Log File Monitoring
Every application prints status messages, error messages, and other critical information in its log. It is very tedious to skim through all these bulky log files to understand application performance. To manage such mission critical applications in real time, monitoring their log files is necessary. OpManager offers agent-based log file monitoring for real-time fault and performance management.
How does log file monitoring work?
The log file monitoring agent installed in the end machine, monitors the log files continuously for the required string (It may even be in regex format). Once that string, or the mentioned regex matching string format, is identified, it immediately notifies the OpManager server, which in-turn raises an alarm based on the polling interval specified for that file monitor.
For Regex pattern string, Kindly make sure that you do not provide the delimiters or flags along with your regex.
Kindly ensure that you have tested your regex internally, before configuring it in OpManager.
For example, in the following, the first regex is acceptable, while the second and third ones are not accepted.
Following are some more examples of how the regex must be used.
|Correct version||Incorrect version|
You can also add a log file monitor from a particular device's snapshot page.
You have successfully created a log file monitor.
If the file monitoring interval is modified, the match string appeared in the current polling span (old monitoring interval) will be ignored and hence the alert will not be generated. The alert will be raised as usual based on the new monitoring interval from next poll.
Once a log file monitor is added and the agent is mapped to a device, a marker will be set at the very end of that log file. OpManager will only monitor strings that are input after this point, and ignores all instances of the same string that were present before the monitor was mapped to the device.
This also applies to poll intervals, where OpManager sets a marker in the monitored file after each poll interval. Only the content after the most recent poll is checked for the search string, to avoid redundant alerts.
OpManager does not take into consideration the number of instances of the string found, it only checks if the provided search string is in the log file or not. For example, if a search string "A" is found 10 times in the log file content in a poll interval of 15 minutes, OpManager raises only one alert for this log file monitor and not 10 alerts.