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diff --git a/doc/rsyslog_conf_modules.html b/doc/rsyslog_conf_modules.html index 675b8bb3..b03313f5 100644 --- a/doc/rsyslog_conf_modules.html +++ b/doc/rsyslog_conf_modules.html @@ -19,29 +19,42 @@ modules solve your need, you may consider writing one or have one written for you by <a href="http://www.rsyslog.com/professional-services">Adiscon's professional services for rsyslog</a> </b>(this often is a very cost-effective and efficient way of getting what you need). +<p>There exist different classes of loadable modules: +<ul> +<li><a href="rsyslog_conf_modules.html#im">Input Modules</a> +<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> -<h2>Input Modules</h2> +<a name"im"></a><h2>Input Modules</h2> <p>Input modules are used to gather messages from various sources. They interface to message generators. <ul> <li><a href="imfile.html">imfile</a> - input module for text files</li> <li><a href="imrelp.html">imrelp</a> - RELP input module</li> <li>imudp - udp syslog message input</li> -<li><a href="imtcp.html">imtcp</a> - input plugin for plain tcp syslog</li> +<li><a href="imtcp.html">imtcp</a> - input plugin for tcp syslog</li> +<li><a href="imptcp.html">imptcp</a> - input plugin for plain tcp syslog (no TLS but faster)</li> <li><a href="imgssapi.html">imgssapi</a> - input plugin for plain tcp and GSS-enabled syslog</li> <li>immark - support for mark messages</li> <li><a href="imklog.html">imklog</a> - kernel logging</li> <li><a href="imuxsock.html">imuxsock</a> - unix sockets, including the system log socket</li> +<li><a href="imsolaris.html">imsolaris</a> - input for the Sun Solaris system log source</li> <li><a href="im3195.html">im3195</a> - accepts syslog messages via RFC 3195</li> +<li><a href="impstats.html">impstats</a> - provides periodic statistics of rsyslog internal counters</li> </ul> -<h2>Output Modules</h2> +<a name"om"></a><h2>Output Modules</h2> <p>Output modules process messages. With them, message formats can be transformed and messages be transmitted to various different targets. <ul> <li><a href="omsnmp.html">omsnmp</a> - SNMP trap output module</li> <li><a href="omstdout.html">omtdout</a> - stdout output module (mainly a test tool)</li> <li><a href="omrelp.html">omrelp</a> - RELP output module</li> +<li><a href="omruleset.html">omruleset</a> - forward message to another ruleset</li> <li>omgssapi - output module for GSS-enabled syslog</li> <li><a href="ommysql.html">ommysql</a> - output module for MySQL</li> <li>ompgsql - output module for PostgreSQL</li> @@ -51,20 +64,115 @@ SQLLite, Ingres, Oracle, mSQL)</li> <li><a href="ommail.html">ommail</a> - permits rsyslog to alert folks by mail if something important happens</li> <li><a href="omoracle.html">omoracle</a> - output module for Oracle (native OCI interface)</li> +<li><a href="omudpspoof.html">omudpspoof</a> - output module sending UDP syslog messages with a spoofed address</li> +<li><a href="omuxsock.html">omuxsock</a> - output module Unix domain sockets</li> +<li><a href="omhdfs.html">omhdfs</a> - output module for Hadoop's HDFS file system</li> +</ul> + +<a name="pm"></a><h2>Parser Modules</h2> +<p>Parser modules are used to parse message content, once the message has been +received. They can be used to process custom message formats or invalidly formatted +messages. For details, please see the <a href="messageparser.html">rsyslog +message parser documentation</a>. +<p>The current modules are currently provided as part of rsyslog: +<ul> +<li>pmrfc5424[builtin] - rsyslog.rfc5424 - +parses RFC5424-formatted messages (the new syslog standard) +<li>pmrfc3164[builtin] - rsyslog.rfc3164 - +the traditional/legacy syslog parser +<li>pmrfc3164sd - rsyslog.rfc3164sd - +a contributed module supporting RFC5424 structured data inside +RFC3164 messages (not supported by the rsyslog team) +<li><a href="pmlastmsg.html">pmlastmsg</a> - rsyslog.lastmsg - +a parser module that handles the typically malformed "last messages +repated n times" messages emitted by some syslogds. </ul> -<h2>Library Modules</h2> +<a name="mm"></a><h2>Message Modification Modules</h2> +<p>Message modification modules are used to change the content of messages being processed. +They can be implemented using either the output module or the parser module interface. +From the rsyslog core's point of view, they actually are output or parser modules, it is their +implementation that makes them special. +<p>Currently, there do not exist any such modules, but could be written with +the methods the engine provides. They could be used, for example, to: +<ul> +<li>anonymize message content +<li>add dynamically computed content to message (fields) +</ul> +<p>Message modification modules are usually written for one specific task and thus +usually are not generic enough to be reused. However, existing module's code is +probably an excellent starting base for writing a new module. Currently, the following +modules existin inside the source tree +<ul> +<li><a href="mmsnmptrapd.html">mmsnmptrapd</a> - uses information provided by snmptrapd inside +the tag to correct the original sender system and priority of messages. Implemented via +the output module interface. +</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 automatically by some components. They are just mentioned so that error messages that point to library moduls can be understood. No module list is provided. +<h2>Where are the modules integrated into the Message Flow?</h2> +<p>Depending on their module type, modules may access and/or modify messages at +various stages during rsyslog's processing. Note that only the "core type" (e.g. input, +output) but not any type derived from it (message modification module) specifies when +a module is called. +<p>The simplified workflow is as follows: +<p align="center"> +<img src="module_workflow.png" alt"rsyslog: loadable modules and message flow"> +<p>As can be seen, messages are received by input modules, then passed to one or many +parser modules, which generate the in-memory representation of the message and may +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. + <p>[<a href="manual.html">manual index</a>] [<a href="rsyslog_conf.html">rsyslog.conf</a>] [<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> |