4 <!--[if IE 8]><html class="no-js lt-ie9" lang="en" > <![endif]-->
5 <!--[if gt IE 8]><!--> <html class="no-js" lang="en" > <!--<![endif]-->
9 <meta name=
"viewport" content=
"width=device-width, initial-scale=1.0">
11 <title>Working with statistical information from a server
— libmemcached
1.0.99 documentation
</title>
20 <script type=
"text/javascript" src=
"../_static/js/modernizr.min.js"></script>
23 <script type=
"text/javascript" id=
"documentation_options" data-url_root=
"../" src=
"../_static/documentation_options.js"></script>
24 <script src=
"../_static/jquery.js"></script>
25 <script src=
"../_static/underscore.js"></script>
26 <script src=
"../_static/doctools.js"></script>
27 <script src=
"../_static/language_data.js"></script>
29 <script type=
"text/javascript" src=
"../_static/js/theme.js"></script>
34 <link rel=
"stylesheet" href=
"../_static/css/theme.css" type=
"text/css" />
35 <link rel=
"stylesheet" href=
"../_static/pygments.css" type=
"text/css" />
36 <link rel=
"index" title=
"Index" href=
"../genindex.html" />
37 <link rel=
"search" title=
"Search" href=
"../search.html" />
38 <link rel=
"copyright" title=
"Copyright" href=
"../copyright.html" />
39 <link rel=
"next" title=
"Deprecated Functionality" href=
"index_deprecated.html" />
40 <link rel=
"prev" title=
"Analyzing servers" href=
"memcached_analyze.html" />
43 <body class=
"wy-body-for-nav">
46 <div class=
"wy-grid-for-nav">
48 <nav data-toggle=
"wy-nav-shift" class=
"wy-nav-side">
49 <div class=
"wy-side-scroll">
50 <div class=
"wy-side-nav-search" >
54 <a href=
"../index.html" class=
"icon icon-home"> libmemcached
71 <form id=
"rtd-search-form" class=
"wy-form" action=
"../search.html" method=
"get">
72 <input type=
"text" name=
"q" placeholder=
"Search docs" />
73 <input type=
"hidden" name=
"check_keywords" value=
"yes" />
74 <input type=
"hidden" name=
"area" value=
"default" />
81 <div class=
"wy-menu wy-menu-vertical" data-spy=
"affix" role=
"navigation" aria-label=
"main navigation">
88 <p class=
"caption"><span class=
"caption-text">libmemcached
</span></p>
90 <li class=
"toctree-l1"><a class=
"reference internal" href=
"../libmemcached.html">Introduction
</a></li>
91 <li class=
"toctree-l1 current"><a class=
"reference internal" href=
"index.html">libmemcached API
</a><ul class=
"current">
92 <li class=
"toctree-l2"><a class=
"reference internal" href=
"index_basics.html">Basics
</a></li>
93 <li class=
"toctree-l2"><a class=
"reference internal" href=
"index_data.html">Working with Data
</a></li>
94 <li class=
"toctree-l2"><a class=
"reference internal" href=
"index_errors.html">Messages and Errors
</a></li>
95 <li class=
"toctree-l2 current"><a class=
"reference internal" href=
"index_advanced.html">Advanced Topics
</a><ul class=
"current">
96 <li class=
"toctree-l3"><a class=
"reference internal" href=
"index_advanced_internals.html">Internal Behavior
</a></li>
97 <li class=
"toctree-l3"><a class=
"reference internal" href=
"index_advanced_aeh.html">Authentication, Encryption
& Hashing
</a></li>
98 <li class=
"toctree-l3"><a class=
"reference internal" href=
"index_advanced_servers.html">Servers and Server Lists
</a></li>
99 <li class=
"toctree-l3"><a class=
"reference internal" href=
"index_advanced_daemon.html">Affecting the memcached Daemon
</a></li>
100 <li class=
"toctree-l3 current"><a class=
"reference internal" href=
"index_advanced_stats.html">Statistics
</a><ul class=
"current">
101 <li class=
"toctree-l4"><a class=
"reference internal" href=
"memcached_analyze.html">Analyzing servers
</a></li>
102 <li class=
"toctree-l4 current"><a class=
"current reference internal" href=
"#">Working with statistical information from a server
</a></li>
107 <li class=
"toctree-l2"><a class=
"reference internal" href=
"index_deprecated.html">Deprecated Functionality
</a></li>
110 <li class=
"toctree-l1"><a class=
"reference internal" href=
"index_misc.html">Misc
</a></li>
112 <p class=
"caption"><span class=
"caption-text">libmemcachedutil
</span></p>
114 <li class=
"toctree-l1"><a class=
"reference internal" href=
"../libmemcachedutil.html">Introduction
</a></li>
115 <li class=
"toctree-l1"><a class=
"reference internal" href=
"../libmemcachedutil/index.html">libmemcachedutil API
</a></li>
117 <p class=
"caption"><span class=
"caption-text">libhashkit
</span></p>
119 <li class=
"toctree-l1"><a class=
"reference internal" href=
"../libhashkit.html">Introduction
</a></li>
120 <li class=
"toctree-l1"><a class=
"reference internal" href=
"../libhashkit/index.html">libhashkit API
</a></li>
122 <p class=
"caption"><span class=
"caption-text">Client Applications
</span></p>
124 <li class=
"toctree-l1"><a class=
"reference internal" href=
"../bin/index.html">Client Applications
</a></li>
126 <p class=
"caption"><span class=
"caption-text">Copyright
</span></p>
128 <li class=
"toctree-l1"><a class=
"reference internal" href=
"../copyright.html">Copyright
</a></li>
137 <section data-toggle=
"wy-nav-shift" class=
"wy-nav-content-wrap">
140 <nav class=
"wy-nav-top" aria-label=
"top navigation">
142 <i data-toggle=
"wy-nav-top" class=
"fa fa-bars"></i>
143 <a href=
"../index.html">libmemcached
</a>
148 <div class=
"wy-nav-content">
150 <div class=
"rst-content">
168 <div role=
"navigation" aria-label=
"breadcrumbs navigation">
170 <ul class=
"wy-breadcrumbs">
172 <li><a href=
"../index.html">Docs
</a> »</li>
174 <li><a href=
"index.html">libmemcached API
</a> »</li>
176 <li><a href=
"index_advanced.html">Advanced Topics
</a> »</li>
178 <li><a href=
"index_advanced_stats.html">Statistics
</a> »</li>
180 <li>Working with statistical information from a server
</li>
183 <li class=
"wy-breadcrumbs-aside">
194 <div role=
"main" class=
"document" itemscope=
"itemscope" itemtype=
"http://schema.org/Article">
195 <div itemprop=
"articleBody">
197 <div class=
"section" id=
"working-with-statistical-information-from-a-server">
198 <h1>Working with statistical information from a server
<a class=
"headerlink" href=
"#working-with-statistical-information-from-a-server" title=
"Permalink to this headline">¶
</a></h1>
199 <p>Get memcached statistics
</p>
200 <div class=
"section" id=
"synopsis">
201 <span id=
"index-0"></span><h2>SYNOPSIS
<a class=
"headerlink" href=
"#synopsis" title=
"Permalink to this headline">¶
</a></h2>
202 <p>#include
<libmemcached/memcached.h
></p>
204 <dt id=
"_CPPv417memcached_stat_st">
205 <span id=
"_CPPv317memcached_stat_st"></span><span id=
"_CPPv217memcached_stat_st"></span><span id=
"memcached_stat_st"></span><em class=
"property">type
</em><code class=
"sig-name descname">memcached_stat_st
</code><a class=
"headerlink" href=
"#_CPPv417memcached_stat_st" title=
"Permalink to this definition">¶
</a><br /></dt>
209 <dt id=
"_CPPv417memcached_stat_fn">
210 <span id=
"_CPPv317memcached_stat_fn"></span><span id=
"_CPPv217memcached_stat_fn"></span><span id=
"memcached_stat_fn"></span><em class=
"property">typedef
</em><a class=
"reference internal" href=
"memcached_return_t.html#_CPPv418memcached_return_t" title=
"memcached_return_t">memcached_return_t
</a> (*
<code class=
"sig-name descname">memcached_stat_fn
</code>)
<span class=
"sig-paren">(
</span><em class=
"property">const
</em> memcached_instance_st *server,
<em class=
"property">const
</em> char *key, size_t key_length,
<em class=
"property">const
</em> char *value, size_t value_length, void *context
<span class=
"sig-paren">)
</span><a class=
"headerlink" href=
"#_CPPv417memcached_stat_fn" title=
"Permalink to this definition">¶
</a><br /></dt>
213 <dl class=
"function">
214 <dt id=
"_CPPv414memcached_statP12memcached_stPcP18memcached_return_t">
215 <span id=
"_CPPv314memcached_statP12memcached_stPcP18memcached_return_t"></span><span id=
"_CPPv214memcached_statP12memcached_stPcP18memcached_return_t"></span><span id=
"memcached_stat__memcached_stP.cP.memcached_return_tP"></span><a class=
"reference internal" href=
"#_CPPv417memcached_stat_st" title=
"memcached_stat_st">memcached_stat_st
</a> *
<code class=
"sig-name descname">memcached_stat
</code><span class=
"sig-paren">(
</span><a class=
"reference internal" href=
"memcached_create.html#_CPPv412memcached_st" title=
"memcached_st">memcached_st
</a> *
<em>ptr
</em>, char *
<em>args
</em>,
<a class=
"reference internal" href=
"memcached_return_t.html#_CPPv418memcached_return_t" title=
"memcached_return_t">memcached_return_t
</a> *
<em>error
</em><span class=
"sig-paren">)
</span><a class=
"headerlink" href=
"#_CPPv414memcached_statP12memcached_stPcP18memcached_return_t" title=
"Permalink to this definition">¶
</a><br /></dt>
218 <dl class=
"function">
219 <dt id=
"_CPPv425memcached_stat_servernameP17memcached_stat_stPcPKc9in_port_t">
220 <span id=
"_CPPv325memcached_stat_servernameP17memcached_stat_stPcPKc9in_port_t"></span><span id=
"_CPPv225memcached_stat_servernameP17memcached_stat_stPcPKc9in_port_t"></span><span id=
"memcached_stat_servername__memcached_stat_stP.cP.cCP.in_port_t"></span><a class=
"reference internal" href=
"memcached_return_t.html#_CPPv418memcached_return_t" title=
"memcached_return_t">memcached_return_t
</a> <code class=
"sig-name descname">memcached_stat_servername
</code><span class=
"sig-paren">(
</span><a class=
"reference internal" href=
"#_CPPv417memcached_stat_st" title=
"memcached_stat_st">memcached_stat_st
</a> *
<em>stat
</em>, char *
<em>args
</em>,
<em class=
"property">const
</em> char *
<em>hostname
</em>, in_port_t
<em>port
</em><span class=
"sig-paren">)
</span><a class=
"headerlink" href=
"#_CPPv425memcached_stat_servernameP17memcached_stat_stPcPKc9in_port_t" title=
"Permalink to this definition">¶
</a><br /></dt>
223 <dl class=
"function">
224 <dt id=
"_CPPv424memcached_stat_get_valueP12memcached_stP17memcached_stat_stPKcP18memcached_return_t">
225 <span id=
"_CPPv324memcached_stat_get_valueP12memcached_stP17memcached_stat_stPKcP18memcached_return_t"></span><span id=
"_CPPv224memcached_stat_get_valueP12memcached_stP17memcached_stat_stPKcP18memcached_return_t"></span><span id=
"memcached_stat_get_value__memcached_stP.memcached_stat_stP.cCP.memcached_return_tP"></span>char *
<code class=
"sig-name descname">memcached_stat_get_value
</code><span class=
"sig-paren">(
</span><a class=
"reference internal" href=
"memcached_create.html#_CPPv412memcached_st" title=
"memcached_st">memcached_st
</a> *
<em>ptr
</em>,
<a class=
"reference internal" href=
"#_CPPv417memcached_stat_st" title=
"memcached_stat_st">memcached_stat_st
</a> *
<em>stat
</em>,
<em class=
"property">const
</em> char *
<em>key
</em>,
<a class=
"reference internal" href=
"memcached_return_t.html#_CPPv418memcached_return_t" title=
"memcached_return_t">memcached_return_t
</a> *
<em>error
</em><span class=
"sig-paren">)
</span><a class=
"headerlink" href=
"#_CPPv424memcached_stat_get_valueP12memcached_stP17memcached_stat_stPKcP18memcached_return_t" title=
"Permalink to this definition">¶
</a><br /></dt>
228 <dl class=
"function">
229 <dt id=
"_CPPv423memcached_stat_get_keysP12memcached_stP17memcached_stat_stP18memcached_return_t">
230 <span id=
"_CPPv323memcached_stat_get_keysP12memcached_stP17memcached_stat_stP18memcached_return_t"></span><span id=
"_CPPv223memcached_stat_get_keysP12memcached_stP17memcached_stat_stP18memcached_return_t"></span><span id=
"memcached_stat_get_keys__memcached_stP.memcached_stat_stP.memcached_return_tP"></span>char **
<code class=
"sig-name descname">memcached_stat_get_keys
</code><span class=
"sig-paren">(
</span><a class=
"reference internal" href=
"memcached_create.html#_CPPv412memcached_st" title=
"memcached_st">memcached_st
</a> *
<em>ptr
</em>,
<a class=
"reference internal" href=
"#_CPPv417memcached_stat_st" title=
"memcached_stat_st">memcached_stat_st
</a> *
<em>stat
</em>,
<a class=
"reference internal" href=
"memcached_return_t.html#_CPPv418memcached_return_t" title=
"memcached_return_t">memcached_return_t
</a> *
<em>error
</em><span class=
"sig-paren">)
</span><a class=
"headerlink" href=
"#_CPPv423memcached_stat_get_keysP12memcached_stP17memcached_stat_stP18memcached_return_t" title=
"Permalink to this definition">¶
</a><br /></dt>
233 <dl class=
"function">
234 <dt id=
"_CPPv422memcached_stat_executeP12memcached_stPKc17memcached_stat_fnPv">
235 <span id=
"_CPPv322memcached_stat_executeP12memcached_stPKc17memcached_stat_fnPv"></span><span id=
"_CPPv222memcached_stat_executeP12memcached_stPKc17memcached_stat_fnPv"></span><span id=
"memcached_stat_execute__memcached_stP.cCP.memcached_stat_fn.voidP"></span><a class=
"reference internal" href=
"memcached_return_t.html#_CPPv418memcached_return_t" title=
"memcached_return_t">memcached_return_t
</a> <code class=
"sig-name descname">memcached_stat_execute
</code><span class=
"sig-paren">(
</span><a class=
"reference internal" href=
"memcached_create.html#_CPPv412memcached_st" title=
"memcached_st">memcached_st
</a> *
<em>memc
</em>,
<em class=
"property">const
</em> char *
<em>args
</em>,
<a class=
"reference internal" href=
"#_CPPv417memcached_stat_fn" title=
"memcached_stat_fn">memcached_stat_fn
</a> <em>func
</em>, void *
<em>context
</em><span class=
"sig-paren">)
</span><a class=
"headerlink" href=
"#_CPPv422memcached_stat_executeP12memcached_stPKc17memcached_stat_fnPv" title=
"Permalink to this definition">¶
</a><br /></dt>
238 <p>Compile and link with -lmemcached
</p>
240 <div class=
"section" id=
"description">
241 <h2>DESCRIPTION
<a class=
"headerlink" href=
"#description" title=
"Permalink to this headline">¶
</a></h2>
242 <p>libmemcached(
3) has the ability to query a memcached server (or collection
243 of servers) for their current state. Queries to find state return a
244 <a class=
"reference internal" href=
"#_CPPv417memcached_stat_st" title=
"memcached_stat_st"><code class=
"xref cpp cpp-type docutils literal notranslate"><span class=
"pre">memcached_stat_st
</span></code></a> structure. You are responsible for freeing this structure. While it is possible to access the structure directly it is not advisable.
<a class=
"reference internal" href=
"#_CPPv424memcached_stat_get_valueP12memcached_stP17memcached_stat_stPKcP18memcached_return_t" title=
"memcached_stat_get_value"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_stat_get_value()
</span></code></a> has been provided to query the structure.
</p>
245 <p><a class=
"reference internal" href=
"#_CPPv422memcached_stat_executeP12memcached_stPKc17memcached_stat_fnPv" title=
"memcached_stat_execute"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_stat_execute()
</span></code></a> uses the servers found in
<a class=
"reference internal" href=
"#_CPPv417memcached_stat_st" title=
"memcached_stat_st"><code class=
"xref cpp cpp-type docutils literal notranslate"><span class=
"pre">memcached_stat_st
</span></code></a> and executes a “stat” command on each server. args is an optional argument that can be passed in to modify the behavior of “stats”. You will need to supply a callback function that will be supplied each pair of values returned by
246 the memcached server.
</p>
247 <p><a class=
"reference internal" href=
"#_CPPv414memcached_statP12memcached_stPcP18memcached_return_t" title=
"memcached_stat"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_stat()
</span></code></a> fetches an array of
<a class=
"reference internal" href=
"#_CPPv417memcached_stat_st" title=
"memcached_stat_st"><code class=
"xref cpp cpp-type docutils literal notranslate"><span class=
"pre">memcached_stat_st
</span></code></a> structures containing the state of all available memcached servers. The return value must be freed by the calling application. If called with the
<a class=
"reference internal" href=
"memcached_behavior.html#_CPPv4N20memcached_behavior_t26MEMCACHED_BEHAVIOR_USE_UDPE" title=
"MEMCACHED_BEHAVIOR_USE_UDP"><code class=
"xref cpp cpp-any docutils literal notranslate"><span class=
"pre">MEMCACHED_BEHAVIOR_USE_UDP
</span></code></a> behavior set, a NULL value is returned and the error parameter is set to
<a class=
"reference internal" href=
"memcached_return_t.html#_CPPv4N18memcached_return_t23MEMCACHED_NOT_SUPPORTEDE" title=
"MEMCACHED_NOT_SUPPORTED"><code class=
"xref cpp cpp-any docutils literal notranslate"><span class=
"pre">MEMCACHED_NOT_SUPPORTED
</span></code></a>.
</p>
248 <p><a class=
"reference internal" href=
"#_CPPv425memcached_stat_servernameP17memcached_stat_stPcPKc9in_port_t" title=
"memcached_stat_servername"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_stat_servername()
</span></code></a> can be used standalone without a
<a class=
"reference internal" href=
"memcached_create.html#_CPPv412memcached_st" title=
"memcached_st"><code class=
"xref cpp cpp-type docutils literal notranslate"><span class=
"pre">memcached_st
</span></code></a> to obtain the state of a particular server. “args” is used to define a particular state object (a list of these are not provided for by either
249 the
<a class=
"reference internal" href=
"#_CPPv423memcached_stat_get_keysP12memcached_stP17memcached_stat_stP18memcached_return_t" title=
"memcached_stat_get_keys"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_stat_get_keys()
</span></code></a> call nor are they defined in the memcached protocol). You must specify the hostname and port of the server you want to
250 obtain information on.
</p>
251 <p><a class=
"reference internal" href=
"#_CPPv424memcached_stat_get_valueP12memcached_stP17memcached_stat_stPKcP18memcached_return_t" title=
"memcached_stat_get_value"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_stat_get_value()
</span></code></a> returns the value of a particular state key. You specify the key you wish to obtain. The key must be null terminated.
</p>
252 <p><a class=
"reference internal" href=
"#_CPPv423memcached_stat_get_keysP12memcached_stP17memcached_stat_stP18memcached_return_t" title=
"memcached_stat_get_keys"><code class=
"xref cpp cpp-func docutils literal notranslate"><span class=
"pre">memcached_stat_get_keys()
</span></code></a> returns a list of keys that the server has state objects on. You are responsible for freeing this list.
</p>
253 <p>A command line tool, memstat(
1), is provided so that you do not have to write
254 an application to do this.
</p>
256 <div class=
"section" id=
"return">
257 <h2>RETURN
<a class=
"headerlink" href=
"#return" title=
"Permalink to this headline">¶
</a></h2>
258 <p>Varies, see particular functions.
</p>
259 <p>Any method returning a
<a class=
"reference internal" href=
"#_CPPv417memcached_stat_st" title=
"memcached_stat_st"><code class=
"xref cpp cpp-type docutils literal notranslate"><span class=
"pre">memcached_stat_st
</span></code></a> expects you to free the
260 memory allocated for it.
</p>
262 <div class=
"section" id=
"see-also">
263 <h2>SEE ALSO
<a class=
"headerlink" href=
"#see-also" title=
"Permalink to this headline">¶
</a></h2>
273 <div class=
"rst-footer-buttons" role=
"navigation" aria-label=
"footer navigation">
275 <a href=
"index_deprecated.html" class=
"btn btn-neutral float-right" title=
"Deprecated Functionality" accesskey=
"n" rel=
"next">Next
<span class=
"fa fa-arrow-circle-right"></span></a>
278 <a href=
"memcached_analyze.html" class=
"btn btn-neutral float-left" title=
"Analyzing servers" accesskey=
"p" rel=
"prev"><span class=
"fa fa-arrow-circle-left"></span> Previous
</a>
285 <div role=
"contentinfo">
287 © <a href=
"../copyright.html">Copyright
</a>
291 Built with
<a href=
"http://sphinx-doc.org/">Sphinx
</a> using a
<a href=
"https://github.com/rtfd/sphinx_rtd_theme">theme
</a> provided by
<a href=
"https://readthedocs.org">Read the Docs
</a>.
304 <script type=
"text/javascript">
306 SphinxRtdTheme.Navigation.enable(true);