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Re: Polling Bandwidth as an Aggregate
From: Chris Adams <cmadams () hiwaay net>
Date: Fri, 20 Jan 2012 09:53:44 -0600
Once upon a time, Leo Bicknell <bicknell () ufp org> said:
To suggest Netflow is more accurate than rrdtool seems rather strange to me. It can be as accurate, but is not the way most people deploy it.
Comparing Netflow to RRDTool is comparing apples to cabinets; one is a source of information and one is a way of storing information.
RRDTool pulls the SNMP counters from an interface and records them to a file.
No, RRDTool stores data given to it by a front end such as MRTG, Cricket, Cacti, etc. That front end can fetch data from any number of sources, including (but not limited to) SNMP. RRDTool then stores information in its database.
With no aggregation, and assuming your device has accurate SNMP, this should be 100% accurate. While you are right that the defaults for RRDTOOL aggregate data (after a day, week, and month, approximately) those aggregates can be disabled keeping the raw data.
RRDTool does not store the raw data. Even for 5-minute intervals, it adjusts the data vs. the timestamp to fit the desired interval. Since you don't read every counter at the exact time of your interval, RRDTool is always manipulating the numbers to fit. The only numbers that are not changed before storing are the timestamp and value for the most recent update (which get overwritten at each update); everything else is adjusted to fit. -- Chris Adams <cmadams () hiwaay net> Systems and Network Administrator - HiWAAY Internet Services I don't speak for anybody but myself - that's enough trouble.
Current thread:
- Polling Bandwidth as an Aggregate Keegan Holley (Jan 19)
- Re: Polling Bandwidth as an Aggregate Dale W. Carder (Jan 19)
- Re: Polling Bandwidth as an Aggregate Jimmy Hess (Jan 19)
- Re: Polling Bandwidth as an Aggregate Leo Bicknell (Jan 20)
- Re: Polling Bandwidth as an Aggregate Keegan Holley (Jan 20)
- Re: Polling Bandwidth as an Aggregate Nick Hilliard (Jan 20)
- Re: Polling Bandwidth as an Aggregate Ian Goodall (Jan 20)
- Re: Polling Bandwidth as an Aggregate Leo Bicknell (Jan 20)
- Re: Polling Bandwidth as an Aggregate Keegan Holley (Jan 20)
- Re: Polling Bandwidth as an Aggregate Nick Hilliard (Jan 20)
- Re: Polling Bandwidth as an Aggregate Jimmy Hess (Jan 19)
- Re: Polling Bandwidth as an Aggregate Dale W. Carder (Jan 19)
- Re: Polling Bandwidth as an Aggregate Chris Adams (Jan 20)
- Re: Polling Bandwidth as an Aggregate Steve Clark (Jan 20)
- Re: Polling Bandwidth as an Aggregate Keegan Holley (Jan 20)
- RE: Polling Bandwidth as an Aggregate Nathan Eisenberg (Jan 20)
- Re: Polling Bandwidth as an Aggregate Matt Addison (Jan 20)
- Re: Polling Bandwidth as an Aggregate Jeff Gehlbach (Jan 20)