Cacti Mismatch values - Realtime grahs vs Normal Graphs

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pradeepspa
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Cacti Mismatch values - Realtime grahs vs Normal Graphs

#1 Post by pradeepspa » Thu Nov 15, 2018 10:30 am

Hello Folks,

I have installed "realtime plugin" which works great. However, I notice the values it shows differ from the normal graphs. I agree the realtime graphs shows the recent updated value and it is not suppose to be same as the normal one but what I am seeing is vast difference.
realtime.JPG
realtime.JPG (36.84 KiB) Viewed 747 times
If you see the above graphs, the first one is from realtime plugin and second is normal trend where you can find the huge difference in "Inbound" traffic. Any reason why it behaves like this way?

pradeepspa
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Re: Cacti Mismatch values - Realtime grahs vs Normal Graphs

#2 Post by pradeepspa » Thu Nov 29, 2018 3:07 pm

Anyone could help me out on this?

netniV
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Re: Cacti Mismatch values - Realtime grahs vs Normal Graphs

#3 Post by netniV » Fri Nov 30, 2018 3:54 am

You are not comparing like for like. The graph on the right is a whole day, not a minute.

pradeepspa
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Re: Cacti Mismatch values - Realtime grahs vs Normal Graphs

#4 Post by pradeepspa » Fri Nov 30, 2018 6:04 am

I agree but the "Inbound" values it shows doesnt doesnt make sense even after averaging.I should see values in "MB" at least in "Maximum" GPRINT.

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Osiris
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Re: Cacti Mismatch values - Realtime grahs vs Normal Graphs

#5 Post by Osiris » Fri Nov 30, 2018 8:06 am

Check the max values on the RRDfile using the "rrdtool info rrdfile" command. I bet that there is a max value on the RRDfile that is clipping the data over longer periods of time.

If this graph was first created on a Cacti version before 0.8.8 (and I can not remember the version of 0.8.8), you may have had an invalid max value. Also, if your ifSpeed or ifHighSpeed snmp values are bogus, you could also get bad values on current versions of Cacti.

You can use the "rrdtool tune rrdfile options" command to correct the maximum values to be more realistic. More options can be found here: https://oss.oetiker.ch/rrdtool/doc/rrdtune.en.html
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pradeepspa
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Re: Cacti Mismatch values - Realtime grahs vs Normal Graphs

#6 Post by pradeepspa » Fri Nov 30, 2018 8:29 am

Here is the 5 minutes interval graphs vs realtime graphs.
Capture.JPG
Capture.JPG (54.76 KiB) Viewed 691 times
The numbers in "Inbound" obviously doesnt make sense where is no units (kb/mb)

On the other hand just to test the working, I created seperate graphs just for inbound and its graphs absolutely fine.
inbound.JPG
inbound.JPG (32.36 KiB) Viewed 691 times
Note: I am not using default snmp graph template for the traffic. I use script/command - data input method.

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Osiris
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Re: Cacti Mismatch values - Realtime grahs vs Normal Graphs

#7 Post by Osiris » Sun Dec 02, 2018 6:58 am

Please reread my comments.
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pradeepspa
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Re: Cacti Mismatch values - Realtime grahs vs Normal Graphs

#8 Post by pradeepspa » Fri Jan 11, 2019 3:37 pm

I tried rrdtool tuning and also tried recreating the graphs from scratch but no luck. Any other ideas? Strange thing is it works only if I use both inbound and outbound data-template in one graph template. Also I am using "script/command" data input method.

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Osiris
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Re: Cacti Mismatch values - Realtime grahs vs Normal Graphs

#9 Post by Osiris » Fri Jan 11, 2019 4:28 pm

For the unit that is showing very small values, use the rrdtool tune <filename> -a:dsname=U. The special character 'U', means no limit.

Basically, if you use 'rrdtool info' your bogus parameter has a max value that is too low. Any values captured above that max value are thrown out.

Cacti has a setting to default the interface to ifHighSpeed if it exists, and if you are using SNMPv2. So, basically:

1) Use only v2 and v3
2) Only use 64bit graphs not the legacy version
3) Ensure ifHighSpeed is set for your interfaces, and if not, tune the rrdfiles directly
Before history, there was a paradise, now dust.

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