MRTG Spike Leveler

A representative MRTG graph depicting network utilization

MRTG is a GREAT tool for network professionals, enabling users to easily monitor what's going on in the network. I personally have seen many instances where we've detected problems in some pretty critical networks - all because MRTG was giving us real time information on network performance.

Since MRTG automatically adjust the 'Y' Axis, based on throughput, it's likely that sooner or later, an unusual spike will result in an unexpected adjustment in the axis which doesn't reflect what's "really" going on. Rather than endure those anomalies, we've preferred to modify the historical data, to have MRTG create graphs which more closely what we're seeing on a regular basis..

I created the utility above to provide users with an easy way to view the data contained in the log files, and to enable users to modify that data when necessary. Users can select a single file, or they can make changes to any number of files in a specified directory simply by tagging multiple files.

I've also modified the system so it'll automatically detect whether the log file is from a Windows Operating System, or a Unix OS.  The difference is that in a Unix OS, a new line is characterized by an ascii (10), while it's represented by an Ascii (10) followed by an Ascii (13) in a Windows environment.  The system handles both - without operator action.

MRTG monitors 4 parameters - the average throughput (in and out), and the maximum throughput (in and out). In this utility you can specify maximum values for any or all of these parameters. Changes will be made ONLY for those parameters where you've specified a maximum value. It's your option whether you prefer to simply delete those data lines with errant data, or to set the value to the maximum you specify.

You can also scroll through the contents of a log file by double-clicking the file. You'll see (at the bottom of the display) the maximum value for each of the monitored parameters. I recommend you use this feature prior to making modifications to the log file.

I also give you the ability to transfer all of the values shown at the bottom of the log analysis directly into the associated parameters on the opening screen.  You should be a bit cautious about simply passing those values to the opening screen because it could radically flatten your curves if you make wholesale changes to your data.

It's smart to retain a backup of the existing data in the event you inadvertently specify a parameter that's far removed from the norm. The system will prompt you on whether you want to save a backup copy.

There's another element you might find useful ..... some users might want to call the program from a cron job, periodically kicking it off and having the system reset the graphs to some preset value.   To accomplish this I give you the ability to save a specific configuration.  You can then invoke the system with the word "auto" as a command line parameter. 

If the key word "auto" is detected in the command line, the system will automatically look for and load a saved configuration, then automatically initiate begin processing the selected files using that saved configuration.  The system will automatically exit the program if run using the command line option.

I've added a simplified help screen which attempts to pass along most of the information in this page.  The help screen is partially shown below.

OK..... you can download the utility by clicking on the 'download' link at the top of this page, or by clicking on the following link -   MRTG Spike Leveler

Please contact me at boumaj@berkutsystems.com if you have any questions or suggestions for improvement.