1 <?xml version="1.0" encoding="ISO-8859-1"?>
2 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
3 <html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head>
4 <meta content="text/html; charset=ISO-8859-1" http-equiv="Content-Type" />
6 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
7 This file is generated from xml source: DO NOT EDIT
8 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
10 <title>mod_session - Apache HTTP Server Version 2.5</title>
11 <link href="../style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" />
12 <link href="../style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" />
13 <link href="../style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" /><link rel="stylesheet" type="text/css" href="../style/css/prettify.css" />
14 <script src="../style/scripts/prettify.min.js" type="text/javascript">
17 <link href="../images/favicon.ico" rel="shortcut icon" /></head>
19 <div id="page-header">
20 <p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/quickreference.html">Directives</a> | <a href="http://wiki.apache.org/httpd/FAQ">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p>
21 <p class="apache">Apache HTTP Server Version 2.5</p>
22 <img alt="" src="../images/feather.gif" /></div>
23 <div class="up"><a href="./"><img title="<-" alt="<-" src="../images/left.gif" /></a></div>
25 <a href="http://www.apache.org/">Apache</a> > <a href="http://httpd.apache.org/">HTTP Server</a> > <a href="http://httpd.apache.org/docs/">Documentation</a> > <a href="../">Version 2.5</a> > <a href="./">Modules</a></div>
26 <div id="page-content">
27 <div id="preamble"><h1>Apache Module mod_session</h1>
29 <p><span>Available Languages: </span><a href="../en/mod/mod_session.html" title="English"> en </a></p>
31 <table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>Session support</td></tr>
32 <tr><th><a href="module-dict.html#Status">Status:</a></th><td>Extension</td></tr>
33 <tr><th><a href="module-dict.html#ModuleIdentifier">Module Identifier:</a></th><td>session_module</td></tr>
34 <tr><th><a href="module-dict.html#SourceFile">Source File:</a></th><td>mod_session.c</td></tr>
35 <tr><th><a href="module-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.3 and later</td></tr></table>
38 <div class="warning"><h3>Warning</h3>
39 <p>The session modules make use of HTTP cookies, and as such can fall
40 victim to Cross Site Scripting attacks, or expose potentially private
41 information to clients. Please ensure that the relevant risks have
42 been taken into account before enabling the session functionality on
46 <p>This module provides support for a server wide per user session
47 interface. Sessions can be used for keeping track of whether a user
48 has been logged in, or for other per user information that should
49 be kept available across requests.</p>
51 <p>Sessions may be stored on the server, or may be stored on the
52 browser. Sessions may also be optionally encrypted for added security.
53 These features are divided into several modules in addition to
54 <code class="module"><a href="../mod/mod_session.html">mod_session</a></code>; <code class="module"><a href="../mod/mod_session_crypto.html">mod_session_crypto</a></code>,
55 <code class="module"><a href="../mod/mod_session_cookie.html">mod_session_cookie</a></code> and <code class="module"><a href="../mod/mod_session_dbd.html">mod_session_dbd</a></code>.
56 Depending on the server requirements, load the appropriate modules
57 into the server (either statically at compile time or dynamically
58 via the <code class="directive"><a href="../mod/mod_so.html#loadmodule">LoadModule</a></code> directive).</p>
60 <p>Sessions may be manipulated from other modules that depend on the
61 session, or the session may be read from and written to using
62 environment variables and HTTP headers, as appropriate.</p>
65 <div id="quickview"><h3>Topics</h3>
67 <li><img alt="" src="../images/down.gif" /> <a href="#whatisasession">What is a session?</a></li>
68 <li><img alt="" src="../images/down.gif" /> <a href="#whocanuseasession">Who can use a session?</a></li>
69 <li><img alt="" src="../images/down.gif" /> <a href="#serversession">Keeping sessions on the server</a></li>
70 <li><img alt="" src="../images/down.gif" /> <a href="#browsersession">Keeping sessions on the browser</a></li>
71 <li><img alt="" src="../images/down.gif" /> <a href="#basicexamples">Basic Examples</a></li>
72 <li><img alt="" src="../images/down.gif" /> <a href="#sessionprivacy">Session Privacy</a></li>
73 <li><img alt="" src="../images/down.gif" /> <a href="#cookieprivacy">Cookie Privacy</a></li>
74 <li><img alt="" src="../images/down.gif" /> <a href="#authentication">Session Support for Authentication</a></li>
75 <li><img alt="" src="../images/down.gif" /> <a href="#integration">Integrating Sessions with External Applications</a></li>
76 </ul><h3 class="directives">Directives</h3>
78 <li><img alt="" src="../images/down.gif" /> <a href="#session">Session</a></li>
79 <li><img alt="" src="../images/down.gif" /> <a href="#sessionenv">SessionEnv</a></li>
80 <li><img alt="" src="../images/down.gif" /> <a href="#sessionexclude">SessionExclude</a></li>
81 <li><img alt="" src="../images/down.gif" /> <a href="#sessionexpiryupdateinterval">SessionExpiryUpdateInterval</a></li>
82 <li><img alt="" src="../images/down.gif" /> <a href="#sessionheader">SessionHeader</a></li>
83 <li><img alt="" src="../images/down.gif" /> <a href="#sessioninclude">SessionInclude</a></li>
84 <li><img alt="" src="../images/down.gif" /> <a href="#sessionmaxage">SessionMaxAge</a></li>
88 <li><code class="module"><a href="../mod/mod_session_cookie.html">mod_session_cookie</a></code></li>
89 <li><code class="module"><a href="../mod/mod_session_crypto.html">mod_session_crypto</a></code></li>
90 <li><code class="module"><a href="../mod/mod_session_dbd.html">mod_session_dbd</a></code></li>
91 </ul><ul class="seealso"><li><a href="#comments_section">Comments</a></li></ul></div>
92 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
94 <h2><a name="whatisasession" id="whatisasession">What is a session?</a></h2>
95 <p>At the core of the session interface is a table of key and value pairs
96 that are made accessible across browser requests. These pairs can be set
97 to any valid string, as needed by the application making use of the
100 <p>The "session" is a <strong>application/x-www-form-urlencoded</strong>
101 string containing these key value pairs, as defined by the
102 <a href="http://www.w3.org/TR/html4/">HTML specification</a>.</p>
104 <p>The session can optionally be encrypted and base64 encoded before
105 being written to the storage mechanism, as defined by the
108 </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
109 <div class="section">
110 <h2><a name="whocanuseasession" id="whocanuseasession">Who can use a session?</a></h2>
111 <p>The session interface is primarily developed for the use by other
112 server modules, such as <code class="module"><a href="../mod/mod_auth_form.html">mod_auth_form</a></code>, however CGI
113 based applications can optionally be granted access to the contents
114 of the session via the HTTP_SESSION environment variable. Sessions
115 have the option to be modified and/or updated by inserting an HTTP
116 response header containing the new session parameters.</p>
118 </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
119 <div class="section">
120 <h2><a name="serversession" id="serversession">Keeping sessions on the server</a></h2>
121 <p>Apache can be configured to keep track of per user sessions stored
122 on a particular server or group of servers. This functionality is
123 similar to the sessions available in typical application servers.</p>
125 <p>If configured, sessions are tracked through the use of a session ID that
126 is stored inside a cookie, or extracted from the parameters embedded
127 within the URL query string, as found in a typical GET request.</p>
129 <p>As the contents of the session are stored exclusively on the server,
130 there is an expectation of privacy of the contents of the session. This
131 does have performance and resource implications should a large number
132 of sessions be present, or where a large number of webservers have to
133 share sessions with one another.</p>
135 <p>The <code class="module"><a href="../mod/mod_session_dbd.html">mod_session_dbd</a></code> module allows the storage of user
136 sessions within a SQL database via <code class="module"><a href="../mod/mod_dbd.html">mod_dbd</a></code>.</p>
138 </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
139 <div class="section">
140 <h2><a name="browsersession" id="browsersession">Keeping sessions on the browser</a></h2>
141 <p>In high traffic environments where keeping track of a session on a
142 server is too resource intensive or inconvenient, the option exists to store
143 the contents of the session within a cookie on the client browser instead.</p>
145 <p>This has the advantage that minimal resources are required on the
146 server to keep track of sessions, and multiple servers within a server
147 farm have no need to share session information.</p>
149 <p>The contents of the session however are exposed to the client, with a
150 corresponding risk of a loss of privacy. The
151 <code class="module"><a href="../mod/mod_session_crypto.html">mod_session_crypto</a></code> module can be configured to encrypt the
152 contents of the session before writing the session to the client.</p>
154 <p>The <code class="module"><a href="../mod/mod_session_cookie.html">mod_session_cookie</a></code> allows the storage of user
155 sessions on the browser within an HTTP cookie.</p>
157 </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
158 <div class="section">
159 <h2><a name="basicexamples" id="basicexamples">Basic Examples</a></h2>
161 <p>Creating a session is as simple as turning the session on, and deciding
162 where the session will be stored. In this example, the session will be
163 stored on the browser, in a cookie called <code>session</code>.</p>
165 <div class="example"><h3>Browser based session</h3><pre class="prettyprint lang-config">Session On
166 SessionCookieName session path=/</pre>
169 <p>The session is not useful unless it can be written to or read from. The
170 following example shows how values can be injected into the session through
171 the use of a predetermined HTTP response header called
172 <code>X-Replace-Session</code>.</p>
174 <div class="example"><h3>Writing to a session</h3><pre class="prettyprint lang-config">Session On
175 SessionCookieName session path=/
176 SessionHeader X-Replace-Session</pre>
179 <p>The header should contain name value pairs expressed in the same format
180 as a query string in a URL, as in the example below. Setting a key to the
181 empty string has the effect of removing that key from the session.</p>
183 <div class="example"><h3>CGI to write to a session</h3><pre class="prettyprint lang-sh">#!/bin/bash
184 echo "Content-Type: text/plain"
185 echo "X-Replace-Session: key1=foo&key2=&key3=bar"
190 <p>If configured, the session can be read back from the HTTP_SESSION
191 environment variable. By default, the session is kept private, so this
192 has to be explicitly turned on with the
193 <code class="directive"><a href="#sessionenv">SessionEnv</a></code> directive.</p>
195 <div class="example"><h3>Read from a session</h3><pre class="prettyprint lang-config">Session On
197 SessionCookieName session path=/
198 SessionHeader X-Replace-Session</pre>
201 <p>Once read, the CGI variable <code>HTTP_SESSION</code> should contain
202 the value <code>key1=foo&key3=bar</code>.</p>
204 </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
205 <div class="section">
206 <h2><a name="sessionprivacy" id="sessionprivacy">Session Privacy</a></h2>
208 <p>Using the "show cookies" feature of your browser, you would have seen
209 a clear text representation of the session. This could potentially be a
210 problem should the end user need to be kept unaware of the contents of
211 the session, or where a third party could gain unauthorised access to the
212 data within the session.</p>
214 <p>The contents of the session can be optionally encrypted before being
215 placed on the browser using the <code class="module"><a href="../mod/mod_session_crypto.html">mod_session_crypto</a></code>
218 <div class="example"><h3>Browser based encrypted session</h3><pre class="prettyprint lang-config">Session On
219 SessionCryptoPassphrase secret
220 SessionCookieName session path=/</pre>
223 <p>The session will be automatically decrypted on load, and encrypted on
224 save by Apache, the underlying application using the session need have
225 no knowledge that encryption is taking place.</p>
227 <p>Sessions stored on the server rather than on the browser can also be
228 encrypted as needed, offering privacy where potentially sensitive
229 information is being shared between webservers in a server farm using
230 the <code class="module"><a href="../mod/mod_session_dbd.html">mod_session_dbd</a></code> module.</p>
232 </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
233 <div class="section">
234 <h2><a name="cookieprivacy" id="cookieprivacy">Cookie Privacy</a></h2>
236 <p>The HTTP cookie mechanism also offers privacy features, such as the
237 ability to restrict cookie transport to SSL protected pages only, or
238 to prevent browser based javascript from gaining access to the contents
241 <div class="warning"><h3>Warning</h3>
242 <p>Some of the HTTP cookie privacy features are either non-standard, or
243 are not implemented consistently across browsers. The session modules
244 allow you to set cookie parameters, but it makes no guarantee that privacy
245 will be respected by the browser. If security is a concern, use the
246 <code class="module"><a href="../mod/mod_session_crypto.html">mod_session_crypto</a></code> to encrypt the contents of the session,
247 or store the session on the server using the <code class="module"><a href="../mod/mod_session_dbd.html">mod_session_dbd</a></code>
251 <p>Standard cookie parameters can be specified after the name of the cookie,
252 as in the example below.</p>
254 <div class="example"><h3>Setting cookie parameters</h3><pre class="prettyprint lang-config">Session On
255 SessionCryptoPassphrase secret
256 SessionCookieName session path=/private;domain=example.com;httponly;secure;</pre>
259 <p>In cases where the Apache server forms the frontend for backend origin servers,
260 it is possible to have the session cookies removed from the incoming HTTP headers using
261 the <code class="directive"><a href="../mod/mod_session_cookie.html#sessioncookieremove">SessionCookieRemove</a></code> directive.
262 This keeps the contents of the session cookies from becoming accessible from the
266 </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
267 <div class="section">
268 <h2><a name="authentication" id="authentication">Session Support for Authentication</a></h2>
270 <p>As is possible within many application servers, authentication modules can use
271 a session for storing the username and password after login. The
272 <code class="module"><a href="../mod/mod_auth_form.html">mod_auth_form</a></code> saves the user's login name and password within
275 <div class="example"><h3>Form based authentication</h3><pre class="prettyprint lang-config">Session On
276 SessionCryptoPassphrase secret
277 SessionCookieName session path=/
278 AuthFormProvider file
279 AuthUserFile "conf/passwd"
285 <p>See the <code class="module"><a href="../mod/mod_auth_form.html">mod_auth_form</a></code> module for documentation and complete
288 </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
289 <div class="section">
290 <h2><a name="integration" id="integration">Integrating Sessions with External Applications</a></h2>
292 <p>In order for sessions to be useful, it must be possible to share the contents
293 of a session with external applications, and it must be possible for an
294 external application to write a session of its own.</p>
296 <p> A typical example might be an application that changes a user's password set by
297 <code class="module"><a href="../mod/mod_auth_form.html">mod_auth_form</a></code>. This application would need to read the current
298 username and password from the session, make the required changes to the user's
299 password, and then write the new password to the session in order to provide a
300 seamless transition to the new password.</p>
302 <p>A second example might involve an application that registers a new user for
303 the first time. When registration is complete, the username and password is
304 written to the session, providing a seamless transition to being logged in.</p>
307 <dt>Apache modules</dt>
308 <dd>Modules within the server that need access to the session can use the
309 <strong>mod_session.h</strong> API in order to read from and write to the
310 session. This mechanism is used by modules like <code class="module"><a href="../mod/mod_auth_form.html">mod_auth_form</a></code>.
313 <dt>CGI programs and scripting languages</dt>
314 <dd>Applications that run within the webserver can optionally retrieve the
315 value of the session from the <strong>HTTP_SESSION</strong> environment
316 variable. The session should be encoded as a
317 <strong>application/x-www-form-urlencoded</strong> string as described by the
318 <a href="http://www.w3.org/TR/html4/">HTML specification</a>. The environment
319 variable is controlled by the setting of the
320 <code class="directive"><a href="#sessionenv">SessionEnv</a></code> directive. The session
321 can be written to by the script by returning a
322 <strong>application/x-www-form-urlencoded</strong> response header with a name
323 set by the <code class="directive"><a href="#sessionheader">SessionHeader</a></code>
324 directive. In both cases, any encryption or decryption, and the reading the
325 session from or writing the session to the chosen storage mechanism is handled
326 by the <code class="module"><a href="../mod/mod_session.html">mod_session</a></code> modules and corresponding configuration.
329 <dt>Applications behind <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code></dt>
330 <dd>If the <code class="directive"><a href="#sessionheader">SessionHeader</a></code>
331 directive is used to define an HTTP request header, the session, encoded as
332 a <strong>application/x-www-form-urlencoded</strong> string, will be made
333 available to the application. If the same header is provided in the response,
334 the value of this response header will be used to replace the session. As
335 above, any encryption or decryption, and the reading the session from or
336 writing the session to the chosen storage mechanism is handled by the
337 <code class="module"><a href="../mod/mod_session.html">mod_session</a></code> modules and corresponding configuration.</dd>
339 <dt>Standalone applications</dt>
340 <dd>Applications might choose to manipulate the session outside the control
341 of the Apache HTTP server. In this case, it is the responsibility of the
342 application to read the session from the chosen storage mechanism,
343 decrypt the session, update the session, encrypt the session and write
344 the session to the chosen storage mechanism, as appropriate.</dd>
348 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
349 <div class="directive-section"><h2><a name="Session" id="Session">Session</a> <a name="session" id="session">Directive</a></h2>
350 <table class="directive">
351 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enables a session for the current directory or location</td></tr>
352 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>Session On|Off</code></td></tr>
353 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>Session Off</code></td></tr>
354 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
355 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</td></tr>
356 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
357 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_session</td></tr>
359 <p>The <code class="directive">Session</code> directive enables a session for the
360 directory or location container. Further directives control where the
361 session will be stored and how privacy is maintained.</p>
364 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
365 <div class="directive-section"><h2><a name="SessionEnv" id="SessionEnv">SessionEnv</a> <a name="sessionenv" id="sessionenv">Directive</a></h2>
366 <table class="directive">
367 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Control whether the contents of the session are written to the
368 <var>HTTP_SESSION</var> environment variable</td></tr>
369 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>SessionEnv On|Off</code></td></tr>
370 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>SessionEnv Off</code></td></tr>
371 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
372 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</td></tr>
373 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
374 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_session</td></tr>
376 <p>If set to <var>On</var>, the <code class="directive">SessionEnv</code> directive
377 causes the contents of the session to be written to a CGI environment
378 variable called <var>HTTP_SESSION</var>.</p>
380 <p>The string is written in the URL query format, for example:</p>
382 <div class="example"><p><code>
383 <code>key1=foo&key3=bar</code>
388 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
389 <div class="directive-section"><h2><a name="SessionExclude" id="SessionExclude">SessionExclude</a> <a name="sessionexclude" id="sessionexclude">Directive</a></h2>
390 <table class="directive">
391 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Define URL prefixes for which a session is ignored</td></tr>
392 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>SessionExclude <var>path</var></code></td></tr>
393 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>none</code></td></tr>
394 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
395 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
396 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_session</td></tr>
398 <p>The <code class="directive">SessionExclude</code> directive allows sessions to
399 be disabled relative to URL prefixes only. This can be used to make a
400 website more efficient, by targeting a more precise URL space for which
401 a session should be maintained. By default, all URLs within the directory
402 or location are included in the session. The
403 <code class="directive"><a href="#sessionexclude">SessionExclude</a></code> directive takes
405 <code class="directive"><a href="#sessioninclude">SessionInclude</a></code> directive.</p>
407 <div class="warning"><h3>Warning</h3>
408 <p>This directive has a similar purpose to the <var>path</var> attribute
409 in HTTP cookies, but should not be confused with this attribute. This
410 directive does not set the <var>path</var> attribute, which must be
411 configured separately.</p></div>
414 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
415 <div class="directive-section"><h2><a name="SessionExpiryUpdateInterval" id="SessionExpiryUpdateInterval">SessionExpiryUpdateInterval</a> <a name="sessionexpiryupdateinterval" id="sessionexpiryupdateinterval">Directive</a></h2>
416 <table class="directive">
417 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Define the number of seconds a session's expiry may change without
418 the session being updated</td></tr>
419 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>SessionExpiryUpdateInterval <var>interval</var></code></td></tr>
420 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>SessionExpiryUpdateInterval 0 (always update)</code></td></tr>
421 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
422 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
423 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_session</td></tr>
425 <p>The <code class="directive">SessionExpiryUpdateInterval</code> directive allows
426 sessions to avoid the cost associated with writing the session each request
427 when only the expiry time has changed. This can be used to make a website
428 more efficient or reduce load on a database when using
429 <code class="module"><a href="../mod/mod_session_dbd.html">mod_session_dbd</a></code>. The session is always written if the data
430 stored in the session has changed or the expiry has changed by more than the
431 configured interval.</p>
433 <p>Setting the interval to zero disables this directive, and the session
434 expiry is refreshed for each request.</p>
436 <p>This directive only has an effect when combined with
437 <code class="directive"><a href="#sessionmaxage">SessionMaxAge</a></code> to enable session
438 expiry. Sessions without an expiry are only written when the data stored in
439 the session has changed.</p>
441 <div class="warning"><h3>Warning</h3>
442 <p>Because the session expiry may not be refreshed with each request, it's
443 possible for sessions to expire up to <var>interval</var> seconds early.
444 Using a small interval usually provides sufficient savings while having a
445 minimal effect on expiry resolution.</p></div>
448 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
449 <div class="directive-section"><h2><a name="SessionHeader" id="SessionHeader">SessionHeader</a> <a name="sessionheader" id="sessionheader">Directive</a></h2>
450 <table class="directive">
451 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Import session updates from a given HTTP response header</td></tr>
452 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>SessionHeader <var>header</var></code></td></tr>
453 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>none</code></td></tr>
454 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
455 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</td></tr>
456 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
457 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_session</td></tr>
459 <p>The <code class="directive">SessionHeader</code> directive defines the name of an
460 HTTP response header which, if present, will be parsed and written to the
463 <p>The header value is expected to be in the URL query format, for example:</p>
465 <div class="example"><p><code>
466 <code>key1=foo&key2=&key3=bar</code>
469 <p>Where a key is set to the empty string, that key will be removed from the
474 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
475 <div class="directive-section"><h2><a name="SessionInclude" id="SessionInclude">SessionInclude</a> <a name="sessioninclude" id="sessioninclude">Directive</a></h2>
476 <table class="directive">
477 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Define URL prefixes for which a session is valid</td></tr>
478 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>SessionInclude <var>path</var></code></td></tr>
479 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>all URLs</code></td></tr>
480 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
481 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</td></tr>
482 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
483 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_session</td></tr>
485 <p>The <code class="directive">SessionInclude</code> directive allows sessions to
486 be made valid for specific URL prefixes only. This can be used to make a
487 website more efficient, by targeting a more precise URL space for which
488 a session should be maintained. By default, all URLs within the directory
489 or location are included in the session.</p>
491 <div class="warning"><h3>Warning</h3>
492 <p>This directive has a similar purpose to the <var>path</var> attribute
493 in HTTP cookies, but should not be confused with this attribute. This
494 directive does not set the <var>path</var> attribute, which must be
495 configured separately.</p></div>
498 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
499 <div class="directive-section"><h2><a name="SessionMaxAge" id="SessionMaxAge">SessionMaxAge</a> <a name="sessionmaxage" id="sessionmaxage">Directive</a></h2>
500 <table class="directive">
501 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Define a maximum age in seconds for a session</td></tr>
502 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>SessionMaxAge <var>maxage</var></code></td></tr>
503 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>SessionMaxAge 0</code></td></tr>
504 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr>
505 <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>AuthConfig</td></tr>
506 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
507 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_session</td></tr>
509 <p>The <code class="directive">SessionMaxAge</code> directive defines a time limit
510 for which a session will remain valid. When a session is saved, this time
511 limit is reset and an existing session can be continued. If a session
512 becomes older than this limit without a request to the server to refresh
513 the session, the session will time out and be removed. Where a session is
514 used to stored user login details, this has the effect of logging the user
515 out automatically after the given time.</p>
517 <p>Setting the maxage to zero disables session expiry.</p>
521 <div class="bottomlang">
522 <p><span>Available Languages: </span><a href="../en/mod/mod_session.html" title="English"> en </a></p>
523 </div><div class="top"><a href="#page-header"><img src="../images/up.gif" alt="top" /></a></div><div class="section"><h2><a id="comments_section" name="comments_section">Comments</a></h2><div class="warning"><strong>Notice:</strong><br />This is not a Q&A section. Comments placed here should be pointed towards suggestions on improving the documentation or server, and may be removed again by our moderators if they are either implemented or considered invalid/off-topic. Questions on how to manage the Apache HTTP Server should be directed at either our IRC channel, #httpd, on Freenode, or sent to our <a href="http://httpd.apache.org/lists.html">mailing lists</a>.</div>
524 <script type="text/javascript"><!--//--><![CDATA[//><!--
525 var comments_shortname = 'httpd';
526 var comments_identifier = 'http://httpd.apache.org/docs/trunk/mod/mod_session.html';
528 if (w.location.hostname.toLowerCase() == "httpd.apache.org") {
529 d.write('<div id="comments_thread"><\/div>');
530 var s = d.createElement('script');
531 s.type = 'text/javascript';
533 s.src = 'https://comments.apache.org/show_comments.lua?site=' + comments_shortname + '&page=' + comments_identifier;
534 (d.getElementsByTagName('head')[0] || d.getElementsByTagName('body')[0]).appendChild(s);
537 d.write('<div id="comments_thread">Comments are disabled for this page at the moment.<\/div>');
539 })(window, document);
540 //--><!]]></script></div><div id="footer">
541 <p class="apache">Copyright 2015 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>
542 <p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/quickreference.html">Directives</a> | <a href="http://wiki.apache.org/httpd/FAQ">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p></div><script type="text/javascript"><!--//--><![CDATA[//><!--
543 if (typeof(prettyPrint) !== 'undefined') {