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
|
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Active Checks</title>
<meta name="generator" content="DocBook XSL Stylesheets V1.75.1">
<meta name="keywords" content="Supervision, Icinga, Nagios, Linux">
<link rel="home" href="index.html" title="Icinga Version 1.0.2 Documentation">
<link rel="up" href="ch05.html" title="Chapter 5. The Basics">
<link rel="prev" href="servicechecks.html" title="Service Checks">
<link rel="next" href="passivechecks.html" title="Passive Checks">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<CENTER><IMG src="../images/logofullsize.png" border="0" alt="Icinga" title="Icinga"></CENTER>
<div class="navheader">
<table width="100%" summary="Navigation header">
<tr><th colspan="3" align="center">Active Checks</th></tr>
<tr>
<td width="20%" align="left">
<a accesskey="p" href="servicechecks.html">Prev</a> </td>
<th width="60%" align="center">Chapter 5. The Basics</th>
<td width="20%" align="right"> <a accesskey="n" href="passivechecks.html">Next</a>
</td>
</tr>
</table>
<hr>
</div>
<div class="section" title="Active Checks">
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="activechecks"></a><a name="active_checks"></a>Active Checks</h2></div></div></div>
<p><span class="bold"><strong>Introduction</strong></span></p>
<p>Icinga is capable of monitoring hosts and services in two ways: actively and passively. Passive checks are
described <a class="link" href="passivechecks.html" title="Passive Checks">elsewhere</a>, so we'll focus on active checks here. Active checks are the most
common method for monitoring hosts and services. The main features of actives checks as as follows:</p>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
<p>Active checks are initiated by the Icinga process</p>
</li>
<li class="listitem">
<p>Active checks are run on a regularly scheduled basis</p>
</li>
</ul></div>
<p><span class="inlinemediaobject"><img src="../images/activechecks.png"></span></p>
<p><span class="bold"><strong>How Are Active Checks Performed?</strong></span></p>
<p>Active checks are initiated by the check logic in the Icinga daemon. When Icinga needs to check the status
of a host or service it will execute a plugin and pass it information about what needs to be checked. The plugin will then check
the operational state of the host or service and report the results back to the Icinga daemon. Icinga will process
the results of the host or service check and take appropriate action as necessary (e.g. send notifications, run event handlers,
etc).</p>
<p>More information on how plugins work can be found <a class="link" href="plugins.html" title="Icinga Plugins">here</a>.</p>
<p><span class="bold"><strong>When Are Active Checks Executed?</strong></span></p>
<p>Active check are executed:</p>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
<p>At regular intervals, as defined by the <span class="emphasis"><em>check_interval</em></span> and <span class="emphasis"><em>retry_interval</em></span>
options in your host and service definitions</p>
</li>
<li class="listitem">
<p>On-demand as needed</p>
</li>
</ul></div>
<p>Regularly scheduled checks occur at intervals equaling either the <span class="emphasis"><em>check_interval</em></span> or the
<span class="emphasis"><em>retry_interval</em></span> in your host or service definitions, depending on what <a class="link" href="statetypes.html" title="State Types">type of
state</a> the host or service is in. If a host or service is in a HARD state, it will be actively checked at intervals equal
to the <span class="emphasis"><em>check_interval</em></span> option. If it is in a SOFT state, it will be checked at intervals equal to the
<span class="emphasis"><em>retry_interval</em></span> option.</p>
<p>On-demand checks are performed whenever Icinga sees a need to obtain the latest status information about a
particular host or service. For example, when Icinga is determining the <a class="link" href="networkreachability.html" title="Determining Status and Reachability of Network Hosts">reachability</a> of a host, it will often perform on-demand checks of parent and child hosts to
accurately determine the status of a particular network segment. On-demand checks also occur in the <a class="link" href="dependencychecks.html" title="Predictive Dependency Checks">predictive dependency check</a> logic in order to ensure Icinga has the most accurate
status information.</p>
<a class="indexterm" name="id1984073"></a>
<a class="indexterm" name="id1984080"></a>
</div>
<div class="navfooter">
<hr>
<table width="100%" summary="Navigation footer">
<tr>
<td width="40%" align="left">
<a accesskey="p" href="servicechecks.html">Prev</a> </td>
<td width="20%" align="center"><a accesskey="u" href="ch05.html">Up</a></td>
<td width="40%" align="right"> <a accesskey="n" href="passivechecks.html">Next</a>
</td>
</tr>
<tr>
<td width="40%" align="left" valign="top">Service Checks </td>
<td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td>
<td width="40%" align="right" valign="top"> Passive Checks</td>
</tr>
</table>
</div>
<P class="copyright">© 2009-2010 Icinga Development Team, http://www.icinga.org</P>
</body>
</html>
|
