added ability to execute actions only after the n-th call of the action

This also lead to the addition of two new config directives:
$ActionExecOnlyEveryNthTime and $ActionExecOnlyEveryNthTimeTimeout
This feature is useful, for example, for alerting: it permits you to
send an alert only after at least n occurences of a specific message
have been seen by rsyslogd. This protectes against false positives
due to waiting for additional confirmation.

3 files changed, 20 insertions, 6 deletions

diff --git a/doc/features.html b/doc/features.html
index 2b3b31d9..8e28daae 100644
--- a/doc/features.html
+++ b/doc/features.html
@@ -94,6 +94,7 @@ loadable plug-in</li>
 via custom plugins</li>
 <li> an easy-to-write to plugin interface</li>
 <li> ability to send SNMP trap messages</li>
+<li> ability to filter out messages based on sequence of arrival</li>
 <li>support for arbitrary complex boolean, string and
 arithmetic expressions in message filters</li>
 </ul>
diff --git a/doc/rsyslog_conf.html b/doc/rsyslog_conf.html
index d2dfaaaf..ac97ecb1 100644
--- a/doc/rsyslog_conf.html
+++ b/doc/rsyslog_conf.html
@@ -79,8 +79,17 @@ default, it is usually well-chosen and applicable in most cases.</p>
 execute action only if the last execute is at last
 &lt;seconds&gt; seconds in the past (more info in <a href="ommail.html">ommail</a>,
 but may be used with any action)</li>
-<li>$ActionFileDefaultTemplate [templateName] - sets a new
-default template for file actions</li>
+<li>$ActionExecOnlyEveryNthTime &lt;number&gt; - If configured, the next action will
+only be executed every n-th time. For example, if configured to 3, the first two messages
+that go into the action will be dropped, the 3rd will actually cause the action to execute,
+the 4th and 5th will be dropped, the 6th executed under the action, ... and so on. Note: 
+this setting is automatically re-set when the actual action is defined.</li>
+<li>$ActionExecOnlyEveryNthTimeTimeout &lt;number-of-seconds&gt; - has a meaning only if
+$ActionExecOnlyEveryNthTime is also configured for the same action. If so, the timeout
+setting specifies after which period the counting of "previous actions" expires and
+a new action count is begun. Specify 0 (the default) to disable timeouts.:w
+
+<li>$ActionFileDefaultTemplate [templateName] - sets a new default template for file actions</li>
 <li>$ActionFileEnableSync [on/<span style="font-weight: bold;">off</span>] - enables file
 syncing capability of omfile</li>
 <li>$ActionForwardDefaultTemplate [templateName] - sets a new
diff --git a/doc/rsyslog_ng_comparison.html b/doc/rsyslog_ng_comparison.html
index 600875a8..74d83f72 100644
--- a/doc/rsyslog_ng_comparison.html
+++ b/doc/rsyslog_ng_comparison.html
@@ -209,10 +209,8 @@ priority</td>
 <td></td>
 </tr>
 <tr>
-<td valign="top">ability to filter on any other
-message
-field not mentioned above
-(including substrings and the like)</td>
+<td valign="top">ability to filter on any other message
+field not mentioned above (including substrings and the like)</td>
 <td valign="top">yes</td>
 <td valign="top">no</td>
 </tr>
@@ -248,6 +246,12 @@ based on filters</td>
 <td></td>
 </tr>
 <tr>
+<td valign="top">ability to filter out messages based on sequence of appearing</td>
+<td valign="top">yes</td>
+<td valign="top">no</td>
+<td></td>
+</tr>
+<tr>
 <td valign="top">powerful BSD-style hostname and
 program name blocks for easy multi-host support</td>
 <td valign="top">yes</td>