 communicate with the remote server; only <code>http</code> is supported by
1333 <div class="example"><h3>Example</h3><p><code>
1334 ProxyRemote http://goodguys.example.com/ http://mirrorguys.example.com:8000<br />
1335 ProxyRemote * http://cleverproxy.localdomain<br />
1336 ProxyRemote ftp http://ftpproxy.mydomain:8080
1339 <p>In the last example, the proxy will forward FTP requests, encapsulated
1340 as yet another HTTP proxy request, to another proxy which can handle
1343 <p>This option also supports reverse proxy configuration - a backend
1344 webserver can be embedded within a virtualhost URL space even if that
1345 server is hidden by another forward proxy.</p>
1348 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1349 <div class="directive-section"><h2><a name="ProxyRemoteMatch" id="ProxyRemoteMatch">ProxyRemoteMatch</a> <a name="proxyremotematch" id="proxyremotematch">Directive</a></h2>
1350 <table class="directive">
1351 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Remote proxy used to handle requests matched by regular
1352 expressions</td></tr>
1353 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyRemoteMatch <var>regex</var> <var>remote-server</var></code></td></tr>
1354 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1355 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
1356 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
1358 <p>The <code class="directive">ProxyRemoteMatch</code> is identical to the
1359 <code class="directive"><a href="#proxyremote">ProxyRemote</a></code> directive, except the
1360 first argument is a <a class="glossarylink" href="../glossary.html#regex" title="see glossary">regular expression</a>
1361 match against the requested URL.</p>
1364 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1365 <div class="directive-section"><h2><a name="ProxyRequests" id="ProxyRequests">ProxyRequests</a> <a name="proxyrequests" id="proxyrequests">Directive</a></h2>
1366 <table class="directive">
1367 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enables forward (standard) proxy requests</td></tr>
1368 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyRequests On|Off</code></td></tr>
1369 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyRequests Off</code></td></tr>
1370 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1371 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
1372 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
1374 <p>This allows or prevents Apache from functioning as a forward proxy
1375 server. (Setting ProxyRequests to <code>Off</code> does not disable use of
1376 the <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive.)</p>
1378 <p>In a typical reverse proxy or gateway configuration, this
1379 option should be set to
1380 <code>Off</code>.</p>
1382 <p>In order to get the functionality of proxying HTTP or FTP sites, you
1383 need also <code class="module"><a href="../mod/mod_proxy_http.html">mod_proxy_http</a></code> or <code class="module"><a href="../mod/mod_proxy_ftp.html">mod_proxy_ftp</a></code>
1384 (or both) present in the server.</p>
1386 <div class="warning"><h3>Warning</h3>
1387 <p>Do not enable proxying with <code class="directive"><a href="#proxyrequests">ProxyRequests</a></code> until you have <a href="#access">secured your server</a>. Open proxy servers are dangerous
1388 both to your network and to the Internet at large.</p>
1393 <li><a href="#forwardreverse">Forward and Reverse Proxies/Gateways</a></li>
1396 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1397 <div class="directive-section"><h2><a name="ProxySet" id="ProxySet">ProxySet</a> <a name="proxyset" id="proxyset">Directive</a></h2>
1398 <table class="directive">
1399 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Set various Proxy balancer or member parameters</td></tr>
1400 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxySet <var>url</var> <var>key=value [key=value ...]</var></code></td></tr>
1401 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>directory</td></tr>
1402 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
1403 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
1404 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>ProxySet is only available in Apache 2.2
1405 and later.</td></tr>
1407 <p>This directive is used as an alternate method of setting any of the
1408 parameters available to Proxy balancers and workers normally done via the
1409 <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive. If used
1410 within a <code><Proxy <var>balancer url|worker url</var>></code>
1411 container directive, the <var>url</var> argument is not required. As a side
1412 effect the respective balancer or worker gets created. This can be useful
1413 when doing reverse proxying via a
1414 <code class="directive"><a href="../mod/mod_rewrite.html#rewriterule">RewriteRule</a></code> instead of a
1415 <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive.</p>
1417 <div class="example"><p><code>
1418 <Proxy balancer://hotcluster><br />
1419 <span class="indent">
1420 BalancerMember http://www2.example.com:8009 loadfactor=1<br />
1421 BalancerMember http://www3.example.com:8009 loadfactor=2<br />
1422 ProxySet lbmethod=bytraffic<br />
1427 <div class="example"><p><code>
1428 <Proxy http://backend><br />
1429 <span class="indent">
1430 ProxySet keepalive=On<br />
1435 <div class="example"><p><code>
1436 ProxySet balancer://foo lbmethod=bytraffic timeout=15
1439 <div class="example"><p><code>
1440 ProxySet ajp://backend:7001 timeout=15
1443 <div class="warning"><h3>Warning</h3>
1444 <p>Keep in mind that the same parameter key can have a different meaning
1445 depending whether it is applied to a balancer or a worker as shown by the two
1446 examples above regarding timeout.</p>
1451 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1452 <div class="directive-section"><h2><a name="ProxyStatus" id="ProxyStatus">ProxyStatus</a> <a name="proxystatus" id="proxystatus">Directive</a></h2>
1453 <table class="directive">
1454 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Show Proxy LoadBalancer status in mod_status</td></tr>
1455 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyStatus Off|On|Full</code></td></tr>
1456 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyStatus Off</code></td></tr>
1457 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1458 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
1459 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
1460 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in version 2.2 and later</td></tr>
1462 <p>This directive determines whether or not proxy
1463 loadbalancer status data is displayed via the <code class="module"><a href="../mod/mod_status.html">mod_status</a></code>
1464 server-status page.</p>
1465 <div class="note"><h3>Note</h3>
1466 <p><strong>Full</strong> is synonymous with <strong>On</strong></p>
1471 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1472 <div class="directive-section"><h2><a name="ProxyTimeout" id="ProxyTimeout">ProxyTimeout</a> <a name="proxytimeout" id="proxytimeout">Directive</a></h2>
1473 <table class="directive">
1474 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Network timeout for proxied requests</td></tr>
1475 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyTimeout <var>seconds</var></code></td></tr>
1476 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Value of <code class="directive"><a href="../mod/core.html#timeout">Timeout</a></code></code></td></tr>
1477 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1478 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
1479 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
1480 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.31 and later</td></tr>
1482 <p>This directive allows a user to specifiy a timeout on proxy requests.
1483 This is useful when you have a slow/buggy appserver which hangs, and you
1484 would rather just return a timeout and fail gracefully instead of waiting
1485 however long it takes the server to return.</p>
1488 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1489 <div class="directive-section"><h2><a name="ProxyVia" id="ProxyVia">ProxyVia</a> <a name="proxyvia" id="proxyvia">Directive</a></h2>
1490 <table class="directive">
1491 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Information provided in the <code>Via</code> HTTP response
1492 header for proxied requests</td></tr>
1493 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyVia On|Off|Full|Block</code></td></tr>
1494 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyVia Off</code></td></tr>
1495 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1496 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
1497 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
1499 <p>This directive controls the use of the <code>Via:</code> HTTP
1500 header by the proxy. Its intended use is to control the flow of
1501 proxy requests along a chain of proxy servers. See <a href="http://www.ietf.org/rfc/rfc2616.txt">RFC 2616</a> (HTTP/1.1), section
1502 14.45 for an explanation of <code>Via:</code> header lines.</p>
1505 <li>If set to <code>Off</code>, which is the default, no special processing
1506 is performed. If a request or reply contains a <code>Via:</code> header,
1507 it is passed through unchanged.</li>
1509 <li>If set to <code>On</code>, each request and reply will get a
1510 <code>Via:</code> header line added for the current host.</li>
1512 <li>If set to <code>Full</code>, each generated <code>Via:</code> header
1513 line will additionally have the Apache server version shown as a
1514 <code>Via:</code> comment field.</li>
1516 <li>If set to <code>Block</code>, every proxy request will have all its
1517 <code>Via:</code> header lines removed. No new <code>Via:</code> header will
1523 <div class="bottomlang">
1524 <p><span>Available Languages: </span><a href="../en/mod/mod_proxy.html" title="English"> en </a> |
1525 <a href="../fr/mod/mod_proxy.html" hreflang="fr" rel="alternate" title="Français"> fr </a> |
1526 <a href="../ja/mod/mod_proxy.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a></p>
1527 </div><div id="footer">
1528 <p class="apache">Copyright 2009 The Apache Software Foundation.<br />Licensed under the <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>.</p>
1529 <p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p></div>