Strange data pattern

[streetcleaner]

I am using cacti (among other tools: eHealth, MRTG) to monitor interface bits in/out on a number of our core backbone routers. We recently had a outage on one of the routers, after the router/interfaces came back up the traffic pattern displayed by Cacti is different than what is seen in eHealth or MRTG. The pattern has changed from a nice, smooth sine wave style pattern to a very spikey pattern. This is happening on all interfaces on this device. Other SNMP tools (including a test version of Cacti) show the traffic pattern to be the smooth sine wave.

What is happening here? I don't want to have to loose the historical data just to get the traffic pattern back the way is should be (as in cr01-clone.png)

Any assistance would be appriciated.

thanks
B

[gandalf]

This may be seen when two processes with a runtime of about 5 min interfere (hope I can express clearily, native german speaker here). This may produce situatione, were
1. cacti reads _before_ the second process runs and produces lots of traffic ("low" spike)
2. cacti reads _after_ the second process runs ("high" spike)
This will not be a good explanation, if the averages do not fit, either
Reinhard