February 03. 2012
logwatch
Author: Mathias Kettner
License: GPL
Distribution: official part of Check_MK
Supported Agents: Linux, Windows, AIX, Solaris
This check processes the output of agents with the logwatch pluing. The windows agent has built
in this extension. The logwatch extension of the Linux/UNIX agents needs a configuration file
that lists all relevant logfiles and lists possible log lines that should result in warning
or critical state. The windows agents does not need any configuration but sends all log files
in the Windows event log. It uses the warning/error classification of Windows.
Relevant log messages found by the agent are stored locally into a text file. The check is
critical, if at least one new or old log message exists that is classified as critical. If
at least one warning message exists but no critical, the check results in a warning state.
The only way to bring the state back to OK is to delete the text file with the stored log
messages. This is stored below /var/lib/check_mk/logwatch. Usually the logwatch webpage is
used to browse and delete the messages. Please refer to the online documentation of check_mk
for more details about logwatch.
Item
The name of the logfile. For Linux/UNIX this is the complete absolute path name of the logfile.
For Windows this is the name as shown in the windows event log, for example Application
(case sensitive!).
Check parameters
| Parameter | Type | Description |
| patterns | list | The parameter can be used to reclassify
log messages sent by the agent. You can assign one of
the three levels 'I' (ignore), 'W' (warning) or
'C' (critical) to each message. It is only possible
to reclassify messages that have already been classified
by the agent with an original level of I, W or C.
As of version 1.1.13i1 the Windows agent supports sending
always all messages and classifying non-problems as I.
This is done by a configution
via check_mk.ini and setting the level for a logfile to all.
Those messages can later be reclassified.
Each entry of the list is a pair of the new level and an
extended regular expression searched in the log line.
Please note, that because logwatch checks are usually
inventorized, it is easier to use the global configuration variable
logwatch_patterns instead of explicit check parameters.
Example: [ ('I', "sshd"), ('C', "foo.*bar") ]
In the current version of this check a level can be substituted
by a pair of numbers, e.g. instead of 'W' you can write (10, 20).
In that case the message will be considered as 'I' for the first
9 appearances, further appearances will be classified as 'W' and
from the 20th message on it will be 'C'. The counts are reset each
time the host is being checked.
|
Performance data
None.
Inventory
All logfiles sent by the agent are automatically inventorized. Please use standard inventory
configuration methods if you want to ignore certain log files.
Configuration variables
| Variable | Type | Description |
| logwatch_patterns | dict | A dictionary for reclassifying
the level of certain messages. This is especially useful
for the Window agent, since that uses the pre-classification
of Windows and might not meet your needs. The key of each entry is the name
of a logfile (see item). The value of each entry is
a list of pairs as described in parameters. It is also
possible to restrict entries to single hosts or groups
of hosts by prepending list of host and host tags to the pairs,
as seen in the example.
|
| logwatch_max_filesize | int | This is preset to 500000
and limits the maximum size of a logfile stored on the monitoring
servers (i.e. the amount of unacknowledged problem messages).
As soon as the maximum size is reached, the check gets critical.
(It probably anyways is with so many problem messages lying around).
|
| logwatch_dir | string | Directory where log messages are
stored. The default value is /var/lib/check_mk/logwatch.
For each host a subdirectory is created. The name of the
files therein are the names of the logfiles with slashes
replaced by backslashes. |
Examples
main.mk
logwatch_patterns = {
"System": [ ('W', "crash"),
('I', "svchost") ],
((10,30), "login.*failed") ],
"/var/log/messages": [ ( ['test'], ALL_HOSTS, 'I', "sshd") ]
}
