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author | Rainer Gerhards <rgerhards@adiscon.com> | 2010-06-04 12:45:31 +0200 |
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committer | Rainer Gerhards <rgerhards@adiscon.com> | 2010-06-04 12:45:31 +0200 |
commit | d9e64c16e52357bae1eb00fc8403c4e63d6365ca (patch) | |
tree | 9a37b8395ff1e8996950328696054b24ddffd564 /doc/rsyslog_conf_modules.html | |
parent | 527bfcea5c9ca5c8414620a022f097d4e53af784 (diff) | |
download | rsyslog-d9e64c16e52357bae1eb00fc8403c4e63d6365ca.tar.gz rsyslog-d9e64c16e52357bae1eb00fc8403c4e63d6365ca.tar.xz rsyslog-d9e64c16e52357bae1eb00fc8403c4e63d6365ca.zip |
finshed implementation of strgen modules
and also provided four build-in modules for the most common use
cases, hopefully resulting in a speedup of around 5% for typical
rsyslog processing.
Diffstat (limited to 'doc/rsyslog_conf_modules.html')
-rw-r--r-- | doc/rsyslog_conf_modules.html | 39 |
1 files changed, 38 insertions, 1 deletions
diff --git a/doc/rsyslog_conf_modules.html b/doc/rsyslog_conf_modules.html index b721c935..57146e88 100644 --- a/doc/rsyslog_conf_modules.html +++ b/doc/rsyslog_conf_modules.html @@ -25,6 +25,7 @@ for you by <li><a href="rsyslog_conf_modules.html#om">Output Modules</a> <li><a href="rsyslog_conf_modules.html#pm">Parser Modules</a> <li><a href="rsyslog_conf_modules.html#mm">Message Modification Modules</a> +<li><a href="rsyslog_conf_modules.html#sm">String Generator Modules</a> <li><a href="rsyslog_conf_modules.html#lm">Library Modules</a> </ul> @@ -87,6 +88,39 @@ the methods the engine provides. They could be used, for example, to: <li>add dynamically computed content to message (fields) </ul> +<a name="lm"></a><h2>String Generator Modules</h2> +<p>String generator modules are used, as the name implies, to generate strings based +on the message content. They are currently tightly coupled with the template system. +Their primary use is to speed up template processing by providing a native C +interface to template generation. These modules exist since 5.5.6. To get an idea +of the potential speedup, the default file format, when generated by a string generator, +provides a roughly 5% speedup. For more complex strings, especially those that include +multiple regular expressions, the speedup may be considerably higher. +<p>String generator modules are written to a quite simple interface. However, a word of +caution is due: they access the rsyslog message object via a low-level interface. +That interface is not guaranteed yet to stay stable. So it may be necessary to +modify string generator modules if the interface changes. Obviously, we will not do that +without good reason, but it may happen. +<p>Rsyslog comes with a set of core, build-in string generators, which are used +to provide those default templates that we consider to be time-critical: +<ul> +<li>smfile - the default rsyslog file format +<li>smfwd - the default rsyslog (network) forwarding format +<li>smtradfile - the traditional syslog file format +<li>smfwd - the traditional syslog (network) forwarding format +</ul> +<p>Note that when you replace these defaults be some custom strings, you will +loose some performance (around 5%). For typical systems, this is not really relevant. +But for a high-performance systems, it may be very relevant. To solve that issue, create +a new string generator module for your custom format, starting out from one of the +default generators provided. If you can not do this yourself, you may want to +contact <a href="mailto:info%40adiscon.com">Adiscon</a> as we offer custom development +of string generators at a very low price. +<p>Note that string generator modules can be dynamically loaded. However, the default +ones provided are so important that they are build right into the executable. But this +does not need to be done that way (and it is straightforward to do it dynamic). + + <a name="lm"></a><h2>Library Modules</h2> <p>Library modules provide dynamically loadable functionality for parts of rsyslog, most often for other loadable modules. They can not be user-configured and are loaded @@ -106,6 +140,9 @@ parser modules, which generate the in-memory representation of the message and m also modify the message itself. The, the internal representation is passed to output modules, which may output a message and (with the interfaces newly introduced in v5) may also modify messageo object content. +<p>String generator modules are not included inside this picture, because they are +not a required part of the workflow. If used, they operate "in front of" the +output modules, because they are called during template generation. <p>Note that the actual flow is much more complex and depends a lot on queue and filter settings. This graphic above is a high-level message flow diagram. @@ -114,7 +151,7 @@ filter settings. This graphic above is a high-level message flow diagram. [<a href="http://www.rsyslog.com/">rsyslog site</a>]</p> <p><font size="2">This documentation is part of the <a href="http://www.rsyslog.com/">rsyslog</a> project.<br> -Copyright © 2008, 2009 by <a href="http://www.gerhards.net/rainer">Rainer Gerhards</a> and +Copyright © 2008-2010 by <a href="http://www.gerhards.net/rainer">Rainer Gerhards</a> and <a href="http://www.adiscon.com/">Adiscon</a>. Released under the GNU GPL version 3 or higher.</font></p> </body> |