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diff --git a/doc/rsyslog_conf_output.html b/doc/rsyslog_conf_output.html new file mode 100644 index 00000000..c52aaa5e --- /dev/null +++ b/doc/rsyslog_conf_output.html @@ -0,0 +1,81 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> +<html><head><title>Output Channels - rsyslog.conf</title></head> +<body> +<p>This is a part of the rsyslog.conf documentation.</p> +<a href="rsyslog_conf.html">back</a> +<h2>Output Channels</h2> +<p>Output Channels are a new concept first introduced in rsyslog +0.9.0. <b>As of this writing, it is most likely that they will +be replaced by something different in the future.</b> So if you +use them, be prepared to change you configuration file syntax when you +upgrade to a later release.<br> +<br> +The idea behind output channel definitions is that it shall provide an +umbrella for any type of output that the user might want. In essence,<br> +this is the "file" part of selector lines (and this is why we are not +sure output channel syntax will stay after the next review). There is a<br> +difference, though: selector channels both have filter conditions +(currently facility and severity) as well as the output destination. +they can only be used to write to files - not pipes, ttys or whatever +Output channels define the output definition, only. As of this build, +else. If we stick with output channels, this will change over time.</p> +<p>In concept, an output channel includes everything needed to +know about an output actions. In practice, the current implementation +only carries<br> +a filename, a maximum file size and a command to be issued when this +file size is reached. More things might be present in future version, +which might also change the syntax of the directive.</p> +<p>Output channels are defined via an $outchannel directive. It's +syntax is as follows:<br> +<br> +$outchannel name,file-name,max-size,action-on-max-size<br> +<br> +name is the name of the output channel (not the file), file-name is the +file name to be written to, max-size the maximum allowed size and +action-on-max-size a command to be issued when the max size is reached. +This command always has exactly one parameter. The binary is that part +of action-on-max-size before the first space, its parameter is +everything behind that space.<br> +<br> +Please note that max-size is queried BEFORE writing the log message to +the file. So be sure to set this limit reasonably low so that any +message might fit. For the current release, setting it 1k lower than +you expected is helpful. The max-size must always be specified in bytes +- there are no special symbols (like 1k, 1m,...) at this point of +development.<br> +<br> +Keep in mind that $outchannel just defines a channel with "name". It +does not activate it. To do so, you must use a selector line (see +below). That selector line includes the channel name plus an $ sign in +front of it. A sample might be:<br> +<br> +*.* $mychannel<br> +<br> +In its current form, output channels primarily provide the ability to +size-limit an output file. To do so, specify a maximum size. When this +size is reached, rsyslogd will execute the action-on-max-size command +and then reopen the file and retry. The command should be something +like a <a href="log_rotation_fix_size.html">log rotation +script</a> or a similar thing.</p> +<p>If there is no action-on-max-size command or the command did +not resolve the situation, the file is closed and never reopened by +rsyslogd (except, of course, by huping it). This logic was integrated +when we first experienced severe issues with files larger 2gb, which +could lead to rsyslogd dumping core. In such cases, it is more +appropriate to stop writing to a single file. Meanwhile, rsyslogd has +been fixed to support files larger 2gb, but obviously only on file +systems and operating system versions that do so. So it can still make +sense to enforce a 2gb file size limit.</p> + +<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 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 2 or higher.</font></p> +</body> +</html> + + |