1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
|
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head><!--
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
This file is generated from xml source: DO NOT EDIT
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
-->
<title>Shared Object Cache in Apache HTTP Server - Apache HTTP Server</title>
<link href="./style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" />
<link href="./style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" />
<link href="./style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" />
<link href="./images/favicon.ico" rel="shortcut icon" /></head>
<body id="manual-page" class="no-sidebar"><div id="page-header">
<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>
<p class="apache">Apache HTTP Server Version 2.5</p>
<img alt="" src="./images/feather.gif" /></div>
<div class="up"><a href="./"><img title="<-" alt="<-" src="./images/left.gif" /></a></div>
<div id="path">
<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></div><div id="page-content"><div id="preamble"><h1>Shared Object Cache in Apache HTTP Server</h1>
<div class="toplang">
<p><span>Available Languages: </span><a href="./en/socache.html" title="English"> en </a></p>
</div>
<p>The Shared Object Cache provides a means to share simple data
across all a server's workers, regardless of <a href="mpm.html">thread
and process models</a>. It is used where the advantages of sharing
data across processes outweigh the performance overhead of
inter-process communication.</p>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
<div class="section">
<h2><a name="providers" id="providers">Shared Object Cache Providers</a></h2>
<p>The shared object cache as such is an abstraction. Four different
modules implement it. To use the cache, one or more of these modules
must be present, and configured.</p>
<p>The only configuration required is to select which cache provider
to use. This is the responsibility of modules using the cache, and
they enable selection using directives such as
<code class="directive"><a href="./mod/mod_authn_socache.html#authncachesocache">AuthnCacheSOCache</a></code>,
<code class="directive"><a href="./mod/mod_ssl.html#sslsessioncache">SSLSessionCache</a></code>, and
<code class="directive"><a href="./mod/mod_ssl.html#sslstaplingcache">SSLStaplingCache</a></code>.</p>
<p>Currently available providers are:</p>
<dl>
<dt>"dbm" (<code class="module"><a href="./mod/mod_socache_dbm.html">mod_socache_dbm</a></code>)</dt>
<dd>This makes use of a DBM hash file.
The choice of underlying DBM used may be configurable
if the installed APR version supports multiple DBM implementations.</dd>
<dt>"dc" (<code class="module"><a href="./mod/mod_socache_dc.html">mod_socache_dc</a></code>)</dt>
<dd>This makes use of the <a href="http://www.distcache.org/">distcache</a>
distributed session caching libraries.</dd>
<dt>"memcache" (<code class="module"><a href="./mod/mod_socache_memcache.html">mod_socache_memcache</a></code>)</dt>
<dd>This makes use of the <a href="http://memcached.org/">memcached</a>
high-performance, distributed memory object caching system.</dd>
<dt>"shmcb" (<code class="module"><a href="./mod/mod_socache_shmcb.html">mod_socache_shmcb</a></code>)</dt>
<dd>This makes use of a high-performance cyclic buffer inside a
shared memory segment.</dd>
</dl>
<p>The API provides the following functions:</p>
<dl>
<dt>const char *create(ap_socache_instance_t **instance, const char *arg,
apr_pool_t *tmp, apr_pool_t *p);</dt>
<dd>Create a session cache based on the given configuration string.
The instance pointer returned in the instance paramater will be
passed as the first argument to subsequent invocations.</dd>
<dt>apr_status_t init(ap_socache_instance_t *instance, const char *cname,
const struct ap_socache_hints *hints,
server_rec *s, apr_pool_t *pool)</dt>
<dd>Initialize the cache. The cname must be of maximum length 16
characters, and uniquely identifies the consumer of the cache
within the server; using the module name is recommended, e.g.
"mod_ssl-sess". This string may be used within a filesystem
path so use of only alphanumeric [a-z0-9_-] characters is
recommended. If hints is non-NULL, it gives a set of hints for
the provider. Return APR error code.</dd>
<dt>void destroy(ap_socache_instance_t *instance, server_rec *s)</dt>
<dd>Destroy a given cache instance object.</dd>
<dt>apr_status_t store(ap_socache_instance_t *instance, server_rec *s,
const unsigned char *id, unsigned int idlen,
apr_time_t expiry,
unsigned char *data, unsigned int datalen,
apr_pool_t *pool)</dt>
<dd>Store an object in a cache instance.</dd>
<dt>apr_status_t retrieve(ap_socache_instance_t *instance, server_rec *s,
const unsigned char *id, unsigned int idlen,
unsigned char *data, unsigned int *datalen,
apr_pool_t *pool)</dt>
<dd>Retrieve a cached object.</dd>
<dt>apr_status_t remove(ap_socache_instance_t *instance, server_rec *s,
const unsigned char *id, unsigned int idlen,
apr_pool_t *pool)</dt>
<dd>Remove an object from the cache.</dd>
<dt>void status(ap_socache_instance_t *instance, request_rec *r, int flags)</dt>
<dd>Dump the status of a cache instance for mod_status.</dd>
<dt>apr_status_t iterate(ap_socache_instance_t *instance, server_rec *s,
void *userctx, ap_socache_iterator_t *iterator,
apr_pool_t *pool)</dt>
<dd>Dump all cached objects through an iterator callback.</dd>
</dl>
</div></div>
<div class="bottomlang">
<p><span>Available Languages: </span><a href="./en/socache.html" title="English"> en </a></p>
</div><div id="footer">
<p class="apache">Copyright 2012 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>
<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>
</body></html>
|
