Graphs acting like 32bit counters

[onfirealot]

Hi all,

I've been experiencing a problem with our Cacti platform (Version 0.8.8a), where sometimes a graph which has been fine with 64 bit counters, suddenly starts looking like a 32bit counter is being used. I end up with the saw tooth look on an interface graph of values going over 114mb/s and dropping values back down to 0mb/s again.

If that doesn't make sense, I've attached two graphs:

First, 24 hour period, graph is fine until ~114mb/s, then drops and starts again.
Second, 1 year period, graph was fine to go above ~114mb/s, then something caused it to act like a 32 bit counter.

I'm not sure why this happened, it didn't occur on all the graphs on the platform, only some. Sometimes new graphs have the same problem, some don't (generally we use the same template). I would assume if there was an issue with 32bit RRDs being used, this would be an issue with every RRD and wouldn't start mid way through a run.

Any advice of where I might start investigating this issue, as I'm stumped.

Cheers
Elliott

[onfirealot]

Just double checking the data collection template to make sure it's correct, not sure why they would have changed.

[onfirealot]

Changing data sources seems to have broken the graph and showing NaN, but RRD looks to have data in it. So I wouldn't have expected the data source to have changed, and carried on working before. I know if I delete and re-add it will work, but I want to work out why this happened, so I can either stop it happening again or fix old graphs.

Edit: Fix64bit plugin does not have an effect.