Re: What does 95th %tile mean?

[Adrian Chadd <adrian () creative net au>]

On Thu, Apr 19, 2001, Greg A. Woods wrote:

> 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.

A little bit of math will show that its actually very feasable to
collect and store minutely or 5-minutely data from a router
and store them in a database. I've done *that* before, and it works
very well.

> 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.

What? You would consider storing samples without a timestamp?
*grin*



Adrian

-- 
Adrian Chadd                    "Two hundred and thirty-three thousand
<adrian () creative net au>       times the speed of light.
                                   Dear holy <censored> <censored>"