All graphs are blank, new rrds created?

[ericwebb]

I have Cacti 1.2.15 on Centos7, and keep running into an issue where all my graphs either stop collecting new data or come up blank - I presume new RRDAs are being created, as I see new ID numbers for the graphs showing up in the 'Graph List' view. I haven't tried digging under the covers too much yet, and I have found various posts that reference seeing this kind of thing happening, but not sure if a fix has been addressed yet. (Unfortunately, 1.2.16 and 1.2.17 don't appear on EPEL yet that I've seen, and I don't believe I see a fix listed in release notes that addresses this.)

Unfortunately, I'm not sure what I did that might have caused this. The first time around I edited an existing device or graph template, had the issue, and went ahead and deleted and recreated all devices.
This second time, however, all I think I did was add a new device. There was a week's gap between when I created the new device and when I next checked all the existing ones, so I'm not sure at what point it fell apart.

I have a feeling the old RRDAs are out there and being written to (the troubleshooter seems to support this) but the front-end is referencing brand-new, blank ones.

I might be able to tackle the SQL to fix or clean these up but at this point I don't really understand what's what... and hate for it to happen again.

Any suggestions on where to begin?


Thanks,
Eric

[ericwebb]

For example, an SNMP bits in/out graph was at ID 313, and I still have an RRD file and the poller_item table still shows this.
But the graph_local table entry now shows ID 419 (no RRD file actually was created). No entry in graph_local for 313.
The poller (built-in, not spine) is still working and collecting data to old IDs/RRDs (for now, anyway... not sure what will happen if I restart it) but the front end is looking at new graph IDs that don't really exist.

Seems like this happened for all my SNMP bits in/out graphs...

Perhaps I can rename the RRDs to the new ID and update the poller_item lines? What else would have to get updated? Such a mess to try to do manually... and that's if I can figure out what was what.

[netniV]

If you delete and recreate your graphs, they get new ID's. As long as you didn't delete the data source then it can be reused.

[ericwebb]

Actually, I discovered that it was the change in polling frequency from 5 mins to 1 min. I reset it back to 5 and data started appearing again. I found other posts that hinted at this potential cause.

But what I don't understand is why did all historical data disappear from the RRD's? I could expect a lack of new data collection, but I wouldn't have expected everything to go blank.
Any insights on how this works?


Thanks,
Eric