Author: buildbot
Date: Tue Aug 13 13:22:21 2013
New Revision: 874466
Log:
Staging update by buildbot for sling
Modified:
websites/staging/sling/trunk/content/ (props changed)
websites/staging/sling/trunk/content/documentation/bundles/sling-health-check-tool.html
Propchange: websites/staging/sling/trunk/content/
------------------------------------------------------------------------------
--- cms:source-revision (original)
+++ cms:source-revision Tue Aug 13 13:22:21 2013
@@ -1 +1 @@
-1513470
+1513475
Modified:
websites/staging/sling/trunk/content/documentation/bundles/sling-health-check-tool.html
==============================================================================
---
websites/staging/sling/trunk/content/documentation/bundles/sling-health-check-tool.html
(original)
+++
websites/staging/sling/trunk/content/documentation/bundles/sling-health-check-tool.html
Tue Aug 13 13:22:21 2013
@@ -85,36 +85,60 @@
<h1>Sling Health Check Tool</h1>
- <p>Based on simple <em>HealthCheck</em> OSGi services, the Sling Health
Check Tool ("hc" in short form) is used to
+ <p>Based on simple <code>HealthCheck</code> OSGi services, the Sling
Health Check Tool ("hc" in short form) is used to
check the health of live Sling systems, based on inputs like JMX MBean
attribute values, OSGi framework
information, Sling requests status, etc.</p>
-<p>Health checks are easily extensible either by configuring the supplied
default <em>HealthCheck</em> services, or
+<p>Health checks are easily extensible either by configuring the supplied
default <code>HealthCheck</code> services, or
by implementing your own services. </p>
<p>Default rules are provided to check JMX MBeans, OSGi bundle states,
disabling of default Sling
accounts, JUnit tests results and the output of scripts written in any
language supported by Sling.</p>
<p>The source code of the hc modules is at <a
href="http://svn.apache.org/repos/asf/sling/trunk/contrib/extensions/healthcheck";>http://svn.apache.org/repos/asf/sling/trunk/contrib/extensions/healthcheck</a>.</p>
-<h2 id="whats-a-healthcheck">What's a HealthCheck ?</h2>
-<p>A <em>HealthCheck</em> is just an OSGi service that returns a
<em>Result</em>.</p>
+<h2 id="whats-a-healthcheck">What's a <code>HealthCheck</code> ?</h2>
+<p>A <code>HealthCheck</code> is just an OSGi service that returns a
<code>Result</code>.</p>
+<div class="codehilite"><pre><span class="n">public</span> <span
class="n">interface</span> <span class="n">HealthCheck</span> <span
class="p">{</span>
+
+ <span class="o">/**</span> <span class="n">Execute</span> <span
class="n">this</span> <span class="n">health</span> <span
class="n">check</span> <span class="n">and</span> <span class="k">return</span>
<span class="n">a</span> <span class="p">{@</span><span class="n">link</span>
<span class="n">Result</span><span class="p">}</span> <span class="o">*/</span>
+ <span class="n">public</span> <span class="n">Result</span> <span
class="n">execute</span><span class="p">();</span>
+
+ <span class="o">/**</span> <span class="n">Additional</span> <span
class="p">(</span><span class="n">static</span><span class="p">)</span> <span
class="n">information</span> <span class="n">about</span>
+ <span class="o">*</span> <span class="n">this</span> <span
class="n">check</span><span class="p">.</span> <span class="p">{@</span><span
class="n">link</span> <span class="n">Constants</span><span class="p">}</span>
<span class="n">defines</span>
+ <span class="o">*</span> <span class="n">some</span> <span
class="n">well</span><span class="o">-</span><span class="n">known</span> <span
class="n">property</span> <span class="n">names</span><span class="p">.</span>
+ <span class="o">*/</span>
+ <span class="n">public</span> <span class="n">Map</span><span
class="o"><</span><span class="n">String</span><span class="p">,</span>
<span class="n">String</span><span class="o">></span> <span
class="n">getInfo</span><span class="p">();</span>
+<span class="p">}</span>
+</pre></div>
+
+
<p>The Result provides a <em>Status</em> (OK, WARN, CRITICAL etc.) and a
human-readable log which provides additional info, including optional DEBUG
messages
-that help troubleshooting. The Result log is not stricly tied to a logging
model, so HealthChecks are free to invent their own types of logging messages
+that help troubleshooting. The Result log is not stricly tied to a logging
model, so <code>HealthCheck</code>s are free to invent their own types of
logging messages
if needed. See the <code>org.apache.sling.hc.api.Result</code> class in the
for more details. </p>
-<p>HealthCheck services can be selected for execution based on their
<em>tags</em>. The <em>HealthCheckFilter</em> utility
-accepts positive and negative tag parameters, so that
<code>-security,sling</code> for example selects all HealthCheck
+<p><code>HealthCheck</code> services can be selected for execution based on
their <em>tags</em>. The <code>HealthCheckFilter</code> utility
+accepts positive and negative tag parameters, so that
<code>-security,sling</code> for example selects all <code>HealthCheck</code>
having the <em>sling</em> tag but not the <em>security</em> tag. </p>
+<h2 id="health-check-subsystem-bundles">Health Check subsystem bundles</h2>
+<p>The Health Check subsystem consists of the following bundles:</p>
+<ul>
+<li>The only required bundle is <code>org.apache.sling.hc.api</code> which
provides the API and some utility classes.</li>
+<li><code>org.apache.sling.hc.healthchecks</code> provides default
<code>HealthCheck</code> services, described below.</li>
+<li><code>org.apache.sling.hc.webconsole</code> provides the Webconsole plugin
described below.</li>
+<li><code>org.apache.sling.hc.jmx</code> provides JMX MBeans to execute
<code>HealthCheck</code>s.</li>
+<li><code>org.apache.sling.hc.samples</code> provides sample OSGi
configurations that demonstrate the default <code>HealthCheck</code>s. These
configurations are provided as Sling content, so the Sling Installer is
required to activate them.</li>
+</ul>
<h2 id="executing-health-checks">Executing health checks</h2>
<p>Besides executing them programatically, Health checks can be executed via a
webconsole plugin or via JMX,
see below for more details.</p>
-<h2 id="default-healthcheck-services-and-samples">Default HealthCheck services
and samples</h2>
-<p>As of mid-August 2013, the <code>org.apache.sling.hc.samples</code> bundle
provides OSGi configurations that demonstrate the following HealthCheck
services:</p>
+<h2 id="default-healthcheck-services-and-samples">Default
<code>HealthCheck</code> services and samples</h2>
+<p>A useful set of default <code>HealthCheck</code>s is provided by the
<code>org.apache.sling.hc.healthchecks</code> bundle. </p>
+<p>The <code>org.apache.sling.hc.samples</code> bundle provides OSGi
configurations that demonstrate the following <code>HealthCheck</code>
services:</p>
<ul>
<li><code>JmxAttributeHealthCheck</code> checks the value of a single JMX
attribute and supports ranges like <em>between 12 and 42</em>. </li>
<li><code>SlingRequestStatusHealthCheck</code> checks the HTTP status of Sling
requests. </li>
<li><code>ScriptableHealthCheck</code> evaluates an expression written in any
scripting language that Sling supports, and provides bindings to access JMX
attributes and OSGi bundles states. </li>
<li><code>DefaultLoginsHealthCheck</code> can be used to verify that the
default Sling logins fail. </li>
-<li><code>CompositeHealthCheck</code> executes a set of HealthCheck selected
by tags, useful to get higher-level management views.</li>
+<li><code>CompositeHealthCheck</code> executes a set of
<code>HealthCheck</code> selected by tags, useful to get higher-level
management views.</li>
</ul>
<h2 id="configuring-health-checks">Configuring health checks</h2>
-<p>Health check services are created via OSGi configurations.</p>
+<p><code>HealthCheck</code> services are created via OSGi configurations.</p>
<p>Here's a <code>ScriptableHealthCheck</code> example configuration provided
by the <code>org.apache.sling.hc.samples</code> bundle:</p>
<p>PID = org.apache.sling.hc.ScriptableHealthCheck.1523a6db-12324
Factory PID = org.apache.sling.hc.ScriptableHealthCheck
@@ -123,24 +147,25 @@ see below for more details.</p>
hc.tags = [bundles, script]
expression = osgi.inactiveBundlesCount() == 0
language.extension = ecma</p>
-<p>Properties starting with the <code>hc.</code> prefix should be provided by
all HealthCheck services.</p>
+<p>Properties starting with the <code>hc.</code> prefix should be provided by
all <code>HealthCheck</code> services.</p>
<h2 id="webconsole-plugin">Webconsole plugin</h2>
-<p>A webconsole plugin at <code>/system/console/healthcheck</code> allows for
executing health checks, optionally selected
-based on their tags.</p>
+<p>If the <code>org.apache.sling.hc.webconsole</code> bundle is active, a
webconsole plugin
+at <code>/system/console/healthcheck allows for executing health checks,
optionally selected
+based on their tags (positive and negative selection,
see</code>HealthCheckFilter` mention above).</p>
<p>The DEBUG logs of health checks can optionally be displayed, and an option
allows for showing only health
checks that have a non-OK status.</p>
<p>The screenshot below shows an example, as of svn revision 1513462.</p>
<p><img alt="" src="sling-hc-plugin.jpg" /></p>
<h2 id="jmx-access-to-health-checks">JMX access to health checks</h2>
-<p>A JMX MBean is created for each HealthCheck, which gives access to the
<code>Result</code> and the log, as shown
-on the screenshot below. </p>
-<p>The MBean name defaults to the <code>hc.name</code> service property of the
<em>HealthCheck</em>, but if an
+<p>If the <code>org.apache.sling.hc.jmx</code> bundle is active, a JMX MBean
is created for each <code>HealthCheck</code>.</p>
+<p>The MBean gives access to the <code>Result</code> and the log, as shown on
the screenshot below. </p>
+<p>The MBean name defaults to the <code>hc.name</code> service property of the
<em><code>HealthCheck</code></em>, but if an
<code>hc.mbean.name</code> property is provided it is used instead. That
property can include a a slash
(as in <code>composite/security</code>) to define the MBean service name,
which by default is <em>HealthCheck</em>.</p>
<p>The example configurations of the <code>org.apache.sling.hc.samples</code>
bundle demonstrate the various features.</p>
<p><img alt="" src="jconsole-hc.jpg" /></p>
<div class="timestamp" style="margin-top: 30px; font-size: 80%;
text-align: right;">
- Rev. 1513470 by bdelacretaz on Tue, 13 Aug 2013 13:11:10 +0000
+ Rev. 1513475 by bdelacretaz on Tue, 13 Aug 2013 13:22:13 +0000
</div>
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