What does 95th %tile mean?

Fri Apr 20 02:58:15 UTC 2001

[ On Thursday, April 19, 2001 at 17:55:28 (-0700), Todd Suiter wrote: ]
> Subject: RE: What does 95th %tile mean?
>
> Along the lines of this thread, What do you folks use for GATHERING said billing
> stats? I use a combination of MRTG and Cricket, which works pretty well, what
> are other folks using? I'm always willing to look at other folks' solutions
> to problems, as none of us, well, except Mr. Frazier, knows everything:).

Neither MRTG nor Cricket (nor anything with RRDtool or anything similar
underlying it), in their standard released form, are truly suitable for
accounting purposes since they both can introduce additional averaging
errors.  You need to keep all of the original sample data.

The best tool will depend on what type of device is being queried, but
in general something like Cricket could provide a decent framework that
already draws pretty pictures for visualisation.  All you'd need to do
is introduce a second call in the collector to send the current samples
to some other recording mechanism so that you can save the original
sample data separate from the Cricket RRDs.  You could simply drop the
samples along with a timestamp into a flat file for later processing, or
you could immediately insert them into some kind of database.  Cricket
would be a good starting point because it already has ability to do not
just SNMP queries but also the ability to take data from any program.
It's also got a half-decent configuration framework.

One thing I should point out is that from an auditing perspective it's
fairly important to try and record the time that the counter sample was
actually taken.  This sample timestamp can be used to assure anyone
looking at the data that even if samples are missing the counter deltas
between samples are still being used to properly calculate the average
rate over the actual sample period.

-- 
							Greg A. Woods

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