SNMP - monitoring large number of devices

William Herrin bill at herrin.us
Tue Sep 29 20:55:13 UTC 2015


On Tue, Sep 29, 2015 at 4:20 PM, Pavel Dimow <paveldimow at gmail.com> wrote:
> recently I have been tasked with a NMS project. The idea is to pool about
> 20 OID's from 50k cable modems in less then 5 minutes (yes, I know it's a
> one million OID's). [...] You always first perform snmp
> walk in order to discover interfaces and then read the values for those
> interfaces.

Hi Pavel,

NMS is ever a trade off between collecting the data you need to manage
your system and minimizing the impact collection has on the equipment
being monitored.

You propose to spend somewhere between 2mbps and 10mbps on SNMP
queries alone 24/7/365 and then do something with the 10ish terabytes
per year of collected data

This is less a network monitoring problem and more a big-data
map-reduce problem. Doable, although you'll likely have to break the
problem up in to a lot of parallel VMs. You'll need a software
developer with big data experience. So far as I know there is no
off-the-shelf software (commercial or open source) kitted out to
facilitate this specific activity. 95% of the software modules needed
to create such a thing is available as open source.

Frankly, it's probably also not a good idea. Lengthen your intervals,
don't collect every piece of information every interval and figure out
a way that you don't have to walk the oids every single time.


On Tue, Sep 29, 2015 at 4:26 PM, Scott Helms <khelms at zcorum.com> wrote:
> From my experience building your server side programming to do 50,000
> modems in <5 minutes is very doable, but unless your dealing with more than
> 10 CMTSs you probably can't do it in production without impacting
> performance.

>From Pavel's question, I infer that he's talking about polling the
CPE. He can forget about driving that number of SNMP queries at the
CMTS's, regardless of how many he has.

Regards,
Bill Herrin



-- 
William Herrin ................ herrin at dirtside.com  bill at herrin.us
Owner, Dirtside Systems ......... Web: <http://www.dirtside.com/>



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