C.6. Logagent; C.6.1. Logagent::log Pattern Match - Red Hat NETWORK SATELLITE 5.1.1 Reference Manual

Appendix C. Probes
Field
Critical Minimum Virtual Memory Free
Table C.29. Linux::Virtual Memory settings

C.6. LogAgent

The probes in this section monitor the log files on your systems. You can use them to query logs for
certain expressions and track the sizes of files. For LogAgent probes to run, the nocpulse user must
be granted read access to your log files.
Note that data from the first run of these probes is not measured against the thresholds to prevent
spurious notifications caused by incomplete metric data. Measurements will begin on the second run.

C.6.1. LogAgent::Log Pattern Match

The LogAgent::Log Pattern Match probe uses regular expressions to match text located within the
monitored log file and collects the following metrics:
• Regular Expression Matches — The number of matches that have occurred since the probe last
ran.
• Regular Expression Match Rate — The number of matches per minute since the probe last ran.
Requirements — The Red Hat Network Monitoring Daemon (rhnmd) must be running on the
monitored system to execute this probe. For this probe to run, the nocpulse user must be granted
read access to your log files.
In addition to the name and location of the log file to be monitored, you must provide a regular
expression to be matched against. The expression must be formatted for egrep, which is equivalent
to grep -E and supports extended regular expressions. This is the regular expression set for egrep:
^ beginning of line
$ end of line
. match one char
* match zero or more chars
[] match one character set, e.g. '[Ff]oo'
[^] match not in set '[^A-F]oo'
+ match one or more of preceding chars
? match zero or one of preceding chars
| or, e.g. a|b
() groups chars, e.g., (foo|bar) or (foo)+
Warning
Do not include single quotation marks (') within the expression. Doing so causes egrep
to fail silently and the probe to time out.
Field
Log file*
Basic regular expression*
220
Value
Value
/var/log/messages