Author: buildbot
Date: Wed Aug 12 14:15:21 2015
New Revision: 961625
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 Wed Aug 12 14:15:21 2015
@@ -1 +1 @@
-1695337
+1695530
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
Wed Aug 12 14:15:21 2015
@@ -39,7 +39,18 @@
</div>
<div class="menu">
- <p><strong><a href="/documentation.html">Documentation</a></strong> <br
/>
+ <style type="text/css">
+/* The following code is added by mdx_elementid.py
+ It was originally lifted from http://subversion.apache.org/style/site.css */
+/*
+ * Hide class="elementid-permalink", except when an enclosing heading
+ * has the :hover property.
+ */
+.headerlink, .elementid-permalink {
+ visibility: hidden;
+}
+h2:hover > .headerlink, h3:hover > .headerlink, h1:hover > .headerlink,
h6:hover > .headerlink, h4:hover > .headerlink, h5:hover > .headerlink,
dt:hover > .elementid-permalink { visibility: visible }</style>
+<p><strong><a href="/documentation.html">Documentation</a></strong> <br />
<a href="/documentation/getting-started.html">Getting Started</a> <br />
<a href="/documentation/the-sling-engine.html">The Sling Engine</a> <br />
<a href="/documentation/development.html">Development</a> <br />
@@ -90,7 +101,18 @@
<h1>Sling Health Check Tools</h1>
- <p>Based on simple <code>HealthCheck</code> OSGi services, the Sling
Health Check Tools ("hc" in short form) are used to
+ <style type="text/css">
+/* The following code is added by mdx_elementid.py
+ It was originally lifted from http://subversion.apache.org/style/site.css */
+/*
+ * Hide class="elementid-permalink", except when an enclosing heading
+ * has the :hover property.
+ */
+.headerlink, .elementid-permalink {
+ visibility: hidden;
+}
+h2:hover > .headerlink, h3:hover > .headerlink, h1:hover > .headerlink,
h6:hover > .headerlink, h4:hover > .headerlink, h5:hover > .headerlink,
dt:hover > .elementid-permalink { visibility: visible }</style>
+<p>Based on simple <code>HealthCheck</code> OSGi services, the Sling Health
Check Tools ("hc" in short form) are 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 <code>HealthCheck</code> services, by
@@ -100,7 +122,7 @@ supplying MBeans that expose the require
<li>Source code at <a
href="http://svn.apache.org/repos/asf/sling/trunk/bundles/extensions/healthcheck";>http://svn.apache.org/repos/asf/sling/trunk/bundles/extensions/healthcheck</a></li>
<li>adaptTo 2013 slides about Health Checks at <a
href="http://www.slideshare.net/bdelacretaz/slinghc-bdelacretazadaptto2013";>http://www.slideshare.net/bdelacretaz/slinghc-bdelacretazadaptto2013</a></li>
</ul>
-<h2 id="use-cases">Use cases</h2>
+<h2 id="use-cases">Use cases<a class="headerlink" href="#use-cases"
title="Permanent link">¶</a></h2>
<p>Health checks can be used for various purposes, for example:</p>
<ul>
<li>Verify that performance counters are in range.</li>
@@ -114,7 +136,7 @@ supplying MBeans that expose the require
checks once they are configured with the corresponding tags.</p>
<p>The out of the box health check services also allow for using them as JMX
aggregators and processors, which take JMX
attribute values as input and make the results accessible via JMX MBeans.</p>
-<h2 id="whats-a-healthcheck">What's a <code>HealthCheck</code> ?</h2>
+<h2 id="whats-a-healthcheck">What's a <code>HealthCheck</code> ?<a
class="headerlink" href="#whats-a-healthcheck" title="Permanent
link">¶</a></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>
@@ -154,7 +176,7 @@ can provide more info about what, if any
selects all <code>HealthCheck</code> having the <code>sling</code> tag but not
the <code>security</code> tag, for example.</p>
<p>Besides executing them programmatically, Health checks can be executed via
a webconsole plugin or via JMX,
as described below.</p>
-<h3 id="slinghealthcheck-annotation">SlingHealthCheck annotation</h3>
+<h3 id="slinghealthcheck-annotation">SlingHealthCheck annotation<a
class="headerlink" href="#slinghealthcheck-annotation" title="Permanent
link">¶</a></h3>
<p>The <code>SlingHealthCheck</code> annotation makes it easier to specify the
required <code>HealthCheck</code> service properties.</p>
<p>Here's an example from the <code>samples</code> module - see the
<code>annotations</code> module for more details.</p>
<div class="codehilite"><pre><span class="p">@</span><span
class="n">SlingHealthCheck</span><span class="p">(</span>
@@ -173,7 +195,7 @@ as described below.</p>
</pre></div>
-<h2 id="health-check-bundles">Health Check bundles</h2>
+<h2 id="health-check-bundles">Health Check bundles<a class="headerlink"
href="#health-check-bundles" title="Permanent link">¶</a></h2>
<p>The Health Check subsystem consists of the following bundles:</p>
<ul>
<li>The only required bundle is <code>org.apache.sling.hc.core</code> which
provides the API, some utility classes and some generally useful
<code>HealthCheck</code> services. </li>
@@ -184,7 +206,7 @@ as described below.</p>
<li><code>org.apache.sling.hc.samples</code> provides sample OSGi
configurations and <code>HealthCheck</code> services. The sample configurations
are provided as Sling content, so the Sling Installer is required to activate
them.</li>
<li><code>org.apache.sling.hc.junit.bridge</code> makes selected Health Checks
available as server-side JUnit tests. See below for more info. </li>
</ul>
-<h2 id="out-of-the-box-healthcheck-services">Out-of-the-box
<code>HealthCheck</code> services</h2>
+<h2 id="out-of-the-box-healthcheck-services">Out-of-the-box
<code>HealthCheck</code> services<a class="headerlink"
href="#out-of-the-box-healthcheck-services" title="Permanent
link">¶</a></h2>
<p>The following default <code>HealthCheck</code> services are provided by the
<code>org.apache.sling.hc.core</code> bundle: </p>
<p>The <code>org.apache.sling.hc.samples</code> bundle provides OSGi
configurations that demonstrate them.</p>
<ul>
@@ -201,7 +223,7 @@ as described below.</p>
the <code>org.apache.sling.junit.healthcheck</code> bundle.</p>
<p>The <code>org.apache.sling.hc.samples</code> bundle provides an example
<code>OsgiScriptBindingsProvider</code> for the default
<code>ScriptableHealthCheck</code>,
which provides OSGi-related information to health check script expressions.</p>
-<h2 id="configuring-health-checks">Configuring health checks</h2>
+<h2 id="configuring-health-checks">Configuring health checks<a
class="headerlink" href="#configuring-health-checks" title="Permanent
link">¶</a></h2>
<p><code>HealthCheck</code> services are created via OSGi configurations, the
details of which are defined by each
service implementation.</p>
<p>As an example, here's a <code>ScriptableHealthCheck</code> configuration
provided by the <code>org.apache.sling.hc.samples</code> bundle:</p>
@@ -218,7 +240,7 @@ service implementation.</p>
is optional, if not provided no MBean is created for that
<code>HealthCheck</code>.</p>
<p>The optional <code>hc.async.cronExpression</code> service property is used
to schedule the execution of a <code>HealthCheck</code> at regular intervals,
using a cron expression as specified by the <a
href="/documentation/bundles/scheduler-service-commons-scheduler.html">Sling
Scheduler</a> module.</p>
-<h2 id="webconsole-plugin">Webconsole plugin</h2>
+<h2 id="webconsole-plugin">Webconsole plugin<a class="headerlink"
href="#webconsole-plugin" title="Permanent link">¶</a></h2>
<p>If the <code>org.apache.sling.hc.webconsole</code> bundle is active, a
webconsole plugin
at <code>/system/console/healthcheck</code> allows for executing health
checks, optionally selected
based on their tags (positive and negative selection, see the
<code>HealthCheckFilter</code> mention above).</p>
@@ -226,14 +248,24 @@ based on their tags (positive and negati
checks that have a non-OK status.</p>
<p>The screenshot below shows an example, as of svn revision 1513462.</p>
<p><img alt="Health Check Webconsole Plugin" src="sling-hc-plugin.jpg" /></p>
-<h2 id="jmx-access-to-health-checks">JMX access to health checks</h2>
+<h2 id="jmx-access-to-health-checks">JMX access to health checks<a
class="headerlink" href="#jmx-access-to-health-checks" title="Permanent
link">¶</a></h2>
<p>If the <code>org.apache.sling.hc.jmx</code> bundle is active, a JMX MBean
is created for each <code>HealthCheck</code> which has the
service property <code>hc.mbean.name</code> service property set. All health
check MBeans are registered in the
domain <code>org.apache.sling.healthcheck</code> with a type of
<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>See the example configurations of the
<code>org.apache.sling.hc.samples</code> for more details.</p>
<p><img alt="JConsole showing Sling Health Check MBeans" src="jconsole-hc.jpg"
/></p>
-<h2 id="health-checks-as-server-side-junit-tests">Health Checks as server-side
JUnit tests</h2>
+<h2 id="health-checks-servlet">Health Checks Servlet<a class="headerlink"
href="#health-checks-servlet" title="Permanent link">¶</a></h2>
+<p>Starting with version 1.2.4 of the <code>org.apache.sling.hc.core</code>
bundle, a flexible Health Checks execution servlet is available. It provides
+similar features to the Web Console plugin described above, with output in
HTML, JSON, JSONP and TXT formats.</p>
+<p>The Health Checks Servlet is disabled by default, to enable it create an
OSGi configuration like</p>
+<p>PID = org.apache.sling.hc.core.impl.servlet.HealthCheckExecutorServlet
+ servletPath = /system/health</p>
+<p>which specifies the servlet's base path. That URL then returns an HTML
page, by default with the results of all active health checks and
+with instructions at the end of the page about which URL parameters can be
used to select specific Health Checks and control their execution
+and output format.</p>
+<p>Note that <em>the Health Checks Servlet doesn't do any access control by
itself</em>, so make sure the configured path is secure before enabling it.</p>
+<h2 id="health-checks-as-server-side-junit-tests">Health Checks as server-side
JUnit tests<a class="headerlink"
href="#health-checks-as-server-side-junit-tests" title="Permanent
link">¶</a></h2>
<p>The <code>org.apache.sling.hc.junit.bridge</code> bundle makes selected
Health Checks available as server-side JUnit tests. </p>
<p>It requires the <code>org.apache.sling.junit.core bundle</code> which
provides the server-side JUnit tests infrastructure.</p>
<p>The idea is to implement the smoke tests of your system, for example, as
health checks. You can then run them
@@ -245,7 +277,7 @@ to run the corresponding Health Checks.<
<p>To run the Health Check tests at build time, see the <a
href="http://svn.apache.org/repos/asf/sling/trunk/testing/samples/integration-tests";>testing/samples/integration-tests</a>
sample module.</p>
<div class="timestamp" style="margin-top: 30px; font-size: 80%;
text-align: right;">
- Rev. 1614841 by bdelacretaz on Thu, 31 Jul 2014 09:40:21 +0000
+ Rev. 1695530 by bdelacretaz on Wed, 12 Aug 2015 14:15:07 +0000
</div>
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