Inability to graph > 100 Mbps

[kerich]

Hi guys, i am graphing bandwidth usage for an ISP and cacti is unable to graph anything more than 100 Mbps.. any assistance is appreciated.

[kerich]

In addition i understand that cacti 32bit cannot see anything over 114Mbps, and that the cacti that needs upgrade to 64bit... any ideas?

[Exo7]

you need to poll SNMP 64 bits counters and use SNMP v2 for your device.

When you create a graph using the SNMP - Interface Statistics data query, select "in/out bits (64-bits counters)" in the drop down menu.

[TobbeJ]

the problem is that a 32 bit snmp counter overflows between the 5 min polling intevals that is used by default.

you have two options:
* use 64 bit snmp counters if your device supports it (probably needs snmp v2 or above)
* use shorter polling interval, for example 1 minute, but note that you need to change more than just the polling interval (graph, rra and so on)

i'm using 1min polling intervals for 32bit counters on 1 gbit interfaces and a different graph+datasource setup, and this works fine.
it also gives better precition for the last couple of ours (1min intervals instead of 5min).

check the forums, there should be some info about this.

[kerich]

Thanks guys, this sure is helpful. I had also checked out the forum and seen this

1. (DEVICE) Change from SNMP v1 to v2
2. (DATA SOURCE) Change to In/Out Bits- 64 bit counters
3. (DEVICE) Reindex the interfaces

However, i will also have to delete the old rrd files for the above configuration. Will try out the one min interval on 32 bit first..

Cheers.
AK

[kerich]

TobbeJ, on your remark "* use shorter polling interval, for example 1 minute, but note that you need to change more than just the polling interval (graph, rra and so on) "

please enlighten me further on what i need to change.. i think this will be a workaround for now before i can upgrade to 64 bit.

Cheers.

AK

[Vins]

* use shorter polling interval, for example 1 minute, but note that you need to change more than just the polling interval (graph, rra and so on) "

I think that changing the poller interval has nothing to do with the 64-bit counter problem... you should already see on your graphs values > 114 mbit/s

[TobbeJ]

* use shorter polling interval, for example 1 minute, but note that you need to change more than just the polling interval (graph, rra and so on) "

I think that changing the poller interval has nothing to do with the 64-bit counter problem... you should already see on your graphs values > 114 mbit/s

if your device dont support 64 bit counters (windows for example) then your stuck with 32 bit counters and need to change polling interval

yes you don't need to go to 64 bit AND change to a shorter polling interval.

[TobbeJ]

TobbeJ, on your remark "* use shorter polling interval, for example 1 minute, but note that you need to change more than just the polling interval (graph, rra and so on) "

please enlighten me further on what i need to change.. i think this will be a workaround for now before i can upgrade to 64 bit.

Cheers.

AK

see the following links:
http://forums.cacti.net/about16482.html the pdf file is the intresting one.
http://forums.cacti.net/about30480.html

if you have a recent cacti, i'm almost sure you dont need the patch, so follow the instructions on how to modify the graph templates.

from memory you need to do a couple of other things.
change cron poller job to run on 1min intervals and you also need to specify your polling interval in the cacti settings somewere.

i think that pdf is what i used a long time ago when setting up my cacti installation for 1min polling.
i've been upgrading in between and havent applied any polling related patches and its working just fine.

i only need to remeber to use the new template for interfaces with speed above 100Mbit.
an added bonus with the 1min polling interval and the changes is that you get a hourly graph with 1min resolution.

when i did this i choosed to create a new graph template so i didn't messup the one that was included.

[TobbeJ]

However, i will also have to delete the old rrd files for the above configuration. Will try out the one min interval on 32 bit first..

you will need to remove the old rrd files for the polling interval change too