Spikes in graphs, found why but no idea to solve it

[yhan_m]

Hi

I 've found huges spikes in my graphs, and I figure out why it's happen.
My data sources are of the type counter, and when those courters are resetted, I've huge spikes in the graphs.

How could I by pass that problem ?
Is that a rrdtool problem related ? or cacti ?

Thanks in advance.

Yhan

[Boostable]

Spikes in the logs is a known problem.

There are quite a few scripts out there that are written specificly to remove these spikes.

do a google on rrdtool +spikes and you will get some results.

Here is a link to one I have used in the past, but im sure there are others.

http://jon.rusts.net/get95/fixspike.pl

JW

[rpingar]

Does the script spikekill2 run on windows?

thanks

[bulek]

How could I by pass that problem ?
Is that a rrdtool problem related ? or cacti ?

It is rrdtool related problem - it tries to handle counters overflow causing spikes in case of device reset. You can avoid such problems by setting correct maximum value in data source settings - then any value above it will be dropped instead of storing in rrdfile.

- Piotr

[branix]

You can avoid such problems by setting correct maximum value in data source settings - then any value above it will be dropped instead of storing in rrdfile.

- Piotr

I for instance have a 100Mbps network interface that is limited by a bridge at a maximum of 8Mbps.
The interface correct maximum value is 100.000.000 bits/s.
The logical correct maximum value is 8.000.000 bits/s.

Setting the max to 100 will bring spikes in my graphs.
Setting the max to 8 (or more) will denaturate the graphs in case of a bridge failure.

So, which one is correct?

[bulek]

First of all maximum value should be set in bytes/s... so in case of fasteth it should be 12,500,000 (or 1,000,000 in case of your bridge restricted speed).

If you normally use bridge I would set it to 8. In case of bridge failure I'd like to see gaps in graph rather than high spikes.

- Piotr

[branix]

I know that you have to enter bytes, the example would be much easier in bits. As well, gaps are what I expect from values bigger than my max value.

The question is: How do I graph the traffic exceding my expectations without spikes? For example I want to know if the traffic was 9Mbps or 34Mbps, because the difference is huge and a step over 10Mbps would cost me a lot of privileges.

[yhan_m]

Thanks for your reply Boostable

Well I don't have problem to remove the spikes, but I would like to have a solution to prevent spikes happens.

Yohan