On Mon, Mar 10, 2008 at 05:08:06PM -0500, Joe Wells wrote: > Yup, it's a counter. I'm re-doing it as gauge to see what happens. Looks > better already, though. > > I thought that this would be a counter, and the JFFNMS docs list it as a > counter. ICMP messages should be a counter. You don't care that there has been 1234,567 icmp messages to your computer, but you might find it interesting that 50 messages/second is the average rate for the last 5 minutes.
> So when should a counter be used and when should it be a gauge? A counter is for a rate, widgets per second A gauge is a level, I have 6 widgets. Speedometer is a counter, I am going 60 miles per hour. It's always discussed as something per time. Counters always need (at least) two measurements to make sense because you need to subtract the difference and divide by the time difference. You measure something now and get 1000, in 5 minutes time you measure it again and get 1300. Your rate is 1 thing/second (1300 - 1000 ) / (5 * 60) Odometer is a counter, my ageing old car has 145,000 miles on it, meaning since it was "started" or created it has done that value. It is almost always a number not per time, just a number. CPU load, free memory, etc are examples of it. Rough rule of thumb, if it subsequent values can be less than what you have, its a counter. Are there exceptions? Yep! Some devices mesaure a current rate and report this directly. So you have your load balancer device and it reports on connections/second Because the obtained value is already in connections/second its a gauge. If you get strange numbers then try multiplying or dividing by 300 and see if it makes more sense. Also be careful that rrd files always store things as a rate so a direct rrdtool dump may look strange all the time. - Craig -- Craig Small GnuPG:1C1B D893 1418 2AF4 45EE 95CB C76C E5AC 12CA DFA5 http://www.enc.com.au/ csmall at : enc.com.au http://www.debian.org/ Debian GNU/Linux, software should be Free ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ jffnms-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/jffnms-users
